Don Terrill’s Speed-Talk

will a high zinc break in oil help or impede chrome ring bedding?

bentvalves wrote: ↑Wed Apr 11, 2018 11:10 am will a high zinc break in oil help or impede chrome ring bedding?

Seeing as the zinc gets depleted sacrificially and generally only acts against microwelding and galling at more extreme temps(during true metal to metal contact situations), I really don't see how it would affect the break in procedure for any ring type. At least no mfgr that I have ever talked with directly has indicated an issue and all my motors have never had breakin seating issues when using it on various rings through the years.

With a chrome ring, the iron bore will become the weakest link there and be sacrificed until fully seated against the hatch anyways, right?

Maybe call that specific mfgr to ask them directly?

X2. A Chrome face ring is far harder then a cast iron cylinder wall which is why you need such a course crosshatch ,so there will be some crosshatch left after break in to retain oil, not to break in the ring face as most people think!

I use a 320 finish with chrome rings.

If you assemble the engine correctly, the rings will be seated in 5 minutes of run time.

thanks fellas, mucho gracias.

statsystems wrote: ↑Wed Apr 11, 2018 12:34 pm I use a 320 finish with chrome rings.

If you assemble the engine correctly, the rings will be seated in 5 minutes of run time.

Which way do you confirm that?

I always used 280 grit and assembled with just wd40 on the rings. I never had a problem getting them to seat.

What is the ring base metal? cast iron or nodular or steel?

no idea, the pistons came with the rings already installed. 1967 Mercedes Benz i-6 gas job.

they wanted piston to wall clearance set at .0009" on a 3.248" piston.

sounded ridiculous. I put it at .002" P to W.



what does the ring base material have to do with the price of tea in china?

steve316 wrote: ↑Wed Apr 11, 2018 2:15 pm I always used 280 grit and assembled with just wd40 on the rings. I never had a problem getting them to seat.

Pretty close to what I do. Finish with 320 and brush 8 strokes. Cylinder walls dry. Rings dry. Very very light coat of Torco assembly lube on the skirts and go.

That's the way I do every ring, not just chrome. Most stuff gets finished with 400 and a brush except the chrome and plain cast. They get 320.

bentvalves wrote: ↑Wed Apr 11, 2018 6:27 pm no idea, the pistons came with the rings already installed. 1967 Mercedes Benz i-6 gas job.

they wanted piston to wall clearance set at .0009" on a 3.248" piston.

sounded ridiculous. I put it at .002" P to W.



what does the ring base material have to do with the price of tea in china?

I just wanted to know...There's constant bitching from guys who build vintage British bikes because the most popular rings now have a chrome plated top ring..Supposedly they are difficult to seat...They generally use a coarse stone like 180 on a cast iron cylinder...I used chrome faced rings a few times in non performance builds and they seated quickly.. If meaning no oil smoke and blowby means seated...I think if they don't seat it's cylinder finish and or break in procedure

Chrome rings are HARD. There is only one way to 'seat' them: do lots of miles, engine run time.

statsystems wrote: ↑Wed Apr 11, 2018 6:47 pm

steve316 wrote: ↑Wed Apr 11, 2018 2:15 pm I always used 280 grit and assembled with just wd40 on the rings. I never had a problem getting them to seat.

Pretty close to what I do. Finish with 320 and brush 8 strokes. Cylinder walls dry. Rings dry. Very very light coat of Torco assembly lube on the skirts and go.

That's the way I do every ring, not just chrome. Most stuff gets finished with 400 and a brush except the chrome and plain cast. They get 320.

Ditto. A little WD40. Nicasil bores and Mazda rotary side seals as well.

Geoff2 wrote: ↑Thu Apr 12, 2018 5:52 am Chrome rings are HARD. There is only one way to 'seat' them: do lots of miles, engine run time.

That is just not my experience. If they were easier to get I'd have used them more than moly. I never liked moly rings. Never will. I also know guys who can't get moly rings to seal either.

statsystems wrote: ↑Thu Apr 12, 2018 10:45 am

Geoff2 wrote: ↑Thu Apr 12, 2018 5:52 am Chrome rings are HARD. There is only one way to 'seat' them: do lots of miles, engine run time.

That is just not my experience. If they were easier to get I'd have used them more than moly. I never liked moly rings. Never will. I also know guys who can't get moly rings to seal either.

x2.

I've never had an issue seating chrome rings, unless someone other than my guy did the machine work.

I also use Quikseat on all my engines.