Engine Tech: Surface Finish After Break-In (Expo 2024 - Episode 37)

In this episode we look at how much surface finish changes between a freshly honed block and after its first break-in run.
Lake Speed Jr heads over to PME Engines where they’ve got one of Lake’s dad’s (Lake Speed Sr) Ford C3 NASCAR blocks freshly honed and ready for assembly.
With a focus on the Rpk (peak) values, Lake takes us through measuring the surface finish in the un-assembled block, again after assembly, and finally after a 30-minute dyno run.
He also provides some insight on what you should be looking for in the best surface finish - one that helps ensure there’s the right amount of oil in the right place at the right time - to ensure optimal engine operations and longevity.
(Segment originally aired live on January 12, 2024)
#clyindersurfacefinish #cylinderhone #surfaceroughness #enginebuilder #machineshop #cylinder #lubrication #performanceengine ‪@themotoroilgeek‬

[@tomstrum6259]

Very interesting test there....What useful effect does cylinder wall Rpk do for Plasma-Moly ring Break-in other than Needless new ring wear (Rpk causing Vertical micro-groove streaking to rings) ?? ...Should cylinders be More plateau Honed to knock off more Rpk to reduce excessive Moly ring Break-in wear ? .....What about more Manual (or machine assisted) crank Rotations with cheap temporary Iron rings to more Pre-finish the cylinder wall Rpk Before final assembly with the Plasma-Moly ring set ?? .....Thx for sharing info.

[@themotoroilgeek]

You are thinking correctly. For plasma moly rings, less Rpk is better.

[@Hjfvvdst]

That's great information. Piston skirt coatings. Does the coating effect the cylinder finish? Does it fill the valleys?

[@kevinwest3689]

My Question is, At what power level is torplate holding necessary. Ive seen the Measurements from a good Machinist. He addressed the different thicknesses of the Cylinder from sides. He absolutely recommends it for something like an fe ford With threads at the top. But say, If you're not building something for Nascar/ 3-4 Thousand hp. Its money that could be spent somewhere else. What do you say?

[@andrewleonard9257]

With all that material coming off just from turning the engine over, is there a case for making the plateau hone smoother? Also, would the removed material be captured by the oil filter during break-in, or is it too fine?

[@EnginePerformanceExpo]

There is a risk of the rings not breaking-in properly if the plateau was too smooth. The small amount of material will be captured by the filter.

[@andrewleonard9257]

@@EnginePerformanceExpo Thanks

[@rollandsicard1628]

This is Incomplete. Put it together, heat up oil and water, completely assemble, run-in under load, then shutdown and turn over, check compression record, leak check record. See if truly broken in. Then use profileometer and record. Publish results. Then you have something.

[@TennTitans]

Who assembles their motor bone dry. I’ve always coated the cylinders in oil and the rings liberally then put it in the hole. Always wet the tip before you stick.