#3 spark plug

[Mylittlepony1966]

I have a 66 mdl & recently put a set of Pacemaker Headers on her. The #3 plug keeps melting the shield & shorting out. Has anyone else had a similar issue & what was your fix. Thinking I may need some heat shield wrap on the header itself.

[FB.65.68.70]

I have a set of pacemaker headers on a 302 windsor with AFR heads, yes had the same issue so I got a set of spark plug heat shields such as :-
 
https://outlawspeed.com.au/shop/insulation?parttype=26373

https://www.vpw.com.au/parts/PFEHS-630106

[Chris66pny]

Similar issue, but I had plug heat shields, still melted them. I've now changed to 90 degree plug leads.

[Mylittlepony1966]

Thanks mate does that give plenty of clearance? Assuming it does if you are happy with them

[GEOFF289]

I have 90 degree plug leads and heat shields on GT40P heads in a '66. No problems.

[Mylittlepony1966]

Thanks Geoff

[USA066]

I had the same problem with my headers, I put a 90 degree plug lead on the culprit lead only and heat shield on all of them in my 66. No further problems. On another issue, also check your starter motor clearance to your headers, I have also heat shielded mind.

[AussiePhil]

Hey Kevin,
Are your plug ends straight or 135 degree.
I have trouble with mine, they are ICE Ignition 135 degree and have heat socks.
One of them is very close!
Never thought about straight, 135 or 90 degree.
I reckon a mix and match for each cylinder may be the best.
I’ve got JBA1650 headers.
I’ll look into that, that’s for the thought.
Cheers Phil.

[Mylittlepony1966]

Hi Phil I have straight leads. I will be trying a 90 deg  lead today. Will probably also try a wrap on the header itself. Only because I don't expect I will be able to get the heat shield for the leads without ordering them. 

[Mylittlepony1966]

Thanks Usa066, I will give the 90deg leads  a go. They make sense.

[GEOFF289]

JBA 1650's on mine too.

[Mylittlepony1966]

90 degree leads have solved the problem.
Tried the heat shields, no good.
Now running 90 degree with the heat shield on #3. Will eventually  wrap the headers to try & minimise a bit more heat.

Thank you all for the feedback

[Mylittlepony1966]

Update:
Still giving me grief occasionally, tried the wrapping of pipes, made it worse. Found 90 degree Bosch leads the best. Just stumbled on to the Accel ceramic  plug covers, rated 2000 deg f.

[AussiePhil]

Hey all,
Just an update on JBA1650 headers.
I did modify my 6 and 8 cylinder ignition lead boots to 90 degree Aeroflow rubber boots 12 months? ago, but they’ve fried as well even with socks fitted as low as I could get them..
With the JBA 1650 headers the 4 and 6 cylinder header pipes go extremely close to the plug boots as you all know.
The other six cylinders have been fine with 135 degree rubber boots with Socks. Ideally number 6 plug boot would be better with a 90 degree boot.
So I’m going all ceramic 135 degree boots a bit late but finally!
Cheers Phil.