Video Description:
If you want to maximize performance when building an engine, then you need to be file-fitting your piston rings. If you are adding boost or nitrous, then absolutely MUST file fit the rings or you could have a major catastrophe down the road.
Jefferson takes you through the process of file-fitting the rings on our 2015 Gen V L83 LT-series engine we are building for boost. The engine will have two turbos, so the rings need a bit more gap than the factory.
We are using a set of Mahle’s new drop-in pistons. These are forged pistons that do not change the balance of the rotating assembly, so you can slap them onto the stock rods, strap the rods to stock crank, and you are ready to go, no machining, no balancing. And they come with some really slick 1mm compression rings.
Jefferson uses a home-made filing rig that he built after a discussion with an engineer from a ring company, and he has been using this setup for the last 15 years. It is a hand-grinding unit bolted to a 2×6 and strapped to a corded drill from Harbor Freight. It works really well and is much cheaper than the powered ring grinders you can buy online.
The rings on our L83 were gapped to .025″, which is 3.79″ (bore) x .0066″, which is a little larger than the minimum spec suggested by Mahle. The minimum for a low-boost street engine is .006, but this is the bare minumum, a little over that is not going cause any issue, and with 1mm rings, you can’t afford to have the rings ends touch.
The 1st and 2nd rings were gapped to the same spec, .025″, and the oil control rings did not need any additional gap, so we just sho the #1 cylinder ring being gapped, the rest as they say, is history. Thanks for watching!
If you left a ring on the piston it would square it self.