boring from .030 to .040

runawy9 · Post by **runawy9** » Mon Mar 10, 2008 9:15 pm

Picked up a 350 block from a friend that was supposed to be a standard bore. The heads have been off of it for a couple years and the cylinders have some rust in them but that isn't a concern because it will be bored .040 over. I get the block home and while disassembling it I found that it has already been bored .030 over. I measured the cylinders and they measure between 4.030 to 4.033 and I want a finished bore of 4.041. So, is .008 enough material to remove and make the cylinder true again? Should I start looking for another block?

Keith Morganstein · Post by **Keith Morganstein** » Mon Mar 10, 2008 9:24 pm

runawy9 wrote:Picked up a 350 block from a friend that was supposed to be a standard bore. The heads have been off of it for a couple years and the cylinders have some rust in them but that isn't a concern because it will be bored .040 over. I get the block home and while disassembling it I found that it has already been bored .030 over. I measured the cylinders and they measure between 4.030 to 4.033 and I want a finished bore of 4.041. So, is .008 enough material to remove and make the cylinder true again? Should I start looking for another block?

Most of the time I will just torque plate hone them the additional .010" .

You need to leave at least .005-.006 for the torque plate hone anyway.

CNC BLOCKS · Post by **CNC BLOCKS** » Mon Mar 10, 2008 10:47 pm

The cylinders true again meaning that the block has been squared and decked and bored to a true 45 and 90 degrees to the main line.

If not as Keith said just plate hone them to the size your looking for.

runawy9 · Post by **runawy9** » Mon Mar 10, 2008 11:20 pm

CNC BLOCKS wrote:The cylinders true again meaning that the block has been squared and decked and bored to a true 45 and 90 degrees to the main line.

Yes, that is what I mean. The block will also be align honed. Thanks for the input. I really value everyone's knowledge on this board.

runawy9 · Post by **runawy9** » Tue Mar 11, 2008 4:28 pm

What would be the best way to clean up the lifter bores of the light rust that is in them?

robert1 · Post by **robert1** » Tue Mar 11, 2008 4:47 pm

Take a piece of 1/4" dia rod cut a slot in it about 1" long. Cut it off about 6" long and put it in a air grinder.

machine shop tom · Post by **machine shop tom** » Tue Mar 11, 2008 4:53 pm

robert1 wrote:Take a piece of 1/4" dia rod cut a slot in it about 1" long. Cut it off about 6" long and put it in a air grinder.

I don't think you finished your thought........

I use the ball-type lifter bore hones.

tom

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boring from .030 to .040

boring from .030 to .040

Re: boring from .030 to .040