Thread: choosing bearings

Well one thing you'll find is that by using plastigage during install, is that they're all damn near exact in comparison to clearances. When building my last DET, we plastigage'd the main bearings during install and found that they were all exactly .062" IIRC? I can't recall the exact clearance measurement, but I know they were all identical. Pretty funny considering the bearing grades for all mains were actually different.

I have a slight rod nock on a VE. I will probably get new ACL race bearings.

So my question is? Should I wait to see the condition of my crank to order bearings?? Or can I just order a set and it would work just fine.

I just read this whole thread and I’m still a little lost..

From what I understand; If the Crankshaft doesn't get modified I could just go by the chart.

But If the Crankshaft does get modified then I would have to use a plastigage to find the correct ones.

So If I go the ACL, route and the crank does get modified; How will I know which bearings to buy?

Any one here who has spun a bearing and FIXED it successfully can you please shed some light!!

chirp chirp..... I hear the crickets.

After all this time I think I see where the confusion is. For the SR20DE engines the FSM says the main bearings use the block info + crank info. But for rod bearings it says to just use the crank info (and makes no mention of using the rod info even though it is there).

In the SR20VE FSM it says you should use the crank info + rod info when choosing the rod bearing grade.

I think that's where the confusion is. Andreas and Lance are using the VE info and applying it to all SR20 engines and they've had great success with that. Others may be using the DE info and applying it to all SR20 engines incorrectly. It would seem from my point of view that for whatever reason, Nissan decided to add an extra element to the proceedings when they moved to the VE engine that wasn't there in the past. I think it's pretty safe to say for DE engines you can do it either way (although I'd still recommend the FSM method based on swiss's findings). And for VE engines it's recommended you follow the more strict procedure for sure.

Edit: Okay I've made things even more confusing. I'm sorry. I was wrong. You can basically ignore this post. I mistook the wrist pin grade number in the VE FSM for a rod journal grade number. See KillerKrossover's post (#20) for what I believe to be the correct info. I never paid close enough attention to the VE FSM.

Whats weird is ive had about 12-14 SR20 engines apart ranging from DE's, VE's, DEt's and ive yet to see a rod grade other than "0" Ive always gone off just the numbers on the crank, but either way i would have been right as all the rod grades were 0 anyways. haha.

We are talking about a .006" difference in each grade. You oil clearance is supposed to be between .0004 and .0022" So if you are in the middle, having it a grade off isnt a bad thing. lol. I always try to aim for an oil clearance of about .0010-.0012.

As far as the acl discussion, ive always used the standard ACL bearings and never had oil clearances less than .010 or greater than .016.

I called ACL on this and they said when they made their Standard size SR20 bearing they used the middle grade as their guide. So again this is why their bearings have been nothing but perfect on every motor ive built. I love the ACL's as they are stronger and better oiling especially on the mains.

The .025 oversize is if you have to have your crank cut down .025 from factory specs which you will if you have a damaged crank from a spun bearing. So thats where that comes into play. You would never use that size unless machine work has been done.

Any other questions? haha

There was a lot of confusion in this thread.

Where does it say that in the SR20VE FSM? It doesn't.

Like I said earlier, the stamped number on the rod is for the small rod end bushing. It has two grades, either 0 or 1. The big end, the one we are concern with, has three grades(0,1,2) and is stamped on the crankshaft.

Rod bearing selection is the same for all the SR20 engine family.

5speed on second look I see that you are correct. I will edit my post.

Sorry I didn't pay enough attention to what you wrote in post #20. I looks like you had it all explained way back then and I stuck my nose into this when it wasn't necessary.

You need to add another 0 to your measurement otherwise you get instant rod knock.

Grade difference is .0006". Maxium oil clearance is .002".

Well now it seems really clear (at least for me) which is the "correct" way and why plenty of others have had success with other, "unofficial" methods. So I'm happy. :o

Fixed that for you