Bearings or Bearings

[EVOCPE]

Ive noticed ARP having 2 different types of race bearings, what i wanna know is whats with the extra oil clearances?? whats the cons/pro

http://www.aclperformance.com.au/Mitsubishi4G634G64Bearings.htm

CONROD

4B1185H - http://catalog.acl.c...P1023&p=IT43037
O/S: STD, .025, .25

4B1185HX - http://catalog.acl.c...P1023&p=IT43037
0.001" extra oil clearance on STD journal.
O/S: STD


MAIN

5M1186H - http://catalog.acl.c...=TP18&p=IT43037
O/S: STD, .025, .25

5M1186HX - http://catalog.acl.c...=TP18&p=IT43037
0.001" extra oil clearance on STD journal.
O/S: STD

 

[4piknup]

I was thinking about this just the otherday and wanted to give it some more thought before I mentioned it.

I was thinking about the guys who had roller turbos, balance shaft delete, no oil squirters, and maybe like the kiggly head restrictor.
Lots of these guys have what seems to be high oil pressure and judging by the oil bypass mods, they have a high volume as well.
I thought it was a shame to waste that oil and what if we run the mains clearance a bit looser in order to direct more oil flow that way.

What they do is give you a fatter oil wedge for the crank and big ends to ride in, offering better bearing protection
The advantages would be better bearing protection, resulting in more higher rpm limit, more power safer. May be able to run a thinner weight of oil as well.
Disadvantages of more crank windage losses. And you are building a engine that is partly worn out. Even lower oil pressure at idle when hot

Would you need them? a history of oil samples that shows bearing material, premature crank bearing wear, and excessive high oil pressure would lean me towards them.

My 5c

 

[BMGTZ]

these could be handy...some of the "new " cranks" Ive had recently have been a tad on the fat side. this has resulted in a tighter clearance than i would like. when you take the crank down for a polish you get told the polishing wont remove any metal...=bullshit it does but you can end up with uneven sizes after. some being loose...some being tight.

 

[DOUGMO]

there is other trains of thought in that a larger clearance will actually push the oil away from the bearings more due to the crank moving inside the bearings more.
looser will cause less drag and possibly more power though, mine are very tight as I want it to hold together a little longer

 

[EVOCPE]

Whats the OEM bearing thickness's? lol

 

[EVOCPE]

And does anyone know anything about Kings performance bearings??

http://www.kingbearings.com/performance.php

Mains are 3/4 grooved for improved oiling to the rod journals

 

[khubner1]

im using kings in my gsr. they're doing the job(but in all honesty i couldn't tell you if there was any difference

 

[EVOCPE]

Kings or Kings Performance??

 

[CYBORG-X]

the extra clearance is for cooling. larger tolerences have more oil thus more cooling, but require alot mor eoil pressure to compensate.

 

[BMGTZ]

I use the basic kings

 

[EVOCPE]

OK so i should stick to the normal size, not xtra clearance

 

[khubner1]

just normal kings

 

[EVOCPE]

Nah just bought some ACL Race Series, cheers

 

[DOUGMO]

whats your bearing clearance going to be?

 

[EVOCPE]

Will find out as soon as the plasti guage and bearings come