How do you spot a block with oversize lifters
#1
How do you spot a block with oversize lifters
Saw this in a FAQ on olds blocks.
Anyone know exactly where to look for the dreaded "O"?
Is it on each of the lifter bore bosses? Just one?
I'm about to buy a 455 to rebuild and seller has provided nice pics.
Would also like your comments on what you see. This will be my first rebuild.
The motor apparently spun a rod bearing (crank section shown in pic 1056)
[Copy from Olds Blocks FAQ;
With any block, watch out for the 'O' stamp on the lifter bore boss,
indicating a 0.010" oversize lifter. Either Oldsmobile would only have stock
0.010" over replacements or THERE ARE NONE AVAILABLE. Which means you either
get to sleeve the lifter bore (difficult and expen$ive), or scrap the block,
or, re-use that old lifter. Resleeving the lifter bore is not fun.
[ Thanks to Chris Witt for this information ][/B]
Rootney
Anyone know exactly where to look for the dreaded "O"?
Is it on each of the lifter bore bosses? Just one?
I'm about to buy a 455 to rebuild and seller has provided nice pics.
Would also like your comments on what you see. This will be my first rebuild.
The motor apparently spun a rod bearing (crank section shown in pic 1056)
[Copy from Olds Blocks FAQ;
With any block, watch out for the 'O' stamp on the lifter bore boss,
indicating a 0.010" oversize lifter. Either Oldsmobile would only have stock
0.010" over replacements or THERE ARE NONE AVAILABLE. Which means you either
get to sleeve the lifter bore (difficult and expen$ive), or scrap the block,
or, re-use that old lifter. Resleeving the lifter bore is not fun.
[ Thanks to Chris Witt for this information ][/B]
Rootney
#3
I ran into this on a 79 HO 350 motor and there were no markings anywhere on the block. It was only discovered by measuring the lifter bores. Aside from installing a sleeve in the oversized lifter bore to bring it back to a std size, Mondello will make a lifter that will work in that .010 oversize bore. It's based on a Ford lifter and it will require a different length pushrod which Mondello also provided. I think the custom lifter and pushrod was around $100 which isn't cheap but it was cheaper the what the machine shop wanted to sleeve that lifter bore. It's worked fine for a number of years now.
#5
I'm guessing its pretty rare for an oversized lifter, I have been involved with probably 25-30 Olds engine builds over the years (and who knows how many blocks I have scrapped) and have never seen a oversized lifter bore.
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