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View Full Version : How close is too close (to a prop)???


magilla
12-11-2007, 03:18 PM
After looking at aviation exhaust systems for my VW engine (my very used, badly welded mild steel exhaust has a crack 6" long right out of the head) I am rather disgusted at the prices...

Revmaster wants $330.00 for a mild steel 4 into 1 exhaust, $480.00 for 304 stainless.

Great Plains wants $395.00 for a 4 into 1 exhaust for a kitfox/avid (mild steel)

The best one I have found is the aerovee, who wants $390.00 for a 304 stainless 2 into 1 system...

So I bought an EMPI 2 into 1 exhaust with built-in muffler, like a Supertrapp. Chrome, $149.00, with inserts.

Here's my question:

After test fitting the EMPI exhaust, itta fitta fine on the engine...

However, when I mounted the prop, there is only 5/8" clearance between the trailing edge of the prop and the radius turn of the exhaust.

With a tractor configuration, I figure that the prop will flex forward, if anything, so 5/8" should be fine.

What do you think?

How does it look?

Ron E
12-11-2007, 04:07 PM
Spencer,

I have a turbo set-up that came off a Revmaster 2100D engine. It includes the turbocharger and intake-side tubing. Just bolt it on, run an oil line to the turbo and add a carb. It is a draw-through system. $385, plus UPS shipping. I'm cleaning out a warehouse.

It came off a running engine several years ago.

scottessex
12-11-2007, 04:42 PM
I would support those mufflers so they don't vibrate and crack off. also I would try to direct the heat from the exhaust away from the aircraft.
could you flip them over? So they would be on the bottom?

magilla
12-11-2007, 04:53 PM
Ron - can you send me a pic so I know what you're talking about?

It sounds REALLY interesting, but I've heard some touchy things about turbos on a vw(heat dissipation).

Will my Holly carb bolt up to it?

Scott, good points about the vibration...

But the exhaust is light, and that it the way it was originally designed, except pointing the other way (towards the prop)

However, the exhaust is only 6" higher than if it flipped around, so no real benefit there..

and, it won't flip over because of the flanges...when I tried, it put the muff right in the middle of the oil cooler.

I think I'm gonna take it back tomorrow...

Damn!

PPG Doug
12-12-2007, 07:18 AM
How about adding a spacer between the hub and the prop, thus moving the prop back a few 1/16's. Might just make the difference you are looking for.

Good Luck!