413 compression question
- Thread starter Greg55_99
- Start date
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What year 413? How far down the hole are the pistons? Heads or Block decked any? What gasket compressed thickness?
Pistons are stock 1965 vintage cast flatops. Can't tell you how far down they are. Deck is stock. Heads are stock 70 440. Head gasket is steel.
A "wag" would be helpful as I put this motor together (poorly) in 1979.
Greg
A "wag" would be helpful as I put this motor together (poorly) in 1979.
Greg
I'd guess anywhere from 9:1 to 10:1, 413 Max wedges were higher compression, somewhere around 11:1 if I remember right. I'm sure someone much more knowledgeable than I will chime in.
moper
Well-Known Member
The original heads would have been closed chamber, and I think the true compression would be around 9:1 with a steel shim gasket (advertised around 10:1 I think). So you're going to an open chamber head - it will be closer to 8:1 espcially if you go with a composite gasket.
To be clear. Are you saying the stock bore 413 with stock flat top pistons, open chamber 440 heads and a steel shim head gasket will get about 9:1 or 8:1?
Greg
moper
Well-Known Member
I'm saying that it's listed as 10:1 with closed chamber heads and steel shim gasket it was actually closer to 9:1. Now add open chamber heads that are 8-10ccs bigger, and gaskets 2-3 times as thick, it will actually measure out below 9:1. Round figures - not empirical measurements.
moe7404
moe7404
all chrysler bodys 314 engines are 10:1 stock. except 300s? from 1959 to 1965. all 4 bbl carb, except 300s that was2 x 4 but 1965 was one 4 bbl. if you can find early 70s 413 truck pistons takes C.R. to 7.5. bolts in no balance change. a 1965 300 L 4,200 LB will do 16.00 sec 1/4. the earlyer 300s went 15.00 1/4 sec. DO note the 300s was NOT a full race car. it was called a gentlemans luxury performance car. good daily drivers.
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