Any negative effect from heat taping headers?

[GaryR]

This would be on an air cooled 911 with SS headers. The positives are less heat transfer to the engine but will holding the heat on the SS instead of letting them cool in the open air negatively impact the steel or even the exhaust ports of the heads? Just curious, haven't seen any 911's done but it's common on other race cars.

[enjefriy]

Bump. I would like to know too as I just ask this in my post. In front engine cars, the use of fibre glass tape is used to reduce under hood temps, as well as maintain heat within the manifold. The idea I believe is to also retain the expansive energy of the hot exhaust gases, inorder to improve it's flow out of the exhaust system.
Hope our engineers chimes in GaryR, as I am considering this install on my sc. Thermo tech makes these.

Wat sorts are u considering btw

[Bill Verburg]

Originally Posted by GaryR

This would be on an air cooled 911 with SS headers. The positives are less heat transfer to the engine but will holding the heat on the SS instead of letting them cool in the open air negatively impact the steel or even the exhaust ports of the heads? Just curious, haven't seen any 911's done but it's common on other race cars.

The insulating tape keeps heat and moisture in, the result will be more rapid deterioration of the steel. there are different grades of ss, 316 is used in marine applications because of it's corrosion resistance, I don't remember what SSI are made from, the most common ss alloy is 304 aka 18/8

[GaryR]

These are custom headers (no heater boxes), I'm fairly sure they are 321, is that possibly correct?

[aftermath]

My race friends say that it has been the cause of fires. They can get oily and therefore more likely to catch fire. The best solution is to get the headers coated. Bills point on rusting are also good to know. My 944 has a LS1 conversion and those headers are wrapped. And I would love to take them off and get them coated, just need to make the time. They are very oily now after having a breather tube break, I can see my friends point.

[GaryR]

So far I have gotten 100% no on HT, but ceramic coating is good. Either I will do nothing or do a ceramic coating (if I have any $ this winter).. Thanks

[JeremyD]

Don't do it - fire hazard if you develop an oil leak - benefits do not outweigh the disadvantages.

SS at 321 grade is just a version of 304 - but with higher heat handling capabilities - typically has a little titanium

It will be prone to pitting and crevice corrosion - even more so if you keep em wrapped up...

JMHO

[Bill Verburg]

Originally Posted by GaryR

These are custom headers (no heater boxes), I'm fairly sure they are 321, is that possibly correct?

yes, 321 is used in higher heat apps, it's good to ~900*C in intermittent service, your use

I'd go for ceramic coating over tape

[Joe Bob]

Rust making pinhole leaks...

[dfink]

Just tried this on a set of european george headers. Didn't believe it could cause any harm the car never sees rain and wanted to protect nearby wires. Well here is what I believe is the scoop. The heat tape does an excellent job keeping the heat in the tubes. So good in fact that they overheat. This causes extreem oxidation on the tubes. When I took the wrap off after one year the oxidized metal came off in sheets. Same effect as heating metal with a torch to cherry red 200 times. So from a disbeliever don't do it.

Also as mentioned the wrap absorbs oil from leaks and greatly prolongs the burn off period. I assume given enough oil and the right conditions it would present a fire hazard.

So none of the, I heard this, someone mentioned that rumors. First hand info that wrapping the headers is not good a good idea. It however looks really cool if you never actually start the engine.

[GaryR]

Dfink - Your George Headers are SS, correct?

[euro911sc]

Originally Posted by dfink

It however looks really cool if you never actually start the engine.

LOL

I did not wrap my headers, but I did wrap the oil line that runs very near the headers to try and prevent some of the heat transfer from header to oil return line. This is the line that runs under the trans bell housing. It gets very close to my Georges headers. So far so good.

-Michael

[Les Paul]

Has some on my Bursh system on the 356. I never understood how I could have so many backfires on letting off. Always thought it was plugged pilot jets. So I'd clean all 4 and usually find some miniscule particle. Ah ha that's it. Long story short I think the heat tape was holding everything together after 15 years. Hundreds of pinholes and paper thin everywhere else.

[911pcars]

Good idea. The exhaust temperature radiating off of the pipes can approach 400ºF. There's an insulation product that's shaped like a tube - slips over each exh. pipe. This could provide a measure of heat insulation w/o trapping excessive heat and moisture.

Combine with ceramic coating.

Insulating adjacent oil lines is another good suggestion; increases the service life of flex oil hose as well.

Sherwood

[KTL]

Here's what thermal tape did to a pipe on a pair of ceramic coated headers I used to have

[RarlyL8]

The material the headers are made of will have a HUGE impact on the TIME it takes heat tape to destroy the headers.
I believe that we are the only manufacturer that uses 321 stainless to produce 911 headers, most are 304 and some are just steel. You can watch steel rust, if wrapped it wouldn't last a year. 304 would last longer and 321 more so but all would be harmed in time.