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Hi everyone. I've pulled a piston to buy new rings. I bought the pistons close to 10 years ago. There are 0 markings. I thought I bought Wiseco. JE says theirs are stamped. It's a VW ABA16vt (9a head). I measured my bore it's standard (82.5). Should I just buy rings according to my bore size?
I've attached pics of the piston and the page for my application. Thank you.
Why are you replacing the rings in un-used pistons?
They were installed 7 years ago and the car sat after I got it running, for about 4,5 years (storage). Long story short, I'm going on my 7th set of plugs; they come out black and oily. There's oil on the pistons too. I changed the valve stem seals and a few were really bad. There's no oil in the coolant, and no coolant in the oil. Engine has maybe 4 miles on it. There's no oil in my intake, or turbo charge pipes. Smoking during accel after stopping. I paid to have the engine built years ago, I just trusted the work was done right.
The car is running at .7 lambda with this issue. So I started with the easy things. 1. Annoy your tuner and find out the tune is fine. 2. Looked for vacuum leaks. 3. Replace coolant and IAT sensor. 4. Injectors cleaned and checked. 5. Replace valve cover gasket. 6. Replace valve stem seals...
I just realized this should probably be in the engine building discussion.
[EDIT] The oil control ring(s) were fitted incorrectly - you can plainly see in the first(?) image the ends of the expander are overlapping, and NOT butting up against each other as they should be. That will prevent the oil control rings working correctly and lead to the oiling condition you're complaining about. You should be fine with pulling all the pistons out, ensuring the oil control rings' expanders are correctly fitted, and reassembling the engine, as the total use is so low. There isn't any sign of any other ring or piston problem and you certainly shouldn't need a new set of rings.
Were ALL the 'plugs getting oily? Do you have the correct valve stem seals, and were they correctly fitted - those two things can cause a lot of your issues. If the back of the intake valves were oily that would be a pointer in that direction, too.
What were the cranking compressions? It isn't evidence of an oil control condition, but a general guide. It would give some indication of sticking rings, though - on that, were any of the rings on the piston you removed sticking? When you checked the oil control rings, were they correctly assembled?  Oh, see above.
All the plugs are getting oily and black. I have the correct 7mm valve stems. When I replaced them, did my drive/datalogging and things were still bad but the lambda gauge wasn't going into red this time. I pulled the plugs and they were "half as bad". Still oil on pistons. To make sure, I pulled the head back apart and rechecked ALL of my work; all the valve stem seals are still in place. All intact.
The back of the valves are dirty from oil, but not wet; as I pulled the head yesterday. And there was oil in my intake, before I replaced seals. I cleaned and nothing after I changed them.
I didn't do a compression test. None of the rings were stuck. I haven't checked the other pistons, but I'm assuming they're all the same.
I'm confused about the expander butting. Do I need to just push it down like I did in the pic? The ring above it does look bent though.
How do I know the other ring gaps are ok? I'm assuming the worst, only because :
1. My engine wasn't timed right when I received it and wouldn't start. I had to redo it.
2. I sent in HD springs for the build. The condition of some of the valve stem seals I replaced, makes me think they weren't very good to start. A. If my springs were installed, they had to have seen them. B. Or the head had HD springs already and they didn't see the seals.
3. One of the nuts on one of the cam bearing cap, was lose. It just turned by hand.
Attached are pics. Also, the oil smells like fuel. Going on my 5th oil change!
Those stem seals look hammered - did you have a higher lift camshaft and/or new valve guides fitted?
It's well into the am here, so I'll pick it up tomorrow.
I didn't buy cams or guides. I thought maybe because it did sit for 5 years, they dried and tore when I did start it. But, I did crank the engine for a few minutes, before realizing the intank pump was dead. And it cranked for a little when I did change the pump. Drove 2 miles. Didnt the oil have plenty of time to circulate while cranking? After that day (last year), off again.
Skip to now, car was towed here and I changed all fluids. And noticed my plugs.
The car went from a driveway, where I got it running. To a shop. To storage. To here. All towed, lol. I can't see how I could've torn those seals. I didn't go over 40mph on the drive. And these little .5 mile drives I do here, when I make a change, are mostly stop signs.
Is it bad if I pull the rings off the pistons and check them?
Is it ok if I spray the backs of the valves with brake cleaner?
Knowing how sooted my pipes are, I'm assuming my o2 sensor is blackened too. Should I change it?
These are the engine specs: Aba 16vt, precisión 6262, ID 2200cc inj, forged pistons and rods - I could've sworn 9.5 compression, VEMS full standalone, short runner intake, 3in straight back to muffler, 2x 044s w/sumptank plus intank pump.
I asked it the engine had a higher lift camshaft, or new valve guides because that sort od damage to seals is usually caused by insufficient clearance between the seal and the underside of the valve spring retained/cap, and those are common issues. The lift should be self evident, but if the valve guides were too long and/or installed too far out of the head, there may not be sufficient clearance. Something else i should have asked was if they were genuine VW seals or aftermarket, as some seals are 'taller' than others when installed. With the right tools and some thought/experience those are easy to check.
With care, the rings can be removed and gaps checked, but keep them in order to go back in the same cylinders with same pistons. However, having seen those stem seals, I would just check the oil rings are correctly installed, as it's sometimes a pain to remove rings without damage to them.
Can't think of any reason not to clean the valves and port with brake cleaner - anyone?
O2 sensors can be contaminated by excessive oil - you could try it first. They are sensitive devices and while you 'may' be able to clean it, check first as some cleaners will definitely affect it.
Quick guide for the oil rings - I would like to have seen him double check the ends butted, though - https://youtu.be/WVTOsYWfkuk - you certainly want to do that before fitting the compressor and installing them.
Thank you Gord!
I installed Victor Reinz seals. It shows these as OEM on the different sites I've checked. The old seals are Elring. They're both the exact same height and width. After I changed them, I drove/logged, came back and still saw oil on plugs and pistons. I removed everything (cams, retainers, springs) and made sure they were all still seated/intact. For my peace of mind.
I can't see the cam lobes pushing far enough to smash the retainers into them. They were all still seated when I removed them, including the 4 torn ones, the rest look fine.
After I changed the seals, I noticed a sound from under the car, like air coming out. My exhaust is v banded from turbo to muffler. All 3 clamps are tight. I read that bad piston rings can make an air rushing sound.
Is that bad blowby? Maybe why my oil keeps smelling like fuel?
I will double check all the piston rings. I have the Wiseco recommendation but not sure where I fall :
Bore x, 1st ring, 2nd ring
High-Performance Street / Strip .0045” .0055”
Street-Moderate Turbo / Nitrous .0050” .0055”
Circle Track/Drag Race .0055” .0060”
I want to drive the car and still be able to push it, likely once a month or 2 at the drag strip. I want to go as fast as I can, with what I have and go from there. Any "driving" will be tame. There's speed cameras everywhere, and I wouldn't want to lose the car.
Thanks for the Mahle video, it seems straight forward. I saw the HPA webinar on rings too.
What numbers should I use, if manufacture is conservative? I've attached pic of Wiseco ring installation, and condition of old seals.
Thank you again for your help.
From those recommendations, and it being NA and a 'street' car, anything over 15 thou' should be fine - Some people will stress out if the ring gap(s) are a little more than specified, but the actual losses are quite minor unless really leaning on the engine and/or they are well over the higher clearance. Anyone care to comment?
Those damaged seals look almost like they've melted in those later pictures, as do some of the others - you can see how a few still have the sharp edge for the seals'wiping edge, but others are worn and rounded off. It may just have been them running dry initially, after sitting so long - especially if the builder didn't lubricate them on installation. If it was, as I initially thought, an interference problem I'd have expected it on all of them.
Sorry I can't be of more help.
The car is turbo, precision 6262. I'll adjust accordingly. Hopefully I can report back and mark this resolved.
wow, fully agreed with Gord here.
I guess i skimmed over the ran slightly before long term storage. The light gray font with white background is hard to read.
Anyway, man. Once the head is refreshed and new rings and a clean break in, that is going to be a very fun highway blaster(I would go with a gtx2867r)
Piston #1 - top ring .017, second ring .023
Is that normal for second ring gap?
I made sure they were perfectly centered before I measured. Also, the new rings say N150. These N50.
I make a safe minumum, with 5 thou/inch to be a fraction over 16 thou, so you should be fine for moderate boost with 17.
It's normal to have a bigger gap for the second rings to reduce gas buildup between the rings which can cause ring flutter and sealing problems.