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Discussion Starter · #1 ·
I secured a 6.2 LS engine for a project. 68K miles. Look at these babies - they look like new, no scratches what so ever. Now the L29 Junkyard special, new lifters with only 2hrs of run time on an engine stand, and I can see scratches already like I always do (valve covers off and I can see into the lifter valley) on these BBC's. Something tells me these BBC's may not really like roller lifters.

68K mile 6.2 LS motor out of Denali:

710842
 

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And no reason to think any special motor was used..............
 

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1968 Malibu sport coupe, 489 ci. 590 hp 600 tq, RV T-400 Freakshow 3200 stall, 3.73 12 bolt posi
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Maybe the thinner oil viscosity used in newer motors gets in tight clearances better, not brand but viscosity?
 

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How clean was the oil? It seems like that as long as the lifters are separated from the bores by a thin film of oil, they wouldn't make contact and wouldn't scuff. Any small vertical scratches would have probably come from tiny debris between the lifter and bore. Considering the angle of the pushrods in a big block with canted valves, I would expect there to be more than on any smallblock with straight valves and a vertical path.
 

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Discussion Starter · #6 ·
In all fairness this is with a stock low-lift cam, new bores, lower springs pressure. Problem as I see it with BBC's is that a higher lift cam lobe (especially) is actually trying to push the lifter sideways. Combine that with high spring pressures that don't want to let the lifter move w/o a real good push, the lifter is getting pushed into the side of the bore. And then you have canted valves, ill-sized bores, lobe design. Amazing these engines even run lol!!!!!
 

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In all fairness this is with a stock low-lift cam, new bores, lower springs pressure. Problem as I see it with BBC's is that a higher lift cam lobe (especially) is actually trying to push the lifter sideways. Combine that with high spring pressures that don't want to let the lifter move w/o a real good push, the lifter is getting pushed into the side of the bore. And then you have canted valves, ill-sized bores, lobe design. Amazing these engines even run lol!!!!!
And, many times they don't run...🤦🏻‍♂️
 

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Discussion Starter · #8 ·
And, many times they don't run...🤦🏻‍♂️
Speaking of lifters and/or not running....what's up with PIA? Haven't heard from you in a while.
 

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Speaking of lifters and/or not running....what's up with PIA? Haven't heard from you in a while.
Well, I will reluctantly say (because of jinx) that PIMA lasted through the winter. It started right up this spring, and the lifters are off/on noisy. My clutch leg has a new knee joint, so I haven't been driving it much.
 

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I love LS engines. No worries. GM fixed everything that was wrong on the old engines.

I do miss the simplicity of an old school engine though
 

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i just took put some .903 hyd roller lifters out of my mk 1V bbc after about 5k they looked like new no scratches but I had the lifter bores bored for tight clearance and indexed the old block were never meant to have the longer roller lifters plus the bores were usually not perfectly indexed im sure its true roller lifters in stock blocks lifter bores are not ar right angles alot of the time
 
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In all fairness this is with a stock low-lift cam, new bores, lower springs pressure. Problem as I see it with BBC's is that a higher lift cam lobe (especially) is actually trying to push the lifter sideways. Combine that with high spring pressures that don't want to let the lifter move w/o a real good push, the lifter is getting pushed into the side of the bore. And then you have canted valves, ill-sized bores, lobe design. Amazing these engines even run lol!!!!!
They run/ ran a hundred thousand miles out of the 60's box
 

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Discussion Starter · #13 ·
i just took put some .903 hyd roller lifters out of my mk 1V bbc after about 5k they looked like new no scratches but I had the lifter bores bored for tight clearance and indexed the old block were never meant to have the longer roller lifters plus the bores were usually not perfectly indexed im sure its true roller lifters in stock blocks lifter bores are not ar right angles alot of the time
That's def the way to do things but let's be honest, not many shops are capable of this. Last shop I used couldn't even get the installed height right with the valve springs.

When you really think about it, it seems like these BBC roller lifter wheels are "behind" the lobe more so than the flat tappets, and hence being pushed more into the bore before finally lifting up.
 
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