flythesky

Is it a problem for those who have an exhaust that is landing on the bottom of the wing and have retracts?
I stopped planning on a side mounted engine when I realized were the exhaust would be going on my first plane with retracts. A fuel soaked wing is what I imagined.

ChuckW

I've had oil get up into the retract wells on a few planes. As long as there is no bare wood for it to soak into or openings where it can get into the wing structure you should be fine. It may not be too good on foam tires either. If anything, it is just annoying to have to clean out the wheel wells and the gear.

Gray Beard

My Feedback: (-1)

Everything in the wheel wells gets sealed and fuel proofed but I have had a binding problem with mechanicals due to first oil then dirt getting between moving parts. My Spring Airs don't seem to have any problems but they aren't in a direct line with the engine snot.

bps

My Feedback: (3)

I used what the locals call a muse muffler to extend the exhaust on my side mounted Saito .82 mounted in a scratch built profile Mustang with retracts. Getting the exhaust behind the opening is the answer.

flythesky

Well that was the problem. The wheel well I could seal, but the slot for the gear leg and the retract itself would let fuel into the wing. One other thing was that it is a twin so the engine was going to be more in line with the retract then a single engine.

flythesky

I did consider a pipe, and a musse can would have been a cheaper alternative, but I've never used either in the past. I finally raised the fuel tank since the side mounting was to get the needle valve in a better relationship with the tank in the first place.
I'm going to keep mosse can construction in mind as a future project because I can see the situation coming up again on another plane I want to build.

da Rock

Guess my P47, Corsair, and F6F's with their side mounted engines didn't know their wheel wells shouldn't be dry as bones, but they are.

Route your exhaust straight down. That's very easy to do thanks to 2 sources of Pitts mufflers. And then add short extensions to the pipes if needed. The exhaust is then blown directly down, between the wheel wells. As the pictures show, the extensions aren't exactly obvious. MOF, I've not bothered to even try shortening them to see if they could be. As it is, neither the Corsair or Hellcat get oil further forward than under the tails. After a day of flying, the paper towel comes away with some but not much. I've put them into the car trunk without wiping (old age gets you one way or the other) and had no drips. There isn't enough to cause drips.

The P47 actually has a stock muffler on it. I took the time to build a tunnel into the fuselage/wing for it. I don't go to that effort now.

I'm just about to re-muffle my Spitfire to route the exhaust out the bottom. It's got an inverted engine with side exhaust. At the time that seemed the only mounting that'd keep the engine from showing, and the muffler out the side was preferable to the engine head and pitts pipes. There is now an "inverted wrap around" available. So I got a new cowling and am about to retrofit. I know that the exhaust location with that muffler, directly out the bottom, will be both clean and not very noticable.

ChuckW

Can you get to the surrounding structure with the retract out and seal it with some epoxy? Might to double duty as protection from oil plus add some strength. It may also be just a matter of a short exhaust extension. It may not take much to make it just miss the retracts.

flythesky

da Rock

I didn't mention that my plane is a twin so the exhaust is in line with the retracts. I will keep in mind that a Pitts style muffler will cut down on the exhaust on the plane. Thanks.

ChuckW

I could build a box around the retract assembly when assembling the wing but it is a little after the fact now. I thought it was a little too much trouble to do after building the wing. Thanks.

da Rock

The simple fix is those silicon pipe extensions. They're sold 2 to a package. They even come in colors. They're basically oversized fuel tubing, or more exactly made from the same stuff. They fit the stock OS muffler pipes and Slimline's pitts' pipes.

Cut the bend off of them and just use the straight section. Or use a bit of the bend to give the outlet a streamlined look. You'd be using them "backwards" then of course.

Here is a red one used on a red airplane. It's put on "forewards".