UnPossible

UnPossible

Well Known Member
Hey - still working on the FWF... As you can see in the picture below, I have installed the heat muff and the scat tubing. However, the scat tubing wants to hang too low between the muff and the FW heat valve. I have used some red high-temp RTV to "lock in" the curve around one of the exhausts, but the scat tubing is hanging too low and rubbing the cowl.

Can anyone offer me any suggestions as how to support the scat tubing up a bit higher so that it does not want to rub on the cowl?

Thanks,
Jason

2n6ym29.jpg
 
How about an Adel clamp (with a half inch or so standoff) bolted to the heat shield? I have a cold air scat tube running by my exhaust with the same type of heat shields and it works fine. In fact, I threw it up there with zip ties as a temporary measure and it has flown like that for many hours - if zip ties can take the heat, an adel certainly should!
 
UnPossible said:
......Can anyone offer me any suggestions as how to support the scat tubing up a bit higher so that it does not want to rub on the cowl?.....
Click to expand...
Jason,

This is a difficult scat tube run to get right. After a lot of trial and error, I settled upon a 90? elbow at the heat muff, secured with an adel clamp assembly on the engine mount.

2hea4ya.jpg
 
It appears as if the rear exhaust stack could have had the slip joint raised up a bit, angled back just slightly so that the straight portion would be longer, and then the heater placed on that one. It would simplify the routing of the hose.

For future exhaust sysytems, of course.....

Dave
 
Last edited:
anybody have any pictures of scat/exhaust standoffs? I have a similar situation to the above pics (scat from firewall area to forward baffle, need to keep off the exhaust). Thinking of a bent stainless strap, hose clamped to the exhaust, with an adel to the scat. I have a few of the stainless heat shields from Spruce.. they seem perfectly adequate as a heat shield but a little wimpy for use as a mounting surface. I'm assuming I really don't want the scat freely rubbing against the shield (or anything else!). Given the distance of my duct run, it really needs to be supported in the center which happens to be right in the vicinity of the exhaust tube, no other stuff close by for mounting. Experimental shortwing piper type of project.
Looking for ideas.
thanks!
 
Last edited:
??

Maybe the muff will fit on #3 down pipe? Sure would make the SCAT runs easier...you might need a cover with the inney-outey in different places? Changing to 1.5" hose might help too...

The existing plan doesn't look like it will last long.

Carry on!
Mark
 
RTV/fiberglass tape

One thing I did to help reinforce & support SCAT in another area on my plane was to impregnate some fiberglass tape with red RTV. Using some fiberglass tape I have, I cut a strip the desired length. I laid the tape out on a piece of plexiglass (wax paper would probably work) and then squeegeed the RTV into the fiberglass on both sides. (use something stiff like a credit card). Once it's cured, you can use it to wrap around areas on the SCAT where you want to put a clamp. Makes a very durable & flexible material. I suppose you could use the red silicone "rescue tape" instead, but don't think it would be as durable.
http://s488.photobucket.com/user/S7A_abi/media/How-to%20Stuff/RTV-impregnated-fiberglass.jpg.html
 
UnPossible said:
Hey - still working on the FWF... As you can see in the picture below, I have installed the heat muff and the scat tubing. However, the scat tubing wants to hang too low between the muff and the FW heat valve. I have used some red high-temp RTV to "lock in" the curve around one of the exhausts, but the scat tubing is hanging too low and rubbing the cowl.

Can anyone offer me any suggestions as how to support the scat tubing up a bit higher so that it does not want to rub on the cowl?

Thanks,
Jason

2n6ym29.jpg
Click to expand...

My initial install was similar to the OP except without the exhaust shield. I have had no evidence of radiant heat issues with the SCAT. It was rubbing very slightly on the cowl. I added a pair of ADELs on the #3 intake and that has raised it off the cowl and stabilized it. No rubs or burning in 140 hrs so far.
 
You must log in or register to reply here.