YellowJacket RV9

YellowJacket RV9

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I am working on fitting my exhaust system, it is the one from Vans, along with their newer crossover heat muff. Out of the box, the openings in the heat muff at either end will not quite fit around the enlarged flanges at the slip joints. Is this just supposed to be a very tight fit, do I need to slightly enlarge the openings, or do I have something wrong? The instructions that I found (https://www.vansaircraft.com/pdf/revisions/other/OP-54.pdf) don't make any mention, other than to say the slip joints must be outside the box. I did measure the openings and found that ones that accommodate the slip joints are 1/16" bigger, but still not quite big enough. Here is a picture of how things look for me:


2j1ajx2.jpg


Any ideas? Thanks!

Chris
 
Hey Chris,

I've got the same heat muff, and I had to do a little Dremel work to enlarge the cutouts. The holes should be centered on the fat parts of the slip joints.

Fortunately, you don't have to remove too much material.

 
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The intent is for a tight net fit.
It is not intended that you would have to enlarge the holes as Doug did, but since the tube expanding process is not high precision, I can see some of them being a bit tight occasionally.
It should only require removing a few thousandths with a sanding drum.
 
I believe they still carry the old style, but this is what is included in their exhaust kit. Some other threads on here indicate that it is supposed to be more effective, and people have been pleased with it.

N941WR said:
Is that crossover heat muff the new "standard" muff?
Click to expand...


Chris
 
YellowJacket RV9 said:
I believe they still carry the old style, but this is what is included in their exhaust kit. Some other threads on here indicate that it is supposed to be more effective, and people have been pleased with it.

Chris
Click to expand...
Thanks! I was just curious.
 
Scat tube from heater to firewall

I'm curious about how you will route your tube from the heat muff and the firewall. I right here and I can't figure where I will route this tube. I don't want to interfer with my throttle cable, the exhaust and the cowl... If someone have a pics of that... Thanks
 
Closterman said:
I'm curious about how you will route your tube from the heat muff and the firewall. I right here and I can't figure where I will route this tube. I don't want to interfer with my throttle cable, the exhaust and the cowl... If someone have a pics of that... Thanks
Click to expand...

There are a few pictures at the end of the OP-54 instructions that I linked too, but I haven't gotten to that point yet.

Chris
 
Running heat muff SCAT tube to fire wall

I used the new style Vans heat muff on my IO-320 RV-8, no issues with the two halves fitting over the pipes, its a tight fit that seemed to form fit after a little bit of tapping with a rubber mallet. I would use care in enlarging the openings that fit over the pipes, they need to be a very tight seal. The most difficult part of the installation was running the SCAT tubing from the bottom of the heat muff (exit faces down to the right) along the RH side of the AFP FM-100, past the throttle linkage, up and around the engine mount, oil lines, fuel lines and other "stuff" to connect at the firewall. It was quite a circuitous routing with plenty of clamping and anti-chafe protection involved. I ran my inlet up to the LH inlet ramp. Thus far on a fairly cold day, it provides plenty of heat, almost too much.
 
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