Re: [pop-pop-steamboats] Re: Big pop-pop engine
----- Original Message -----
From: "Jean-Yves Renaud" <boite.de.j-y@...>
> You will
see that it is more powerful with air inside.
I used another mean when testing some engines. The engines were filled
and started as usual, and then with a syringe and a soft plastic tube I
introduced a well know quantity of air to increase the delivered power.
See "Gas in a pop-pop engine" on www.eclecticspace.net
I have found that engine completely filled with water gets more powerful
after running a while, and then can fade.
A possible explanation is that boiling the water releases air which at
first improves performance by proving a "spring" for the moving water to
bounce off, and then degrades it by not allowing water near enough to the
Is this covering old ground, or is it rubbish?
- Hi dan,
I'm presently travelling far from my pop-pop engines. The pipe of the big engine is approx 75cm long. It is going up for the first 10cm and then it is straight and slightluy inclined down. More details in a couple of weeks when I am back to my "laboratory".
> Message du 19/03/07 00:15
> De : "danoyes1" <danoyes1@...>
> A : email@example.com
> Copie à :
> Objet : [pop-pop-steamboats] Re: Big pop-pop engine
> Hi all
> Jean I look foreward to hearing the test results you get for your
> big drum evaporator. how long is the pulse pipe on your new engine?
> it's good to hear that it had such a powerfull thrust pulse and ran
> without incident.
> --- In firstname.lastname@example.org, "Slater Harrison"
> <Sharrison@...> wrote:
> > I was just looking at Dan's and Jean-Yves' pictures. Wow! I've been
> > following pop pop engines for a couple of decades and I knew of two
> > types: the diaphragm type and the coil type. I've never seen
> > like the hammer head! Where did this design come from? How long
> has it
> > been around?
> > Slater
> > -----Original Message-----
> > From: email@example.com
> > [mailto:firstname.lastname@example.org] On Behalf Of Jean-Yves
> > Renaud
> > Sent: Thursday, March 15, 2007 1:58 PM
> > To: email@example.com
> > Subject: [pop-pop-steamboats] Re: Big pop-pop engine
> > Hi all,
> > Up to now, my biggest pop-pop engine had a pipe of ID 10mm, and
> > engine was far from optimized because at that time I didn't know
> as much
> > as I know today. Encouraged by Dan's messages and by the pictures
> of his
> > engines, I built a big one. I wanted to call it the 4 dollar engine
> > because 2 coins of 2 Canadian $ would have been perfect to close
> > evaporator. Unfortunately (that's the appropriate word) I had only
> > coin left over from my last visit in Canada. I tried the Italian
> > coin. It fitted too...but I had only one. Therefore, as I didn't
> want to
> > be responsible of a war between Canada and Italy (with all the
> > corresponding messages on the forum!!!), I decided to build 2
> > caps by myself. (see the photo album).
> > Two hours later the engine ran at the first attempt. The
> evaporator ID
> > is 28mm and the pipe ID is 12mm. The engine seems very powerful.
> > water level in my (small) test tank (approx 15cm x 30cm) was 30mm
> > the top, but the waves succeeded to flood my work bench.
> > When I have time (i.e. probably not before next month) I will test
> > engine with appropriate measuring instruments and I'll let you
> > Jean-Yves