LS4 crank in LM7 block??
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Staging Lane
Joined: Apr 2015
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LS4 crank in LM7 block?? I am in the middle of a teardown of an LM7 I'm freshening up (spun rod bearing) to put into my Audi (with a couple snails hanging off of it). The audi has a small engine compartment and I'm trying to get all the space I can in the front. I'm wanting to kind of build a Longitudinal, iron block "Ls4". My question: Without taking into account the accessory drive, will an LS4 crankshaft physically fit into an LM7 block? I know its accessory drive snout is 10mm shorter than a std 3.622" crank, and the rear is 3mm shorter, But will there be any issue with using LM7 rear main and front seals?
Thank you in advance.
Thank you in advance.
Last edited by BoostForBreakfast; Apr 16, 2015 at 02:18 AM.
TECH Enthusiast
Joined: Nov 2008
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internally all but the LS7 are the same crankshaft (in dimensions) (materials/manufacturing as in cast, nodular) You will however have to match the reluctor wheel to your computer (24x or 58x)or get the aftermarket electronic adapter. As for flexplate/flywheel you will have to consider the missing difference on the tail.
Thread Starter
Staging Lane
Joined: Apr 2015
Posts: 54
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Thank you for the verification of that. I figured I might as well pick up an ls4 crank while it's apart, instead of sourcing a new standard crank which I would most likely have to shorten/modify.
And is the reluctor wheel in the same location/alignment as a longitudinal block?
And is the reluctor wheel in the same location/alignment as a longitudinal block?
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The LS4 rods are powdered metal with full floating wrist pins, they are strong but basic. There are many different rods used in the LS motors and with the exact same dimensions... so to answer, you would have to verify which "better" rods you have.
Last edited by Ill_Born_ss; Apr 17, 2015 at 07:04 AM.
