Generation IV Internal Engine - Stock LS2 rod weight




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jmm98LS1
09-26-2008, 01:08 PM
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
09-26-2008, 01:23 PM
653.17 grams

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

jmm98LS1
09-26-2008, 03:23 PM
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
09-26-2008, 04:00 PM
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
09-26-2008, 04:48 PM
Weird. I'll have to post up pictures this weekend, they definitely look different.

drain89
09-27-2008, 04:43 AM
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
09-27-2008, 08:12 AM
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
09-27-2008, 10:11 AM
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
09-29-2008, 07:54 AM
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
09-29-2008, 12:34 PM
Awesome, thank you!!!!!:)