hotter spark plugs
 

I am wanting to put a hotter plug in a 76 farm truck-never gets warmed up to really clean up the plugs. It calls for an AC Delco R44T. I can't locate any R45T locally, but have found some R45TS. The are about 1/8" longer from the tapered seat to the tip. Can anyone tell me it these will work without hitting the piston, or should I just order the R45T and wait? Thank you.

Re: hotter spark plugs
 

I'm not sure that engine temp correlates to the spark plug heat range. The heat index refers to the insulators ability to pull heat out of the plug itself. Unless you've altered the factory compression ratio, I don't know why you would want a hotter plug?

Re: hotter spark plugs
 

Guessing the OP is having a carbon problem since the average farm trail doesn't encourage speed driving. Hotter plug might help some. Leaning the idle mix a bit might help also. Plus leaning the choke as much as possible and still get a good cold start. Bumping the initial timing might help as well.

To OP: what motor?

Re: hotter spark plugs
 

It is a 350 with a quadrajet. You are correct about the low speed driving. The truck gets up to operating temperature just fine, but a lot of putting around and idling. The plugs aren't clean-burning, like they might be if I was running the highway some. It has always been my understanding that a hotter plug might help with that-fire through the "crud".

Re: hotter spark plugs
 

Give it the 6 ounce tune up!
Dribble some water into the carb at high idle and it’ll clean those plugs off pronto!

Re: hotter spark plugs
 

My 83 came with R45TS plugs in the 305 with no problems :smoke:

Re: hotter spark plugs
 

Auto-Lite plugs are a good brand for your
application.
They work well in a (Also an oil burner) truck
that does not see the Hi-way often.
I have had Great luck with this.











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Re: hotter spark plugs
 

Thanks for all of the thoughts and suggestions! Doug