Will
Will SuperDork
5/12/14 3:43 p.m.

I just picked up my rods and pistons from the machine shop. These are stock GM parts, but after spinning some rod bearings, I had to have new rods pressed into my old pistons.

Anyway, on 4 rod/piston combos, the dot on the piston (which should face forward) faces the flatter edge of the rod (which I believe should also face forward, but I'm not positive). On the other 4, the dot faces the rounder edge of the rod.

Is this correct, or do I need to take the parts back? I know the rods have to mate to the crank a certain way, but if the rods are in the correct position and the piston dots on one bank face the rear, am I going to have a problem?

Knurled
Knurled GRM+ Memberand PowerDork
5/13/14 1:05 p.m.

Rods face a certain way because of the chamfer on the rod journal. They do not all face the same way. The LT1 rods I have sitting here suggest the round sides face each other on the same journal, since the bearings go right up to the edge on the rounded side, but check yours to be sure.

Will
Will SuperDork
5/13/14 5:28 p.m.

I ended up taking the rods & pistons back to the machine shop. He protested a bit, but all the credible, documented evidence I can find says that with factory rods, the rods all need to face the same way.

Examples:

Alldata says:

Also, p.113 of Car Tech's "How to Rebuild GM LS-Series Engines"

Knurled
Knurled GRM+ Memberand PowerDork
5/13/14 5:59 p.m.

Can't argue with the evidence of the ol' glazzies

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