512 4-Bolt Block, +0.060 Price Hit?

[scuncio]

I'm looking at a 4-bolt 512 block but it's already 0.060 over. Machine work looks good and ready to build. My question...how much does the 0.060 overbore affect the value?

Thanks,
Tony

[jeff morocco]

IMO i dont think it should hurt value, i have a 512 block thats .125 over so id say its at half its life expectancy. as long as you dont "window" the block that is.....

[Jerry@CHP]

Tony,

Sometimes .060" blocks will run hotter on the street. That was the case with a .060" over 427 that I had in my SS396 Chevelle back in the early 1970s. If it's not a street motor, then I doubt you'll have anything to worry about.

Make sure that your piston to cylinder wall clearance will be okay at .060" over and that you "plate hone" the block before final assembly. Much better ring seal doing that.

Good luck,

Jerry

[scuncio]

Thanks for the feedback. Jerry, this will be a street motor so I hope I don't have the cooling issues you had. I'm not sure I understand your comment about the piston to wall clearance at a 0.060" overbore - if it was honed correctly with a torque plate, can I expect it to be ok?

[Jerry@CHP]

Tony,

You have to have your pistons in hand to know exactly what your piston to cylinder wall clearance is. All piston manufactures machine to slightly different tolerances so you won't know until you have the pistons. Also very important to check cylinder wall taper. Any machine shop can do that for you. At this point in time, many of the 512 blocks have been used up and that is why it's very important to make sure EVERYTHING is good.

Back in the old days, we would always sonic test these 512 blocks because they varied on wall thickness due to core shift, etc. Some are better than others. Many can go .125" over and others can't.

Jerry

[scuncio]

Jerry,
Appreciate the help. Will have the taper checked before I hand over the $. Hopefully the cylinder size is compatible with a TRW forging. I take for granted my old machine shop in CA that took care of this stuff. I'll have to see if I can find some literature on those pistons.

Thanks again,
Tony

[TDW]

Hey Tony...Is that the same machine shop that did the machine work on my "magazine 427"? If so, I would think all is good.

[BARRY]

HI the question is if i had a standard block 3,000 or 30 over 2500 or 60 1500 -2000

[scuncio]

Thanks guys. Tony, no, different shop. I meant to say that I would have no concerns if JMS (the shop that did your engine) had done the work.

[Jerry@CHP]

We can still get sonic testing done at my shop and it's reasonable. Accurate to .002",

Jerry