Thermo Plugs Arent Working

[1/4 Mile Style]

So I got these plugs in for my heads that Sleeper suggested and they dont fit. Seem too big??

Any other ideas for plugging the emission holes on the back of the head or is there some trick to getting these in....

...this is the only thing holding me up from getting the car running now.


TIA, Jon

 

[Vinnietbird]

I cut the ends off of the thermactor pipe,and tuned them backwards,used a little Permatwx,and bolted them on.No leaks for three years so far.Took about 5 minutes total.

 

[Mustang5L5]

I beleive they are the same threads as spark plugs. I think i've heard of guys using two old plugs and breaking the porcelean head off.

 

[liljoe07]

Should be 5/8-11 thread. You can get them at Home depot or lowes with and allen head. Just like a set screw. Make sure your not using the crossover tube mounting hole instead of the actual thermactor port.

 

[4G-KDMP]

The bolt is 5/8-11 thread the same as a spark plug. Sounds like there could be a lot of carbon build up on the threads, did you try cleaning the threads in the back of the heads?

 

[1/4 Mile Style]

Whats the diff between the thermo port and the crossover tube port? Theres only one hole on each head in the bottom outside corner on mine. The plugs I bought are the TF 5/8-11's but they definately dont thread in.

Just tried an old spark plug and that seems spot on but they are a little smaller than the therm plugs & are a fine thread v.s course.

I dont guess it matters if it crossthreads as these will never be coming out of my motor????

 

[1/4 Mile Style]

This pics shows that the therm plugs that I got are indeed a little bigger than the spark plugs....

 

[1/4 Mile Style]

Think I got it figured out. Used the broke off sprak plugs. These pupies are SNUG. I dont see any way theyre coming out.