Is .60 over too much for an over bore?

[16Pilot]

I may go with maching my block out of a 1990 S-10. I ran across a good deal on some pistons(New) but they are .60 over ????? Any comments

 

[16Pilot]

Re: Is .60 over too much for an over bore?

sorry guys the motor is a 4.3L V6 1990

 

[f_inscreenname]

Re: Is .60 over too much for an over bore?

The cylinder walls would be a little to thin for a boat motor for me.

 

[rodbolt]

Re: Is .60 over too much for an over bore?

.60 is way to much. you will strike water. .060 would be ok. no worries.<br /> good luck and keep posting

 

[16Pilot]

Re: Is .60 over too much for an over bore?

i am a little new at the rebuilding experience Rod Bolt...thanks for your help! I assume its .060 right?

 

[Bondo]

Re: Is .60 over too much for an over bore?

.060, Sixty-Thousandths, is at the Outer Limits of an over-bore on a SBC,<br />But, for the Savings you're looking at,<br />It'll Work........<br /><br />BTW,<br />.60 is Six Hundred Thousandths.......<br />A Little Over a Half-Inch..................

 

[MooseHootie]

Re: Is .60 over too much for an over bore?

I race engines in cars. I have bored many engines to .060. But like everyone says, the cylinder walls are real thin. What happens is when they mold these block some have core shift making some cylinders thinner in one place than the other. I have had two engines that have split the cylinders.

 

[Rainmaker]

Re: Is .60 over too much for an over bore?

Went .060" over on my old Chevy 250 (165 OMC). Never had a problem but never overheated the engine either.<br /><br />Current vessel has 350's. The engines were already .030" over and since I take it way offshore, I decided not to go any further than .040" over just to have some margin. Speed-Pro and a few other manufacturers make .040" pistons for SBCs. I believe your 4.3 can use SBC pistons. <br /><br />Have you determined if the bores will clean up with only .040" over?

 

[16Pilot]

Re: Is .60 over too much for an over bore?

I went 60 because I got such a good deal on them.

 

[f_inscreenname]

Re: Is .60 over too much for an over bore?

It will be a good deal till you break something (if it does). Just remember you are taking it to the limit so treat the motor accordingly. Good luck.