please help identify these 'ls7' crankshafts
11-08-2012, 04:58 PM
#1
please help identify these 'ls7' crankshafts 
in this picture is one i just recieved from lg motorsports on the top and the one out of the engine below (not original engine but am ls7 long block part number 19181062) that race proven motors installed for the previous owner.
others here: https://plus.google.com/photos/11444...185?banner=pwa
they are very different. they are different castings, was there an early and late version?
bottom line, are they interchangable?
this **** blows. 
11-09-2012, 01:45 AM
#3
as long as they are both long snout they will both have the same size journals
u will need to re balance if u don't use the same rods and pistons so all should be good
top one may be a gmpp scat eagle replacement crank ?
the bottom one is a ls7 forgeing 4sure
u will need to re balance if u don't use the same rods and pistons so all should be good
top one may be a gmpp scat eagle replacement crank ?
the bottom one is a ls7 forgeing 4sure
11-09-2012, 07:27 AM
#4
the reason i bought it was to do a direct swap of my (damaged) ls7 crank.
don't want to do a rebalance, or a complete teardown of the engine.
only one crank has the qr code and part number on it
hopefully i get an explanation from lg on it today. at a bare minimum its not what i understood i was buying.
don't want to do a rebalance, or a complete teardown of the engine.
only one crank has the qr code and part number on it
hopefully i get an explanation from lg on it today. at a bare minimum its not what i understood i was buying.
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11-12-2012, 01:07 PM
#9
09 on the top, 06 on the bottom
09 on the left, 06 on the right
09 on the right, 06 on the left
09 crank weight- 57.65
06 crank weight 56.40
The difference must have been 08? Pistons and rods appear to be identical. I have not checked bob weight, doubt I will.
So, In summary, 06 crank is what I sent david. 09 crank weighs more, and has some subtle changes to the counterweights, rods and pistons are the same, appearance wise, between all years.
FWIW, norton manufacturing is who makes the stock GM LS7 crank. They were acquired by SMI cranks/ Sumitomo in 08.... This could explain some differences in manufacturing.
http://www.smicrankshaft.com/CompanyProfile.aspx
09 on the left, 06 on the right
09 on the right, 06 on the left
09 crank weight- 57.65
06 crank weight 56.40
The difference must have been 08? Pistons and rods appear to be identical. I have not checked bob weight, doubt I will.
So, In summary, 06 crank is what I sent david. 09 crank weighs more, and has some subtle changes to the counterweights, rods and pistons are the same, appearance wise, between all years.
FWIW, norton manufacturing is who makes the stock GM LS7 crank. They were acquired by SMI cranks/ Sumitomo in 08.... This could explain some differences in manufacturing.
http://www.smicrankshaft.com/CompanyProfile.aspx
11-12-2012, 01:10 PM
#10
thanks for your investigation louis!
to avoid a bunch more potentially unnecessary shipping. i'll just take this unit to the machine shop and see how it balances compared to my prev. unit.
if they are cool with it, then so am i.
to avoid a bunch more potentially unnecessary shipping. i'll just take this unit to the machine shop and see how it balances compared to my prev. unit.
if they are cool with it, then so am i.
11-16-2012, 08:38 AM
#12
Louis, I will be using the crank, its an ls7 crank, just like i asked for, just like you claimed.. happend to be an older one... machine shop said it balanced out nicer than the one out of it.. so I thank you for that and thanks for clearing up the discrepancy.
