2v oil scraper ring tension?

I've not seen that on rebuilds typically, but did have a build 8-10yrs ago, JE pistons and their rings that was a nightmare on blowby. Ended up switching them out to total seal, helped but the pistons ended up being replaced as well as CR was not correct. No more problem. I don't have a problem per say with JE pistons but we don't use them. Custom from Carrillo, CPS, RP, etc..

I've done a few total seal gapless builds and you do notice the increased friction before it's run. But it's not been a running problem.
Could be their ring supplier/mfg. Everybody has their preference of course. I've had no issues with total seal.

 

Maybe it's the liners

 

I had no idea these cars burn a quart of oil every 400-600 miles! After reading another thread of misfire I'm wondering how the poor spark plugs function at all with that much oil running through them.

 

I wouldn't use JE pistons for free. Junk. There are too many good pistons around to get stuck with crap. Wossner has off the shelf 308 2v pistons in your choice of size and compression. Wossner is the supplier GTO Engineering uses. Good product. Building a 330 right now with Wisecos. Have Wisecos in my 3.5 liter 328.
There are 2 brands of rings I'll use. Mahle and Nippon. Lots of custom pistons come with Nippon. Wiseco does, a set of custom Italian pistons Scott supplied me came with Nippon rings. Zero issues ever.

 

Thats a lot less than from the factory. We had customers with 80-82 308s bought brand new who could not go a full tank of gas without having oil pressure problems from lack of oil. Factory paid for a lot of engine rebuilds.

 

If the client ever needs to use the dipstick I have failed in my job. Boxers will always use a little oil. All flat motors do. No excuse for a Daytona to use any degree of oil. We are no longer using Victorian era technology.

When Ferrari built the 80-82 308 they burned oil like there was no tomorrow. Starting with the 4 valve the problem disappeared. There was one meaningful difference. Mahle rings. Mahle is still the best but there are others who are great and that you can actually deal with. Nippons list of customers is second only to Mahle.

 

Not a 2v expert by any means however mine, 78 GTS US, 120K + miles which I've had since 1980, uses about 1/2 qt per 3k miles with no oil residue in air cleaner blow by vent in normal around down and freeway driving (not much over 6K and 3/4 throttle ). If driven hard with lots of high RPM (right at red line if not a little above) full throttle up and engine braking down will use the same 1/2 qt in a couple of hundred miles with heavy oil trail on both bottom and top of air cleaner. Don't really see how it can be anything but loss of ring seal.

I'm currently running Castrol 20/50 synthetic blend with a quart of Lucus oil stabilizer which improved hot around town slow idle (850 RPM with AC and both fans on) oil pressure. (I've never had the oil light come on but it got below the low mark on the gauge). I'm going to change to Mobil 20/50 full synthetic next oil change.

Back in the day we drag raced Mopar 426 ci Wedge and Hemi NA in NHRA Super Stock, C and A gas classes. At the time we used dykes "L shaped" top ring with low tension tapered scraper and low tension 3 piece oil rings supplied by Chrysler or Sealed Power. We attended all the Mopar seminars and blow by and ring seal was always a hot topic. As a point of reference the Hemi rev limiter was set at 8700 with slick shifted stick shift. Mopar allowed as how there was no way to maintain perfect ring seal and prevent blow by. The standard rule of thumb is don't worry about it unless the valve cover breathers (push on type) moved more than 1/2 inch up on the tube. Kind of crude but a sure sign of trouble. We did lots of leak down testing with the pushrods out and found we would get different numbers at different piston positions. Mopar allowed as how it is impossible to compensate for various engine temperatures as well as head stud, main stud and cross bolt stress even when bored and honed with torque plates..

The thing we discovered in our NA engines was that the expander in the 3 piece oil ring is critical. To little tension and it will blow oil like a chimney, to much and it would gall pistons.

Any one interested in this topic should review some of the YTUBE video's on engine rings. Sealed Power has a bunch of them as well as many top engine builders. The thing they keep coming up with regarding oil burning is cylinder roundness, especially in an aluminum sleeved block, and cylinder finish. They are using hones with eight or twelve stones followed by some kind of rubber smoothing pad (stone) followed by electronically mapping the cylinder roundness and finish for the entire bore.

Just a quick thought when did Ferrari switch to the coated sleeves? Does that correspond to the reduction in oil consumption?
Barry

 

Obviously Ferrari must have improved something about cylinder sealing as time went on - my '89 328 "burns" about 1/2 qt of oil in 3k miles.

Re Mopars...I wrenched a 340 and 426 Hemi in NHRA Super Stock years ago. A major thing we learned at the Mopar Direct Connection seminars was to look for engine blocks with thicker cylinder walls on the thrust side. Engines with thicker cyl walls on the thrust side maintained their "roundness" at operating temp thus reducing blowby. Since the blocks were cast (iron) there was inherent shifting in the the cylinder wall thickness from block to block during production. This was (is?) common for cast blocks of any manufacturer. So in mass production it was just LUCK that determined if you had a great engine, an average engine, or a (relatively) poor engine. We dynoed many stock Hemis and got numbers from 430 to 510HP for factory "identical" engines. FWIW, IMO the best engine Mopar produced in the muscle car era was the 340, NOT the Hemi though the Hemi gets all the attention.

The head of the Direct Connection program, at one of the seminars, explained that when he "ordered" his 426 Hemi he actually went to the factory, measured the wall thickness on a bunch of blocks and selected the specific block for his car.

 

Fwiw, (probably not much here) in my 426 hemi I use total seal .043 AP top .043 2nd napier 3.0mm oil ring 15lbs.

Lateral gas ports in piston. Vacuum pump. Iron block. Uses no measurable amount of oil. Shifted at 7900.

For me, always conventional. I do not like any of the gapless rings.

IMO you would be better off going thinner on the rings for more bore conformity rather than the other way around.

 

In the dealer network we never used synthetic oil in 2 valve and earlier engines. The piston ring design was ancient. In 4 valve they went to Mahle and it was a very different story. To this day I will not use synthetic in the iron cylinder engines.

 

Agree.

 

Are you using big end gaps in second rings?

 

I gave been using classic mineral 20W 50 in my 77 - 2 V carb based on this ……the iron liners , slack ( by modern stds ) rings.
It’s changed annually @ 2-3 k kms . It does darken

The other thing with carbs is potentially oil dilution at start ups fuel washing past these loose rings.More so if a bit of choke is applied
I think the mineral oils are better coping with this .

It never needs a top up and there’s no blue smoke - wife has followed me occasionally.

 

Learned from a guy at Honda Racing a long time ago to run 2nd ring gaps at least 1.3 or 1.4 times as big as top ring. Gas trapped between the 2 keeps oil scraper from working.

 

The Wisecos I am putting in a 330 right now has .9mm top, 1mm scraper. The last set I installed had .95mm top, 1.1 mm scraper.

For what its worth, I never tell a shoe maker how to make shoes. I let the piston guys tell me what rings to use. If I was so smart I'd be in their business.

 

Makes a person wonder about ring packs made with a gapless 2nd ring

(Still top gapless is trash to me as well)

 

Main thing we found re rings was re the oil rings - reducing the oil ring friction had a noticeable effect on power output. There was relatively little difference with various tensions of the other rings and even with various gaps, sometimes considerably wider than the typical .004" per inch of bore. I don't know the specific numbers as far as oil ring tension but I remember that we ended up using oil rings that were, per the ring guy, less than 40% of the tension of standard oil rings for the engine application.

We tried gapless rings but didn't really see any consistent difference in power output. There was a lot more to be gained by careful cylinder wall prep/proper ring material selection.