How far off are the bob weights
03-08-2013, 06:55 PM
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How far off are the bob weights I am debating reusing a LS-1 eagle crank stock sroke and bore in an Ls-3 build.
I am bound by rules to have no weight advantage over the factory LS-3 crank.
Because of the larger piston bore on the LS-3 will the bob weights be off using the Eagle crank. I do need to verify the overall weights.Eagle crank Vs GM performance LS-3 crank.
I am trying to justify tearing down LS-1 engines I have to cannibalize. re using the entire bottom end The connecting rod lengths and size are the same( new pistons rings) would I have to Add to the bob weight with the bore change.
Rules made the LS-3 a better engine. The LS-1's became irrelevant with the stroke of a pen(Actually the size of a restrictor)
Regards
Tsheehan
I am bound by rules to have no weight advantage over the factory LS-3 crank.
Because of the larger piston bore on the LS-3 will the bob weights be off using the Eagle crank. I do need to verify the overall weights.Eagle crank Vs GM performance LS-3 crank.
I am trying to justify tearing down LS-1 engines I have to cannibalize. re using the entire bottom end The connecting rod lengths and size are the same( new pistons rings) would I have to Add to the bob weight with the bore change.
Rules made the LS-3 a better engine. The LS-1's became irrelevant with the stroke of a pen(Actually the size of a restrictor)
Regards
Tsheehan
03-09-2013, 06:31 AM
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More specific information. The crank(s) I have That I would like to use are Eagle 434636226100 3.622 stroke target bob weight 1800
The Gm crank is part 12584997 or 12597569
I don't have great information on the Gm target bob weight If any one can help me there.
I am pulling a stock GM ls-3 crank out to compare scale weights. should be fairly easy as the oil pan removed itself along with half of the connecting rods and a couple mains.
Either way the new engine will use Eagle rods 6.125
Part CRS612503D200 650 grams
Pistons are aftermarket Molly just going to be bigger due to the increases bore.
Regards
Tom
The Gm crank is part 12584997 or 12597569
I don't have great information on the Gm target bob weight If any one can help me there.
I am pulling a stock GM ls-3 crank out to compare scale weights. should be fairly easy as the oil pan removed itself along with half of the connecting rods and a couple mains.
Either way the new engine will use Eagle rods 6.125
Part CRS612503D200 650 grams
Pistons are aftermarket Molly just going to be bigger due to the increases bore.
Regards
Tom
03-24-2013, 06:02 AM
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The results of my findings. The stock GM lS-3 Nodular Iron crank is 51 lbs
The forged Eagle 3.622 stroke crank is 53 lbs
The bob weights on the crank out of a LS-1 going into a LS-3 with the increased bore were out some 70 grams, due to the added material on the pistons . If the crank is to be used The bob weights will have to be supplemented with heavy metal. This crank was previously balanced for an LS-1 assembly.
hope this helps the next guy.
The forged Eagle 3.622 stroke crank is 53 lbs
The bob weights on the crank out of a LS-1 going into a LS-3 with the increased bore were out some 70 grams, due to the added material on the pistons . If the crank is to be used The bob weights will have to be supplemented with heavy metal. This crank was previously balanced for an LS-1 assembly.
hope this helps the next guy.
