Re: piston rings?
 

I've been a lot of places in 44 years for engines. He's absolutely the best cylinder wall guy in the world. Absolutely. And his valve jobs are tremendous. We had one engine pick up 0.11 after another builders valve job. Now that is not normal but on the average friends and myself pick up .03 over anybody else's valve job.

Re: piston rings?
 

That's what I do. Patterson hones my blocks with his Rottler diamond hone. I've used 4 1/5 lb rings, but not as dry as 6.

Re: piston rings?
 

They're also very good. I use their piston work, but never had a block by them.

Re: piston rings?
 

They did all my short block machine work, and sold me all the parts except the camshaft. Gordon Holloway at Comp works with me there.

Re: piston rings?
 

About 6# tangential is what I have successfully run and had no oiling. with a Total Seal Napier cut second ring.

With 3/16" rings, my usual approach is to buy open stock Speed Pro SS50U oil rings, and use bore size rails with smaller bore size expanders.

Unfortunately, Speed Pro has been bought several times over the last decade or so. They've become less and less oriented toward customer service and open stock sales, also, I've been told that as the SS50U tooling wears out, they're not going to repair or replace it. In my experience, the Speed Pro SS50U oil ring is the finest in design and quality, as well as the most friendly to the machinist, builder, and assembler.

The expander in the SS50U is what controls ring tension, and the radial width of the rail is consistent and stable, as well as easy to assemble. Not so with the Hastings/Perfect Circle oil ring with the gold expander. In near 40 years of doing this, I've never had a problem, or a customer with a problem with the SS50U. Not true at all with the Hasting/Perfect Circle.

As far as testing tension goes, my method is similar to many others. I oil the cylinder with the oil to be used when the engine is being raced, carefully wiping it until it is wet, but not completely slathered in oil. I install the piston with the oil ring only into the bore, with a pin in the piston, and the pin connected to a 0-12# scale. I then roll the engine inverted, and pull the piston from the deck toward the crankcase, and record the drag.

Re: piston rings?
 

Carl where do you find low tension 1mm 1mm 2mm rings Mahle only makes std. tension rings in 1mm 1mm 2mm thanks John

Re: piston rings?
 

As far as I'm concerned, along with some of the factors already mentioned - piston skirt design, piston oil groove drain back design, oil kinematic viscosity at your operating oil temp, rod bearing clearance, isolated cam tunnel or not - can also impact the minimum oil ring tension or drag required for acceptable oil control.

I use the Hastings flex vent style oil ring in all cases where it is available. I pull the piston/pin assembly with WD-40 and a fish scale I've had for years, and have a backlog of data with. As far as adjusting tension, I'll get smaller or larger bore expanders and adjust as necessary. If I can't get the tension down to where I want, I'll install each oil ring expander with excessively gapped oil rails on an undersized piston, and use a band style ring compressor to squeeze some tension and circumference out of the expander. If I need more tension, I'll stand the expander upright on a flat surface, and press an ever so slightly larger drill bit in between each lug of the expander to increase it's circumference and tension.

Also, each lb. of oil ring tension removed per set is worth ~ 1 lb. of torque at the flywheel.

Re: piston rings?
 

You keep the correct rails for the bore, and expander for a smaller bore size. Expanders from a .030" smaller bore is usually pretty safe.

Re: piston rings?
 

I never measure the drag with a fish scale LOL. Compared to a standard tension Speed Pro set I can push the the piston in with two fingers

I don't know what they base there standard tension but its a lot different tension then every one else.

You have to remember the top and second are on 1 MM and the radial depth is not much so it makes the drag a lot less then a 1/16/ 1/16/ 3/16 ring pack.

Mahle has just come out with them in the last 6 months and only have used a maybe 7 or 8 sets they seem to work fine so far.