AC R45S in 327/365....

[Jim V.]

Just being paranoid I guess, but any folks out there use these plugs in a hi-horse 11:1 motor? My motor is .030 over, and I am a tad, scootch, bit...concerned about piston clearance.

I noticed that the insulators are also LARGER than the old style R45 (and R45S) that I last purchased 2-3 years ago. They are soo big they may even have some shielding clearance issues.

Thanks
JimV

[William C.]

Re: AC R45S in 327/365....

In years past, I successfully closed the gaps on some "extended tip" plugs using exuberant driving (7000 rpm) in my 327 fueler. I doubt it would be a problem with normal rpm unless the deck or heads have been cut.

[Jim V.]

Re: AC R45S in 327/365....

Closed the gap....hummmm sounds like a euphamism for blown the motor. Years ago during those bygone drag racing days, I recall "tapping a valve" and rolling through the gates with water poring out of the exhaust headers.

Yep, I believe the heads were decked a tad. Sounds like a crap shoot! Forget the extended tippers....

Thanks
JimV

[Mike McKown]

Re: AC R45S in 327/365....

Well, I don't know what the NEW "S" plugs look like from AC but I'd think the worst you would do is mash the gap either shut or closer together. Either case, wouldn't hurt anything except your ambition to pull the plugs again.

In my lifetime, I've heard of ONE SHP ENGINE that had as MANUFACTURED deck clearance that had a problem with the extended tip design of the Delco "S" plug.

Proceed as you see fit.

[Clem Z.]

index the ground electrode at any place BUT

6:00 o'clock and you will have no problems. mark the location of the ground electrode on the outside of the plug,i use the insulator,with a magic marker. tighten the plug into the head and if you can see your mark the ground electrode is not in the way of the piston dome

[Jim V.]

Clem...great but...

What if it is near the 6 oclock...how can you adjust it?

Thanks
JimV

[Mike McKown]

That's great if you're short on clearance

crank the thing on in there and roll it over and see what happens!

If you feel the need to index the thing, different plugs will give you different indexing.

[Clem Z.]

Re: Clem...great but...

try moving the plug to a diffent cylinder.