Exhaust Wrapping...

[DustyR/T]

Ok, I guess I didn't think it would be too hard. But it was a tedious task. It's a good thing the engine was out anyways. Anyways, I used the thin 1" exhaust wrap and it turned out pretty good. I painted them with the silicone black after and used their ties. Has anyone else here wrapped their exhaust successfully and noticed a difference in temps?

[Ondonti]

I have always been to worried about rust to do it...but our stock manifolds are so rusty anyways, and Ive never heard of them havign problems with cracking (wrap often causes that).

Do you mean underhood temps or coolant temps or both?

What did you do with the crossover. Did you remove the heatshield? How did you wrap the rear manifold?

[c2xejk]

For the manifolds and crossoverpipe, I would ceramic coating them would be a better option... Coating the inside limits the amount of heat that gets into the manifold/pipe...

I am doing this for my turbo setup.

Lookin did this with her setup and I can say that even after an hour drive you could touch the manifolds without burning yourself... I have no AB comparison to say if it helps with hp, but it should help with underhood temps.

[lookin]

Getting mine coated has worked out well for me, and it has been over two years now with no problems. I am glad I spent the money, and I recommend doing it.

[detobias]

I have read that wrapping exh pipe like headers will accelerate the oxidation

I have wrapped a 2.2 header, and there was a noticeable reduction in underhood temps

I did not have the car long enough after that job to be able to comment on the accelerated oxidation issue, but it does make sense

[DustyR/T]

Sourced from Exhaust Wrap & Heat Protection

Exhaust Wrap & Heat Protection
Exhaust Wraps: The truth about Wrapping
DEI Technical Article (Issue 1.1)
I can't tell you the number of calls I get from customers who are interested in DEI exhaust wraps but are afraid that the wrap may damage their pipes. Though a credible concern, I'm not sure who started the rumor, but for some people this myth has been inaccurately embedded as common knowledge to many. Wrapping pipes will not damage your pipes.* It will not make the metal brittle or promote any enhanced corrosion. I've yet to see a picture of a header, turbo down pipe, or exhaust pipe that was damaged by wrap as one would think that with all the information and images available on the internet someone would have been able to provide proof of such negative occurrences. I was really shocked after reading several forum threads from the "self-proclaimed know-it-alls" that consistently post replies in response to inquiries from other members citing a story or rumor rather than from personal experience.

THE TRUTH
Basically, every time you start up an engine the exhaust system pipes heat up and undergo an aging process that is so nominal it would take 50+ years to actually see any kind of change in the metals composition. Exhaust wraps do accelerate this ageing process, but even so it could take up to 30+ years to see any real degradation of the metal "AND" even that would be nominal at best! The same applies to ceramic jet coatings so don't let anyone tell you otherwise (that it's better because it doesn't make a difference).

*NOTE
In rare instances rust and corrosion may occur on lower grade metals so be sure to use DEI HT Silicone Coating to repel water and debris).

As with any product, DEI has made available product FAQ and Instruction sheets online in PDF format.

[c2xejk]

The "50+ years" part sounds strange... Standard exhaust systems rust out in way less than 50 years... Maybe if you have stainless steel pipes to start with... Manifolds would take a lot longer to rust through, but the FAQ says "pipe" not "manifold"...

That said, if the pipes last 2, 3, 4 or ?? years, is that a problem? The stock crossover pipes seems very sold even after 10+ years.

Also, as far as I know the comment about ceramic coatings is completely bogus... First the coating (as I have seen it applied goes on both the inside and outside. of the pipe/manifold and prevents oxidation...

If there was oxidation, then the material would flake off. What I saw of Lookin's setup indicated that oxidation does _NOT_ happen.

As for hp gains from the ceramic coatings, the only AB testing I have heard of was by a guy doing the Engine Masters challenge. He saw ~9 hp gain on 600 hp "race" engine on an engine dyne. So about a 1.5% gain.

For us that would be about a 2hp gain using linear scaling... Could be more, could be less...

[Ondonti]

He basically admitted they remove "40%" of a manifolds life.

And since we know he is just making up the "50 years" part, I dont really believe much of what he has to say :P
Countless people have ruined headers with wrapping them. Some manifolds are more robust then others, and stock cast manifolds qualify in that category. There is plenty of metal to rust through before putting a hole in something...as long as the metal doesn't crack first.

I like how that was written by an representative of an exhaust wrap company and he doesnt have the balls to cite his name. All that and he is blabbering about "know it alls"

[lookin]

Quote:

Originally Posted by c2xejk Also, as far as I know the comment about ceramic coatings is completely bogus... First the coating (as I have seen it applied goes on both the inside and outside. of the pipe/manifold and prevents oxidation... If there was oxidation, then the material would flake off. What I saw of Lookin's setup indicated that oxidation does _NOT_ happen. As for hp gains from the ceramic coatings, the only AB testing I have heard of was by a guy doing the Engine Masters challenge. He saw ~9 hp gain on 600 hp "race" engine on an engine dyne. So about a 1.5% gain. For us that would be about a 2hp gain using linear scaling... Could be more, could be less...

True. I doubt I got any real HP gains from having my stock exhaust manifolds coated, but it sure didn't hurt.

I have lower engine compartment temps and rust free e-manifolds, and maybe they flow a tiny bit better than uncoated ones. I dunno. I wouldn't bet money on it though.

[SpeedyEd]

I sold a set of Dynomax ceramic coated headers to a customer who installed them on his 3/4 ton Chevy PU. He wrapped them. The truck was used to tow a modified stock car. Two months later the collector flange broke off. The collector was cracked.
The one header was replaced, & shortly thereafter the other one started to leak. When that one was returned I saw pieces of header wrap on it (I had forgotten he wrapped them).
This header had cracks in the collector area also.
Hedman & Hooker will not warranty any headers that have been wrapped.
Perhaps the combo of ceramic & wrap is a problem. The unwrapped headers did not have any problems under similar conditions.
I've sold wrap for use on diesel generators & it lowered noise & heat in the engine room. No complaints from them.
SpeedyEd

[DustyR/T]

Well, maybe they weren't sealed right. There is a reason silicone sealer spray exists for wrapped or un-wrapped exhaust. I am not saying anyone is wrong or right, but I did it right and it looks good. The cam gears are on and everything is just about together. I will have some pics in the next day or so that are sure to make a few people get excited. I have sand-blasted and repainted everything that came off with rust. The upgrades that will be in this engine are

52mm TB
Forged .100 over pistons and gapless rings
Free-Floating balanced rotating assembly
Cryo-tempered block, crank, pistons, etc.
Adjustable cam gears from RPW
Milled heads .029
5 angle valve job
custom crower grinds
ported upper intake runners and plenum
UDP
Fidanza flywheel
T2/T3 clutch assy
17^ Timing
All in all, it should run pretty well...honestly, if it runs half as well as it looks I will be happy.