I have a 74 454 and when I bought it, it already had headers installed. A few months later I found out the the headers are melting the spark plug boots. I think part of the issue might be that the spark plug sits almost behind the header tube. But anyway, I bought boot sleeves and it burned all the way through. Any suggestions?

 

You could wrap the headers where they are close to the spark plugs.

 

What is your timing set to?

 

Gm makes some metal heat shields that are gm# 465840. Maybe look into some of those.

 

Yes...check timing......improper timing setting can elevate EGT's to the point where it will cook anything you try to use....you also will not get peak performance...and overall, the whole engine will run hot.
BTW...are the headers ceramic coated? This will lower temps about 300-400 degrees at the tube. Should be around 280-300 degrees with an infrared gun. 600 or so with naked tubes.

Jebby

 

I had that problem too. Changed the plug wires to ones with ceramic boots. No more problem.

 

Melted several sets until I put on ceramic boots

 

Another vote for ceramic boots. My wires are a little close on a couple of plugs, finally just put ceramic boots on some new wires custom fit and NO ISSUES with burnt boots and motor runs just fine. I bought the boots separate and made my own wire lengths to fit. They are easy to install. GL

 

Maybe some shorty header plugs will help?

https://www.summitracing.com/search/...spark-plug/yes

Tom

 

Thanks everyone for helping! When the weather gets a little warmer I'll definitely be checking the timing. I have no idea what the timing is at now but my mechanic installed a distributor cap last summer. As for the headers being ceramic coated, I don't believe so cuz the engine compartment gets so hot I can feel it thru the firewall.

 

What I did 4 years ago & no problems since.

 

Ceramic Coated headers have that look to them, different than paint. Somewhat of a sheen, usually silver in color but not always. Ceramic coating still puts off heat on the firewall. That's just how C3 are.

If you are considering Shorty plugs, I would do lots of homework before buying. The plugs have a short reach in the chamber too as in .430 of an inch. Feed back on Summit says it may be difficult to find the proper heat range.
The plugs may not work on aluminum heads, which most heads require .750 reach, chamber side. May not work with tapered seat heads. May not work with Vortec heads. May not work with washers, etc, etc, etc.
Double check first.

I would never buy / install a sparkplug just to clear the headers / plug-wires. There are better solutions with better plugs and proper heat range.

As far as the insulating plug boots, check out my profile, then photo album part of my build. I believe those boots are Moroso. I bought four, cut them in half, made eight and discarded the metal ring inside. I only had one boot slightly toast when it laid on the header all day long, my fault.

 

Obviously get plugs that fit your heads and engine application.
These are nothing new. Shorty, or header, plugs have been around for decades. Probably almost as long as companies have been making headers. You can get them in short reach or long reach, gasketed or tapered seat. Many applications. They may not be your solution or maybe they will. Just a thought.

Tom

 

The NOM 454 with headers in my 68 convert melted the boots even with those fiberglas heat wraps. Accel ceramic boot spark plug wires fixed the problem.

 

FWIW,
I used Taylor 135 deg wires and the #1 burn through the sleeve and the boot since they sat basically right against the header




I tried to fit the taylor heat shields on the #1 cyl but they ran into header worse than anything



Accel ceramic boot (again 135 deg)


Wouldn't fit, too long

Went to a 135 traditional round boot Taylor just on #1, the rest are always fine, with the sleeves and it's been ok for a couple of years now but I've got a new set of Accel 8.8mm variangle wires that will be going on this spring sometime so I hope to create a little more room with them
M

 

Same problem here years ago and went with ceramic boots...problem solved...would a 90 degree ceramic boot fit instead of that 45 degree in the pic? These are XS Power LTH 1 7/8 inch primaries on a 355 SBC L-82 motor.....

 

I could only get the 90 degree on if it pointed more or less down/back which made the wiring have a weird loop but that might just be on my McJacks
M