.020 or .030 for Rebuild

[twstdv6]

Doing a rebuild, machine shop say's order .020 pistons, as block was in very good condition. I know .030 is bigger, but would it be wise to go .030 bore? or stay at .020. and only go bigger if you have to? I will be using Stock block, Rods and crank. Diamond pistons and rings. I will be driving it daily and want to keep pretty good gas mileage. If going with a bigger bore, would this affect gas mileage? or what would be the + & - of this?

 

[750H.P.V6]

If the block will clean up at the smaller bore size then go .020" over. This will leave extra material for future rebuilds. The difference in bore size won't affect gas mileage etc.

Neal

 

[conn84gn]

I agree stay with 0.020"

 

[Underboost]

I Agree with Neal

 

[mikestertwo]

I Agree with Neal

Ditto!

 

[blown okie]

If the block will clean up at the smaller bore size then go .020" over. This will leave extra material for future rebuilds. The difference in bore size won't affect gas mileage etc.

Neal

thicker walls are always "worth more" in the long run than a cubic inch or 2 imo.
we "rock" or grout fill the blocks in the stock/super stock stuff to help stiffen/support the cylinders walls its worth about .010 +/- in e.t. by keeping the walls for moving as much, so anything to keep the walls thicker and strong should be better. just my $.02

 

[Underboost]

thicker walls are always "worth more" in the long run than a cubic inch or 2 imo.
we "rock" or grout fill the blocks in the stock/super stock stuff to help stiffen/support the cylinders walls its worth about .010 +/- in e.t. by keeping the walls for moving as much, so anything to keep the walls thicker and strong should be better. just my $.02

Has anyone ever filled a 109 block with rock, or grout? I know It's been done with the Iron Stage II's.

 

[blown okie]

Has anyone ever filled a 109 block with rock, or grout? I know It's been done with the Iron Stage II's.

Not sure, it should work all the same, we specialize in FE fords (390, 427, 428 etc.) one can approach stiffening walls several ways, another is to take a larger bore block and sleeve it down to a desired bore size, for example sleeve a 4.1 block down to 3.8 bore size not only does this thicken and stiffen the walls, but the material of the sleeves are way better than the cast iron were honing, surface finish, and wear is concerned, however sleeving a block in this fashion can get expensive, but people are always looking for a better way to go faster & it usually costs money, and stock/super stock guys will kill for a tenth or 2.

 

[Underboost]

Not sure, it should work all the same, we specialize in FE fords (390, 427, 428 etc.) one can approach stiffening walls several ways, another is to take a larger bore block and sleeve it down to a desired bore size, for example sleeve a 4.1 block down to 3.8 bore size not only does this thicken and stiffen the walls, but the material of the sleeves are way better than the cast iron were honing, surface finish, and wear is concerned, however sleeving a block in this fashion can get expensive, but people are always looking for a better way to go faster & it usually costs money, and stock/super stock guys will kill for a tenth or 2.

 

[twstdv6]

Thank You for your input!

I will stay with the with the .020, I just wanted to know the difference, if any. Thanks! for all the input.