Delayed Sealing piston Rings(Rings haven't seated yet?)

[Cliff Foster]

I have a question about piston ring sealing. I have come to the board here quite a few times. Yes, I am the guy with the screwy 408ci stroker motor, but it still makes lots of power. I came to you about "white plugs/black oil/oil consumption", turned out the black oil is a rich condition and the "white plugs" was too hot of a heat index on the plugs. I still haven't solved the oil consumtion issue.
I have talked to a few mechs and some thought that it may be valves sucking oil into the intake and out the exhaust valves. OR. It could be "blow-by" in the combustion chamber because of the rings which in turn helps blacken the oil.

Here is my scenario: 360ci bored and stroked to 408ci. Initial break-in 500mi(10w30) regular oil; then another 1000mi(10w30). 1500mi total breakin. I then went to 15w50 Mobil1 synthetic 3000mi(AZ to GA). Actually only 2000mi here plus mileage in GA. On the way from AZ, I added an extra 6-8qts of oil. One qt per gas stop.(DAMN! $4.50/qt). Next oil change was to (5w30 petrolium based) winter oil for another 3000 mi(+6 more qts additional). Then back to 10w40synthetic Castrol for the last 5000miles.

The last mech that I talked to works on a IHRA dragster and he thinks that the rings never seated and he thinks that they still can. He said that the synthetic oil won't let the rings seat! He also said that I should try a petrolium based oil and see if they will. I have bought Valvoline 20w50($1.94/qt whew!) petrolium based oil and I will run that for the rest of the summer and maybe longer.

My question is this: Is there any chance in hell that he could be right and the regular oil just might help these piston rings to seat? My next option is to have the motor torn down and the rings replaced in the fall sometime.
My next major purchase is a supercharger and it may not like the rings not sealing, but this has to be fixed first. What are my chances?????????? How many miles do you think it will take on the regular oil?

Pistons are ROSS forged aluminum
Rings are chrome moly coated
Motor currently has about 12000miles(+) on it.

[ehostler]

You need a good amount of friction for the rings to seat. As synthetics are supposed to prevent that kind of friction, it is possible that could be the cause.

[dwc43]

If that is your problem, and after 12,000 miles on it, they aint going to seal no matter what oil you run.
Possible 'causes,did not use honning plates, out of round cylinders,wrong size or gap rings,did not get the proper cross hatch finish during honning on the cylinders, fuel wash down, and there's probably more I'm not thinking of just now.

[MitchB]

Do a leak down test and see what you come up with. If it's your rings and not the valve seals/guides, then you should see it on the leak down. Find out as much as you can before you tear the motor down. You might have a good leak down, but with poor oil control. If your oil control rings have not yet seated, they probably never will.

Mitch

[skankweirdall]

Are those chrome rings or moly coated? Either way they need different cylinder wall finishes. Chrome rings are very hard and don't seat well without the correct finish on the cylinder wall. If you purchased your parts and told them of your intention to build a blower motor then you may indeed have chrome rings. Who ever bored and honed the block might not have comprehended what kind of ring you had. There really aren't any "chrome moly" rings per se, but that is what a lot of people call moly coated rings. So they may have just assumed you were using moly coated rings.

[holshotbb]

I agree with there not going to seat,do the leak down then open motor for the needed repair.Most likly IMO was the too rich condition in the beginning washed the rings and glazed the wall finish.Youll probaly need a light hone and new rings.PS when open make sure end gaps were staggered.

[Cliff Foster]

I didn't actually do the engine build. I had a friend (Mopar parts guy)of mine order all of the parts and he sent the block to a respectable engine shop in the Phnx area. They build lots of racing engines and they knew that it was going to be a blower motor, so did the guy who ordered the parts for me. I had a different guy put the motor together. I don't know what the hell is wrong with this thing. Could I possibly lose that much oil with bad valve guides? Could I possibly develope a rough running engine with the rings being bad?

[6 packin]

That sucks man! Are the ring chrome or moly? I didnt think they could be both. There very hard to seat, somthimes they dont seat that well. What temp does your engine run? Try switching to a hotter thermo stat for a few thousand miles or so. Try between 200-210 degs, this is safe temprature to run. Most new cars run that temprature no problem. My 96 Dodge truck runs over 200 deg and has 200,000 miles plus with little to no oil consumption. The hotter temps will help seat the rings in, if they will. Run a 10W-40 oil, petrolum based. 12000 miles is not that much. My wifes 2001 SS chebby used oil since day one. After 25,000 miles the computer was recalibrated for the high idle. It loosen up 200-400 rpms at idle. It ran alot better too. That car runs between 210-225 deg. Dont give up yet. You probably should have gone with a cast ring for street use. Alot of race rings are expected to consume some oil. A Cat diesal engine are made to consume oil.
Hope this helps.

[Cliff Foster]

I think that the guy that ordered my stuff told me that the rings were Chrome moly coated. I'll call him again to be sure. I have a 180deg thermostat in it right now.
I just had another friend of mine tell me that if therings haven't seated yet they possibly still could. He works on a NHRA top fuel Dragster, but he is in AZ. He said that some of the rings that they use seat while they are hand turning the engine before the assembly is complete.

[PRO]

Fuel wash is the biggest deterrent of ring seating due to the fuel mix being too rich,what happens is you end up with unburned fuel in the topend when the mix is too rich which then runs down the cyl wall dilutiing the protective oil film and keeps the rings from seating,some of this diluted oil burns and escapes out the exhaust and some ends up in the oil pan turning the oil black within a couple hundred miles,usually if you can rejet it properly the rings will go ahead and seat,Ive seen several engines that had over 20K and "always used some oil" according to the owners go ahead and seat,whether this is your actual prob its hard to say but do a leakdown first,your looking for all 8 cyls reading about the same,disregard the actual numbers for now because they wont mean much untill the rings seat,barring 1 or 2 cyls showing alot more than the others,10%-15% variance should be the max diff you see,then change the oil to a NON synthetic,I never run synthetic or any additive like slick 50 until you have 5K with no oil consumption,Ive re honed 3 engines after the owners added slick 50 within the 1st 500 mi,it wont let the rings seat.Id actually go leaner until I knew it was too lean then richen it back up 2 steps or so,do this carefully,dont have your 5th wheel hooked up and run up the Baker grade in mid July,just tool around the block,keep looking at your ceramic insulator for a medium to light brown coating,post your carb and jetting and Ill see if I can help you with a baseline,you do have a PCV valve hooked up correct? and whats your actaul compression? hope this helps.......PRO.........

[rustycowl]

If the intention was for a blown application, then I am guessing they ordered chrome rings, which are notoriously slow seating rings, which require a relatively rough cyl wall finish.
If you used moly coated ring(s), they require a much smoother micro finish. They usually seat nearly instantaneously.

[Cliff Foster]

The rings that I have are moly-coated. I just called the guy who oredered my parts and asked him. He doesn't think that the rings have a chance to seat because it's been so many miles already. I do have the ability to run a little leaner computer than the one that I had remapped. It's the Mopar performance computer for 318ci. It doesn't seem to have any problems running the engine. The check engine light comes on every now and then, but it does that with the other computer as well. It only stays on for a day or so then it goes off.
"Pro":I had mentioned to my NHRA buddy about the fuel wash down on the cylinder walls. He sad that it was a possibility. He also said that it would cause my oil to thin and also fill my pan because of the ecxess fluid(fuel) being there. He said to check for that he would take out the dipstick and put a cigarette lighter flame to it and see if it burned. That would indicate fuel in the oil. I may just have him to refinishe the cylinder this Fall if at all possible because I know he will do it right. I am still trying to set up the leakdown test as soon as possible. Me and the guy here are missing each other. He's still servicing that IHRA car on the weekends. As soon as I use the last 2.5 qts of this 10w40 sythetic, I am changing to a regular 20w50 valvoline to see if that works. That should take about 2 weeks, depending on how I drive and I want this other oil in.
Thanks you guy for all of the suggestions and keep 'em coming. And when I know more so will you guys.

[skankweirdall]

Too heavy of an oil. Use 10w30.

[jelsr]

Give it a try with the conventional oil, and like skank suggested use a lighter weight. Don't know the topography where you are but if you have a hilly section try luggin it up the hills and get out of it going down, try to make it grunt not whistle like a siren. The synthetics are great oils but not for breakin. Found this out years ago when I was still racing my H-D. After we switched to Amzoil we had trouble with the bike smoking after doing a top end. Found out we could run it for 15-20 min on the chassis dyno with a light load and conv. oil, drain it and fill with synthetic, and presto, no smoke. This was with chrome rings. I would think the moly filled rings would seat anyway, but I was wrong once years ago.

[Cliff Foster]

I have already bought the heavy(20w50) stuff and I am going to use it for the initial change and then thereafter I will use the lighter(10w30) stuff. That has been recommended to me by quite a few people. I tried 5w30 and the motor ticked(aluminum roller rockers) like crazy. I don't think it likes the light stuff, but we will see. But I will for sure stay with the conventional motor oil for a while.

[Cliff Foster]

So then once I change the oil, I should drive it like I did when I broke it in? Never really let the RPMs get too much over 2500. How long should I giveand how many oil changes? Or should I just stay with it?

[Dart_440]

I think your problem is that you are listening to everybodys opinion and trying to use them all. Listen to 1 person and stay with his opinion then trying asking everybody. A friend did that and his motor didnt turn out right because they all had different ideas on how to machine, assemble and run the motor.

[cuda66273]

So why not just leak the motor and see what you've got?