327 spark plugs
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 2,839
Likes: 19
From: Folsom CA
327 spark plugs
Bought a 64 Corvette that has been raced in Northern California historic races. It has a "legal" 327 race engine and has a great history. The person I bought the car from owned it for over 3 years and never raced it. I pulled the plugs yesterday and they are Champion J 6 C plugs. When I looked this plug up online it listed it as a plug for small outboard boat engines. The dyno sheet for the engine listed the plugs used as Champion J4. These also show up as a small engine plug. Engine runs on 110 octane race gas and has all the "legal" tricks done to it. I sent Champion an e-mail about the plugs but have not heard back. Wondering if any of you know about these plugs. I was thinking that maybe they were an older car plug and now there is a new numbering system.
thanks,
Larry
thanks,
Larry
Burning Brakes
Joined: Jan 2003
Posts: 755
Likes: 32
From: Roswell Georgia
Larry, when I ran B Production back in the day, my '64 327/365 SBC ran a Champion's J-6J plug with a gap of 0.028". (The extra "J" on the end was for a cut-back side electrode.) These racing plugs are no longer available from Champion. If the J-4C or J-6C spark plugs are what the engine maker recommends, I'd try using them. They are about as close as you'll get to these out-of-production racing plugs.
If you decide to use the Champion's website spark plug selector, they'll recommend a RJ12YC plug for a carbureted/FI '64 327. That breaks down to a 14mm resistor spark plug with a 13/16" hex pattern w/gasket, 3/8" reach, projected core nose, with a copper core. Looking up the plug itself, it has a J-gap between the shell and center electrode. (Heat range "12" is towards the hotter end of the scale for Champion. "6" is towards the middle, and "4" is towards the cold end of their scale.)
Since your engine is built for racing and not the street, you shouldn't need a resistor plug. You preferred heat range is "4" according to the builder. Having a projected core spark plug would allow you to run a "hotter" plug as they run cooler than regular spark plugs; however, be sure to check your clearance as you might have larger than stock intake valves installed; and I seem to remember the early "fuelie" heads had interference problems until the spark plug's hole position was changed in later heads.
Hope this helps. Good Luck!
Hope this helps.
If you decide to use the Champion's website spark plug selector, they'll recommend a RJ12YC plug for a carbureted/FI '64 327. That breaks down to a 14mm resistor spark plug with a 13/16" hex pattern w/gasket, 3/8" reach, projected core nose, with a copper core. Looking up the plug itself, it has a J-gap between the shell and center electrode. (Heat range "12" is towards the hotter end of the scale for Champion. "6" is towards the middle, and "4" is towards the cold end of their scale.)
Since your engine is built for racing and not the street, you shouldn't need a resistor plug. You preferred heat range is "4" according to the builder. Having a projected core spark plug would allow you to run a "hotter" plug as they run cooler than regular spark plugs; however, be sure to check your clearance as you might have larger than stock intake valves installed; and I seem to remember the early "fuelie" heads had interference problems until the spark plug's hole position was changed in later heads.
Hope this helps. Good Luck!
Hope this helps.
Thread Starter
Melting Slicks
Joined: Nov 2005
Posts: 2,839
Likes: 19
From: Folsom CA
Larry, when I ran B Production back in the day, my '64 327/365 SBC ran a Champion's J-6J plug with a gap of 0.028". (The extra "J" on the end was for a cut-back side electrode.) These racing plugs are no longer available from Champion. If the J-4C or J-6C spark plugs are what the engine maker recommends, I'd try using them. They are about as close as you'll get to these out-of-production racing plugs.
If you decide to use the Champion's website spark plug selector, they'll recommend a RJ12YC plug for a carbureted/FI '64 327. That breaks down to a 14mm resistor spark plug with a 13/16" hex pattern w/gasket, 3/8" reach, projected core nose, with a copper core. Looking up the plug itself, it has a J-gap between the shell and center electrode. (Heat range "12" is towards the hotter end of the scale for Champion. "6" is towards the middle, and "4" is towards the cold end of their scale.)
Since your engine is built for racing and not the street, you shouldn't need a resistor plug. You preferred heat range is "4" according to the builder. Having a projected core spark plug would allow you to run a "hotter" plug as they run cooler than regular spark plugs; however, be sure to check your clearance as you might have larger than stock intake valves installed; and I seem to remember the early "fuelie" heads had interference problems until the spark plug's hole position was changed in later heads.
Hope this helps. Good Luck!
Hope this helps.
If you decide to use the Champion's website spark plug selector, they'll recommend a RJ12YC plug for a carbureted/FI '64 327. That breaks down to a 14mm resistor spark plug with a 13/16" hex pattern w/gasket, 3/8" reach, projected core nose, with a copper core. Looking up the plug itself, it has a J-gap between the shell and center electrode. (Heat range "12" is towards the hotter end of the scale for Champion. "6" is towards the middle, and "4" is towards the cold end of their scale.)
Since your engine is built for racing and not the street, you shouldn't need a resistor plug. You preferred heat range is "4" according to the builder. Having a projected core spark plug would allow you to run a "hotter" plug as they run cooler than regular spark plugs; however, be sure to check your clearance as you might have larger than stock intake valves installed; and I seem to remember the early "fuelie" heads had interference problems until the spark plug's hole position was changed in later heads.
Hope this helps. Good Luck!
Hope this helps.
Thank you very much for the response: thumbs: I was getting ready to make a few calls this morning since I have not heard back from Champion.
Larry
