I am debating wrapping my headers to reduce the heat in my engine compartment. I have a 77 coupe with with a 72 4 bolt motor with a cam and 1970 heads and air gap intake. It gets pretty hot in the engine compartment, (melted one plug wire) already. I think the headers are ceramic coated already. I have read about wrapping them with the titanium wrap and just want to get opinions. I am a rookie mechanic and open to suggestions. I think this should reduce the heat enough to help, plus I live the Georgia's hot summer. Thanks in advance...
Tim

 

Engine compartment heat didn't melt your plug wire. It had to be touching a header tube.

 

just Wrap the plug wire end that melted instead,with High Temp tape . it was touching or very close to touching the tube. .. wrapping headers causes rust and its nearly impossible to do a nice job in the car

 

The wraps do work , but they may also make it very hard to get spark plugs and plug wires to fit.

If this is an issue for you you can try http://www.ebay.com/itm/like/161632830787?lpid=82&chn=ps&ul_noapp=true
These go on the spark plug end of the wire and prevent headers from melting the wires ..

 

I used those sleeves on my 79 Trans-Am. I have my Olds 455 in there and with the headers, it's pretty tight. They work pretty well.

I've used the wrap on quite a few cars, and I won't use it anymore. For one, it looks horrible, get's dirty and after it gets wet, it only serves to rust out the headers and create "hot spots".

A few years back, I bought the "titanium wrap". I figured,... that color will look a bit nicer etc. (Still looks like crap).

Just my opinion. The wrap does have a place though.


In the end though. A few years back I "went back to cast iron". Although I was thrilled with the lower heat "radiation" of cast iron, I obviously was not happy with the performance of the stock cast iron but ..... if your budget allows, possibly look into these:

http://www.summitracing.com/parts/sn...FYdehgodcywLNw

I was VERY happy with them. Performance-wise and Heat-wise. Sanderson makes some great products. I looked at various cast iron options and landed on these. Well worth the money. I really should have removed them when I sold the car (90 Z-28) since now I'm working on an 85 Iroc project that they would be perfect on. I can attest that low and high end felt great. I can't say a bad thing about them. These will be my first choice again. (so far). Sanderson does make some other cast iron options as well.

Hooker (and other makers now) also makes a longer tube set if the "shorties" aren't what you need. The prices have actually come down a bit.

To be fair, I didn't do any dyno testing between standard headers and the cast iron (I may if I get a set for the Iroc), but I feel they are comparable (or at least more free flowing than a stock cast iron manifold.). I'm looking at the set by Hooker now. I'll post the link.

EDIT: These are the hookers (Which I am looking at now - they they can be ordered ceramic coated - but may be a bit warmer than a traditional cast iron. Checking into the now). I don't think they will compare with the Sandersons but will be ok for this project (just a street car).

http://www.summitracing.com/parts/ho...FdNahgodXCUOSg


I also ran across these Flowtech's. They are more of a block hugger design though. They me be similar "performance wise" to a Rams Horn - (I like the "tube size" for the outsides but, like the rams horns, they really don't have much tube for the inner ports. (Which I've always found to be ok for a street driven / moderate HP / Cruisin' car. Not something I'd use for a bracket car obviously, where I'd want some equal length tubes.

 

Lower heat radiation of cast iron, as opposed to steel? I don't know about that. Assuming exhaust passing thru headers and manifolds is the same temperature, then the headers and manifolds both eventually heat up to the same surface temperature. If that's true, then the only reason to believe headers increase underhood temps more than manifolds is because there is more surface area under the hood with headers than with manifolds. But I think it is insignificant anyway. Also, when the car is moving there has got to be significant air changes under the hood by virtue of air moving in from below and thru the grill.

 

Maybe "radiation" is the wrong word but ... cooler under hood , cooler near/on the wires and cooler temp of the cast iron as opposed to the header? In most every case of mine - 100% yes. With headers, you simply have more "mass" under the hood than with the cast iron. It's like having 2 radiators in there throwing off heat. (just like you say).

Lay an old spark plug wire or boot on a header and a cast iron intake and go for a ride. See which one is melted first. (I've got a wire on my 350 Chevy that's been laying on the top of the manifold for a year now. If I had headers on the truck, the wire would have been melted in short order,.

Look at something like an old cast iron cooking pot compared to steel. Heat up the burner. The center of the cast iron pot comes up to temp quick and as you get further toward the edge, it's cooler (and pretty much stays that way). It has cooler spots throughout it's mass, hot in center and cooler on the edges. In most cases, the outside of a cast iron exhaust manifold is cooler than the inside surface. I'd be willing to bet that the outside of a header tube is exactly the same as the inside surface. Heat transfers through thin steel better than thick cast.

A steel pot's lower surface is much more consistent and hot all the way out to the edges. If I put an infrared thermometer on a cast header, it's cooler just before you get to the collector (Which is higher than where a traditional long tube header collector is admittedly). The heat from a tubular header stays hot further down each tube and into the collector. Much more mass to radiate heat into the engine compartment.

Don't get me wrong. Cast Iron also does radiate / keep more "heat to the head" ( in my experience, at least with the track cars) so I'm not saying use cast iron for those applications. My headers in the Trans-Am could be just about glowing at the end of a pass. Cast Iron, no way.

.... But radiation probably isn't really the right word like I mentioned in my first post.

 

Ceramic coated headers are "supposed" to keep more heat IN the tube, less heat in engine compartment.

I used the wrap after the long tube collectors, worked well.

 

I was kind of wondering if his were coated on the inside as well? I hear that can make a difference. I've only had one pair of ceramic coated headers (just on the outside) and they seemed to do pretty well from what I remember.

 

I have wrapped both headers and plan to wray the entire exhaust, this is an early shot of the header partially wrapped.



Sorry now and then I channel my inner FOOSE ... LOL!

Dave

 

Interesting Dave! What wrap did you use? And how did you do that getting it wrapped where it bolts to the head itself? Detail this operation for us. Since it looks like you are already finished with yours and if you didn't takes pics along the way, you can come do mine and I will take lots of pictures to post!

 

I used DEI wrap, it's the blonde or tan color. I've been told you can wet it down and stretch it on as you wrap, you band your starting course and then just be sure to overlap as you proceed along.

I first did the wrap on my Camaro exhaust, and over a short time it unraveled, for this time round I picked up some thin stainless mechanics wire and I did a kind of running hook and loop along the tubes to keep it tight and in place. After that I used header paint to coat the wrap ... in white ... yeah it likely won't stay long but looks cool right now. My plan is to wrap the entire exhaust out the back, I'll post pics on my thread when I get to that point.

Dave

 

I will concede to any challenge of the next statement, but neither headers or cast iron manifolds create heat......right? The heat comes from the combustion process and gases exits the cylinder heads.....so, again......headers don't create one degree of temperature more than the cast iron headers, because they don't create heat.

Now, I might be able to understand the headers have more surface area to transfer heat, but again, there is no more heat with a header than with a cast iron manifold.

But, I am no scientist or engineer. I will concede to any disagreement. ANd its a very common statement to say that uncoated headers cause higher under hood heat.

I am hoping its not a problem, cause I have Stainless Works uncoated stainless headers on my car.....and they are very nice, so I hope the don't create a heat issue. But I have never understood the science behind the myth.

 

I would say your statement regarding the source of the heat to be correct, but long tube headers are great radiators of heat, this combined with the wider dispersion of the heat closer to the floor boards, can cause some foot-well discomfort if your car is missing any insulation.

By wrapping my un-coated older headers I hope to accomplish three things, control the distribution heat, protect my plug wires and give them an ol'school race look. I've used the plug wire boots and though they did the job extremely well I found them cumbersome when working on the plugs.

I'm sure your stainless headers are going to look and perform great, we'd love to see some pics when you install them and I'm sure the original poster would appreciate some feedback on their performance.

Dave