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needle bearings

 
redneckjoe69
Everything in my driveway’s a Chevy
Posts: 612
Joined: 02/10
Posted: 03/09/10 03:03 AM

does anyone know if its possible to instal needle bearings on the big end of the connecting rod/crank? i know they are in use on racing aplications like cam bearings, but how would you put them on the crank? wouldnt this free up the h.p. & r.p.m. potential? any thoughts would be appreciated.  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 03/09/10 05:27 PM

how are you going to assemble the crank without splitting the bearing races...

harley and others have a 3 piece crank..   the rod journal is pressed in with the rod already hung...

i don't know how other 2 stroke motors do it..

we can always ask the 912 porsche techs...   i ran across my 911/912 repair manual just today..


i am not saying its impossible..


there is also the problem of the amount of power applied to the reduced surface area of the rollers or needle bearings.. and having it dent the races..  any torsion winding the crank up and exerting  twisting force on the mains will wipe out the mains..

there is one thing..  they might actually be in formula one motors..



edit...

just had a flash of brilliance..

it is possible...  but ....

custom block and cranks would be needed.. as least to do a needle or roller bearing main....

Giant main bores...   giant main journals..

it actually.. it could be possible to run them....    CNC machined cranks.. with the main journals undercut..  

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55Guy
Administrator
Posts: 1153
Joined: 07/06
Posted: 03/10/10 06:47 AM

NASCAR engine builders messed around with that years ago, and it's still used in some racing engines.

For a street engine, doing this is pointless. A street engine doesn't turn the RPMs (or hold them) like a hard core race engine does where installing roller bearings on the crank bearings will do any good.

For the street, a good set of coated rod bearings will be just fine.  

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gettnlarge01
Everything in my driveway’s a Chevy
Posts: 545
Joined: 01/10
Posted: 03/10/10 05:45 PM

lot of money gone fast  
luck is when skill and opportunity meet

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redneckjoe69
Everything in my driveway’s a Chevy
Posts: 612
Joined: 02/10
Posted: 03/10/10 11:52 PM

thanx for the info.i guess youd have to split the crank at every journal, like a motorcycle. and how strong would that be on a v-8? did i hear something about ceramic bearings being used now? is this the "NEW THING"? call me dumb, but i cant figure out why a motorcycle can easily run up to 16,000 rpm, but a car motor on the street rarely goes over7,500rpm. i know some would say the cam is the limiting factor, or valve springs. so what is so different?  

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bdvdw
I love my Chevy Chevette!
Posts: 7
Joined: 01/10
Posted: 03/11/10 04:20 PM

weight of rotating assembly, and engine life span. of a motorcycle are way different.
but you do make a point concerning valvesprings on a bike unless it's a2cycle in which case the point is mute.  

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gettnlarge01
Everything in my driveway’s a Chevy
Posts: 545
Joined: 01/10
Posted: 03/12/10 03:07 AM

+1 bd,the weight of a V8 rotating assembly is massive compared to that of a motorcycle  
luck is when skill and opportunity meet

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redneckjoe69
Everything in my driveway’s a Chevy
Posts: 612
Joined: 02/10
Posted: 03/13/10 01:31 AM

makes sense.thanx.  

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skpbearings
I love my Chevy Chevette!
Posts: 1
Joined: 10/17
Posted: 10/12/17 12:53 AM

The crankshaft, connecting http://rollers.skpbearings.com/needle-roller.php are boosting large in every engine build, whether mild or wild, because they disciple the reciprocating motion of the pistons into rotational torque. The longer the stroke, the greater the leverage effect and the greater the torque output of the engine. There are three things that need to be considered when replacing a crank, rods and bearings.

1)  Strength
2)  Bearing clearance
3)  Balance  

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