Heat Tape

[abrumley]

I am thinking about taking off the factory heat shield that surrounds my cat bypass pipe. Is it safe to wrap the bypass pipe with header tape. Or will that transfer heat to the exhaust manifolds? Thanks i appreciate your input.

[MBAtarga]

It's there for a reason.

Edit - saw your response below. I didn't notice you stated - cat bypass - above.
Remove the shield - will make valve adjustments easier too.

[abrumley]

Yea i know but my thought was since there is no longer a cat there maybe it does not generate as much heat? Also it would keep more heat off of my valve cover.

[rudderboost]

I'm curious about this as well. I have a bypass pipe, but no shield at all. Am I looking at problems in the future? Maybe the tape would be the way to go.

[tcar]

If you don't have a CAT, there is no more heat generated than from a regular exhaust pipe.

CATs can get very hot, but not just a pipe like that.

Don't see any point in wrapping it w/ header tape.

[abrumley]

bump

[Ole Petter]

Hi, I am running headers on my car that has been wrapped in heat tape...
When the car is warm I can actually TOUCH the headers with my fingers without beeing burned!!! That is how effective these things are...

Go for it! It even speeds up the exhaust gasses... Feels great!

[Quicksilver]

Originally Posted by Ole Petter

. . .

Go for it! It even speeds up the exhaust gasses... Feels great!

To be more accurate: It inhibits the cooling of the exhaust gases that would in turn reduce the velocity. That can help with savaging. Reducing the heat soak in surrounding areas is positive too.

The only real downside is if retaining the heat causes the exhaust pipe to break down because of the increased heat. If you don't have good stainless pipes that might be possible but the removal of the cat reduces a lot of the heat involved.

One thing you don't want to do is wrap a cat with heat tape. It was designed to generate a certain quantity of heat and that takes into account heat losses to the outside of the cat.

[joe payne]

I did it when the top end on my car was rebuilt. I took home the exhaust and degreased it and wrapped the cat by pass. It keeps things nice and cool under there.

[rudderboost]

Is there any issues with the wrap getting wet and holding in moisture, or is there still enough heat to keep the covering nice and dry? Any higher risk of fire if the wrap gets oil or (hopefully not) fuel on it?

[calling911]

Originally Posted by joe payne

I did it when the top end on my car was rebuilt. I took home the exhaust and degreased it and wrapped the cat by pass. It keeps things nice and cool under there.

Those pipes will be history soon. Heat wrap is for race cars.. If you want those pipes to last you will get rid of that heat tape.

[911Freak]

I use the HEAT SHEILDS that they sell here... work Great! They block the heat soak from the cat or cat bypass from the lower head... lite weight and under $100, made out of stainless steel...

[joe payne]

To be honest with you, It hardly ever rains in Southern California so I don't really have to deal with water saturation issues.
The pipe will rust away anyway and I'll have to buy another one. Not a big deal.
Oil and gasoline dripping on it would create other issues, and the fact I have heat tape
on my cat by pass would be my last problem.
I just wish I could swap out the entire exhaust for headers or S.S.I.'s. (Thanks Terminator).

[911pcars]

"...The pipe will rust away anyway and I'll have to buy another one. Not a big deal...."

My steel HE pipes are original (39 years), but 16 years of that were in storage. They were powder coated 10 years ago and they're still fine, although probably rusting from the inside out. Steel has a circle of life, but I don't know too many who plan for periodic replacement with anticipation.

I'm of the "rust-will-lighten-your-HEs" persuasion. However, if periodic replacement is in your maintenance schedule, it won't be a problem for you.

While rain isn't a common occurrence in So. Cal, this phenomenon does happen every once in a while. Do they allow water puddles where you drive?

Sherwood

[calling911]

Originally Posted by joe payne

To be honest with you, It hardly ever rains in Southern California so I don't really have to deal with water saturation issues.
The pipe will rust away anyway and I'll have to buy another one. Not a big deal.
Oil and gasoline dripping on it would create other issues, and the fact I have heat tape
on my cat by pass would be my last problem.
I just wish I could swap out the entire exhaust for headers or S.S.I.'s. (Thanks Terminator).

It's not the rain or the oil, its the intense heat kept on the steel. I have torn apart many race headers and they deterioriate rapidly.. If you are okay with this than you are good to go..

I will say this though.. the reason you tape headers is to avoid heat soaking your motor. Your headers will not put out anywhere near the amount of heat your cylinder heads will when driving on the street. Unless you are racing that car that heat tape will be of very little benefit to you. You're better off making your pipes last twice as long by removing it.

It will help you on track days though.. basically this is a great idea when you are at full throttle more often than part throttle..

[Ole Petter]

I was not aware of the heat-tape would make the exhaust-"piping" detoriate faster than without tape... I drove with this tape the whole of last summer, but had to remove the tape, cos I "had to" modify the rest of the exhaust. The headers looked just as good as they had in spring! But I guess one summer of driving makes little difference. Maybe the life-span of the headers will be half that of running without tape.

Or is racing-headers made of other/lighter materials?

What I know is that adding headers and heat-tape has reduced my oil temperature from 210+ to a relaxed 180 degrees F. Maybe this is more to to with increased air-flow than anything else? Anyway, I will continue with heat-tape and have a more relaxed/powerful engine...

I have some concerns about the heads and where the exhaust mounts to the heads when using the heat-hape, as if that will make the temperature higher there? And so make more heat in the mounting. But as the car has formerly had thermal reactors, this may be of little concern???

Ole

[calling911]

Originally Posted by Ole Petter

I was not aware of the heat-tape would make the exhaust-"piping" detoriate faster than without tape... I drove with this tape the whole of last summer, but had to remove the tape, cos I "had to" modify the rest of the exhaust. The headers looked just as good as they had in spring! But I guess one summer of driving makes little difference. Maybe the life-span of the headers will be half that of running without tape.

Or is racing-headers made of other/lighter materials?

What I know is that adding headers and heat-tape has reduced my oil temperature from 210+ to a relaxed 180 degrees F. Maybe this is more to to with increased air-flow than anything else? Anyway, I will continue with heat-tape and have a more relaxed/powerful engine...

I have some concerns about the heads and where the exhaust mounts to the heads when using the heat-hape, as if that will make the temperature higher there? And so make more heat in the mounting. But as the car has formerly had thermal reactors, this may be of little concern???

Ole

No, racing headers are usually about the same gauge or even thicker than street headers. I doubt that heat tape on a street engine dropped oil temps that much.. actually, I dont think they would drop your oil temps even one degree under normal driving circumstances. Im guessing another change occured.

Your engine is more "relaxed"?... sounds like you need some "red" ignition wires Good for 20hp!

[Ole Petter]

As I wrote, probably caused by improved air-flow, when I removed the heater-boxes! Anyway, the oil-temp gauge went down more than 30 degrees F! The oil-cooler is getting much more air-flow now, so that is probably the answer. The heater-boxes all but kept air from flowing around the standard oil-cooler.

But I am very happy now. Of course the engine produces more power with a more relaxed oil-temp? It will make the engine last longer as well!

Ole

[Formerly Steve Wilkinson]

On my airplane (a Falco), which had its entire exhaust system, manifolding as well as exhaust tailpipes, wrapped with heat tape for lower under-cowl temperatures, I would remove the tape once a year and inspect ths system for cracks when I did the annual. In five years and 400 hours, there was never a problem.

Having said that, a Lycoming exhaust system is of far better quality than any but the finest professional "race headers." But an aircraft engine does run at constant power settings way closer to a racecar than to any road car in the world.

[hcoles]

I have the cat out on my car and test pipe in with heat tape. The one thing that is not mentioned is the very high heat next to the shock. I wrapped the tape to cover the test pipe in this area. I haven't noticed any significant deterioration of the test pipe with the heat "tape" on. I do think that the exhaust gas temp. is higher going into the muffler.. but I haven't seen any problems associated with that.

89 3.2 coupe