870 block .060 over

[Robert B.]

If a block, 327 (870) is bored out to .060, is it necessary to have it sonic tested. ? Thanks

[Wayne L.]

Re: 870 block .060 over

It would be a very good idea.

[Michael F.]

Re: 870 block .060 over

I agree, be safe not sorry and do it.

[David K.]

Re: 870 block .060 over

Do you need to go .060 over. Could you do .030 ??

[Leif A.]

Re: 870 block .060 over

Do you need to go .060 over. Could you do .030 ??

Something's telling me that it has already been bored out to .060 over.

[Joseph S.]

Re: 870 block .060 over

Bob, My experience is that the 327's run very hot when bored to .060. We always have them sleeved back to 0 if they have been or need to be bored to .060. Regards, Joe

[Timothy B.]

Re: 870 block .060 over

My 63 engine is .060 and it runs good but on a hot day at idle in the garage it will hit the 240 mark and fluid seeps from the 13 psi radiator cap. It's probably normal because if the hood is open approx 30% of the radiator is not getting air.

I have always thought about sleeving back to 4" but don't want to create any problems.

[Joe L.]

Re: 870 block .060 over

If a block, 327 (870) is bored out to .060, is it necessary to have it sonic tested. ? Thanks

Robert-------


Here's a clue: the largest oversize SERVICE piston that GM ever had available for ANY 327 was 0.030" over.

[Jack H.]

Re: 870 block .060 over

Do you need to go .060 over. Could you do .030 ??

Some 327 pistons are available in .040 also. I know the hi-perf domed pistons (11:1, i.e. L2166NF) are available in .040.

[Joe L.]

Re: 870 block .060 over

Some 327 pistons are available in .040 also. I know the hi-perf domed pistons (11:1, i.e. L2166NF) are available in .040.

Jack------


Yes, aftermarket 0.040" over pistons are available. My basic rule: NEVER use a larger over-size than absolutely necessary. Most machine shops want to do a 0.030" over from standard. I ALWAYS recommend going only 0.020" over if that's sufficient.

[Steven B.]

Re: 870 block .060 over

Egge machine will make size to order. Steve

[Michael H.]

Re: 870 block .060 over

Bob, My experience is that the 327's run very hot when bored to .060. We always have them sleeved back to 0 if they have been or need to be bored to .060. Regards, Joe

I agree with Joe, also the more metal you can leave on the engine the better to help dissipate the heat, you also take a chance in getting pin holes in the cylinder walls and you'll have water in the cylinders. So if it was me and I had to go .060 over I would sleeve the block.

Mike

[Stan E.]

Re: 870 block .060 over

Be smart and sleeve it , save the numbers! You only have one. Good Luck!

[Donald A.]

Re: 870 block .060 over

My .60 over 327 in the 63 runs fine temp wise. I did put a new DeWitts radiator in it. Also I did a partial block of the bypass ( upper hose to intake manifold that doesn't go through radiator). Not my choice to go .60 over but block needed it. It checked fine so did not consider sleeving it.