Header Wrap (1 Viewer)

[David70FJ40]

I am getting a lot of heat from the floor boards and tranny hump when I drive. I installed insulation under the floor mats which helped and will be adding some self-adhesive insulation under the tranny hump this week. I am considering wrapping the headers and down pipe with a wrap. Has anyone here had any experience with wrapping headers who would be willing to share their experiences?

 

[spotcruiser]

I haven't wrapped headers, but I have wrapped the exhaust pipe under the driver's floor. When I built my exhaust, I ran it above the lowest point of the frame and up over the cross-member, so it's pretty close to the floor. Prior to the wrap, if I placed something in a plastic bag under the driver's seat I would find the bag melted at the end of a wheeling trip. The wrap has worked surprisingly well and it seems to be in perfect condition still after 4-5 years. I no longer melt plastic bags under the seat.

 

[1911]

also, make sure the vacuum advance on your distributor is working correctly (they tend to rust out, especially if the dizzy venting vacuum tube circuit is non-operative or has been removed). If your timing ends up even a little retarded (from not enough advance), it will heat up your exhaust in a hurry.

 

[David70FJ40]

I have to admit, when I first got the 40 one of the things I had done was install an electronic pick up in the dist. I took it to a dist expert nearby who does a lot of work on race engines and he set the dist to run without the vacuum advance since the mechanics were toast and I didn't have the funds for a new dist. I guess maybe I need to get a new dist with the vacuum advance so it runs better.

 

[1911]

I have to admit, when I first got the 40 one of the things I had done was install an electronic pick up in the dist. I took it to a dist expert nearby who does a lot of work on race engines and he set the dist to run without the vacuum advance since the mechanics were toast and I didn't have the funds for a new dist. I guess maybe I need to get a new dist with the vacuum advance so it runs better.

I think you will be pleasantly surprised on how much difference it will make. These old engines like quite a bit of advance at highway rpm's.

 

[David70FJ40]

Started the search a few minutes ago. CCOT has a reasonably priced dist I can move the electronic parts to. JTO has a non-USA spec dist that I can get and still move all the electronic parts over to. CCOT is cheaper but JTO has a Toyota part number on theirs which I believe might make it a better replacement.

 

[456z]

When I rebuilt my 79 I added a o2 sensor just downstream of my header collector. Found it was running rich and had a lot of exhaust heat coming into the cabin (gozzard tub with lizzard skin on bottom of tub). After getting the jetting dialed in the heat was gone.
So I would suggest also checking your jetting . I then later added a header wrap to keep the heat in the header because my o2 sensor was getting cooled off at hyway speeds and this was a big job with the fender on.

 

[kcustom73]

I did the turbo downpipe on the GM 6.5 in my 40 and it helped quite a bit with managing heat. If the headers are out of the vehicle, I would say go for it (even if you get everything else running right) as it would be a fairly easy job. Trying to do it with the headers installed, I think it would be hard to do a good job.

 

[David70FJ40]

I have ordered the wrap and clamps and am waiting for everything to arrive. I can take the intake off then disconnect the downpipe from the muffler pipe and take it out in one piece for easier wrapping. No way would I try to do it while the exhaust was still in the vehicle.

 

[Downey]

WARNING, WARNING, WARNING- - -thin Header pipes literally MELT inside Header wrap- - -don't do it unless you can afford a new Header every 6 months.

 

[David70FJ40]

Would that apply to the headers Man-A-Fre sells?

 

[jvincig01]

I have wrapped headers and it really does help

 

[cjgoode]

Its literally called header wrap not sure why it would melt the headers, I have seen a lot of threads on FJ40 and jeeps using it with no problems. I do not have a header but I did buy some and wrapped my exhaust from the manifold to the tail pipe right before it leaves the body, including the muffler. What a huge difference in heat as well as the noise. I would get the header as rust free if possible if steel and painted with high temp paint first. These are not high performance race engines cranking out excessive heat I cannot picture it causing a header in reasonable shape to melt even if you engine is not perfectly timed. I have seen a lot of jeep posts about headers melting without a wrap, but they are always talking about the welds cracking which is much more likely from flexing and nothing to do with melting the welds. When torqued engines move different then bodies and that can really stress those welds.

 

[1911]

... I cannot picture it causing a header in reasonable shape to melt even if you engine is not perfectly timed.

I have never seen headers "melt", but I have seen them glowing cherry red - from running a short time with retarded timing. Hence my recommendation for the OP to sort out his distributor advance issues first, before proceeding to other heat abatement measures.

My own experience with headers on F-series engines (and everything else for that matter) is, they always rust out eventually. I got tired of taking them off to weld up or replace, and just go with the stock cast iron manifold now.

 

[David70FJ40]

I have never seen headers "melt", but I have seen them glowing cherry red - from running a short time with retarded timing. Hence my recommendation for the OP to sort out his distributor advance issues first, before proceeding to other heat abatement measures.

The distributor has been ordered. Thanks!

 

[Spike Strip]

This stuff is meant to spray on header wrap to keep from holding moisture and rusting the pipe. I haven't use it yet, but plan to.

 

[Downey]

Headers that are wrapped don't physically melt, they just get hair line cracks throughout the tubes. The guys who successfully use Header wrap are racers who frequently remove the wrap between races/engine builds. Thicker wall 14 gauge Headers will no doubt hold up better than thinner wall 16-20 gauge Headers, but the thinner wall tubes simply can not tolerate exhaust heat being held in for long periods.

 

[Mace]

lol "melt"

WARNING, WARNING, WARNING- - -thin Header pipes literally MELT inside Header wrap- - -don't do it unless you can afford a new Header every 6 months.

Seen a lot of headers wrapped. The very thin crappy 6:1 designs ended up with cracks, but they always do anyway.. And it took years not months. I've seen a set of Downey's headers last for 20+ years wrapped in Vegas.


That being said, I found that header wrap did not help as much as a simple heat shield on the exhaust did. On my 60, it went from burning my carpet to completely benign with a simple dual wall cookie sheet

 

[gator25]

I wrapped the ones one my old chevy before putting on, a few years later pulled them off because one tube had cracked at the collector. All the way around right before the weld and had come completely lose. I unwrapped them to find them oddly shaped like they had melted in the wrap, given these were cheap headers. I have never wrapped any since.

 

[alabamatacomaguy]

lol "melt"


Seen a lot of headers wrapped. The very thin crappy 6:1 designs ended up with cracks, but they always do anyway.. And it took years not months. I've seen a set of Downey's headers last for 20+ years wrapped in Vegas.


That being said, I found that header wrap did not help as much as a simple heat shield on the exhaust did. On my 60, it went from burning my carpet to completely benign with a simple dual wall cookie sheet

Interesting
I like this idea