Another spark plug thread

[shadango]

Lots of threads out there but lots of variables...

I have been using an Accell #115 in the car since I got it because that is what was in the engine when I got it.......

Well, Accel no longer makes a 115 -- there is a substitute part number which is a resistor plug, (the 115 is not).....so I figured I would see what else I could try.

Stopped into autozone and had the auto expert there cross reference the accel 115 to autolite and he gave me a 103.  Got them home and realized they are WRONG.....tapered seat instead of flat/gasket, different size hex etc. so they have to go back.....started looking around online for myself.

My fish has a 318 -- purple shaft, 4bbl eddie, performer manifold, dougs headers, chrome ignition box and J heads.....no idea on valve size....I dont get ANY pinging on 87 octane.......the plugs burn nice and clean, tan electrodes....not much carbon etc......so in theory the engine is running good on the 115s.

According to autozone, the correct plug for a 72 stock 318 is an autolite 66....using the cross reference tables an accel 115 (what has been in it) equals a Autolite 63, which would be a colder plug (right?).

A guy I hang out with sometimes at the cruises has a real nice magnum 360 in his Challenger swears by autolites....says his 360 runs the best on them.  I didnt ask what number.....

Should I go with an autolite 63 (which in theory would equal the heat range on the accels) or try a stock plug?   Am I losing power by running the colder plug?  Is there anything to gain by trying a hotter plug like the 66?

Thanks all.

[cudabob496]

lotta guys use NGKs

http://www.ngksparkplugs.com/tech_support/spark_plugs/p2.asp

[jhaag]

Don't overthink it. Remember there are only a few actual manufacturers of spark plugs. Why not use the accell resistor replacement? Would work fine.  My preference in a mopar would be Champion, and I would use the stock replacement PN. Yes heat range will affect the way the car runs. Too cold will be easily fouled, poor starting, poor idle, etc. Too hot, preignition, and engine damage.

[shadango]

Don't overthink it. Remember there are only a few actual manufacturers of spark plugs. Why not use the accell resistor replacement? Would work fine.  My preference in a mopar would be Champion, and I would use the stock replacement PN. Yes heat range will affect the way the car runs. Too cold will be easily fouled, poor starting, poor idle, etc. Too hot, preignition, and engine damage.

"Too cold will be easily fouled, poor starting, poor idle, etc. Too hot, preignition, and engine damage." -- and this is why I am overthinking it.     

But I get your drift --- if the plug reads good now, stick with what I have......Just figured that since I have to change plugs anyways (the 115 is no longer made ---accel tech said "its the closest we make now to what you had).......figured if I could get an extra edge in any of those things you listed .....

[jhaag]

Exactly, stick with what works. Don't stray from OE heat range unless your combination dictates it. Yours apparently doesn't.   

[shadango]

Exactly, stick with what works. Don't stray from OE heat range unless your combination dictates it. Yours apparently doesn't.   

. Actually I am not using the OEM heat range now....its a colder plug.....and w
And am wondering what going to an OEM plug would do with my setup..... In other words am I running a colder plug for no reason and losing power potential?

[Strawdawg]

probably fouls quicker, but little effect upon performance unless they are way out of the range or fouled

[Cudaragtop]

For those that would like to stock up on some Champion RC12YC

Amazon has 24 pack for $45.08 delivered. They make great stocking stuffers...   

http://www.amazon.com/Champion-71S-RC12YC-Shop-Spark/dp/B000H5R5YM/ref=au_as_r?_encoding=UTF8&Make=Plymouth%7C43&Model=Cuda%7C2307&Year=1970%7C1970&ie=UTF8&n=15684181&s=automotive&vehicleId=2&vehicleType=automotive

[shadango]

probably fouls quicker, but little effect upon performance unless they are way out of the range or fouled

Thanks.

I decided to go with the autolite #63 -- a cross for the accell 115s I have......the old plugs don't foul or anything so like has been said, why mess with it...