Which Bore Size? Std, .20 or .30

[87WE4BOOSTED]

I’ve spent some time searching the forum, looking for some info on why someone would choose to go with a .20 bore versus .30, or even Std. I’m getting ready to send my short block in for a rebuild and I’m at the point where I need to pick my piston size. I’m using a stock crank and rods. Should I go straight to .30, or start with a .20? I’m a believer on bigger is better, but is it needed? I see many builds like mine using .30 and .20 size pistons. I even see new rebuilds using Std. What should I factor in to determine which size to go with?

Thanks in advance.

 

[turbogray]

What determines how much to bore is how much wear the bore has .
My opinion is just bore it untill it cleans up . no need to go big.

 

[87WE4BOOSTED]

What determines the bore size is how much wear the bore has .
My opinion is just bore it untill it cleans up . no need to go big.

So if it cleans up at .20, stop there? Cool. I ill find out soon.

Thanks for the response.

 

[ryan319]

yes, you always want to do the minimum. this leaves more meat for the future if you need to do it again.

 

[Steve]

I agree, go only as large as needed to clean up the cylinders. One thing to keep in mind is that there will always be some wear on the cylinders so even standard will be slightly over by the time you get it honed and I was unable to find file fit standard bore rings for my motor. My motor was low mileage and was able to stay standard and use standard fit rings with no excess end gap but if there is very much wear .020 will likely be needed to get the ring gaps right.

 

[regal454]

Nothing to gain..

You will not recognize any performance gains by boring the block to .030" over standard. Go the min it takes to clean it up and leave some meat on the cylinder walls for future rebuilds

 

[87WE4BOOSTED]

Thanks Guys,

Made the choice easy.