oil weight with 2.2 thousanths bearing clearance

[SR5]

Originally Posted By: HosteenJorje
That's diametral clearance, right? The clearance you would see using Plastigauge. Seems too much to be radial clearance.


Good point, I was talking diameter.
If the OP could confirm how the measurement was take and if it's radius or diameter, that would stop any confusion.

If it is radius. even more reason to say: Run a Thicker Oil !!
Or rebuild the engine.

 

[Yah-Tah-Hey]

If that's radial clearance, he doesn't have oil pressure and that sucker is knocking.

 

[nitrouspaul]

thanks for all the support i wasnt expecting so many replies but i shall try to address questions.
My engin has aftermarket rotating assembly all forged with replaced forged main caps and larger studs. It has aftermarket high flowing cylinder heads.

As a result of a jesel rocker break i decided to look at everything. My main bearings are 2.1 2.2 clearance using plastiguage.

I have used 20w50 in past times with good results but this seems dated by todays standards so i went with 40 weight castrol edge full synthetic this past 2 summers.

I am making in the order of 750rwhp so the crank sees about 875. I rev max to 6900.

I see bearing wipe to a slight degree, I certainly have enough pressure and volume 60 psi at 6500 rpm and enough clearance, so i am assuming the film is going away due to viscosity , lingenfelter uses some wierd oil in his engines a 15w50 or something like that, being said is it oil quality i need to address or maybe add some zzdp. or just go back to 20w50, i worry about my turbo bearings and such with such a heavy oil to push thru. I drive only in summer weather. i may try redline oils next

 

[aquariuscsm]

Originally Posted By: nitrouspaul
thanks for all the support i wasnt expecting so many replies but i shall try to address questions.
My engin has aftermarket rotating assembly all forged with replaced forged main caps and larger studs. It has aftermarket high flowing cylinder heads.

As a result of a jesel rocker break i decided to look at everything. My main bearings are 2.1 2.2 clearance using plastiguage.

I have used 20w50 in past times with good results but this seems dated by todays standards so i went with 40 weight castrol edge full synthetic this past 2 summers.

I am making in the order of 750rwhp so the crank sees about 875. I rev max to 6900.

I see bearing wipe to a slight degree, I certainly have enough pressure and volume 60 psi at 6500 rpm and enough clearance, so i am assuming the film is going away due to viscosity , lingenfelter uses some wierd oil in his engines a 15w50 or something like that, being said is it oil quality i need to address or maybe add some zzdp. or just go back to 20w50, i worry about my turbo bearings and such with such a heavy oil to push thru. I drive only in summer weather. i may try redline oils next


You said you had good results with 20W50. I'd go back to that.