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10.8:1 C/R Plug Suggestions

Old 11-11-2008, 09:37 AM
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10.8:1 C/R Plug Suggestions

The pistons say they are good for 10.3:1 with 67cc heads. I am running a zero deck (if not its DAMN close) and a slight mill on the 64cc heads to clean them up. So, I am guessing the 10.8:1.

Going to try to start at around 34* total timing if the dizzy cooperates. This is .576/.600 lift cam and 242/248 @ .050.


I need a 14mm, .750" reach, gasket seat, resistor plug.

Thinking of sticking with the Autolite 3923's http://store.summitracing.com/partde...?part=frm-3923.

These are two heat ranges colder than stock from what I gather (3926, 3924, 3923...what happened to 3925?). However, I am open to anything.


Also, do I want a projected or non-projected tip?
Old 11-11-2008, 09:49 AM
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Re: 10.8:1 C/R Plug Suggestions

Alright, this http://www.campbellenterprises.com/R...o%20calculator says I could be close to 11:1!!!
Old 11-11-2008, 10:07 AM
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Re: 10.8:1 C/R Plug Suggestions

Autolite tech suggested starting out with the 3922's (the coldest they make in a resistor plug). Projected tip is better if you have room to put the electrode nearest the center of the combustion chamber you can.
Old 11-12-2008, 09:56 AM
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Re: 10.8:1 C/R Plug Suggestions

Having a tough time finding the 3922's...cross-referencing as much as I can but still open to suggestions :::::echo:::::
Old 11-12-2008, 10:39 AM
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Re: 10.8:1 C/R Plug Suggestions

http://www.napaonline.com/NOLPPSE/(S...Dn=0&Dk=1&Dp=3

Napa has a nice little way to cross referance almost anything.... I think I would try the 3923's first and read the plugs, and adjust accordingly.
Old 11-12-2008, 10:57 AM
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Re: 10.8:1 C/R Plug Suggestions

Yea I thought that too since the 3922's are impossible to find. However, I don't want a hole in my piston!

After the zero deck, .039" head gasket, -5.4cc reliefs, and slight mill on 62cc heads I'm looking at well over 11.1:1!!!
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