Okay, it's going on 2 months now that I've been trying to find main bearings for my hybrid buildup. I pulled GM bearings that were .016mm oversize out. I had a set of standard bearings that I put in... Oil clearance was too great as measured by Plastigage. Bought the wrong oversize bearings first, had to toss them. Ordered a set of .010" mains last week. Got them today. Put them in. Crank don't turn. Yes, I did lube the bearings, both with assembly lube and then with some engine oil (not used, obviously). Crank turns just fine when I loosen the bearing caps. If I tighten just the number 3 main cap to 11 ft/lbs, as per the FSM's first step for it, the crank refuses to budge.

Where am I supposed to get the right main bearings? According to the FSM, standard, .016 and .032mm standard bearings are available. In a paragraph above that, it says that .025mm is .001", roughly. Should I wing it with another set of standard bearings (I already tossed them and the oversize ones bought previously, and have spent about $120 just on the mains so far... Luckily the standard rod bearings I had fit)? Oh, and GM wants $25 a piece for the things. Per bearing, not per set.

And yes, I know I should have put this in my other thread, but I was hoping this might get looked at this way...

 

PM "SappySE107" over at 60degreev6.com he could probably help you find the right bearings, he runs www.wot-tech.com He has alot of parts for our motors

 

king engine bearings hands down


wat was the actual clearance on the plastigauge with the std set?

 

You need to take your crank to a machine shop and have them mike your crank. Then they should be able to get you the right bearings.

 

project, I had the wrong Plastigage when I checked it (blue and not green ). The gauge was only slightly more enlarged than the widest strip on the package which indicated .004" clearance. And yes, if the new Plastigage indicates I'm within the GM spec, I'll throw down and get King bearings. I tried to get a set but the eBay seller never got back to me .

I'll get another set of standard bearings and check again. I can't stress enough that I CANNOT afford to have the crank machined any more than I can afford GM's ridiculous prices for the bearing set ($100). It's bad enough I need to have the flywheel turned (heat checked).

 

hmm i run mine loose lemme see if i can find what specs i run mine at

 

LMK on those specs... If it's going to be okay somewhat loose, I'll throw in the King bearings and call it a day.

Also, you have any tips on P&Ping the 3100 heads? They're clean now, but I'd like to do some minor work to clean up the castings.

 

loose is key to surving higher rpms, i run mine 3-4 thousands over stock specs , but i also shim my oil pumps presure relief vavles



do a gasket match and just clean up and ruff casting lines, and a lil attentin in the bowl area/shortside radius will help out a good deal , also do a brush oer of the whole port with an 80-100 grit sanding roll for a nice ruffed up finish

 

Thing is that mine's mostly going to see street duty but I want the potential for some butt-kicking. I'm sick of getting embarrassed, especially by an older Toyota with 3 people in it or a Saturn sedan with some cargo .

 

I ordered the bearings (standard) from RockAuto last night and we'll see what happens when they get here. I'll get the Plastigage when I get the bearings.