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Heat Wrap

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Old May 24, 2013 | 02:37 PM
  #51  
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The only reason i would wrap an exhaust on a renny is to keep heat out of the engine bay not a misguided attempt at gaining power.
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Old May 24, 2013 | 02:38 PM
  #52  
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From: Between Cones
i wouldn't wrap a renesis exhaust at all
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Old May 24, 2013 | 07:21 PM
  #53  
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Originally Posted by paimon.soror
i wouldn't wrap a renesis exhaust at all
Why not? That bad boy gets super hot if not using a stock mani.
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Old May 24, 2013 | 07:37 PM
  #54  
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take a temperature measurement of the exhaust header flange before and after wrapping and you will see why i wouldn't wrap a renesis. Take that into consideration, along with the mating surface of the header flange (the side plates) and the increased rate of fatigue in the side seals and side oil rings/springs and you got bad news bears after extended use.

Different story on peripheral port exhausts as the mating surface on those engines against the manifold was the actual rotor housing.

Use sheet metal shielding if you want to reduce engine bay temps.

Header wrap has no purpose on our cars.
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Old May 24, 2013 | 08:38 PM
  #55  
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Originally Posted by paimon.soror
take a temperature measurement of the exhaust header flange before and after wrapping and you will see why i wouldn't wrap a renesis. Take that into consideration, along with the mating surface of the header flange (the side plates) and the increased rate of fatigue in the side seals and side oil rings/springs and you got bad news bears after extended use.

Different story on peripheral port exhausts as the mating surface on those engines against the manifold was the actual rotor housing.

Use sheet metal shielding if you want to reduce engine bay temps.

Header wrap has no purpose on our cars.
the peripheral port engines cook the header, so a shield is better on those also.

to say header wrap has no purpose is kind of a strong statement though, it might be applicable by the diff, or transmission.

and then B just because it says header wrap doesn't mean you can't use it for other things too, for example on my peripheral port engine, the intake and exhausts are really close together, so i wrapped the intake.
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Old May 24, 2013 | 08:50 PM
  #56  
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Originally Posted by j9fd3s
the peripheral port engines cook the header, so a shield is better on those also.

to say header wrap has no purpose is kind of a strong statement though, it might be applicable by the diff, or transmission.

and then B just because it says header wrap doesn't mean you can't use it for other things too, for example on my peripheral port engine, the intake and exhausts are really close together, so i wrapped the intake.
You are right, i should have said "thermal wrap has no purpose on the ex manifold of our engine"
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Old May 24, 2013 | 11:34 PM
  #57  
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O i agree 100% but if i was to use header wrap it would be for the excess heat and not a HP gain. I wish i could trust a thermal coating on the inside of my mani but just cant with my turbo in place. I have a external thermal coating on the mani and lots of heat shield around any thing within two feet of the turbo.
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Old May 25, 2013 | 08:43 AM
  #58  
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Great conversation guys.
I've got nothing to add except I wish I had seen or remembered about this thread before I put header wrap on my mani.

So far so good anyways.
Well I did have to add some shielding around my OMP electrical connector ... umm slightly melted but still functional. <fail>

It's on my To Do list if I can ever get through my Honey Do List.
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Old May 25, 2013 | 11:24 AM
  #59  
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Originally Posted by paimon.soror
You are right, i should have said "thermal wrap has no purpose on the ex manifold of our engine"
you say potato i say potatoe!
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Old May 25, 2013 | 02:08 PM
  #60  
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Originally Posted by paimon.soror
i dont understand the point of wrapping a header to be honest, and you have to ask yourself exactly what your main purpose is.

For example, why would you increase the velocity of the exhaust ? what is the purpose? No, it will not give you any gain on a renesis. Exhaust wraps main purpose was to improve exhaust scavaging at the header, and considering the renesis is a zero overlap engine ... there really is no point.

Second, like OD said, wrapping the exhaust INCREASES temps at BOTH ends. Now, consider "both ends" of the exhaust... what is on one side? the tips right? so what, you melt a shroud, nothing to cry about ... what is on the other side of the header? The side plates of the rotor housing. Now do a little reading on the renesis engine and realize that the main caveat of its design is that its exhaust flow goes through the side plates ... those side plates thus have a hotter deltaT than the rotor itself. What does that affect? One of the most critical failure points of a side exhaust rotary engine ... the side seals.

Ok fine ... lets just forget about that problem, and lets consider that heat doesn't just magically dissapear (mr 'i quote thermoD but clearly dont know a lick of **** about it). Anyone ever see what an exhaust header gasket looks like after miles of abuse on a wrapped header? you would be surprised how badly it is trashed.

Again, this isn't something new, and has been discussed ad nauseum on this forum. They have even been discussed in VARIOUS books on the renesis engine. Like I said bud, you are retired ... you stated you have plenty of time on your hands .... pick up a good book and do some reading... you would be surprised what the world outside of a "Harley" entails

I have read a lot lately on it and I agree with you and have given up on that idea . research saves you money in the end.
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