Mixing xtra clearance rod bearings question

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cawcislo

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I needed an extra 0.0005 clearance on my rods so I bought 0.001 bearings and plan to use one standard size half shell and one extra clearance half shell to get me the clearance I need.

Does it matter how I arrange this? Does each crank journal for the pair of rods have to set up the same? Example cylinders 1&2 do I have to use extra clearance top halves on both rods and standard halves on the bottom (or vice versa), or can one rod be setup one way and one rod setup the other Example one rod gets an extra clearance top half and on gets an extra clearance bottom half?

thanks.
 
Sounds like a recipe for disaster to me. Bearings need to be round once they're torqued into the rod. Having two different spec bearings on the same rod....I don't know how you would accomplish that. Would it run that way? Probably, for a while anyway, but, why not do it right and have the crank ground to the proper size for the bearings?
 
cudamark said:
Sounds like a recipe for disaster to me. Bearings need to be round once they're torqued into the rod. Having two different spec bearings on the same rod....I don't know how you would accomplish that. Would it run that way? Probably, for a while anyway, but, why not do it right and have the crank ground to the proper size for the bearings?
Click to expand...

I have never done the mixing thing , but have read about success of people doing it ----------as long as thier the same brand and mat`l
 
cudamark said:
Sounds like a recipe for disaster to me. Bearings need to be round once they're torqued into the rod. Having two different spec bearings on the same rod....I don't know how you would accomplish that. Would it run that way? Probably, for a while anyway, but, why not do it right and have the crank ground to the proper size for the bearings?
Click to expand...

It’s a brand new crank. Why grind when there’s bearings to make up the extra clearance.

High Performance Engines Bearing Clearance - Customize Those Bearing Clearance - Car Craft Magazine
 
As long as both halves of the bearings are the same, I would agree. We're talking about a tiny amount needed to gain the clearance desired. Either get one bearing set that will work, polish the crank a bit, or hone the big ends of the rods a touch.
 
Use both of the new bearings. Ur motor will never know the difference. More clearance is better than less at this point. Ur Overthinking this!!! Kim
 
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done it lots of times
I've done both ways does not seem to make any difference on rods
on mains I put the larger in the block
or what kim said
noone can grind that little off the block
except maybe the same grider on the same grinder
what oil? match to clerence
 
I have taken many bearings out of diesel engines to in frame them and found many rod bearings shimmed with a single piece of news paper under the lower rod bearing this was normal in the 70/80 for cummins and detroit engines. but not done today
 
Yeah, but those engines didn't see the revs that a gasoline engine does.
 
600 hp at 2200 rpm's 1600 lbs of torque that's a load at any speed with 30 psi of boost
 
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