Exhaust coatings

whiskeypapa · #1 01-09-2009, 09:08 PM

I'm curious what exhaust and intake tube coatings others have used as a thermal barrier. Also, has anyone noted a performance increase? Were any self applied?

Bill Prouty
RV-4 Flying

frankh · #2 01-10-2009, 10:04 AM

To cover the exhaust pipe but it has been done. Exhausts tend to crack due to thermal expansion and wrapping them makes the expansion problem worse.

If you are going to do this then make sure you install the exhaust stress free. A lot of folk simply bolt on the exhaust and if its slightly out of line simply torque up the flange nuts to make it fir..bad idea as this will torque the slip joints and it will be more difficult for the pipe to grow and the joints to slip...So it bends and cracks instead.

Purely personally I would wrap the intake pipes and leave the exhaust uncovered..But I haven't done this yet.

Frank

rv8ch · #3 01-10-2009, 11:09 AM

There is some discussion on this subject here:

http://www.vansairforce.com/communit...ead.php?t=3228

Regards,
Mickey

whiskeypapa · #4 01-10-2009, 01:29 PM

Thanks for the link, Mickey.

Bill Prouty
RV-4 Flying

rvbuilder2002 · #5 01-10-2009, 04:11 PM

I didn't take the time to read the thread posted by Mickey, but thought I would mention that I pretty sure Larry Vetterman (Makes the exhaust systems) highly discourages coating or wrapping the systems he makes. They are very thin wall tubes compared to automotive exhaust systems and teh high heat retention of the pipe caused by the insulating qualities of the wrap or coating will cause the pipe to erode from the inside out.

Mel · #6 01-10-2009, 04:21 PM

I can confirm what Scott says. Larry says definitely do not wrap exhaust systems.

whiskeypapa · #7 01-10-2009, 11:30 PM

First of all, thanks to each of you for your responses. I think the verdict is out on wrapping and it is a resounding "NO"! And I agree whole heartedly. But that's not what I meant - I'll try to be more clear. I'm curious about ceramic coatings applied w/ a spray gun to the inside and outside of the exhaust pipes and also to the induction tubes in order to keep the fuel/air mixture as cool and dense as possible. It's big in the race car world and I know some folks have done it in our world and I'm just curious about their results. As you know, some of us just can't seem to leave well enough alone.

Thanks again,

Bill Prouty
RV-4 Flying

tin man · #8 01-11-2009, 12:04 AM

FWIW Endeavor the Reno Air Race F1 winner and record holder coated the inside of his pipes, tuned 4 into 1. No money has been spared on that airplane.
tm

RV6_flyer · #9 01-11-2009, 06:24 AM

Just another data point. I know the Vetterman recommends against wrapping. I just removed a Vetterman exhaust that was wrapped for more than 10-years and 2,000 hobbs hours. It was replaced with a new Vetterman exhaust when I installed new cylinders. Vetterman does recommend replacing the exhaust at overhaul time due to the number of heat cool cycles.

PJSeipel · #10 01-11-2009, 06:56 AM

Quote:

Originally Posted by whiskeypapa

First of all, thanks to each of you for your responses. I think the verdict is out on wrapping and it is a resounding "NO"! And I agree whole heartedly. But that's not what I meant - I'll try to be more clear. I'm curious about ceramic coatings applied w/ a spray gun to the inside and outside of the exhaust pipes and also to the induction tubes in order to keep the fuel/air mixture as cool and dense as possible. It's big in the race car world and I know some folks have done it in our world and I'm just curious about their results. As you know, some of us just can't seem to leave well enough alone.

Thanks again,

Bill Prouty
RV-4 Flying

You might give John Forsling at Forsling Aviation a call. He ceramic coats his exhaust inside and out. I haven't flown with it yet, so I can't give you any real feedback, but he probably can. His number is (303) 841-6054.

PJ Seipel
RV-10 #40032