Which spark plugs to use?
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Le Mans Master
Joined: Oct 2005
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From: Macon, GA
Which spark plugs to use?
Picked up the subject from a thread a couple of months ago. I'm trying to find the correct plug to use on my 327. I do have the TRW pop up pistons (10.3:1) and I'm running 64cc Edelbrock Performer RPM heads. I also have Hooker side mount headers so I need a plug that is as short as possible. I'm not a big fan of Accel and I read in the quotes below about the NGK's. My only question is are the NGK's correct for my application (Summit says I need an "S" heat range plug) and are they shorter than stock?
Thanks in advance.
Scott
Sorry - I meant o add I'm running a stock HEI distributor.
Thanks in advance.
Scott
Sorry - I meant o add I'm running a stock HEI distributor.
The original plug for Corvette 327s through '68 was the AC 44. In 1969, it was the R44. The 44 series is not available anymore, but no matter as it was really a bit too cold for normal driving. The 45 series is better.
There is no real performance difference in the 45 or R45. The R is for resistor plugs which help reduce ignition noise in radios. The R45S has an extended tip which helps keep it cleaner from fouling and so it runs a bit better. However, if you have high domed pistons or the heads have been shaved, you could hit. You need to install the plugs, turn the engine over, and then check the plugs if you have any performance work done on the engine.
If you are running the R43S, you'd better be doing hot laps most of the day, because it is far too cold for the street.
There is no real performance difference in the 45 or R45. The R is for resistor plugs which help reduce ignition noise in radios. The R45S has an extended tip which helps keep it cleaner from fouling and so it runs a bit better. However, if you have high domed pistons or the heads have been shaved, you could hit. You need to install the plugs, turn the engine over, and then check the plugs if you have any performance work done on the engine.
If you are running the R43S, you'd better be doing hot laps most of the day, because it is far too cold for the street.
Last edited by sperkins; Apr 8, 2007 at 02:12 AM.
Le Mans Master
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I can't tell you if that's the right plug. I can tell you that NGK plugs are the best I've ever used in my Vette...............
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Bosch Platinum # 4236 is a terrific spark plug. It is a 45 heat range. I use it in my L79 65. and it runs better than any plug I have used in 35 years on this car. I do not disagree with NGK as others have mentioned. They are great plugs too.
