i have a 2000 ls1 block. stock deck height and stock bore. i found a set of je pistons and eagle h beam rods and was told they were out of a ls1 motor. i had them checked and the pistons were right to the bore but the rods measure 6.125. yet the stock rod length is 6.100. stock shows a .008 (above deck) piston height.

is there a issue with valve clearance with the longer rod? or is it taken care of with the valve reliefs and or piston pin placement?

my only problem is the pistons are early versions and have no part #s to give me specs. and i don't want to pay 75 bucks to have je reverse engineer them.

any help would be appreciated. thxs

 

you need to know the "compression height" of the piston. This is the dimension from the center-line of the wrist pin to the top surface of the piston. You can measure this with a $20 digital caliper, then add the radius of the wrist pin. Does that make sense?

Then just confirm that the total rotating assembly height matches to the OEM setup. Here is a figure:

 

No because usually that is made up in the piston compression height, so a longer rod will mean a shorter piston.

In the end, both rod/piston combination will have just about the same length.

 

thxs for the info. will have the machine shop check the measurements.