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Re: RevMaster: rough on take off only

PostPosted: Wed Jul 20, 2022 12:49 pm
by flyingbear
My Aerovee does EXACTLY what Mikes does- exactly. And the solution is the same- lean a bit (or advance throttle slowly). I lean my mixture at all times,even at idle after startup.

Re: RevMaster: rough on take off only

PostPosted: Wed Jul 20, 2022 2:07 pm
by pilotyoung
My AeroVee does the same thing. As soon as I start it, I lean it aggressively and shut off the secondary ignition. That way at low engine power the secondary ignition is not drawing power. Then I put it full rich before I do the run up. Leaning aggressively is not my idea, I got it from another member on here. By leaning aggressively, if you forget to push the mixture to full rich, when you give it power for takeoff, the engine will miss.

Re: RevMaster: rough on take off only

PostPosted: Wed Jul 20, 2022 3:19 pm
by BRS
pilotyoung wrote:My AeroVee does the same thing. As soon as I start it, I lean it aggressively


Thanks, ground leaning is already something I do, which I learned on certified aircraft. Seems these engines with their slide carb needs it more than the Lyc/Cont engines do.

The next thing I need to learn is how to best lean during low/idle power descents. I want to get to where I can fly base and final on idle but I'm afraid of the engine stopping. Had that happen while taxiing in once.

Does anyone with a Prince P-tip know what airspeed is required to keep the prop turning?

Re: RevMaster: rough on take off only

PostPosted: Thu Jul 21, 2022 12:24 pm
by Onex107
I can't count the number of times I have heard the "mixture problems" at idle comments. I know you won't believe me but the #2 and #21/2 needles in the Aeroinjector both had that problem. After extensive testing and needle making, I found the #3 needle moves the idle sweet spot to where it is in the correct position with the slide valve closed, at idle. I never have had to adjust the mixture during or after landing and only adjust at cruise to raise the EGT temps to a leaner mix. With the two lower needles I had to lean during taxi or the engine would stop.

Re: RevMaster: rough on take off only

PostPosted: Thu Jul 21, 2022 9:03 pm
by BRS
Onex107 wrote:...I know you won't believe me but ...


I believe you. Hmmm wonder if Revmaster has a different profile metering-needle.

Thanks.

RevMaster: SOLVED! (Bell Crank)

PostPosted: Fri Sep 09, 2022 5:53 pm
by BRS
After months of wrestling with this Revmaster "RevFlow" carb I finally purchased an AeroInjector. After a few hours of adjusting it was ready to test fly. Bottom line - it works! Not balking, no hesitation, full 3200- static rpms. EGT's cool in flight.

Following are some pictures for the setup.

First off I needed to fabricate a cable reversal bell crank. I built it such that 3" pull on the control is 1.5" push on the aeroInjector. Sorry the pictures are so large, you'll have to click on them to see the full image.

BellCran_b4_install.jpg
BellCran_b4_install.jpg (196.24 KiB) Viewed 4199 times


BellCrank_top.jpg


BellCrank_Underside.jpg
BellCrank_Underside.jpg (117.77 KiB) Viewed 4199 times


The bellcrank base is made from 2" angle. The radius didn't quite fit the 1/2" Diameter engine mount tube but with some sanding it was not far off. Then the radius was liberally filled with RTV and loosely set in place to dry before tightening the hose clamps. The hose clamps are protected with Adel clamp rubber strips so as to not damage the mount.

With the engine off the control works smooth as butter but there is a bit of resistance felt when accelerating. Thinking this is normal as a sucking engine will pull that slide tight. It's not too much, just different.

Now onto the carb.....

RevMaster: SOLVED! (Carb Swap)

PostPosted: Fri Sep 09, 2022 6:11 pm
by BRS
The RevFlow carb is 35+mm which was replaced with the 32mm AeroInjector. 32mm works well. I noticed right away that the S flange almost fit into the Revmaster flared intake tube and that sizing was such that a rubber coupler would be problamatic. So I drilled and slit the end of the revmaster flared intake flange so that a hose clamp could be used on it. Next I turned down the S-flange by .020' which fit perfectly...

Flange_turned.jpg
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From this angle these carbs look about the same in size. But the AeroInjector feels about half the weight of the RevFlow carb.
Both_Carbs_size.jpg
Both_Carbs_size.jpg (247.61 KiB) Viewed 4193 times


Here you can see where all that extra weight comes from.
Both_Carbs.jpg
Both_Carbs.jpg (249.27 KiB) Viewed 4193 times


The drilled hole and slit (under the first hose clamp) in the intake tube is covered completely by the S-flange. It was also sealed with a bit of RTV to boot. The second hose clamp is only for the safety wire attachment.
AeroCarbInstalled.jpg


No doubt there will be more tuning to be done but so far the Revmaster seems to be running very well - finally.