sr20det oil clearances

[4x4le]

Ok so Andy (AutoVaughn Performance) has built several ka, sr, rb, and ca's and has always used good undamaged cranks, and matched bearings with the codes on the block and crank using nissan bearings or used standard sets from acl or clevite. When using arp main studs we have the machine shop line hone and check clearances to ensure that were within spec using a standard set.

Anyways with this build of mine were using a stroker crank and arp main studs.

Main clearances taken with standard clevites are as follows: (front to rear)
.0013 .0014 .0014 .0014 .0016 (inches)

It fine to me that the rear is a little looser, I know people sometimes intentionally do this.

My question regarding this is what do you guys run clearance wise. ALL of the engines Andy has built see much more street duty than track and mine is an exception to this. It gets tailored to the track and back home. The car makes it out for meets rarely, and sometimes on nice cool nights (when I dont mind not having ac) if I notice people have their go fast toys out in town Ill go home and get it and bring it out. Very rare.
So Im really thinking I should maybe loosen it up some. Im not looking into turning the crank down any, but Im also thinking that the acl's with the extra .001 would be too loose. Someone suggested to me to run half of a std acl and half of a .001 in each cap and that would be like running a .0005 in each cap but that sounds haggard to me.

If someone knew the thickness of a std clevite (I dont have an accurate way of measuring this) I could possibly pick an oem bearing that could give me a desired result using this chart.
http://i272.photobucket.com/albums/jj194/sr20det_motor_build/bearingcode5.jpg


What are you guys' $0.02

edit: And I have searched. I actually have 7 tabs that have been open for about 2 days and they pretty much all contradict each other, possibly because some are n/a sr's, and some guys obviously have some math problems or talk about how they check it with "plastic gauge", and I would rather have a conversation about my particular engine.

Im going to rev between 7800 and 8k and make 400 or more tq and ~400 hp (dyno dynamics numbers) estimated.

[Def]

Mixing a std and +0.001" bearing shell is common practice.

Your clearances sound fine to me, being about in the middle of the FSM range. For a pure track car I think closer to 0.0016-0.0020" would be more in the range I'd target.

Your current clearances are in the FSM range, so I'm betting they'd be fine. Just don't run something like a 15W-50 or anything like that.

[smelly240]

You're doing it right ;)

It is safe to do - we have 2 8sec B-series hondas and a 9 sec honda that all have the one half a extra clearance - and one std half. My SR's are both this way also.

[4x4le]

^^ That is what was told to me about mixing shells. I guess its so subtle that it works but I was picturing a step and tight on bottom and loose on top. Im guessing that isnt actually the case but possibly you could see where I would think this.

The oil I ran on my last engine (and loved) was rotella t 5w40 synthetic. My engine after 3.5 years looked great, no wear on any bearings aside from the one that spun when the s13 oil pickup broke. The cyl bore looked excellent, it honestly still looked how it did when it came back from the machine shop before it was assembled the first time. I was hoping to run it again if the oil temp and pressure gauges agree with it.
I am going to run a cooler on this setup too.


I guess I can just buy 2 sets of bearings and after a couple of years just tear it down and inspect everything and rebuild it.


I dont claim to be an engine builder, Im actually stupid when it comes to that (but andy is pretty sharp about it although all out race engines are not his forte), so here is a noob question:
Does it matter if the std or oversized goes on the upper half or lower? Im assuming not and if it actually gives me .0005 then it would be perfect really

[smelly240]

just as long as you do all of them the same - it shouldnt matter...

We order a set of each - and it seems to work out that they're proper for the next one (or next time for that one).

unfortunately sometimes you get stuck with a full set of one or the other - those either go back or get stuck in the case to sell em.

[4x4le]

well cool. I guess now Im just going to have to wait till tuesday and see if one of my dealers have these both in stock, or at least hope they are not back ordered.

Would you recommend std on rods or going halfseys on them too? I have an untouched set of clevites but im in no way trying to be cheap when dealing with my darton block, k1 stroker kit, and custom 90mm 10:1 weiscos

[smelly240]

I would measure the clearance with those clevites before you order new stuff.

Our distributor usually has B, H, SR, KA, and all the different subaru bearings in stock - the ACL H's and HX's anyways.

[4x4le]

send me a pm of your dist if you dont mind as I may need to go to them as I want to get them asap. I want to get the engine together, clutch broken in, and tuned before an event in october which the proceeds are going to breast cancer. I dont have weeks to wait on bearings lol. I had to wait months for all of my other parts and work