jmm98LS1

iTrader: (28)

Anybody know what a stock LS2 connecting rod weighs (in grams)? I've searched and searched with no success. Wondering if LS2 rods can be swapped in place of LS1 rods w/out significantly altering the bob weight, eliminating the need for balancing.

69LT1Bird

iTrader: (1)

653.17 grams

The same rod is used in all of the LS engines except the LS7 and LS9 by the way.

jmm98LS1

iTrader: (28)

So you physically weighed a LS2 rod at 653g? I've got some conflicting info here to make this confusing lol:
LS2 rods physically look like a different (beefier) "forging" than the LQ4 rods that came out of my '00 6.0 donor, which are supposedly the same as all 5.7 rods. I have read on here that LS2 rods are in fact different (stronger) than 5.7 rods, and I've read a few places that 5.7 rods weigh ~609g. Is any of that true/false?

69LT1Bird

iTrader: (1)

The part number is the same if you went to buy a new rod from GM. I got the weight from the GM parts system. I did not personally weight the rods myself.

jmm98LS1

iTrader: (28)

Weird. I'll have to post up pictures this weekend, they definitely look different.

drain89

iTrader: (13)

Then why are gen 4 rods (ls2, ls3, l92, and l76 for example) bushed, whereas ls1 and other gen 3 rods are press fit pin?
I couldn't imagine them to be the same approximate weight.

69LT1Bird

iTrader: (1)

I can double check on Monday and pull all of the part numbers. There is a breakpoint that they went from non-bushed to bushed. There is also a breakpoint when they went from nonfloating to floating pin also.

67SS509

iTrader: (25)

I would defiantly rebalance. I went out and weighed a LS1 rod and a LS2 rod. The LS2 was 35.6 grams (648.2) heavier than the LS1. 30 grams bobweight difference is typically what I see in the cranks when balancing them.

69LT1Bird

iTrader: (1)

I looked into the numbers further, here are the results:

12607475 - LS2 (w/floating pin), LS3, LS4, LS6, LQ4/LQ9 (w/floating pin), 2004-05 LS1 (w/floating pin) - 1.41 lbs (639.565 grams)

12568734 - 1997-2003 LS1, 99-04 LQ4 with fixed pin (non-bushed) 1.36 lbs (616.886 grams)

jmm98LS1

iTrader: (28)

Awesome, thank you!!!!!

NOS327

iTrader: (30)

I'm bumping this thread because I posted in another thread that referenced it.. My (cheap) scale nearly reproduces 67SS509 number for rods I pulled out of a GTO LS2. But I found some odd ball floating pin rods when I tore into a reman motor that had floating pin rods in it. A few of them were slightly different just above the parting line on the smooth side of the rod (looked the same on the dimple side of the beam) and scale out to be around 10g lighter. Compare the two rods in the pictures below.

rod out of LS2


Lighter rod from reman motor, note only 3 of the 8 in reman were like this.