Re: [Small4-strokeEngines] Re: DragonFly 1000cc Generac First Reports
- What is the HP stock? Is the porting what boosted HP to 50?Will,The Generac is a 4 stroke. At this time I am gathering up the data on cost to reproduce this DragonFire motor. My goal is to offer a complete set up, to includeThis balanced and blueprinted 1000cc version complete with dual Mikunis as pictured here, a rock solid re-drive and the Dagster Prop.I am working with my vendors on pricing. The motor begins as stock Generac. Then it is tore down. Heads ported and polished. A custom ground cam is installed.The complete internals are balancedto very strict tolerances then re assembled. As for the carbon fiber(look) cowl it will not have that as standard. Its not carbon fiber. Its hydro-diped to look like carbon fiber. If one insist I may consider it as an option. Its a pain to do$I have on on the bench now going through the process. If any one is interested . I can be contacted via email or 931-215-0211.On Aug 27, 2013, at 10:17 PM, Will Warren <wwarrn@...> wrote:Darrell, is your engine a 4 cycle or 2 cycle, and where do I go to buy this smooth running rocket ?!
On Aug 27, 2013, at 10:36 PM, John Spradlin <spikews@...> wrote:I just wanted to tell you that your new Generac V-twin looks fantastic. John S
John W. Spradlin www.standard1320.com
Date: Tue, 27 Aug 2013 13:32:20 +0000
Subject: [Small4-strokeEngines] Re: DragonFly 1000cc Generac First Reports
Not sure if the link to the photos is working.
--- In Small4-strokeEngines@yahoogroups.com, "Dagwood" <dagwodzz@...> wrote:
> Its been real crazy this past week! ALL of the parts for the DragonFire Motor hit at once. My goal was to have it ready for a fly- in this past weekend. Parts came in on Wednesday late. Worked on it all night. Was not able to finish it up to leave on Thursday AM as planned. Thrashed on it till 6:00 PM Thursday. Started it, it ran, loaded it in the trailer and headed up to ILL. an 8 HR trip. WOW was I toast! Friday morning I arrived. Did a test run up with a friend holding her down.
> First impression was OMG is it ever smooth! Guys, keep in mind I have been playing with these motors since 2006 when Buckeye first started installing industrial 4 stokes on the Dragonfly. From the Honda's to the Generac's. They all had a tendency to have an inherit vibration to them. Being one of the test pilots on the project
> I watched the evolution of props, motor mounts etc all in order to tame the beast. It was finally just accepted they it was just the nature of the beast. I am real familiar
> with their personalities.
> Well today I can honestly say that this DragonFire motor is as smooth at my cruise RPM now (3060) up from 3000 Rpm as any 2 stoke I ever flew, period! Prior to this the motor shook to the point the fuel often bubbled up and out the overflow tube. Not now…. smooth. It was also hard to read the instruments. Now… clear as a new pair of glasses. As for the power? its a tad stronger than the 992. I wasn't really expecting monster gains. But it did gain some. I saw 700 FPM ROC. It was HOT and Sticky at the fly-in. I did have to add pitch to the blades as it wanted to over rev.(4500 Rpm) This alone tells me I gained some HP. as it pushed way past my previous red line(4180) and floated the valves. So, Friday night?am? 1:00AM... I added some pitch to the prop. Ended up landing on about 4200 Rpm. Perfect.
> The newly designed "active" revive worked out real sweet. Its not completely finished as I want the idler pulley larger in diameter and located more in the center of the spread. I just ran out of time but its in the works. More important is the pulsating vibration (death vibe) that faded in and out is also gone! That was the crank killer.
> After exhausting research I do believe I have cured that problem as well.
> The exhaust, I re-did as well. Just trying this out' for now. Does not sound as good as the header but seems to work well for now. All and all the DragonFire is now a viable option. I will put it through its passes this fall and continue to gather data. Did I mention fuel burn went down from 2.2 GPH to 1.6 GPG at cruise. My guess is the added torque does not require me to open the throttle as much even though its spinning 60 RPM more at cruise.
- GeoB,There was more than one type of vibration going on. Each required its own remedy. The "active" re-drive is as it sounds. Most re-drives just stretch out the pulleys from each other thus putting tension on the belt. Effective but crude. The active re-drive uses an idler pulley to draw up slack. The idler is spring loaded to allow the belt to be "active" in dampening the harmonic headed back to the crank. Doing so allows for less belt tension . That is beneficial in many ways. Less side load on the crank bearing. Less heat, just to name a few. There is now a simple, easy and "proper" way to measure belt tension.Thanks for your interest.DragonFire. 1000cc Generac.On Sep 7, 2013, at 2:58 PM, GeoB <gab16@...> wrote:
> First impression was OMG is it ever smooth!
Dag, I have been following your build of this engine, I have known most of your mods. To what do you attribute the new smoothness? I know you mentioned balancing, but had you not done this on previous renditions of this engine?
> The newly designed "active" revive
I don't understand this, is it a typo?