.30 over or 40 over??318

[Youngthrill]

i just picked up a 318 taking it down the machine shop tommarow...planning on useing kieth black pistons from summit racing ..what should i bore it out to???useing stock head going to get them redone with springs stock rollers planning on usein the xe 268 can i need to know before i go with the wrong size...trying to achieve max torque...thanks fabo

 

[RustyRatRod]

.030.

 

[cudamark]

Unless you're trying to get max horsepower, I would go to whatever the next oversize is that the block will clean to. Price of pistons might enter into your budget decision.

 

[Mad Dart]

.030 or .040 don't make much difference. I have bored a 318 over .100's before with no issues at all. Them 318's got some Meat.

 

[Salty Dog]

Bore as little as possible since the a overbored engine makes nominal more power over a unbored engine, cubic inch displacement being the starting line.

A 318 standard bore vs. a 318 @ a .030 overbore makes nearly identical power numbers.

 

[Youngthrill]

thanks

 

[rumblefish360]

The thicker cylinder is a stronger cylinder. It is stiffer, flex's less and has the abilty to be more durable, seal the rings better under high stress and loads. This equals more power.