compression sb 402 stroker magnum

[stroker402]

I have a technical question for you guys ....
My engine is a bone stock 2002 mopar magnum crate 360 stroked to 402 cubes.
spec sheet says it is a 9:1 compression engine..
well how can that be if I just did a compression check on it hot and the butterflies open on the carb >>> all cylinders were at 180 #'s cranking pressure . seems ways high i thought .
cam is a hyd roller 288-292 duration ... 501-513 lift . not sure on the lobe sep.
RT cast iron heads 2.02 's

 

[OldmanRick]

Originally it was close to 9to1. Depending on the compression height of the stroker pistons and with your cranking compression i'm gonna guess your closer to the 10-10.5 range.

 

[sireland67]

10 yr old motor with 180 in every cylinder your good.

 

[stroker402]

oldmanrick..... is this another issue that mopar messed up when building engines? If they claim it's a 9:1 compression engine . when does the cranking pressures show way higher?
I'm not complaining about the compression .. if it higher than stated that is fine with me.. But that would explain why it is such a beast !:cheers:

 

[stroker402]

sireland67...yeah...... it's is hard to believe that this stroker mag from chrysler had No issues for 10 years .. and I beat the snot out of it.
Never even had the intake or valve covers off .
From what lot of people said about these mopar crate engines on these sites,, heads were junk .tolerances were way off etc etc.. I surprised this engine runs so good.. must of been a monday on the essembly line that day.:cheers: