I'm not, this is actually very common in post 06 Lexus as well as post 2010 Toyota and 2004 and up BMW......basically anything that uses low tension rings and or relies on the PCV to keep a vacuum in the crankcase. The N62 V8 actually has a vacuum pump on it to run brakes since so much manifold vacuum is devoted to this.....

Low tension rings+DI injection leads to very easy carbon lock of rings if you don't use correct oil on time and sometimes flog the car/actually use max power. The LS460 is infamous for massive oil use to the tune of up to 3qt per 1000 miles if the rings lock up or the PCV fails. The PCV issue allows too much oil to remain in suspension allowing to be ingested vs dropping out of the airstream and back to the sump......or lack of flow entirely leading to acid varnish buildup and lack of vacuum on the crankcase stressing out the rings.

This can be corrected if you amend your practices to using the right oil, on time, not allowing any crankcase air leaks (if it's leaking oil it's leaking air), and making sure the PCV is working and occasionally doing full redline.

My A8 used oil when I first bought it at only 70k miles, so did my 460 for its first 500 miles to the tune of 3/4 QT. The Audi ate 2 in 1000 miles......both were corrected by me simply running hell out of the A8 once I brought all maintenance up to date so I knew I could take it up to 180 and the 460 was fine once I fixed the leaking high pressure pump oil seals. That slowed the issue since the PCV resumed working correctly and then a week of HEAVY (every red light, stop-sign, was full power to as fast i as I had room, freeway at 130) driving got the rings moving again and now it hasn't moved for a full oil change interval.

You need to catch it before the locked rings score the bores too much though, there is a point of no return. All of my flagships have oil level sensors and all my trucks have level or real pressure gauges so I've never actually been too nervous about oil levels. I also always check them when I get gas or park them and put them on their tender so it's never a surprise moment of low oil/anything unexpected.

My customers Hyundai/Kia cars do not have such systems, they can be 3/4 the way out of oil and have no warning. They also are usually not the type of owners to even check at just fuel stops/understand the importance of doing so....it has lead to me replacing over 10 4cyl and 6cyl engines and one 5.0 from the results.

The other way is to remove all plugs, seafoam soak all cylinders and hand turn it 180* of the crank rotation 4 times, soaking it at each position for 2-4 hours. That will chemically free it and is what I normally do for customer cars with the issue since it doesn't require me to drive the hell out of them. I do not prefer that way on my own since it really strips off oil protection of the cylinders and just makes me a little anxious every time....but I'm not taking a customer car to high enough speeds to burn stuff free/driving it hard like that. Plus honestly it's more fun doing it on my own cars that way, I tend to drive like that often enough as is lol!

 

There is no way piston rings are going to make more than a 0.1% difference.

 

Oh they can and do, there is a LOT of drag from those believe it or not. 5% in some cases can be gained from rings alone if you are updating from 50s era tech

 

Nope. A bare block with crank and pistons installed spins super easy. Maybe 5% compared to ancient engines but modern then going to a low tension ring is irrelevant IMO.

 

Spin it up to 2000 rpm. It makes a major difference when you scale it across 100000 cars for fuel averaging

 

Cam to valve spring action takes vastly more energy it's not even close. And that's not how scaling works the % of friction in each engine doesn't go up the more engines you make, are you serious?

 

Dude. I've built many engines and just having the pistons and crank in requires a decent amount of force to rotate the engine at 10 rpm. Spinning it to 2000 requires a lot and a 10-20% reduction in drag there pays off a lot....that's why high end rings used in racing have very complex geometry to minimize ring contact with the walls while remaining strong.

You would ask do well to look into modern valve spring designs and retainer designs since they also take the same approach vs older fixed diameter springs. They are weaker and lead to a bunch of dropped valves when manufactures first tried them but they ultimately require less force and are lighter with less fiction.

Valvetrain doesn't require nearly as much to operate since everything is operating via mechanical advantage at lower than crank speed. Most cars use springs that are maybe 120-130 open pressure with fully roller valve trains, it's not like it's a 425lb flat tappet system.....and even that is easier to run than the ring packs as you speed up.

A 1-2% reduction doesn't seem worth it unless you scale up to an entire fleet of cars across a manufacture bound by CAFE ratings. That's what I meant by scaled up

https://www.dragzine.com/tech-stories/engine-tech-understanding-piston-ring-tension/

https://www.enginebuildermag.com/2011/02/how-piston-rings-affect-horsepower/

You can pick up 10%+ HP from JUST modern/advanced rings, going from a standard valve train to full roller is maybe 1-2% and of the rings the oil ring has THE most friction. It's not even close in terms of drag reduction by moving the oil rings to low tension vs any other changes.

 

Check this video out at 13:50

 

Looks like I was very wrong, I'm in disbelief given how freely a bare engine rotates vs. assembled (no spark plugs no compression).
I have a question about engine assembly what is a good way to keep the rings in place when putting the pistons into the bores? I always muddle through it but the rings move so easily I am never sure if they ended up in the correct position.

 

It's misleading since the valve springs feel super heavy when you try to turn it over but in reality when the cams are already moving they have MORE than enough inertia to easily open everything and the load needed to open valves does NOT increase as RPM builds...it actually goes down since the cam is already carrying a lot of momentum. Ring drag goes WAY WAY WAY up with rpm, most of the heat outside of the BOOM from your engine operating is from ring drag. Fluid drag at the bearings and literally "along" the crankshaft would shock you as well. Bearing fluid drag is a very real thing and stepping from a 5w-40 oil to a 5w-20 is 3-5% HP gain even with a REALLY good reduced section modern bearing....issue is film strength relative to parts loading and oil velocity. You NEED to be able to move oil past a point at high flow to provide cooling to parts, it's not just about enough pressure to get the hydrodynamic effect working since if the oil idles too long it will heat up and shear no matter how heavy it is. 5W-20 oil is great since it has a good film strength and doesn't require an insane pump to flow enough to attain pressure and if you keep it cool you will never have sheerdown.....unless you have smaller parts with massive loading. You generally want to run the lightest oil you possibly can for a given parts loading level PROVIDED you have a pump and cooling solution that can flow enough oil to maintain 60PSI at 6k rpm.

The crank and any spinning parts can have a "cloak" of oil from around it that slows it down, you can counter this with an ultra tightly fit plate called a scraper or a windage tray....I have both in my 410CID engine since the camshaft provides enough splash to keep the bores happy and I also selected a crosshatch finish that retains more oil than normal for the bottom 1/8 of my cylinders so there is always a reserve since the Chrysler small block doesn't have oil jets. The upper 7/8s are honed to spec to match my stainless top ring and Napier 2nd rings and mid tension oil rings since it is a FI engine and full low tension rings can't seal properly. Ideally you want oil to ONLY be were it is supposed to hence why you see dry sump systems actively recover oil by force from all areas of an engine.

I use a bore specific tapered sleeve that only fits ONE very specific bore size, for example 4.030 inch bores.....it progressively and very gently compresses everything to the point you can just press with your hand. The normal way is to put all your rings on and use an adjustable "clamping" type that I am sure you are familiar with, to use those you just need to be careful and not over compress past what you actually need to carefully tap the assembly into the block.

My suggestion is to do each ring in sequence when putting the piston into the tool so you can manually compress each one so you can be certain they went in correctly, you should be able to compress even the top ring with just your hand to guide it into the install tool. That or get a tool that allows you to loose fit all rings then set it over all of them at once and give them just enough tension to allow the assembly to fit into the bore with no major blows needed. Always use a rubber dead blow.

 

Nice, reminds me of when I put the crank in my 410, with just the crank I could spin it with one finger and it kept going for a few turns! Radials are insanely low friction at the bearing surfaces, that's nuts to see it just bob back and forth like that....

 

I have the tool you imagine even thought mine is decades old, it works of course but not exactly ideal. I'm thinking of cutting a piece of PVC pipe maybe 1" high so I can compress each ring set at a time like you're saying. I tap the piston in with the rubber handle of a hammer.

wait are you talking about a tool like this?

 

This one is what I mean/use
You need to buy one for each size you work with, I have one for each of my personal engines that I would rebuild......by that I mean the 410, 5.7/4.6 and my Jeep. For everything else the checkered flag one you linked is very close in performance but those generally are sized for domestic V8 bore sizes aka LORG.

Rubber hammer works GREAT, use dexron 3 as the lube when you install them. Works better than engine oil since it will not turn to carbon as readily in the ring-lands when you start the engine the first time, also make sure to use a lot of assembly lube on the wrist pin since it takes a second/10 for splash to make it to those for the first time.

 

I need one for an 87.1 mm bore which is 3.43" I see how that works it is exactly the size of the cylinder at the bottom that's neat. They have one at 87mm that should work fine. Thanks for the tip on using ATF, the pistons are already lubed up I soaked them for a week in motor oil got almost all of the carbon off without me doing any manual work. The tops were perfectly clean due to the engine eating coolant.

oops the engine is 86mm was thinking of another block, engine is a 3S-GTE.