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Author Topic:   Spark plug recommendation
posted September 11, 2003 04:53 PM
Small block chevy 350 .030"over, 3.5"stroke, turning 6200rpm, Pro Topline Amuminum Lightning 200cc heads. Recommended starting point is Champion C57C but Autolite AR3932 is supposed to be the same thing. I have no idea where to start with spark plugs and am curious if there would be a better starting point like Autolite AR3933 or something else? Thanks for your help.

posted September 11, 2003 08:11 PM
ac r45ts

posted September 11, 2003 11:34 PM
We use the AR3933 and C59CX plugs in our gas engines , and anywhere from a C53CX to a C57CX in the alky engines .


Hendren Racing Engines
Rutherfordton , NC

posted September 12, 2003 07:24 AM
Is the AR3933 plug hotter than the AR3932? I tried a cross reference but I don't know alot about the Champion plug numbering system. Typically I run the Autolite 303 in my fuelie heads. Also, is there a difference between the spark plugs used in aluminum vs cast iron heads? I notice both Pro Topline and Dart list V59C for iron heads and both list C57C or C59C for the aluminum versions. What would be the difference if I went with too hot or too cold of a plug?

[This message has been edited by sbc350 (edited September 12, 2003).]

posted September 12, 2003 09:08 AM
You'd much rather be too cold than too hot. Too hot leads to detonation and holes in pistons... not a good thing. Too cold leads to fouled plugs, a ****ed driver and a motor ready for a plug swap and another try at it. I'd try the AR3932 first, then if it looks like it's fouling, move up to the 3933.

Aluminum heads will pull heat from the plugs faster, so all things being totally equal, a hotter plug COULD be used in an aluminum head versus an iron head. But each motor will respond differently. I use AR72's in my old 461 castings and AR133 or 134's in the newer 041 castings. Each motor seems to be just about right with 10.3-10.5:1 and 6000-6500rpm.

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