oil clearances

[gotbl4d3]

Hey all i was womdering what size acl tri metal bearings i should run srd or .001 clearence i will have all forged internals including crank and will strictly be a race car could anybody give me any input on this i am shooting for 600 horsepower.... thanks

 

[white92talontsi]

.003" for the mains and the rods. More HP will require more clearance.

 

[gotbl4d3]

Okay cool what kind of wieght oil to use for break in and what kind of weight and brand would you reccomended after break in

 

[TSIfreek]

Stick with stock main and rod bearing clearances. I like to see .002 but no more than .003. You will just need the stock bearings not oversize or under unless the crank has been cut then you need overs.
Break in oil really doesnt matter as long as its standard oil. Get the cheapest 10/40 you can find as it wont be in the motor that long. As far as oil after break in run 20/50 brad penn if you can get it.

 

[My1GLaser]

This has all been answered before and will probably end up merged.

The oil you should choose is directly related to the clearances you choose. If you are running closer to stock then you need to run closer to stock weight oil. By the same logic, you need to run higher viscosity oil to match looser tolerances. It also depends on the age of your oil pump and if you have balance shafts and oil squirters still.

FWIW, my rods are .0025" and the mains are .002" I have a BSE and oil squirters and my oil pump gears were replaced but the pump housing is kind of old. I run Rotella 15w40. I tried 20w50 and my pressure was too high. I used SAE 30ND oil to break in the motor.

 

[white92talontsi]

Looser is better.

I build these engines on a daily basis and for a car 600whp and above .002" is too tight.

.0025" at a minimum with 20-50 Brad Penn.

A better question is what kind of RPM will the motor be turning?

 

[gotbl4d3]

I wanna at least run it to seven or eight thousand rpm

 

[curt-s]

Huge difference between the two.

 

[gotbl4d3]

Okay well its only gonna see the track so 85000 rpm

 

[born2tune]

Okay well its only gonna see the track so 85000 rpm

he ment 8,500 rpm

 

[gotbl4d3]

Oh ya your right woops sorry. So i know i should run a bigger oil clearence ffor my engine .002 or .003 and my balance shafs are gonna be eliminated should i keep my squitres or throw them i amrunning 8.5:1 wiesco forged pistons

 

[gotbl4d3]

Anybody have any suggestions...

 

[Bmxr152]

I have always used delo 15w40 for my break ins with good results. I always run .002 for my clearances and made 512whp with no issues. Right now I'm at 456whp on my Galant with a 180k mile short block with no issues either. I rev to 8500 rpm and boosting 30lbs on a hx40. I think stock clearances is what you want.

 

[gotbl4d3]

Alright thanks for the input i appreciate it i have another question about oil squirters should i use them or plug them off. I am running all forged internals also

 

[Bmxr152]

I would run them. Always have and had no problems. If you have the block out you can trim up and smooth out all castings. This will help with oil drainback and strength. Also a kiggy girdle is a good idea if you have the extra cash.

 

[gotbl4d3]

hey sounds great thanks for the quick reply i will .002 and keep my oil squirters thanks again