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Don't Do This..

Oooh, let me play!

I see something nobody has mentioned (I think). That screw’s factory end is on the back side of the heat shield…the hot side, right up against the exhaust pipe. Isn’t that transmitting heat right up through the screw body to the adel clamp? Into the rubber cushion? And into (and melting) the nylon in the nut?

Maybe, maybe not. Still…

I’m in the camp that says, without scientific analysis, that there are still plenty of ‘sensical’ reasons not to do it this way. If it makes Charlie Berens say, “Well, cripes, that there’s yer problem,” at some point, scientific analysis becomes…well, rather academic.

And I do respectfully tip my hat to this group’s scientists, analysts, and academicians.

To Brother Dan, I say: Excellent catch!
 
Roadjunkie1 said:
Give it a good shake and see how much movement there actually is! 😲 IMHO, of course.. YMMV.....
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You're right, and that would be true if the heat shield in question was down at the "movable" end of the exhaust pipe. But: If you look closely at the photo, you'll see that the heat shield is very close to the cylinder, well before even the ball joint in the exhaust that allows movement that the Vetterman mount is designed to cushion. This section of exhaust is *very* rigidly attached to the engine, and does not move when you wiggle the exhaust pipes at the cowling exit...
 
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Snowflake said:
You're right, and that would be true if the heat shield in question was down at the "movable" end of the exhaust pipe. But: If you look closely at the photo, you'll see that the heat shield is very close to the cylinder, well before even the ball joint in the exhaust that allows movement that the Vetterman mount is designed to cushion. This section of exhaust is *very* rigidly attached to the engine, and does not move when you wiggle the exhaust pipes at the cowling exit...
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A question based on Dans analysis: say that this is an only option routing. Might be a different kit, not a Vans. How useful would a second shield be to disperse the radiant heat? Ist shield as shown with a spacer and another above. But of coarse not attaching the Adele to either.
 
Blain said:
A question based on Dans analysis: say that this is an only option routing. Might be a different kit, not a Vans. How useful would a second shield be to disperse the radiant heat? Ist shield as shown with a spacer and another above. But of coarse not attaching the Adele to either.
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If I'm understanding you, a second one won't appreciably help. As a radiant barrier. It could be infinitely thin and block that energy xfer, just has to be in the way. Sure, some thickness helps because the shield does conduct but you're way into diminished returns relative to the added weight/cost. The material thickness is probably chosen for durability and relative economy.
 
Blain said:
How useful would a second shield be to disperse the radiant heat? Ist shield as shown with a spacer and another above. But of coarse not attaching the Adele to either.
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Recall a shield disperses heat (to use your description) by reflection (very good), conduction to the air (ok for our purposes), and conduction to the opposite side with re-radiation (not desired).

Given a single shield, we can reduce re-radiation by reducing conduction from the hot side to the cool side. That means an insulated shield. I've described how to do it elsewhere.

If additional shielding is desired, your goal should be to first maximize reflection at the second shield.

Ok, think practical. Heat tends to increase oxidation. Oxidized surfaces don't reflect well. A shield stacked on top of another shield on a hot exhaust header is going to be oxidized, and probably dirty on its hidden hot side. It's not likely to be a good performer.

Instead, put a reflector on the victim. There are numerous slip-on sleeves available, all with shiny reflective foil outer skins. Ordinary aluminum foil tape is every bit as effective.

It is common to see a length of ordinary orange firesleeve slipped over a hose or cable, with the expectation of successfully insulating the component. Better than nothing for sure, but fails address a fundamental physical property, the poor absorptivity and emissivity values for a rubber surface. Ballpark, you're looking at 0.9, vs 0.1 for a shiny aluminum foil surface. The silicone sheath provides fire protection and oil resistance, but it's a lousy reflector. Wrap it in shiny tape or buy a reflective sleeve.
 
A friend of mine has used some of this stuff on his Bücker Jungmann replica. Worked well for him and is flexible enough to follow curves. Available at Summit Racing and other places.
 

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Scott Hersha said:
A friend of mine has used some of this stuff on his Bücker Jungmann replica. Worked well for him and is flexible enough to follow curves. Available at Summit Racing and other places.
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Most of our exhaust suppliers recommend against wraps, and a clamp-on sleeve is pretty much the same thing. I'd stick with the usual sheet metal shield, and then put a reflector on the victim component if needed.

As before, plain old aluminum tape is a good add-on reflector, and aluminum tape over 970 fiberfrax felt is a good reflector/insulator combination. However, if you want to spend money with Thermo-Tec, here's the right idea: https://www.thermotec.com/product/thermo-sleeve-2000-degree-f-slip-thermo-tec
 
DanH said:
Most of our exhaust suppliers recommend against wraps, and a clamp-on sleeve is pretty much the same thing. I'd stick with the usual sheet metal shield, and then put a reflector on the victim component if needed.

As before, plain old aluminum tape is a good add-on reflector, and aluminum tape over 970 fiberfrax felt is a good reflector/insulator combination. However, if you want to spend money with Thermo-Tec, here's the right idea: https://www.thermotec.com/product/thermo-sleeve-2000-degree-f-slip-thermo-tec
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Agreed. I wouldn’t wrap my exhaust pipe with that stuff, but it might work well as a shield/thermal barrier for the victim fuel line or other component in certain areas. That’s what my Bucker Jungman buddy did with it.
 
I got to thinking about this thread (I know: dangerous) and had to go back and read through the posts to see if there is an ACCEPTABLE distance from, oh, say a fuel line and an exhaust system. All of what we do FWF is in a very confined space and EVERYthing is close to everything else. SO: for future builders (or for those flying who want to go look at their own rides): consensus on what an acceptable distance would be from, for example, a fire-sleeved fuel line and a non-shielded exhaust part. Tom suggests 'proper routing' but what does that mean? Yes, there have been some scary examples :oops: of what NOT to do but somebody pulling up this thread is not going to find information on what TO do. Thoughts?
 
Roadjunkie1 said:
I got to thinking about this thread (I know: dangerous) and had to go back and read through the posts to see if there is an ACCEPTABLE distance from, oh, say a fuel line and an exhaust system. All of what we do FWF is in a very confined space and EVERYthing is close to everything else. SO: for future builders (or for those flying who want to go look at their own rides): consensus on what an acceptable distance would be from, for example, a fire-sleeved fuel line and a non-shielded exhaust part. Tom suggests 'proper routing' but what does that mean? Yes, there have been some scary examples :oops: of what NOT to do but somebody pulling up this thread is not going to find information on what TO do. Thoughts?
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The acceptable distance for a rubber core hose and a teflon core hose would be entirely different. And distance is only one of several variables. Quick, how hot is the exhaust pipe at the location of interest?

"Acceptable" tends to be used as a justification for crappy work. Plenty of ugly examples declared acceptable by multiple persons. The real goal is finding the best possible installation, not the minimum.
 
Dan, just did a prebuy on a beautiful plane.. priced a little too high IMO.. check out this fuel line resting (burning) on the muffler! Even the high ends planes aren’t immune.. I made them a rubber hose/ziptie stand off.. also some heat shields here and there, but could use more.
 

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Roadjunkie1 said:
It's resting on the cabin heat muff. I wonder what the inside of that fuel line looks like........... 😳
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Heat muff.. that’s what I meant.. I didn’t mean muffler.. yeah the fire sleeve was melted a little too.. and it’s been though several condition inspections from some well known names!! It’s possible that someone changed something between then and now, but I doubt it.. always good to have a second set of eyes!
 
Taltruda said:
Heat muff.. that’s what I meant.. I didn’t mean muffler.. yeah the fire sleeve was melted a little too.. and it’s been though several condition inspections from some well known names!! It’s possible that someone changed something between then and now, but I doubt it.. always good to have a second set of eyes!
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Michael, its teflon
Taltruda said:
Heat muff.. that’s what I meant.. I didn’t mean muffler.. yeah the fire sleeve was melted a little too.. and it’s been though several condition inspections from some well known names!! It’s possible that someone changed something between then and now, but I doubt it.. always good to have a second set of eyes!
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Michael, its a Stratoflex 124J teflon hose. Great hose with a thick outer high temp silicone cover. Even so, bad routing can shorten its service life. Why expose it to extra heat, just because it's rated for heat? (LOL, when you turn on the burner on your stove, do you touch it to see if its hot?) . Granted the temps in that location are lower that at the combustion chamber in the cylinder, but still high enough to melt some materials. My Dad used to tell me that good prior planning prevents poor performance ( He was a USMC EOD officer), and there was no excuse for bad preparation. Best advice is to have a really great overview of the project, and to see how all the little subsystems interact, and make a safe, reliable well thoughtout plan.
 
also they should have a drain hose on that sniffle valve.. keeps the fuel from dripping directly on the pipes..

Oh, why bother..........!!:oops::oops::oops:
 
I‘m almost afraid to ask - What’s the curved tube with the protector on it?
 
Mel said:
My guess is that you are talking about the fuel tank vent.
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That is what that is, judging by it's location. Must be in a place with a high mud dauber population! I have seen that protecting tab on Vintage pitot tubes (which is, I belive, what they were originally made for) but aren't seen very often even there. Interesting what people come up with..... Evidently not concerned about drag.....or some other things..... 😊
 
I agree it’s too far inboard to be the pitot but we both know you have seen things that will make your hair fall out.
 
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