How long before rebuilt engine rings seat? EDIT. Help a 1st time engine builder.

[butters]

I drove the car for a day without the oil filler cap, dipstick tube, and crankcase vent hose attached

wait what

[brianao34]

It seems unlikely to me that ALL of the ring sets would be bad. Are you sure the oil couldn't have been entering from another source? PCV system maybe?

Yea, I'm sure. I drove the car for a day without the oil filler cap, dipstick tube, and crankcase vent hose attached. still had the same amount of oil consumption. That was my last ditch effort. It seems feasible to me that he sent me a set of the wrong oil scraper rings or maybe it was a bad batch or even the wrong design oil scraper.

I've read a few horror stories online of the compression rings seating but not the oil scraper rings.

But I'm past the depression part of it and ready to get the car running! :D

[Exodus_2pt0]

It seems unlikely to me that ALL of the ring sets would be bad. Are you sure the oil couldn't have been entering from another source? PCV system maybe?

[brianao34]

Sorry to hear about your troubles... However, why are you so against replacing the block? Do you really want to risk putting it back together just to find out that there is a problem with the block repair? You cannot put a price on piece of mind.

I know it almost sounds foolish not to replace the block. But I've already got a lot of money tied up in the machining in that block and to me I don't see what could be wrong. It's a sleeve in a block, and it was put there correctly by a reputable shop.

And when I took the exhaust manifolds off it was obvious that every cylinder looked just as black and coated in burnt oil as the rest.

I want to find out was is/was wrong. And all signs are pointing towards the rings, not block, not head, not anything else.

I hate when inanimate objects outsmart me. Makes me feel oh so dumb.

[Exodus_2pt0]

Ahh, come on, someone give a random story of hope for me

When I rebuilt my 2.0T it smoked for about 300 miles until the rings seated. Compression went for 130psi after first start up to about 180psi around the time it stopped smoking.... Then again I did not lap the cylinders, due to being plasma coated, so that explains the 300 miles.

120 is too soon to tell.

EDIT: Just saw the smoke like a train comment.... None of my rebuilt motors have ever done that.

Sorry to hear about your troubles... However, why are you so against replacing the block? Do you really want to risk putting it back together just to find out that there is a problem with the block repair? You cannot put a price on piece of mind.

[brianao34]

Mini-update:
Engine is torn down and pistons and rings were sent back to Deve's for inspection/replacement of rings.
Cylinder walls looked perfect and so did everything else.
I'm having a hard time believing there's something wrong with the block/head. Has to be rings.

This horse will be beat.
Not looking for another block/head/engine.
I will figure this out and this thread will be updated. I hate when threads are left without a posted resolution.

[adjmcloon]

I'm not sure what your situation is, but from reading this thread, I am reminded of the saying "A man has got to know his limitations." I would probably be looking for a donor motor and start over. At least you can most likely reuse some of your parts.

Sucks man, I've been there, but like you said, live and learn.

[brianao34]

Haha, it was a good spring project last year!

[delatlanta1281]

You probably don't want to hear this again man, but that block is suspect. I wouldn't blame all your woes on it, but as Jim and FF said, the block is a glaring problem.
Live and learn most definetly, bu I would plan on a total tear down. Look at it his way, it's a good spring project!

[brianao34]

Jim has done nothing but try and help you, all he is doing is telling you the truth. We build engines often and there's certain thing we will no accept. Cracked block goes in the scrap pile, so does scored pistons - we won't even turn a BMW crank to .010" under (micro-polish only). Some of us have been building engines longer than many members here have been alive and will give advice based on experience - not what we read on a forum.

I think what I said is pretty much what any engine builder would have said. It isn't arrogance.

Excuse me. I wasn't trying to be rude. Just extremely cautious when it comes to forum advice. It's hard to credentialize (made that up) people online. No harm intended.

So should I plan on replacing the block? Or do you guys just not resleeve blocks because it's usually the same cost to get a good used one?

Also, I didn't realize how skewed plastigage readings can be. After doing some research I realize. But that's not the issue at hand I believe.

Live and learn though.

[butters]

damn im worried about doing this now. but i cant turn back cus i already bought the parts.

I bought OE parts and supplied to my builder, after they confirmed bearing size (on the replacement crank I had to source - as per above, the original was too far out on one journal for micro-polish). It's not too late for you to go to the pros.

[ForcedFirebird]

Your arrogance concerns me.

Jim has done nothing but try and help you, all he is doing is telling you the truth. We build engines often and there's certain thing we will no accept. Cracked block goes in the scrap pile, so does scored pistons - we won't even turn a BMW crank to .010" under (micro-polish only). Some of us have been building engines longer than many members here have been alive and will give advice based on experience - not what we read on a forum.

[jlevie]

Your arrogance concerns me.

I think what I said is pretty much what any engine builder would have said. It isn't arrogance.

[brianao34]

Plastigauge is okay for a crude sanity check, but when it comes to bearings the only reliable method is to measure each journal and pick the "color" of bearing that results in the correct clearance. If you are lucky one "color" of bearing will work for all of the mains and rods. But it isn't uncommon to need bearings from two or more "color" sets.

A ring gap check only tells you that the ring gap is correct at the top of the cylinder. It says nothing about how much wear the cylinder has, which will be at the bottom.

A cracked cylinder from an over rev? That block is maybe good enough to be a buoy anchor, but certainly not good enough to be a motor.

It is really simpler than that on a BMW engine. Piston skirt scored, new pistons. Ring grove damage, new pistons. Bore damaged or worn beyond spec, overbore & new pistons. Crank journal out of round, scored, or worn below minimum, new crank. Cam worn or scored, new cam. Etc.

Your arrogance concerns me.

[jlevie]

That was my first mistake on my first build. I didn't get any hard numbers from the machinist, just, "standard size is good." As far as the bearings, I plastigage'd each one and they were all well within spec. I assume that after checking the ring end gap that would tell me that the cylinders were within spec.

Plastigauge is okay for a crude sanity check, but when it comes to bearings the only reliable method is to measure each journal and pick the "color" of bearing that results in the correct clearance. If you are lucky one "color" of bearing will work for all of the mains and rods. But it isn't uncommon to need bearings from two or more "color" sets.

A ring gap check only tells you that the ring gap is correct at the top of the cylinder. It says nothing about how much wear the cylinder has, which will be at the bottom.

Mileage was unknown. The engine was pieced together. The block according to the previous owner was recently rebuilt and R3v-shifted and cracked #4 cyl. I had the cyl resleeved and after some research and inspecting it it looked like he did a great job.

A cracked cylinder from an over rev? That block is maybe good enough to be a buoy anchor, but certainly not good enough to be a motor.

Yea, it's not rocket science at all, but then again as a first time builder you run into things like, is the piston skirt too scored? Or, this piston ringland has a slight imperfection, can I just file it smooth or is that something that shouldn't be done? That's my problem, I have no one close to me that has done it to ask simple questions that I end up searching for hours on the internet before I see that one guy says, "it worked for me."

It is really simpler than that on a BMW engine. Piston skirt scored, new pistons. Ring grove damage, new pistons. Bore damaged or worn beyond spec, overbore & new pistons. Crank journal out of round, scored, or worn below minimum, new crank. Cam worn or scored, new cam. Etc.