Is 0.030 overbore worth it?

[Boss 351]

The engine block doesn't need it, only a simple honing is only needed because the cylinder walls are in pretty good shape. Is getting 0.030 oversize pistons worth it? We are talking roughly a $360.00 (301.00 USD) difference for the extra machining and different pistons.

I doubt that a 0.030 overbore is a performance mod since it won't give that much more power. I tend to see it as only fixing the cylinder walls. Other wise I plan to only freshen up the walls a little, new pistons, rings, etc... That will give me room to play if something happens to the engine later on anyway.

What do you think?

 

[BlackFox5.0]

No it's not worth it. Unless you have a deep ridge at the top of the cylinder wall, then there is no need to bore it. Just do a hone.

 

[HISSIN50]

i agree with Chris. you could see like 4-5 hp from the overbore, if you got really really lucky.

if the bores can be honed, i would do that.

good luck and let us know how it goes.

 

[5spd GT]

The difference between a worn out 302 and a freshly "walled" 306 can be a nice difference...of course with the matching pistons and rings...

If money isn't a problem I would go ahead and do it...besides if something "happens" to your engine and you want a little wall to play with...that "happen" (accident) will probably make the engine not runable...(cracked block, crank, etc...) and those parts flying around in there at a given rpm aren't going to make a few of those cylinder walls look to pretty...you mys well just buy a new shortblock if that happens...

A hone would be fine...

 

[HISSIN50]

The difference between a worn out 302 and a freshly "walled" 306 can be a nice difference...of course with the matching pistons and rings...

well said. i omitted to say a fresh ring-to-bore 302 vs a freshly bored 306 might not be a huge gain (my thinking was along the lines of not much power increase from the mere displacement increase). you are absolutely right.

 

[mackey]

Boring only comes into a "necessary" mod when you have to run in classes that have a 310Cubic Inch restriction.

 

[5spd GT]

well said. i omitted to say a fresh ring-to-bore 302 vs a freshly bored 306 might not be a huge gain (my thinking was along the lines of not much power increase from the mere displacement increase). you are absolutely right.

Well with someone of your knowledge I knew what you were referring to with the power difference of 4-5 hp...I just figured I would jab that in there with the non-fresh and the fresh

 

[hllon4whls]

Besides the extra few cubes, an overbore increases hp by unshrouding the valves. How much, I am not sure.

 

[HISSIN50]

Well with someone of your knowledge

touche.

and your point was quite valid.