Anybody see any issues with wrapping a cat?

 

Yes. It will get too hot and destroy itself from the inside out. I have never been a fan of wrap in the first place. Its traps moisture and increases the rate of deterioration of the pipes. I prefer making heat shields to go on the floor or trans tunnel.

 

Unless you declaw them you will get scratched really good and your G-F/ wife may notice the cat missing after awhile..

 

hahah .. i agree , wise man right there

 

I have wrapped headers for 5 years now, unwrapped them a few weeks ago, and although they do not look brand new, they look slightly dull, I saw no rust and no issues.

The concern is a valid one, but in my case, JET HOT COATED, it caused no issues.

I will however make soem shields out of some 304 SS and clamp them on

TOP350 and red l98, you can both go back to reading MAD magazine

 

this one

 

my cats are metallic SS and my pipes are SS

 

dont wrap a cat.

 

Did the older car have heat shields on the tunnel from the factory? My '90 did, but when I did custom exhaust I have to extend them to cover where the new cats where. I have an old picture from when I did my exhaust. The blue is factory, and the red is what I added.

 

To quote Pee Wee Herman, "I'm a rebell dolly"... I am a not concerned about rust, so that leaves the potential of a fire hazard as being "my" only concern,,,

I stumbled across this info, from the people that actually make header wrap,,, Food for thought

http://www.thermotec.com/resources/category/7/faqs.html

FAQ's
Wrap amount required for headers? - Necessary amount of exhaust insulating wrap to wrap a set of headers

Why wrap only part of the primaries on an RV? - Wrapping only 18 to 20 inches of the primaries on a RV or towing vehicle is all that is needed.

Why do you use only a 1/4 inch overlap? - Using more than 1/4 inch overlap you may cause fatiguing due to hot spots in your tubes.

Does wrap overheat components? - Increasing flow increases the amount of heat extracted from the engine and manifold.

Can I use header wrap on cast iron exhaust manifolds? - Stock or modified exhaust manifolds and housing on a turbo engine

Use header wrap on a catalytic converter? - Exhaust wrapping a catalytic converter can actually increase performance

 

I will try the wrap until I can make some formed shields

 

nothing to do with rust, those cat rocks have a degradation point, wrap'em up, degrade'em quicker, I've seen them melted

 

cat rock? what degrades?

and I think I mentioned I HAVE SPIRAL METAL as well...

 

While using a heat-resistant wrap can keep temps down in the interior, the problem with wraps will arise when they cool off and condensation forms. That condensation will eventually rust away the outer skin of the cat.

Same with headers; a wrap will trap condensation and rust will eventually start. Of course it depends on the climate of a region; using a header wrap in dry climates such as Southern California probably won't hurt anything. Use a wrap in a region with lots of rain or snow where salt is used on roads and that can be a big problem.

You will find that nearly every header manufacturer will say their warranty will be voided if a wrap is used on their headers. With a 3rd party coating like Jet-Hot, that company may say it's OK to use a wrap, but it's possible the header manufacturer may void their warranty because Jet-Hot was used.

 

they are actually metal , but when you take it into a shop, they will tell you your 'cat rock' is loose or has melted or has plugged from over heating. in the industry its refered to as a 'rock' cause when it comes loose it sounds like a rock rattleing around inside, unless you're politically correct, then you will use the term, 'catylitic media' hope this helps

 

About me....

http://www.youtube.com/watch?v=mKLizztikRk


From DEI....
Larry, We do not offer a clamp on heat shield but you can wrap the converter. We also offer an adhesive backed product that would work a little better than the wrap. Here is a link- http://www.designengineering.com/cat...und-insulation
Let me know if I can help in further detail.

 

Id do the shields those things get awful warm but sounds like the mfr says its Ok.

lol

 

I have the heat shield on the floor board but I ordered some of the new DEI stuff too, I'm always a big fan of overkill

I will remove the from X pipe and weld 4 short 3/8" square standoffs to each Catalytic with an air gap of up to 1/2", then I will roll a piece of thin gage sheet metal and bolt it to the standoffs, cant get any better than that.

But until then, I will wrap the cats,,, I need to get a bunch of small things done before the hot rod power tour June 2nd, so wrapping the cats is a quick and easy fix for now.

 

well times have changed, good luck

 

when I put an 345 hp crate 350 (clone) in a 75 chevy monza, I used the factory V8 exhaust system which wraps tightly aound the oil pan.
The exhaust pipe was blazing hot, and I'm sure much of that heat migrated into the oil pan. What to do ? at the time, the car was still on the smog clock, so modifying the exhaust was out of the question. I used heat wrap on the exhaust, and the exhaust pipe temperature dropped from you couldn't put your hand anywhere near it, to, you could pretty much lay your hand on it.

the instructions said to usen water to soak and help the wrap conorm to the pipe. Rather than follow instructions (what fun is that ?) and use water, I used High Temperature exhaust paint (white), and lots and lots of it, to soak the wrap as I installed it. I probably also used about twice the amount of wrap as necessary.

the High Heat paint made an attractive surface that seemed to be pretty impervious to water, oil and dirt. All in all, I had no problems with the exhaust deteriorating or rust and it really, really cut down on radiated heat from the exhaust.

perhaps a professor of thermodynamic's can explain this better, but the higher the temperature that can be maintained in the exhaust, the greater the velocity of the exhaust gases. which is supposedly a good thing.