legacycentral bbs

Hey everyone,

New to the board big question. I had a shop rebuild a ej20k. Had a shop service block and heads and i supplied them with everything but rings. He said they had a set and not to worry. He knew it was an ej20k. And has a great reputation for jdm work.

My question, i just dropped the motor in fired it up did an initial 30 min break in/leak check fluids etc. During that the exhaust was puffing whitish/blueish smoke smelling of oil not coolant. Thought no big deal, then i drove it for about an hour to start breaking in and seat rings. 35 mph varying load staying outa boost etc.

Its still smoking like crazy. Should i expect the rings to have seated enough for it to have stopped? Or does it need more time. Ive never had a rebuilt motor smoke like this before.

This is why i first asked if the ej20k rings are different than usdm. Is it possible he put usdm rings in thinking they would be close enough and they just are never going to seat right?

Second question. Would a compression test or leak down even show me anything at this point with maybe 30miles and 1.5 hrs of run time?

Am i just over reacting? The thing runs like a champ otherwise, smooth, idles perfect, revs nicely. No indicators of any issue other than the clouds of smoke.

could it maybe be a bad turbo seal which is why engine runs smooth but still getting the smoke down stream?

TIA

Welcome to the BBS.

The rings should have sealed by now and you shouldn't really be getting clouds of smoke....or at least my rebuilds didn't do that.

I would do a compression check to see what you're getting. That would be the easiest option and maybe help point to a turbo issue or something with the rings.

What is the condition of the turbo?

What is the engine setup (pistons, etc.)?

Its a stock ej20k. Pistons were in great shape i just had the shop hone cylinders and replace rings, bearings, and all gaskets/seals service the heads and shim valves. I sourced all the parts from japan and off the nasioc interchangeability list for that. My only concern is that he used the wrong rings because i didn't specially source those, and he may have been under the impression that the usdm rings would work. But I havent been able to track any info down if there is a difference in rings or not yet. Although I would assume as long as the ring gap is right that the rings should be fine. I just want to cover my bases before I accuse him of faulty work and make him go through it all over again.

The turbo is a used td05 off a car that ran fine. I didnt check the seals or anything. Ill do a compression test to see if i can take that variable out of the equation. Any idea of what numbers i should expect if the rings havent seated? The amount of smoke is making me nervous even driving it down the street because I feel like ill get stopped immediately if im seen.

rome20k wrote: ↑Wed Sep 18, 2019 8:33 pm ...i just had the shop hone cylinders and replace rings...

This is probably why its smoking. You should not have had the cylinders honed. Who rebuilt the engine, was a Subaru specific shop with experience machining a split-block engine, or was it a hot rod shop that's used to iron block V8s?

https://www.ultimatesubaru.org/forum/to ... nt=1406764

Called the shop, he did not hone the cylinders. the shop is subaru specific. They said the rings should have been right, and is calling me back after he locates the paperwork with part numbers.

I take it from both of you comments that the usdm rings should be fine on the 20k pistons right? Please confirm if you can.

Other than that, i am checking the intercooler piping for oil, also i had added an oil catch can so im going to make sure i routed everything right. (PCV valce was just rplaced). Then ill do a compression test to try and locate any possible issues. If i havent figured it out by then, i guess ill be forced to do a leak down which i dont want to do.

Is there any recommendation on other things i should check while im under the hood?

I don't think anyone here knows the answer to the ring question. The ej20k's came with forged or cast pistons, and I believe I read those had different rings depending on piston material.

Ill ask my buddy who rebuilt a factory forged pistons ej20k block, which rings he used. That engine went into silenc3r's SS, and he didn't have issues with oil burning or consumption.

I had an ej20k back in the day too, I had it inspected by a good machine shop, and they said the cylinders were out of round, aka ovaled. They told me they had to bore it out to first oversize piston or I'd use oil.

My friend said he reused the ej20k rings, making sure they went back in they cylinders they came out of.

I never ended using my ej20k shortblock, just it's heads, so thats no help to you either.

Rings should match the pistons and I don't know that the rings should be drastically different, but I can't say for sure.