BadAssed93Z

my LT1 is bored .030 over to a 355, the 3.75 inch crank brings it to a 383, right?

a friend of mine said that some one on a mustang board told him the 6 inch rods make it a 388. i didnt think it did since it wouldnt increase the com,bustion area at all it would just add 3 tenths of an inch to the bottom and top of the stroke. so its still a 383 right?

i apreciate all responces. i just need some reassurance on this, id feel like a jack *** building a motor and not even knowing what i had.

thanks

mongse_1

Rod length has no influence on cubic inches...just rod/stroke ratio.

Cubic inches = ((cylinder radius squared * 3.14)*stroke length)*# of cylinders

BTW, a 388 is attained by boring the block .060" over (4.060" bore) and using a standard 400 stroke (3.75").

Anderson

Just wondering, do you guys loose usable safe RPM's when you go to a longer stroked engine??

Dave88LX

When you use a longer rod, you are locating the pin .3" up higher in the piston, cubic inches is the same.

GreenDemon

I wouldn't think so, the difference isn't very big, and most aftermarket stuff is at least a little better than stock. Not to mention that most engine breakdowns are usually caused by problems other than the rotating assembly reaching it's limits, it's usually the valvetrain or a fuel problem that turns a cylinder into a heathouse or a valve gets in the way, etc.

On that same note, you would lose usable rpms if you're running the same lift #s, of course, but it wouldn't hurt the engine to take it to the same point it was before.