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Baffling


borris

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Here's the run down.

 

Bought Varieze with RW-100 engine

Removed engine and installed C-85

Have plans with RW-100 plans

 

 

So, here's the problem. I only have simple drawings of the baffles, but I'm fairly proficient with 3D modeling and CAD. So I took some known measurements off the engine and scaled them to the drawings. So I've made all the baffles out of posterboard and they seem to look ok, but I was wondering if there was anyone out there that could send me some photos of what their baffles look like before I invest the time and material fabricating them out of metal?

 

Someone told me their were updates to the baffles as well. Are there any updates that would help in the aid of cooling?

 

I also have the Hal Hunt exhaust. If anyone has these, how did these work with your rear baffles?

 

Thank you for your help. I should have the plane ready in about a month, if all works to plan.

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  • 2 weeks later...

Borris,

You may want to look into making some additons/changes to the standard

Varieze baffles. I would recommend you get some current info on installing 'clam shells' on the cylinders with radius entry and exits for the air.

I installed something similar ten or so years ago and my cylinder temps are much closer to being equal than they were before.

Also, you will need a four position switch for the cyl temps or you won't be getting any good temperature information.

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Thank you very much for responding to me. Just wondering if you might know where I can find some of these updates and / or "clam shell" designs? I've got most of the CP newsletters. So far I don't see anything in it.

 

I'm putting in a 4 probe CHT/EGT unit. I know the value of knowing what's going on in each cylinder.

 

Thanks again.

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I will look thru various sources and see what I can find. I did it over ten years ago and know there was some info on the size of openings on each side of the cylinder, but also some seat of the pants experimenting.....

Roughly, there is about 2.5 inches opening on the bottom side and 2.0 inches on the top (for up draft cooling). The upper and lower ends of the 'clam shells' turn out and are rounded at an approximate 5/8 inch diameter........think I used a piece of alum tubing to round the sheet metal with.

I will get back with you if I find anything. I did have a friend who now lives down in Texas that was giving me some advice since he was a Boeing engineer......and I can check with him.

If you have any specific questions, I may have an answer.

Also, number four cylinder has always been the coolest, so I know that I was doing some compensating for that by cutting down the opening. And there are two sets for each cylinder over each set of fins.

Maybe someone else can jump in with some good info.

 

Good luck !

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  • 1 month later...
  • 7 months later...

Thank you for all the pictures and emails on baffles. I did complete the project and flying almost everyday. The VE performs well. Climb I will see 404 on one cylinder and in cruise, typical CHTs are around 360. I'd say that's pretty impressive.

 

Cruise is 187 if I really push it, most of the time 2650 rpm at SL will yield a cruise of 170+ mph.

 

Of course, now I'm addicted to speed and would like to figure out how to get more out of my stock VE.

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  • 4 weeks later...

Hello Borris,

I fly a VE too; Lyc 235 powered. Gary Hertzler prop (very nice!).

Currently no wheel pants (planned...)

Same bafflings as yours/WTJohnson. CHT ok (single #4 probe; 3 other received from Wicks few days ago; will be installed this week-end).

 

>>Cruise is 187 if I really push it, most of the time 2650 rpm at SL will yield a >>cruise of 170+ mph. :thumbsup:

 

How many galon per hour at 17O mph ?

 

Regards.

VE F-PMPZ @ LFPK

Gilbert.

VE 1736

F-PMPZ @ LFPK (France)

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Borris,

If you get CHT probes on all four cylinders with your Continental engine, you may (probably) find that the #4 cyl is running cooler than the others. I have made a few adjustments to bring it up to the others by closing up the clam shells a bit. I think in cruise my CHT's are all within about 25 deg.

I think the #4 runs cooler because it is so close to the prop....

If anyone has any other ideas, thoughts or observations they would be appreciated .....

Wayne

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