Rb26/30

[jas/slo32]

Just after some advice on main/conrod bearing clearance after my new engine spun a bearing

Engine will be for race use only

Any replies or pm's would be appreciated

Thanks Jason

[r33_racer]

2.5/2.5 thou

But we run a thicker oil also, a 20-50 non detergent.

[jas/slo32]

2.5/2.5 thou

But we run a thicker oil also, a 20-50 non detergent.

Thanks for your reply clearances seem on par with a few other reliable sources.

[r33_racer]

what sort of crush? you could spin if there is insufficient crush? lol i guess the same goes for too much as well.

was it a main or big end that spun? If you dont mind me asking....can pm.

[jas/slo32]

pm sent

[DRIFTER]

i run 2.5

[T04GTR]

ive had great success with 2 on mains and 1.8 on bigends with 4 thrust , using a 15w40 or 10w60 with a jun pump hot max oil pressure is 7-7.5 bar by 4500

[r33_racer]

Not entirely ontopic....

Does anyone know what conrod side clearance they run? I think factory spec is 8 - 12 thou with limit at 16 thou.

[r33_racer]

Nobody knows or wants to share?

I have a feeling this can be quite critical on inline 6 motors, as the crank flexs, with too little side clearance, it can grab or nick bearings on the outer edges.

The last motor we put together, we had 10 thou side clearance.

[Craved]

Bringing this back as there is no point making a new thread

just dummied up a block with 2 different cranks

clearances on both cranks start at 2thou rear and work up to 5thou at the front.

Any ideas what might cause this issue?

cheers

[Craved]

NEVERMIND lol

we were using the wrong girdle, swapped that over and got 3 thou all along lol

maybe help someone else along the line somewhere

[BoostdR]

use the RB26 main bearings on the RB30 as they are 20mm wide apposed to 19mm.. also have the extra oil holes.

Matt

[bubba]

use the RB26 main bearings on the RB30 as they are 20mm wide apposed to 19mm.. also have the extra oil holes.

Matt

I guess that doesn't apply to bearing that is also the thrust washer?

[BoostdR]

It does, just has to be clearanced

[r33_racer]

Yeh we used to groove the block and fit gtr mains. However I was not aware they were a fraction wider then std rb30 mains.