It's a wrap

[geoffreywh]

I just finished wrapping the exhaust pipes on my ST1100 sidecar outfit. I was getting "Hot Legs" ok now in the winter but hell in the summer. The effect is stunning! from red hot (not quite ) to put your hand on it difference. There are plenty of suppliers, the wrap is cheap , light, and not flammable and the s/steel ties are 10 dollars a hundred. How might the wrap help engine cooling in an aircraft? Is there any point in say , a 6 cylinder jab's headers being made heat proof? They run very close to the inlet tracts, might it help?

 

 

[facthunter]

The pipes themselves will run hotter as the insulation keeps the heat in. If hot enough it will weaken them. Maybe stainless less so. Nev

 

 

[geoffreywh]

Agreed, My St1100 pipes are stainless, Jab pipes are stainless. But would it benefit the Jab cooling? EGT might go up, but so what. I could do it to the Jodel as see what effect it might have.But that wont work, the engine never gets hot enough!

 

 

[Yenn]

How could it benefit the engine cooling. If heat cannot get away from the exhaust pipe itself, it must have to go out the end and that takes longer, so more heat back at the engine.

 

Somewhere I saw info on heat wrapping exhausts for aircraft, which reckoned that there was no advantage. Can't remember where but possibly the EAA magazine or Kitplanes.

 

 

[biggles]

How could it benefit the engine cooling. If heat cannot get away from the exhaust pipe itself, it must have to go out the end and that takes longer, so more heat back at the engine.Somewhere I saw info on heat wrapping exhausts for aircraft, which reckoned that there was no advantage. Can't remember where but possibly the EAA magazine or Kitplanes.

That's right Yenn , cool the exhaust pipe and shrink the gas volume allowing higher gas velocity...... Bob

 

 

[KRviator]

Be careful wrapping aircraft exhaust pipes, as depending on the alloy used, wrapping them makes them hotter which can increase the oxidation rate, leading to premature failure, which you may not well see if it is under the wrap.

 

Vetterman - the RV exhaust Guru - specifically advises RV'ers not to wrap their exhaust for this reason.

 

 

[spacesailor]

I see your point, Geoff, but radiant heat warming the headers might help ward off icing.

 

spacesailor

 

 

[Thunda]

G'day.

 

Just ta stick me nose in.

 

I wrapped my exhaust (912 in a Baby Super Great Lakes) with this stuff and low and behold, BIG drama.

 

After about 100 hrs lost one pipe at the head, another at the muffler.

 

Keeps the heat out of the engine bay an off the firewall an keeps it in the engine and burns out the pipes.

 

Toss it!

 

 

[facthunter]

Use a shield where you must. Canopy etc. Wrapping is risky. The hotter gas is less viscous and flows easier and that's often quoted by the ones who advocate it. Exhaust pipe failure more likely and could be dangerous. Nev

 

 

[geoffreywh]

OK, I see. Although I don't know about "keeping the heat in the engine" My bike has suffered no discernable ill effects. Anyway thanks everybody. I shall leave well alone and trundle happily with cool legs...at least..

 

 

[Thunda]

I wrapped my Shovel Head's pipes and they were straight out slash cut.

 

The engine was worked and a strong runner, and didn't have trouble with it.

 

I can only assume that because the pipes weren't short and in the breeze it didn't rot them.

 

However the pipes on a plane are protected somewhat more from direct airflow.

 

I don't know enough about this stuff, but I do know the different effect it had between the two.

 

 

[Downunder]

Ok, Had my pipes on a 912 ceramic coated then wrapped for a few years now.

 

I'm on my second "set" of wrapping which is just starting to fail. The heat of aircraft exhausts seems to be well above auto/Mcycle temps.

 

So I'm on the hunt for wrapping that will take up to 850C.

 

As Rotax's have lots of rubber hose, I think wrapping is great for keeping the heat off them and reducing under cowl temps in general.

 

 

[facthunter]

Bikes aren't like planes. Your aero engine runs continuously at 75% for cruise and more for climb. Nev

 

 

[Thunda]

Me thinks Fact finder has it wrapped up.

 

(Pun intended)

 

A Harley Shovel takes a littler longer down the quarter mile than a rice burner.

 

Gets hot, but not for long.

 

And I really can't bring to mind a time or tide when it was ever in cruise mode.

 

So, it appears we may have arrived at the facts, bad investment in aircraft application but looks impressive on motor sickles.

 

Keep ya knees in the breeze.

 

(Even if ya have to live in shame of riding a ricer. Snigger, snigger giggle.)

 

 

[facthunter]

There's plenty of radiant heat around in the cowl especially with a "good" exhaust designed for power and even flow, but they are bulky give out a lot of heat and are heavier. I'd rather use a heatshield or glue something on the cowl in the local area than wrap the pipes. Mild steel loses strength at red heat and that's what you get near the ports unwrapped. Once you wrap them you don't really know what's happening. Jap bikes often have two pipes one inside the other to stop bluing of the outer one. The proper grade of stainless is usually thinner and therefore lighter and takes more temperature because it's made to do it. It would almost be mandated on a turbo charged engine .Nev

 

 

[Thunda]

This all seems to work out well for anyone who has a concern or inquiries in regards to most things aviation or otherwise.

 

Apparent case of constructive advise from a diverse field of experience.

 

I'm impressed.

 

 

[facthunter]

Satisfy yourself about the validity of any advice you get though. Flying isn't kind to fools (or the ignorant) and there's no shortage of advice out there. Question it if you feel the need. Ask why is that so? (with acknowledgement to Julius Summner Miller. Nev

 

 

[Thunda]

red 750 has a link to a video of the plane that had the exhaust system wrapped in that stuff.

 

As I'm a bit of a dummy in the ways of technology. if he is willing he may like to post it.

 

Just fer a giggle, the sound of it is a good indication why wrapping is not a good idea on air scooters.

 

 

[geoffreywh]

The pipes on my st1100 quite small in diameter and cooked my legs nicely in the summer. (fairing removed) I did it before on a K1100 for several years with no ill effects on bike or pipes ( small dia s/steel. ) but I wont bother trying it on the aeroplane

 

 

[Thunda]

Don't see many chairs around these days, good on ya.

 

Back in my wild and crazy days a mate and I made a frame up and mounted an old club lounge on it, complete with table and food rests. Hooked up to a WLA.

 

The coppers didn't like the idea that much.

 

Almost needed a wide load escort.