Headers getting too hot

[Pony Rider]

I just had a new set of shortys from Wild Horses and a complete exhaust system installed on my 75 Bronco. I drove it for about a 100 miles and noticed a miss. When I checked I found the shop cracked 3 spark plugs when they R&Rd the old headers.

I changed the spark plugs (autolite platnums set at .44) and started the engine. Idle was great but when I hold it at 3,000 rpm for about a minute the headers become cherry red. With my gearing I have to run around 3,000 rpm to do 60mph.

Is this normal? If not what could be the problem? This just seems too hot to be right.

I am running a 351w with a mass air EEC-IV efi system off a 1990 mustang.

Please help!

 

[bronconutt2005]

I just had a new set of shortys from Wild Horses and a complete exhaust system installed on my 75 Bronco. I drove it for about a 100 miles and noticed a miss. When I checked I found the shop cracked 3 spark plugs when they R&Rd the old headers.
I changed the spark plugs (autolite platnums set at .44) and started the engine. Idle was great but when I hold it at 3,000 rpm for about a minute the headers become cherry red. With my gearing I have to run around 3,000 rpm to do 60mph.

Is this normal? If not what could be the problem? This just seems too hot to be right.

I am running a 351w with a mass air EEC-IV efi system off a 1990 mustang.

Please help!

I seen a manifold turn red on a jeep once. ended up the converter fell apart and blocked the system

 

[dewshan]

I just had a new set of shortys from Wild Horses and a complete exhaust system installed on my 75 Bronco. I drove it for about a 100 miles and noticed a miss. When I checked I found the shop cracked 3 spark plugs when they R&Rd the old headers.
I changed the spark plugs (autolite platnums set at .44) and started the engine. Idle was great but when I hold it at 3,000 rpm for about a minute the headers become cherry red. With my gearing I have to run around 3,000 rpm to do 60mph.

Is this normal? If not what could be the problem? This just seems too hot to be right.

I am running a 351w with a mass air EEC-IV efi system off a 1990 mustang.

Please help!

I think if the engine is running too lean it can heat up and also if the timing is to far advanced. I would also check the connection at the muffler etc. I had a muffler that was pushed too far onto the exhaust pipe that worked to restrict the flow and it was very hot.

 

[STLKIKN]

Also, you have to remember that you were sitting still doing 3000 rpm, and had no airflow through your engine compartment.... shouldn't run quite as hot when its moving. Although, that said, I know I burned the paint off my long tubes within a week of installing them.

 

[Broncobill78]

I just had a new set of shortys from Wild Horses and a complete exhaust system installed on my 75 Bronco. I drove it for about a 100 miles and noticed a miss. When I checked I found the shop cracked 3 spark plugs when they R&Rd the old headers.
I changed the spark plugs (autolite platnums set at .44) and started the engine. Idle was great but when I hold it at 3,000 rpm for about a minute the headers become cherry red. With my gearing I have to run around 3,000 rpm to do 60mph.

Is this normal? If not what could be the problem? This just seems too hot to be right.

I am running a 351w with a mass air EEC-IV efi system off a 1990 mustang.

Please help!

Yes & no. Headers are notorious for running hot (got the scars on the backs of my hands & wrists to prove it) and as the previous poster noted you were running it at a fairly high rev with no airflow thru the compartment. The problem of excessive header heat is usually solved (these days at least) by ceramacoating or JetHotting them. A lot of manufacturers offer this now right out of the box as an option for new headers. Companies like JetHot have adapted the high-tech coatings used on military & commercial jet engine parts to automotive headers http://www.jet-hot.com/ but unfortunately for you any sort of coating is going to involve removing the headers, sending them out & then reinstalling them (sorry but that's just the way it is). If they wind up making the floorboards uncomfortably hot then you might not have a choice about it. As far as dealing with it now that they're on there about the only option you have left is to wrap them. Men have been wrappping headers since the first guy burned his hand & dropped his wrench to cuss. The old asbestos wraps that you soaked in water & stretched around them have gone the way of the dinasour but they're still around now using materials like Kevlar so it shouldn't be too hard to find a couple rolls of the stuff at the local speed shop. Now I don't know what material your headers are but the cheap-o brand-X headers will usually self-destruct afetr a few years of being wrapped (not right away mind you but most of them die in the end) the thinwall tubing just doesn't provide enough material there to absorb & contain all that heat and they develop blow-holes. Good quality thickwall tubes will usually stand-up to it ok and if they're stainless you've got nothing to worry about. I haven't had the need to check lately but it used to be that wrapping your headers voided any sort of warranty that you had. The Jet-hot & ceramic coatings are a different deal since the headers are *dipped* into it and coated both inside & out and this provides much better protection for the tubes as well as containing the heat & sending it aft with the rest of the exhaust. In addition to the rolls of wrap I've also seen header sleeves that you can install over them that are essentially the same thing but in the form of an easier to install & looser fitting blanket type sleeve cut to fit shorty's or longtubes.

Sorry to be so longwinded, I guess the short answer would have been, Yes it's normal. (unless of course you're running blocked cats or an excessively rich mixture. Might be worth confirming the O2 sensor is ok and the mixture is correct or at least close to right)