Loading ...
Sorry, an error occurred while loading the content.
 

Re: [Cadillac_Performance_Association] Re: The '49-'62 V8... anything out there?

Expand Messages
  • Preston III
    The road draft tube is pre-PCV-valve technology. It comes from the top of the engine, and points toward the road, extending into the airflow under the car.
    Message 1 of 25 , Dec 8, 2004
      The road draft tube is pre-PCV-valve technology.

      It comes from the top of the engine, and points
      toward the road, extending into the airflow
      under the car. It's function was to siphon off
      crankcase vapors when the car was in motion, and
      also serve as a place to vent pressure in the
      crankcase due to engine part failure. Most cars
      had some version prior to the mid 60's.

      Many had a wire screen somewhere near the engine
      mounting that served as a filter to keep bulk
      raw oil from pooring out of the tube. If the
      screen gets "coked" up, and plugged, the gaskets
      throughout the engine could be subjected to internal
      pressure, and oil leaks can come from everywhere as
      the pressure blows it out where it can.

      The PCV valve replaced it with a controlled sucking
      of the internal vapors into the intake manifold.

      Pretty neet idea actually.


      Preston III

      --- dave <inanno@...> wrote:

      > It's a long tube, about 1" diameter that runs from the
      > back of the valley cover and down towards the ground.
      > i believe it serves as a crankcase vent. i don't know
      > if they had them on all years, but i had them on both
      > my '62s, and a spare '59 motor i got.
      >
      > ...dave
      >
      >
      > --- Cirilian <cirilian@...> wrote:
      >
      > >
      > > You'll forgive my ignorance but what exactly is the
      > > road draft tube?
      > > I was considering one of these finned valey covers
      > > for my "60.
      > > Thanks,
      > > Richard
      > >
      >
      >
      > =====
      > '63-'64 Chrysler fans- we have a home! Check out
      > http://groups.yahoo.com/group/63-64Chryslers
      > - -
      > "If elected mayor, my first act will be to kill the whole lot of you, and burn your town to
      > cinders!"
      >
      >
      >
      > __________________________________
      > Do you Yahoo!?
      > The all-new My Yahoo! - Get yours free!
      > http://my.yahoo.com
      >
      >
      >




      __________________________________
      Do you Yahoo!?
      Yahoo! Mail - now with 250MB free storage. Learn more.
      http://info.mail.yahoo.com/mail_250
    • jvandecreek25
      ... My 62 is pcv equipped, looks all factory.
      Message 2 of 25 , Dec 8, 2004
        --- In Cadillac_Performance_Association@yahoogroups.com, dave
        <inanno@y...> wrote:
        > It's a long tube, about 1" diameter that runs from the
        > back of the valley cover and down towards the ground.
        > i believe it serves as a crankcase vent. i don't know
        > if they had them on all years, but i had them on both
        > my '62s, and a spare '59 motor i got.

        My '62 is pcv equipped, looks all factory.
      • Jerry Brown
        You have to be an old guy to remember crankcase breathers. All the cars had them until the smog nazis took control. Actually no one knew any better than to let
        Message 3 of 25 , Dec 8, 2004
          You have to be an old guy to remember crankcase breathers. All the cars had
          them until the smog nazis took control. Actually no one knew any better than
          to let the vapors out. It relieved pressure in the crankcase from blowby on
          the cylinders. Now of course that is all handled and recycled back through
          the intake again and then out the exhaust. no doubt better now for our
          lungs. It used to be a really easy way to check engine condition to just put
          your hand over the breather tube with the engine at idle and if you felt the
          pressure you knew there was too much blow by. Rocker arm covers were also
          vented directly to the air back then.
          Jerry Brown (an old guy)

          PS...I'm looking at a 76 Cad 500 engine for my 36 Chev coupe. Engine tests
          out at 123-128 psi on all cyl. so I'm thinking its pretty good. Seller wants
          $375. I'm new to the cad engine market so don't know if this is a good buy
          or not. Any advice?

          -----Original Message-----
          From: dave [mailto:inanno@...]
          Sent: Wednesday, December 08, 2004 5:11 PM
          To: Cadillac_Performance_Association@yahoogroups.com
          Subject: Re: [Cadillac_Performance_Association] Re: The '49-'62 V8...
          anything out there?



          It's a long tube, about 1" diameter that runs from the
          back of the valley cover and down towards the ground.
          i believe it serves as a crankcase vent. i don't know
          if they had them on all years, but i had them on both
          my '62s, and a spare '59 motor i got.

          ..dave


          --- Cirilian <cirilian@...> wrote:

          >
          > You'll forgive my ignorance but what exactly is the
          > road draft tube?
          > I was considering one of these finned valey covers
          > for my "60.
          > Thanks,
          > Richard
          >


          =====
          '63-'64 Chrysler fans- we have a home! Check out
          http://groups.yahoo.com/group/63-64Chryslers
          - -
          "If elected mayor, my first act will be to kill the whole lot of you, and
          burn your town to cinders!"



          __________________________________
          Do you Yahoo!?
          The all-new My Yahoo! - Get yours free!
          http://my.yahoo.com






          Yahoo! Groups Links
        • Pollorey
          Doesn t sound like a bad price. ... From: Jerry Brown [mailto:jerome@pacifier.com] Sent: Wednesday, December 08, 2004 11:01 PM To:
          Message 4 of 25 , Dec 9, 2004
            Doesn't sound like a bad price.

            -----Original Message-----
            From: Jerry Brown [mailto:jerome@...]
            Sent: Wednesday, December 08, 2004 11:01 PM
            To: Cadillac_Performance_Association@yahoogroups.com
            Subject: RE: [Cadillac_Performance_Association] Re: The '49-'62 V8...
            anything out there?


            You have to be an old guy to remember crankcase breathers. All the cars had
            them until the smog nazis took control. Actually no one knew any better than
            to let the vapors out. It relieved pressure in the crankcase from blowby on
            the cylinders. Now of course that is all handled and recycled back through
            the intake again and then out the exhaust. no doubt better now for our
            lungs. It used to be a really easy way to check engine condition to just put
            your hand over the breather tube with the engine at idle and if you felt the
            pressure you knew there was too much blow by. Rocker arm covers were also
            vented directly to the air back then.
            Jerry Brown (an old guy)

            PS...I'm looking at a 76 Cad 500 engine for my 36 Chev coupe. Engine tests
            out at 123-128 psi on all cyl. so I'm thinking its pretty good. Seller wants
            $375. I'm new to the cad engine market so don't know if this is a good buy
            or not. Any advice?

            -----Original Message-----
            From: dave [mailto:inanno@...]
            Sent: Wednesday, December 08, 2004 5:11 PM
            To: Cadillac_Performance_Association@yahoogroups.com
            Subject: Re: [Cadillac_Performance_Association] Re: The '49-'62 V8...
            anything out there?



            It's a long tube, about 1" diameter that runs from the
            back of the valley cover and down towards the ground.
            i believe it serves as a crankcase vent. i don't know
            if they had them on all years, but i had them on both
            my '62s, and a spare '59 motor i got.

            ..dave


            --- Cirilian <cirilian@...> wrote:

            >
            > You'll forgive my ignorance but what exactly is the
            > road draft tube?
            > I was considering one of these finned valey covers
            > for my "60.
            > Thanks,
            > Richard
            >


            =====
            '63-'64 Chrysler fans- we have a home! Check out
            http://groups.yahoo.com/group/63-64Chryslers
            - -
            "If elected mayor, my first act will be to kill the whole lot of you, and
            burn your town to cinders!"



            __________________________________
            Do you Yahoo!?
            The all-new My Yahoo! - Get yours free!
            http://my.yahoo.com






            Yahoo! Groups Links













            Yahoo! Groups Links
          • Scott Pearson
            I m not an old guy and I know what a road vent tube is. That s not a bad price for a decent, even rebuildable, Caddy motor. It seems that alot of it depends on
            Message 5 of 25 , Dec 9, 2004
              I'm not an old guy and I know what a road vent tube is.

              That's not a bad price for a decent, even rebuildable, Caddy motor. It seems
              that alot of it depends on where you live. In my area there's not much
              demand, so prices are quite low. I've bought several for $100 or even 'you
              take it out, it's yours'

              Scott

              ----- Original Message -----
              From: "Jerry Brown" <jerome@...>
              To: <Cadillac_Performance_Association@yahoogroups.com>
              Sent: Wednesday, December 08, 2004 10:00 PM
              Subject: RE: [Cadillac_Performance_Association] Re: The '49-'62 V8...
              anything out there?


              >
              > You have to be an old guy to remember crankcase breathers. All the cars
              > had
              > them until the smog nazis took control. Actually no one knew any better
              > than
              > to let the vapors out. It relieved pressure in the crankcase from blowby
              > on
              > the cylinders. Now of course that is all handled and recycled back through
              > the intake again and then out the exhaust. no doubt better now for our
              > lungs. It used to be a really easy way to check engine condition to just
              > put
              > your hand over the breather tube with the engine at idle and if you felt
              > the
              > pressure you knew there was too much blow by. Rocker arm covers were also
              > vented directly to the air back then.
              > Jerry Brown (an old guy)
              >
              > PS...I'm looking at a 76 Cad 500 engine for my 36 Chev coupe. Engine tests
              > out at 123-128 psi on all cyl. so I'm thinking its pretty good. Seller
              > wants
              > $375. I'm new to the cad engine market so don't know if this is a good buy
              > or not. Any advice?
              >
              > -----Original Message-----
              > From: dave [mailto:inanno@...]
              > Sent: Wednesday, December 08, 2004 5:11 PM
              > To: Cadillac_Performance_Association@yahoogroups.com
              > Subject: Re: [Cadillac_Performance_Association] Re: The '49-'62 V8...
              > anything out there?
              >
              >
              >
              > It's a long tube, about 1" diameter that runs from the
              > back of the valley cover and down towards the ground.
              > i believe it serves as a crankcase vent. i don't know
              > if they had them on all years, but i had them on both
              > my '62s, and a spare '59 motor i got.
              >
              > ..dave
              >
              >
              > --- Cirilian <cirilian@...> wrote:
              >
              >>
              >> You'll forgive my ignorance but what exactly is the
              >> road draft tube?
              >> I was considering one of these finned valey covers
              >> for my "60.
              >> Thanks,
              >> Richard
              >>
              >
              >
              > =====
              > '63-'64 Chrysler fans- we have a home! Check out
              > http://groups.yahoo.com/group/63-64Chryslers
              > - -
              > "If elected mayor, my first act will be to kill the whole lot of you, and
              > burn your town to cinders!"
              >
              >
              >
              > __________________________________
              > Do you Yahoo!?
              > The all-new My Yahoo! - Get yours free!
              > http://my.yahoo.com
              >
              >
              >
              >
              >
              >
              > Yahoo! Groups Links
              >
              >
              >
              >
              >
              >
              >
              >
              >
              >
              >
              >
              >
              > Yahoo! Groups Links
              >
              >
              >
              >
              >
              >
              >
              >
            • jvandecreek25
              ... Engine tests ... Seller wants ... good buy ... That s not a bad price if it is complete, if you have to spend extra to replace missing accessories, like
              Message 6 of 25 , Dec 9, 2004
                > Jerry Brown (an old guy)
                >
                > PS...I'm looking at a 76 Cad 500 engine for my 36 Chev coupe.
                Engine tests
                > out at 123-128 psi on all cyl. so I'm thinking its pretty good.
                Seller wants
                > $375. I'm new to the cad engine market so don't know if this is a
                good buy
                > or not. Any advice?

                That's not a bad price if it is complete, if you have to spend
                extra to replace missing accessories, like manifolds, brackets and
                pulleys, the price could easily double, so try to find as complete a
                package as you can, Does it include the trans? most DeVills (RWD)
                will come with the trans, but Eldos usually don't.
              • Jerry Brown
                PS...I m looking at a 76 Cad 500 engine for my 36 Chev coupe. Engine tests ... Seller wants ... good buy ... That s not a bad price if it is complete, if you
                Message 7 of 25 , Dec 9, 2004
                  PS...I'm looking at a 76 Cad 500 engine for my 36 Chev coupe.
                  Engine tests
                  > out at 123-128 psi on all cyl. so I'm thinking its pretty good.
                  Seller wants
                  > $375. I'm new to the cad engine market so don't know if this is a
                  good buy
                  > or not. Any advice?

                  That's not a bad price if it is complete, if you have to spend
                  extra to replace missing accessories, like manifolds, brackets and
                  pulleys, the price could easily double, so try to find as complete a
                  package as you can, Does it include the trans? most DeVills (RWD)
                  will come with the trans, but Eldos usually don't.


                  Its complete right down to A/C compressor, alternator, belts, carb,
                  manifolds and some wiring. No transmission but that is no problem as I have
                  a recently rebuilt TH400 from a 74 472 engine that is a basket case. I
                  assume the bell housing is the same whether DeVille or Eldorado. Am I
                  correct?

                  I looked up the HP and Torque for this engine and have to say its less than
                  impressive for the displacement. I can see why so many go to higher
                  compression, performance cam, headers and different intake.

                  Nother question: Is it acceptable practice to mill the heads to raise
                  compression a point to a point-and-a-half? If so do you have to go to
                  different length pushrods or will there still be sufficient clearance
                  between valves and piston? I'm looking for about 9.5:1 CR to help out
                  performance. I know the best way to go is usually different pistons but I'm
                  trying to keep the costs reasonable.

                  Thanks. You guys have been great with the information and advice.

                  Jerry Brown
                • jvandecreek25
                  ... a ... as I have ... case. I ... Am I ... less than ... raise ... to ... clearance ... out ... pistons but I m ... Don t worry too much about the seemingly
                  Message 8 of 25 , Dec 9, 2004
                    --- In Cadillac_Performance_Association@yahoogroups.com, "Jerry
                    Brown" <jerome@p...> wrote:
                    > PS...I'm looking at a 76 Cad 500 engine for my 36 Chev coupe.
                    > Engine tests
                    > > out at 123-128 psi on all cyl. so I'm thinking its pretty good.
                    > Seller wants
                    > > $375. I'm new to the cad engine market so don't know if this is a
                    > good buy
                    > > or not. Any advice?
                    >
                    > That's not a bad price if it is complete, if you have to spend
                    > extra to replace missing accessories, like manifolds, brackets and
                    > pulleys, the price could easily double, so try to find as complete
                    a
                    > package as you can, Does it include the trans? most DeVills (RWD)
                    > will come with the trans, but Eldos usually don't.
                    >
                    >
                    > Its complete right down to A/C compressor, alternator, belts, carb,
                    > manifolds and some wiring. No transmission but that is no problem
                    as I have
                    > a recently rebuilt TH400 from a 74 472 engine that is a basket
                    case. I
                    > assume the bell housing is the same whether DeVille or Eldorado.
                    Am I
                    > correct?
                    >
                    > I looked up the HP and Torque for this engine and have to say its
                    less than
                    > impressive for the displacement. I can see why so many go to higher
                    > compression, performance cam, headers and different intake.
                    >
                    > Nother question: Is it acceptable practice to mill the heads to
                    raise
                    > compression a point to a point-and-a-half? If so do you have to go
                    to
                    > different length pushrods or will there still be sufficient
                    clearance
                    > between valves and piston? I'm looking for about 9.5:1 CR to help
                    out
                    > performance. I know the best way to go is usually different
                    pistons but I'm
                    > trying to keep the costs reasonable.
                    >
                    > Thanks. You guys have been great with the information and advice.
                    >
                    > Jerry Brown
                    Don't worry too much about the seemingly low hp. ratings, in actual
                    performance in a light vehicle there is not of much noticable
                    difference, you could mill the heads but a better choice is to swap
                    on a set of 425 heads, compression will be about 10:5 and will give
                    you and easy 40 hp more, not the best breathing for all out racing,
                    but fine up to around 4500 rpm, making for strong street performance
                    cheap, next best change is a good cam, then an Edelbrock intake.
                    Your 472 Trans will bolt right up.
                  • Jerry Brown
                    Thanks for the additional information re. 425 heads on 500 engine. Are the differences in the combustion chamber so that I don t need to change out valve train
                    Message 9 of 25 , Dec 9, 2004
                      Thanks for the additional information re. 425 heads on 500 engine. Are the
                      differences in the combustion chamber so that I don't need to change out
                      valve train etc.?

                      Don't worry too much about the seemingly low hp. ratings, in actual
                      performance in a light vehicle there is not of much noticable
                      difference, you could mill the heads but a better choice is to swap
                      on a set of 425 heads, compression will be about 10:5 and will give
                      you and easy 40 hp more, not the best breathing for all out racing,
                      but fine up to around 4500 rpm, making for strong street performance
                      cheap,
                    • jvandecreek25
                      ... Are the ... change out ... The late 500 heads have 120cc chambers, while the 425 heads have 96cc chambers, this is where the increase in compression comes
                      Message 10 of 25 , Dec 9, 2004
                        --- In Cadillac_Performance_Association@yahoogroups.com, "Jerry
                        Brown" <jerome@p...> wrote:
                        > Thanks for the additional information re. 425 heads on 500 engine.
                        Are the
                        > differences in the combustion chamber so that I don't need to
                        change out
                        > valve train etc.?

                        The late 500 heads have 120cc chambers, while the 425 heads have
                        96cc chambers, this is where the increase in compression comes from.
                        The 425 head has the same valve sizes, and the same intake and
                        exhaust ports as the late 500 head, the factory did remove some
                        weight by opening up the area where the push-rods pass through, but
                        this change has no effect on performance or durability.
                        Earlier '69-'73 heads do have better, more direct exhaust ports and
                        work better on a race type engine, but the compression goes to over
                        12:1 when used with the flat top pistons of a '74-'76 500(and 472)
                        and these stock cast pistons are prone to disintegrating at those
                        compression ratios, this combination is not at all streetable on
                        available pump gas.
                        So for "Bang for the buck",
                        Install the 425 heads, use a 425 head gasket(can be an old used
                        one) to locate the positions of the extra steam holes that will need
                        to be drilled in the block deck of the 500, a 3/8" electric drill
                        with the appropriate size bit is all that will be required, assemble
                        the heads to the block using 500 head gaskets. no other
                        modifications or non stock parts are needed.
                      • david brode
                        Jerry, The 74- 76 500s have 120+ cc chambers and a very small dish. If the bores look good, you could just deck the block for a .040 or so assembled quench,
                        Message 11 of 25 , Dec 11, 2004
                          Jerry,

                          The '74-'76 500s have 120+ cc chambers and a very small dish. If the
                          bores look good, you could just deck the block for a .040" or so
                          assembled quench, and whack the heads to get to *maybe* 9.5-1. Fyi -
                          KB makes no dish flat tops for it if it needs bored [which I doubt it
                          will].

                          Another option would be dished KB designed for the early heads. They
                          give 10-2-1 or so with the '68-'73 heads [76cc]. Another option is to
                          use 107cc 425 heads on your shortblock. They'll put you a little over
                          9.5-1. The 425 heads don't flow as well as yours, but a little work
                          and they'll do ok. The 76cc heads flow better than yours, btw, but
                          not much in stock form. More fyi - 2.11"/1.66&1.77" pontiac valves
                          fit the 107 and 120cc heads perfectly. For larger valves on the 76cc,
                          aftermarket valves are available from the caddy
                          parts vendors.
                          Dave




                          > Nother question: Is it acceptable practice to mill the heads to
                          raise
                          > compression a point to a point-and-a-half? If so do you have to go
                          to
                          > different length pushrods or will there still be sufficient
                          clearance
                          > between valves and piston? I'm looking for about 9.5:1 CR to help
                          out
                          > performance. I know the best way to go is usually different pistons
                          but I'm
                          > trying to keep the costs reasonable.
                          >
                          > Thanks. You guys have been great with the information and advice.
                          >
                          > Jerry Brown
                        • david brode
                          jvandecreek25, The 425 heads will not gain near that much in compression. It has been said that they are 96cc, but I believe they are more like 107cc or so.
                          Message 12 of 25 , Dec 11, 2004
                            jvandecreek25,

                            The 425 heads will not gain near that much in compression. It has
                            been said that they are 96cc, but I believe they are more like 107cc
                            or so. That figure comes from experts that I trust.

                            CR on a stock engine can vary. Assuming a stock late 500 is 8-1, and
                            the heads are 120cc, the 13cc reduction in combustion space would
                            raise the CR to 8.7-1. Assuming the stock engine was 8.5-1, the
                            change would give 9.25-1.

                            It would take a change in combustion space of apx 27.5cc to raise
                            compression of an 8.5-1 engine to 10.5-1.
                            Dave




                            much about the seemingly low hp. ratings, in actual
                            > performance in a light vehicle there is not of much noticable
                            > difference, you could mill the heads but a better choice is to swap
                            > on a set of 425 heads, compression will be about 10:5 and will give
                            > you and easy 40 hp more, not the best breathing for all out racing,
                            > but fine up to around 4500 rpm, making for strong street
                            performance
                            > cheap, next best change is a good cam, then an Edelbrock intake.
                            > Your 472 Trans will bolt right up.
                          • jvandecreek25
                            ... 107cc ... and ... After I posted I realised I had over-shot on the amount of compression increase, the figure I gave was one I had seen posted
                            Message 13 of 25 , Dec 12, 2004
                              --- In Cadillac_Performance_Association@yahoogroups.com, "david
                              brode" <dbrode@h...> wrote:
                              >
                              > jvandecreek25,
                              >
                              > The 425 heads will not gain near that much in compression. It has
                              > been said that they are 96cc, but I believe they are more like
                              107cc
                              > or so. That figure comes from experts that I trust.
                              >
                              > CR on a stock engine can vary. Assuming a stock late 500 is 8-1,
                              and
                              > the heads are 120cc, the 13cc reduction in combustion space would
                              > raise the CR to 8.7-1. Assuming the stock engine was 8.5-1, the
                              > change would give 9.25-1.
                              >
                              > It would take a change in combustion space of apx 27.5cc to raise
                              > compression of an 8.5-1 engine to 10.5-1.
                              > Dave

                              After I posted I realised I had over-shot on the amount of
                              compression increase, the figure I gave was one I had seen posted
                              elsewhere,and I never took time to confirm it.
                              However the figure for the 40 hp increase did come directly from Al
                              Betker of MTS,one of the most experienced Cadillac builders to be
                              found.
                              If this 40 hp improvement comes from an increase to only 9.25-1,
                              then so much the better.
                            • jvandecreek25
                              ... the ... Fyi - ... it ... They ... to ... over ... work ... 76cc, ... I m looking for about 9.5:1 CR to help out performance. I know the best way to go is
                              Message 14 of 25 , Dec 12, 2004
                                --- In Cadillac_Performance_Association@yahoogroups.com, "david
                                brode" <dbrode@h...> wrote:
                                >
                                > Jerry,
                                >
                                > The '74-'76 500s have 120+ cc chambers and a very small dish. If
                                the
                                > bores look good, you could just deck the block for a .040" or so
                                > assembled quench, and whack the heads to get to *maybe* 9.5-1.
                                Fyi -
                                > KB makes no dish flat tops for it if it needs bored [which I doubt
                                it
                                > will].
                                >
                                > Another option would be dished KB designed for the early heads.
                                They
                                > give 10-2-1 or so with the '68-'73 heads [76cc]. Another option is
                                to
                                > use 107cc 425 heads on your shortblock. They'll put you a little
                                over
                                > 9.5-1. The 425 heads don't flow as well as yours, but a little
                                work
                                > and they'll do ok. The 76cc heads flow better than yours, btw, but
                                > not much in stock form. More fyi - 2.11"/1.66&1.77" pontiac valves
                                > fit the 107 and 120cc heads perfectly. For larger valves on the
                                76cc,
                                > aftermarket valves are available from the caddy
                                > parts vendors.
                                > Dave


                                I'm looking for about 9.5:1 CR to help out performance. I know the
                                best way to go is usually different pistons but I'm trying to keep
                                the costs reasonable.
                                Jerry Brown


                                Jerry wanted to keep the costs reasonable, to "deck the block "
                                will require a complete disassembly, and is hardly a way to keep the
                                cost down, and as he stated he did not want to get into piston
                                changes.
                                I made my recommendation based on the premise that he wanted an
                                inexpensive power increase for a engine that was going into a street
                                rod, no it is not the 'ultimate' performance build up, but if it is
                                not being used as a race car, there is no need to pursue a lot of
                                expensive modifications that are unnecessary for strong street
                                performance. Jessie
                              • Jerry Brown
                                Actually I was speculating about just milling the 500 heads to get the increased compression ratio. Since the engine would be out of the car its no big deal to
                                Message 15 of 25 , Dec 12, 2004
                                  Actually I was speculating about just milling the 500 heads to get the
                                  increased compression ratio. Since the engine would be out of the car its no
                                  big deal to pull the heads and have a valve job done and to mill them for
                                  increased compression...So long as you don't booger up the valve train
                                  ratios. It seems to me that if you mill the heads, say .040, that it would
                                  drop the head lower with respect to the valve train i.e., closer to the
                                  center of the camshaft, and might result in any of a number of unintended
                                  results.
                                  In order to keep everything in the same ratio you would have to account for
                                  being .040 closer. Seems to me that pushrods that are .040 shorter should
                                  compensate or taking .040 off the top of the valve stem might as long as the
                                  keepers would still fit. Doesn't seem right that you wouldn't have to do
                                  anything but mill to do the job right. Likewise decking the block would have
                                  the same result of moving the head closer to the center of the cam. I guess
                                  the right question is can milling or decking be done without unintended
                                  catastrophic consequences and if so how should one compensate for the
                                  changes.

                                  Jerry Brown


                                  -----Original Message-----
                                  From: jvandecreek25 [mailto:jvandecreek@...]
                                  Sent: Sunday, December 12, 2004 1:15 PM
                                  To: Cadillac_Performance_Association@yahoogroups.com
                                  Subject: [Cadillac_Performance_Association] Re: The '49-'62 V8...
                                  anything out there?




                                  --- In Cadillac_Performance_Association@yahoogroups.com, "david
                                  brode" <dbrode@h...> wrote:
                                  >
                                  > Jerry,
                                  >
                                  > The '74-'76 500s have 120+ cc chambers and a very small dish. If
                                  the
                                  > bores look good, you could just deck the block for a .040" or so
                                  > assembled quench, and whack the heads to get to *maybe* 9.5-1.
                                  Fyi -
                                  > KB makes no dish flat tops for it if it needs bored [which I doubt
                                  it
                                  > will].
                                  >
                                  > Another option would be dished KB designed for the early heads.
                                  They
                                  > give 10-2-1 or so with the '68-'73 heads [76cc]. Another option is
                                  to
                                  > use 107cc 425 heads on your shortblock. They'll put you a little
                                  over
                                  > 9.5-1. The 425 heads don't flow as well as yours, but a little
                                  work
                                  > and they'll do ok. The 76cc heads flow better than yours, btw, but
                                  > not much in stock form. More fyi - 2.11"/1.66&1.77" pontiac valves
                                  > fit the 107 and 120cc heads perfectly. For larger valves on the
                                  76cc,
                                  > aftermarket valves are available from the caddy
                                  > parts vendors.
                                  > Dave


                                  I'm looking for about 9.5:1 CR to help out performance. I know the
                                  best way to go is usually different pistons but I'm trying to keep
                                  the costs reasonable.
                                  Jerry Brown


                                  Jerry wanted to keep the costs reasonable, to "deck the block "
                                  will require a complete disassembly, and is hardly a way to keep the
                                  cost down, and as he stated he did not want to get into piston
                                  changes.
                                  I made my recommendation based on the premise that he wanted an
                                  inexpensive power increase for a engine that was going into a street
                                  rod, no it is not the 'ultimate' performance build up, but if it is
                                  not being used as a race car, there is no need to pursue a lot of
                                  expensive modifications that are unnecessary for strong street
                                  performance. Jessie








                                  Yahoo! Groups Links
                                • david brode
                                  jvandecreek25, [bottom post] ... Al ... I have never CC d a pair myself. Al claims they re 96cc, iirc. Other experts claim 107cc. Dave
                                  Message 16 of 25 , Dec 12, 2004
                                    jvandecreek25,

                                    [bottom post]

                                    <dbrode@h...> wrote:
                                    > >
                                    > > jvandecreek25,
                                    > >
                                    > > The 425 heads will not gain near that much in compression. It has
                                    > > been said that they are 96cc, but I believe they are more like
                                    > 107cc or so. That figure comes from experts that I trust.
                                    > >
                                    > > CR on a stock engine can vary. Assuming a stock late 500 is 8-1,
                                    > and
                                    > > the heads are 120cc, the 13cc reduction in combustion space would
                                    > > raise the CR to 8.7-1. Assuming the stock engine was 8.5-1, the
                                    > > change would give 9.25-1.
                                    > >
                                    > > It would take a change in combustion space of apx 27.5cc to raise
                                    > > compression of an 8.5-1 engine to 10.5-1.
                                    > > Dave
                                    >
                                    > After I posted I realised I had over-shot on the amount of
                                    > compression increase, the figure I gave was one I had seen posted
                                    > elsewhere,and I never took time to confirm it.
                                    > However the figure for the 40 hp increase did come directly from
                                    Al
                                    > Betker of MTS,one of the most experienced Cadillac builders to be
                                    > found.
                                    > If this 40 hp improvement comes from an increase to only 9.25-1,
                                    > then so much the better.

                                    I have never CC'd a pair myself. Al claims they're 96cc, iirc. Other
                                    experts claim 107cc.
                                    Dave
                                  • david brode
                                    Jessie, [bottom]
                                    Message 17 of 25 , Dec 12, 2004
                                      Jessie,

                                      [bottom]


                                      <snip

                                      > Jerry wanted to keep the costs reasonable, to "deck the block "
                                      > will require a complete disassembly, and is hardly a way to keep
                                      the
                                      > cost down, and as he stated he did not want to get into piston
                                      > changes.
                                      > I made my recommendation based on the premise that he wanted an
                                      > inexpensive power increase for a engine that was going into a
                                      street
                                      > rod, no it is not the 'ultimate' performance build up, but if it is
                                      > not being used as a race car, there is no need to pursue a lot of
                                      > expensive modifications that are unnecessary for strong street
                                      > performance. Jessie

                                      Well, the reason I suggested decking the block for a tight quench and
                                      whacking the heads a bit, was because he said that money was an
                                      issue. Decking the block 20-30 thou costs just $65-$80 around here.
                                      Cutting the heads .050" or so would be a few more bucks, but not too
                                      much. Of course, once it's apart, hot tanmk, cam bearings, etc would
                                      cost him some. Personally, I would want to ring and bearing it
                                      anyway.

                                      The 425 head swap might be a much better bang per buck, I admit. As I
                                      see it, for a '74-'76 500, other than the 425 heads, the only other
                                      affordable option is to change to the dished KBs and 76cc heads to
                                      get any decent compression increase. Even the true flat top KBs on
                                      the 120cc heads aren't going to gain much over the very small dish
                                      stock late pistons.
                                      Dave
                                    • Preston III
                                      I ve never decked the block, or shaved the heads of a Caddy engine, but if it s anything like a Chevrolet small block, there s a limit that you can go before
                                      Message 18 of 25 , Dec 12, 2004
                                        I've never decked the block, or shaved the heads of a Caddy
                                        engine, but if it's anything like a Chevrolet small block,
                                        there's a limit that you can go before you have to do some
                                        machining to the intake manifold too. I expect that if you
                                        go past a certain extent, then you'll be in for spending
                                        even a few dollars more!

                                        Don't forget to inquire as to whether the changing geometry,
                                        and clearances of the intake/head surfaces may require a
                                        specific gasket, such as something extra thick.

                                        Also, in a true performance application, you may consider
                                        port matching the intake manifold to the intake side of
                                        the cylinder heads, as this is the dimension that will change
                                        as you go shaving things.


                                        Preston III


                                        --- david brode <dbrode@...> wrote:

                                        >
                                        > Jessie,
                                        >
                                        > [bottom]
                                        >
                                        >
                                        > <snip
                                        >
                                        > > Jerry wanted to keep the costs reasonable, to "deck the block "
                                        > > will require a complete disassembly, and is hardly a way to keep
                                        > the
                                        > > cost down, and as he stated he did not want to get into piston
                                        > > changes.
                                        > > I made my recommendation based on the premise that he wanted an
                                        > > inexpensive power increase for a engine that was going into a
                                        > street
                                        > > rod, no it is not the 'ultimate' performance build up, but if it is
                                        > > not being used as a race car, there is no need to pursue a lot of
                                        > > expensive modifications that are unnecessary for strong street
                                        > > performance. Jessie
                                        >
                                        > Well, the reason I suggested decking the block for a tight quench and
                                        > whacking the heads a bit, was because he said that money was an
                                        > issue. Decking the block 20-30 thou costs just $65-$80 around here.
                                        > Cutting the heads .050" or so would be a few more bucks, but not too
                                        > much. Of course, once it's apart, hot tanmk, cam bearings, etc would
                                        > cost him some. Personally, I would want to ring and bearing it
                                        > anyway.
                                        >
                                        > The 425 head swap might be a much better bang per buck, I admit. As I
                                        > see it, for a '74-'76 500, other than the 425 heads, the only other
                                        > affordable option is to change to the dished KBs and 76cc heads to
                                        > get any decent compression increase. Even the true flat top KBs on
                                        > the 120cc heads aren't going to gain much over the very small dish
                                        > stock late pistons.
                                        > Dave
                                        >
                                        >
                                        >
                                        >
                                        >




                                        __________________________________
                                        Do you Yahoo!?
                                        Yahoo! Mail - Find what you need with new enhanced search.
                                        http://info.mail.yahoo.com/mail_250
                                      • david brode
                                        Jerry, I ve only seen a few late 500s apart, but they all were pretty decent as far as deck to piston. Assuming you have eom pistons and they re good shape,
                                        Message 19 of 25 , Dec 12, 2004
                                          Jerry,

                                          I've only seen a few late 500s apart, but they all were pretty decent
                                          as far as deck to piston. Assuming you have eom pistons and they're
                                          good shape, and a 40-50 thou gasket is used, a .020" to *maybe .025"
                                          deck cut will give you a nice tight assembled quench. El-cheapo cast
                                          replacement pistons are often 20+ thou shorter than oem. I would
                                          shoot for 040" assembled quench, regardless. Experts use either
                                          Felpro of Corteco gaskets. The Coretcos are a little better, but
                                          thicker, btw. .044"-.048" installed, iirc. You may need to stick the
                                          piston out of the hole a bit wioth those. The 472/500 heads can be
                                          cut way down. 050" is nothing on those, afaik. The 425 heads' deck
                                          isn't as thick, and experts say not to cut them much over 040".

                                          As far as rocker geometry, you can use shorter pushrods. You can also
                                          have a good stock cam re-ground, and that'll reduce the base circle a
                                          bit. Maybe enough to make up for the head/block cut. Most of the
                                          caddy parts vendors offer re-ground cams, btw, but most grinders will
                                          do one for you if you have a decent stock core. A note on that; most
                                          grinders want to use profiles with 10+ extra exhaust duration. Afaik,
                                          it's not needed on a caddy, esp with the 76cc heads. Even the 120cc
                                          heads' stock exhaust port flows well enough to allow same duration on
                                          intake and exh. Some experts even say that when ported, the caddy
                                          heads flow so well on exhaust side that they use a little less
                                          exhaust duration!

                                          As far as higher lift cams, you may need to snip a little from the
                                          top of the guides for clearance there. The '68 up seals are a joke.
                                          You can use the normal old umbrella valve seals from the '67 429
                                          caddys. SBchevy springs can be used, but you'll need to get creative
                                          with shimming. The caddy springs are very tall. The new behive
                                          springs offered for fords and LS1 chevs work better, with a retainer
                                          change, as they fit the caddy spring pad, and are taller than std sbc
                                          springs. If you have a freindly machine shop, they'll probably have
                                          some larger diameter used retainers from something that'll fit the
                                          behive springs. Just make sure they fit with the 11/32" valve
                                          keepers. Unlike the sbc or behive springs, larger o.d. springs will
                                          require pricey spring seats and more machine work. If you don't have
                                          a machine shop that you can trust, you might want to buy a spring
                                          package from one of the vendors. If you use stock rockers, choose a
                                          cam grind with nice slow ramps, as quick ramps are hard on the stock
                                          stuff. When cam shopping, make sure to tell them that you want slooow
                                          ramps. Fast ramps are hard on the stock T pedistals and rockers.
                                          Dave

                                          Brown" <jerome@p...> wrote:
                                          > Actually I was speculating about just milling the 500 heads to get
                                          the
                                          > increased compression ratio. Since the engine would be out of the
                                          car its no
                                          > big deal to pull the heads and have a valve job done and to mill
                                          them for
                                          > increased compression...So long as you don't booger up the valve
                                          train
                                          > ratios. It seems to me that if you mill the heads, say .040, that
                                          it would
                                          > drop the head lower with respect to the valve train i.e., closer to
                                          the
                                          > center of the camshaft, and might result in any of a number of
                                          unintended
                                          > results.
                                          > In order to keep everything in the same ratio you would have to
                                          account for
                                          > being .040 closer. Seems to me that pushrods that are .040 shorter
                                          should
                                          > compensate or taking .040 off the top of the valve stem might as
                                          long as the
                                          > keepers would still fit. Doesn't seem right that you wouldn't have
                                          to do
                                          > anything but mill to do the job right. Likewise decking the block
                                          would have
                                          > the same result of moving the head closer to the center of the cam.
                                          I guess
                                          > the right question is can milling or decking be done without
                                          unintended
                                          > catastrophic consequences and if so how should one compensate for
                                          the
                                          > changes.
                                          >
                                          > Jerry Brown
                                          >
                                          >
                                          > -----Original Message-----
                                          > From: jvandecreek25 [mailto:jvandecreek@c...]
                                          > Sent: Sunday, December 12, 2004 1:15 PM
                                          > To: Cadillac_Performance_Association@yahoogroups.com
                                          > Subject: [Cadillac_Performance_Association] Re: The '49-'62 V8...
                                          > anything out there?
                                          >
                                          >
                                          >
                                          >
                                          > --- In Cadillac_Performance_Association@yahoogroups.com, "david
                                          > brode" <dbrode@h...> wrote:
                                          > >
                                          > > Jerry,
                                          > >
                                          > > The '74-'76 500s have 120+ cc chambers and a very small dish. If
                                          > the
                                          > > bores look good, you could just deck the block for a .040" or so
                                          > > assembled quench, and whack the heads to get to *maybe* 9.5-1.
                                          > Fyi -
                                          > > KB makes no dish flat tops for it if it needs bored [which I doubt
                                          > it
                                          > > will].
                                          > >
                                          > > Another option would be dished KB designed for the early heads.
                                          > They
                                          > > give 10-2-1 or so with the '68-'73 heads [76cc]. Another option is
                                          > to
                                          > > use 107cc 425 heads on your shortblock. They'll put you a little
                                          > over
                                          > > 9.5-1. The 425 heads don't flow as well as yours, but a little
                                          > work
                                          > > and they'll do ok. The 76cc heads flow better than yours, btw, but
                                          > > not much in stock form. More fyi - 2.11"/1.66&1.77" pontiac valves
                                          > > fit the 107 and 120cc heads perfectly. For larger valves on the
                                          > 76cc,
                                          > > aftermarket valves are available from the caddy
                                          > > parts vendors.
                                          > > Dave
                                          >
                                          >
                                          > I'm looking for about 9.5:1 CR to help out performance. I know the
                                          > best way to go is usually different pistons but I'm trying to keep
                                          > the costs reasonable.
                                          > Jerry Brown
                                          >
                                          >
                                          > Jerry wanted to keep the costs reasonable, to "deck the block "
                                          > will require a complete disassembly, and is hardly a way to keep the
                                          > cost down, and as he stated he did not want to get into piston
                                          > changes.
                                          > I made my recommendation based on the premise that he wanted an
                                          > inexpensive power increase for a engine that was going into a street
                                          > rod, no it is not the 'ultimate' performance build up, but if it is
                                          > not being used as a race car, there is no need to pursue a lot of
                                          > expensive modifications that are unnecessary for strong street
                                          > performance. Jessie
                                          >
                                          >
                                          >
                                          >
                                          >
                                          >
                                          >
                                          >
                                          > Yahoo! Groups Links
                                        • david brode
                                          Preston, Good point. I ve decked a couple of them, but only 10-20. There was no need to cut the intake, or intake side of head. The intake may ride up on the
                                          Message 20 of 25 , Dec 12, 2004
                                            Preston,

                                            Good point. I've decked a couple of them, but only 10-20. There was
                                            no need to cut the intake, or intake side of head. The intake may
                                            ride up on the heads a wee bit, but unless a large amount of mat'l
                                            was cut, the ports can be re-aligned when port matching.

                                            If it was a problem, the intake could be cut, or the intake side of
                                            the head, although the valve cover bolt hole bosses there make it a
                                            bit tricky.

                                            I know that this issue is common, as the .015" shorter 6.735" forged
                                            olds rods are often used in the caddy. Another old combo is 7" olds
                                            rods and 403" olds pistons. That combo is 40-50 thou short, so I'm
                                            sure it's been addressed.
                                            Dave


                                            III <prestoniii2002@y...> wrote:
                                            > I've never decked the block, or shaved the heads of a Caddy
                                            > engine, but if it's anything like a Chevrolet small block,
                                            > there's a limit that you can go before you have to do some
                                            > machining to the intake manifold too. I expect that if you
                                            > go past a certain extent, then you'll be in for spending
                                            > even a few dollars more!
                                            >
                                            > Don't forget to inquire as to whether the changing geometry,
                                            > and clearances of the intake/head surfaces may require a
                                            > specific gasket, such as something extra thick.
                                            >
                                            > Also, in a true performance application, you may consider
                                            > port matching the intake manifold to the intake side of
                                            > the cylinder heads, as this is the dimension that will change
                                            > as you go shaving things.
                                            >
                                            >
                                            > Preston III
                                            <snipped
                                          Your message has been successfully submitted and would be delivered to recipients shortly.