Hi guys,

Today I was measuring the main bearing clearances with plastigauge on my new LT1 shortblock.

Specs:
357 cid Eagle Competition Rotating Assembly

* Eagle 4340 Non-Twist Forged Steel Crankshaft (3.500" Stroke - 1pc Seal)
* Eagle 3-D 4340 Forged Steel H Beam Connecting Rods (5.700" Bushed)
* SRP forged aluminum -5cc Flat Top pistons,& piston pins (4.030" Bore)
* Premium plasma moly file fit piston ring set
* Clevite 77 Race H Series Rod and Main Bearings - MS909H & CB663H
* Fully internally balanced rotating assembly

The problem is, I don't like what i see after squishing down the plasti things. (picture below). It has an oval shape on all journals, and I bet it's not supposed to look like that What could be the problem?

Anyway, measuring at the widest point, it says I have the following main clearances:
#1 - .0018
#2 - .0015
#3 - .0015
#4 - .0015
#5 - .0025

For my preference it's pretty tight, I would shoot for 2.5 thou on 1-4 and 3.5 on the rear. (357 LT1 - LE2 heads - 200 shot)

What do you 'old boys' shoot for?

 

Okay, don't want to be toooooooo........ much of a "stickler" for details here, (and I assume you already know you've misspoken in your post here), but the 25 "thou" you're referring to is not 25 thousandths of and inch but rather 25 ten-thousandths of and inch or, two and a half "thou".

It always worries me when people take a measurement and miss it by ten times what it truly is.

Oh, and yes those main bearing spacings look "about" right for an engine set up to run 5w20/5w30 oil.

 

97 6SPEED Z: Yes, thanks for clearing up, I meant 2.5 thousands, iow .0025"

Just corrected the original post.