What spark plugs

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Retroboy

Retroboy

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Hey might sound basic to some of you but what plugs in a 9.5:1 360 with ST21 Racer Brown stick, Vertex maggie, and mechanical injection on methonal?
Cheers
Tony
 
Retroboy said:
Hey might sound basic to some of you but what plugs in a 9.5:1 360 with ST21 Racer Brown stick, Vertex maggie, and mechanical injection on methonal?
Cheers
Tony
Click to expand...

Hard question to answer definitively. Have you tried anything in particular?

9.5:1 compression ratio seems light for that type of setup. I could be wrong but relatively lower compression on an injected alcohol combo just seems like an odd situation.

Does the methanol make it run cooler? Might want to consider a hotter plug but again, I am really not sure on that.

In any event, can you get Autolite in Australia? #3924 seems to be a popular choice. I use them, no problems. Seemed to work as well as the Champion RC9YC that I replaced. I have a more conventional set up though; approximately 10.5:1 C.R., open chamber iron heads, carbureted on pump gas.
 
All I know is that all my mopars past & present love champions. Better gas mileage & performance
 
rmchrgr said:
Hard question to answer definitively. Have you tried anything in particular?

9.5:1 compression ratio seems light for that type of setup. I could be wrong but relatively lower compression on an injected alcohol combo just seems like an odd situation.

Does the methanol make it run cooler? Might want to consider a hotter plug but again, I am really not sure on that.

In any event, can you get Autolite in Australia? #3924 seems to be a popular choice. I use them, no problems. Seemed to work as well as the Champion RC9YC that I replaced. I have a more conventional set up though; approximately 10.5:1 C.R., open chamber iron heads, carbureted on pump gas.
Click to expand...


Just a guess on the comp so I ran a compression gauge over it yesterday and it's 165 PSI cranking. The injection will give fantastic throttle response and I run a dry block with no water in my FED so the meths will help keep it cool.
 
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