what piston did a 318 use?

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trbodrt

trbodrt

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I was wondering if anyone knows what compression piston was used in a 1972 318. 8:1, 9:1?
 
I beleive it was a round one....sorry could not resist...sitting here at work and needed a laugh!!!!!
 
Theres several different compresion heights used through out the years. Try a look around Summit racings sight, they give the compresion height of pistons sometimes...if available.
Also, Federal Mougal also has this info.
 
My books say the compression ratio on a '72 318 was 8.6:1. Compression ratio is not just a function of the piston, however. The size of the combustion chamber in the cylinder head is the other major determining factor, with head gasket thickness also contributing.

For instance, the '71 318 also has an 8.6:1 compression ratio, but the piston sits deeper in the block, while the combustion chamber is smaller than the '71.

FWIW the 72-86 318s used the same piston.
 
Poor little 318 never really got better than 8.5:1. I think the best stock piston for boosting compression would be a roller cam 318 piston,from about 85-89.

Your compression is better than my 83 cop engine . 7.5:1
 
I have a 68 318 engine and it states that it is 9.5 to 1 comp ratio my pistons have valve cut outs in them both sides I know they are factory ones as I have owned it for 32 years and both previous owners were known to me , I also have a 78 block and the pistons are flat top and 30 thou lower in the bore than the 68's hope this helps
 
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