V-10 Killer

iTrader: (22)

I'm starting pre-assembly checkouts on my LS2 402 and plastigage'd the mains and rod bearings so far. I got 0.002" on all the rod bearings, I'm good with that. But I also got 0.002" on the center 3 main bearings, and a little bigger (0.0022-0.0025ish)on the front and rear mains. I've heard 0.0025" a lot on the forums for high horsepower builds, and my engine builder recommended 0.003" I used Clevite MS2199H bearings. I'm debating on sending these back and ordering the MS2199HX bearings to get another 0.001" of clearance. Is there a better way of gaining around half a ten thousandth?

Also, I'm using Weisco -20cc pistons. The widest ring gap suggested in the box (for full race application) was 0.0060 x bore (4.005")on the top ring, and 0.0063 x bore (4.005") on the second ring. That gives me 0.024" and 0.025". The recommendation for performance/mild race was more like 0.022" first and 0.023" second. The most this car really see's is test and tune a few times a year. I've seen quite a few threads using quite a bit larger gap, but has anyone had a failure at these factory recommended settings? I'm gonna start the file fitting this afternoon and just wanted to make sure they sounded right.

My goals for this motor are 800-850 rwhp with a turbo (probably 6500 rpm max), so I want to make sure I have enough room. I only have plastigage to work with so measuring in the ten thousandths is beyond what I have. Half a ten thousandth is the best I can do accurately.

Thanks for reading all this and giving feedback

Ari G

iTrader: (25)

Plastigauge is not the best method for measuring it but..

This is for Coated bearings
Iron block .003-.0035 on mains
Aluminum block .0022-.0025

Rods .0022-.0026

I would use coated bearings for your FI build as you dont know how much the crank whatever it is will flex

V-10 Killer

iTrader: (22)

Well.. I ordered a decent .0001 mic and some telescoping t-bore gauges and re-measured everything 3x per journal. Here were my averages.
Journal 1
0.0015-0.0017"
Journal 2
0.0015-0.0016"
Journal 3
0.0017-0.0018"
Journal 4
0.0018-0.0019"
Journal 5
0.0018-0.0021"

At this point, I guess I'll go ahead and order some undersized bearings and try again.
There shouldn't be any issues mixing and matching between a standard and a 0.001" undersize set should there?

I tell ya, the way this budget on this engine refresh is running away, I'll be amazed if I have anything left for turbo parts lol. Always one more $200 item in line. I'm really starting to understand the whole "throw in a junkyard motor and run it til it blows" approach.

handyandy496

iTrader: (9)

Yeah. I know the light wallet feeling too. Always something. lol.
From everything I have read on here there is no problem mixing bearings to get your specs right. I read just last week here a guy mixing undersized halves with std half bearings to get it right on the money. Ill be doing the same thing soon.

A_VAS

iTrader: (16)

you don't want undersized main bearings...your clearances are fine right now. If anything get a +001 set and use one shell from that set to give you another .0005 if you want to open them up

RezinTexas

I agree, those numbers look good for aluminum block.

KCS

iTrader: (20)

Too tight for a power adder IMO

v8pwr

iTrader: (19)

NA it would be fine but for a power adder it's too tight.

5 Liter Eater

iTrader: (5)

Ditto. Even on an iron block I'd say thats too tight for FI.

V-10 Killer

iTrader: (22)

I thought I'd already updated this but I did buy some undersized bearings and mixed the uppers from one set with the lowers from the other. Tolerances on the mains are more like 0.0023 now.