racerage7

Im building a new short block for my 2002 Harley F-150 and need to know what the ring gap should be for all the rings,especially the two bottom oil control rings.Im using Mahle 20 over bore pistons.Everyone I have talked to has giving me defferent measurements.And I havent been able to contact Mahle. Thanks for any help!!

Dbl G

You should contact the manufacture them self's, ring gaps can be funky.......

http://www.carcraft.com/techarticles...ng_technology/

http://www.circletrack.com/howto/463..._piston_rings/

http://www.jepistons.com/dept/tech/d...instrc4032.pdf

http://www.aa1car.com/library/ring_end_gap.htm

Harley#356

i'll try to talk to Spanky and see what we set mine at. he's built a few motors, stock bore & 0.020 over. just get ya some more #'s to go with all the others you got haha

Dbl G

It really depends on the rings them selfs and the piston verses the bore size. Approximations from others set ups are not really advised.

racerage7

Man thanks alot guys for the quick info and support. I am new to your forum and have posted the same question on several other ones with no response in a week. I realize that the correct gap is dependent on the application and what piston manufacture I am using recommends.I am trying to see what ballpark it needs to be in. Once again thanks for the quick response and effort.

Harley#356

hey, sorry it took so long. just finally saw my buddy online who helped me build my motor last winter.

we set the 1st & 2nd ring gap at 0.025, & oil control rings to a minimum of 0.015 but we didnt touch those (& the middle wavy expander ring was not touched). was kind of surprising because i had stock bore, stock pistons, and original rings all from the same motor (3K miles) and every single 1st and 2nd ring gap was way too tight. every one had to be ground down at least a few thousands. The ONLY 1st or 2nd ring that was in spec for 0.025 was the #8 cylinder 2nd ring because the stupid ring compressor tool snapped the end off the ring, and we had to rip my old motor apart to salvage a ring off my 40K mile N/A motor and that was the only one that didnt need to be ground down at all lol

anyway, just some #'s to give you a reference point

racerage7

Hey thanks Harley#356 for the info. I finally got in touch with Mahle also and they verified the gap for there pistons and my application.

Dbl G

BIngo, good advice,, But the best is check the manufacture ......