What should I see when I pull the heads off that would tell me I need rings?
Thanks

 

Nothing, visually.

Buy a vacuum gauge, read up on how to use it, and that will tell you if you need to investigate further with a compression or leak down test if the vac gauge indicates worn rings.

Doug

 

You can see the connecting rods, crank or oil pan. Get approx. 8 pistons while you're at it.

 

If you could see the connecting rods, crank etc with just the heads off, you're a better man than me.
Comedians....everyone's a comedian.

 

You could sure waste a lot of key strokes on this question unless we knew what you were trying to accomplish.

Why do you even raise the question for starters?

 

one of the keys here is how much ridge is at the top of the bores
also look for scoring or vertical scrapes along the bore walls
while these are not a true way to test ring conditions, these isues are a good indicator of the over all condition of the mill

there are times when a valve job or head replacement is done on a worn short block and the mill actually uses more oil or smokes because the vacuum pulls oil past the rings......good luck, hope this helps.....

 

The quick check for bad rings is a compression test. If compression is low, squirt some oil through the spark plug hole and redo the compression check. If the compression come up, the rings are bad.

tc

 

exactly right!

 

How many miles on the motor?

 

If the engine still runs you have a better chance of determining Piston Ring sealing. If you have all ready torn it down and the heads are off ring seal is impossible to determine for sure. If the cross hatch is still visible and it is proper cross hatch, you need someone that really knows internals to determine this you may know if properly sealed rings would work in this block but you will not know if the rings are actually sealed.
Cross Hatch should be at a 45 degree angle with an RA of 16 -20 or so for Moly rings.
The Cross hatch in a good used block should be pretty much the same on the thrust side and non thrust side of the pistons with very little or no ridge build up if you are planning to run this engine as is with no rebuild other than heads.
If the pistons are out of the block ring seal can be read by the wear pattern on the second ring if the top rings are Moly or Chrome or both the top and second if the rings are cast iron. There is much more on this subject but as Mike pointed out, why are you asking and what are you trying to learn?

 

"there are times when a valve job or head replacement is done on a worn short block and the mill actually uses more oil or smokes because the vacuum pulls oil past the rings......" exactly

The engine(29k) blew oil through the air cleaner/blow-by pipe. Figured it probably was the rings, talked to the engine builder before taking it apart. In the course of the conversation he said I'd know right away if it needed rings when I pulled the heads off. After pulling the heads off, I wondered what he meant because I don't see anything obviously wrong.
I was just curious before dropping it off to him. When I do, I'll ask him what he meant.
That's why I "raised the question for starters."

 

YES you need rings. You are pulling the heads and looking for something. That means you have a problem with the engine and you are trying to determine what that problem is. Don't stop with the heads. Pull the engine out, have it properly rebuilt and reinstall it. You have fixed your problem and there is nothing left to attempt to diagnose.

Now enjoy your car.

 

[QUOTE=joseph p;1577813681

In the course of the conversation he said I'd know right away if it needed rings when I pulled the heads off. After pulling the heads off, I wondered what he meant because I don't see anything obviously wrong.
I was just curious before dropping it off to him. When I do, I'll ask him what he meant.
That's why I "raised the question for starters."[/QUOTE]

You'd been far better off to ask the question BEFORE you pulled the heads. In the meantime, review post #10.

I don't think "most people" "would know right away" when they pulled the heads if an engine needs rings.

Your symptoms have causes other than bad ring seal.

 

I guess I'm not making myself clear, sorry. The engine is out, disassembled and ready to go to the engine builder. Since the heads are off, I asked the question. The real story will be handled at the shop.
Thanks

 

Having an engine out of the car, disassembled and ready to ship out for overhaul and then NOT putting new rings in it is like having the doctor tell you that you have a tumor and you ask him if he can't just "touch up the X-rays" instead of operating.

Of course, put rings in it -- I would be more concerned that your mechanic thought the need for them would just jump out once you pulled the heads off....makes me wonder about his capabilities....assuming you quoted him correctly..

 

Joe,

Whether or not it needs rings is mute. You already have it out and going to the rebuilder. Anytime you rebuild an engine the rings need to be changed. If you are asking just for the knowledge you should have asked the question prior to pulling the engine out and disassembling it. It is much easier to determine when the engine is in the car.

By the way, if the rebuilder told you that you would be able to tell if you needed rings when you pulled the heads off, I think I'd check into finding another shop to rebuild the engine.

 

i don't think the builder should be bashed here as any good builder can tell the condition of the bores with a slight glance
if it needs a re bore then certainly new rings are a must and maybe that's what his builder is speaking about
once again, this post was not written well at the start by someone who is seeking info. about a 3rd persons opinion.
any knowledge of the workings of an internal combustion engine will go directly to a leak down or at the least a compression check before the mill is broken down
if someone brought me a short block (heads off) as the op stated, i could tell right away if rings were needed by the amount of ridge, taper and the lack of crosshatch as many others have stated.........

 

I always go by the rule of thumb

"If she stops putting out, it's definately time for a new ring."

 

Joseph,

There’s more than one answer to your question since rings serve two jobs. That of sealing the combustion chambers to create cylinder pressure (the compression rings) and lubricatingthe cylinder walls (the oil rings).

If you haven’t already pulled the heads, you can do some diagnostics by the way the engine performs.
If the engine smokes a lot (Generally Bluish colored smoke) on start up after the car has set for a while but then clears out, that indicates you have bad valve guides.

If it smokes all the time, that indicates bad Oil rings. If it smokes all the time and doesn’t have the same power as it did before, that indicates bad oil and compression rings (and maybe bad valves). Unless there is a large quantity of black wet oil in on the pistons and combustion chambers you can’t really tell by pulling the heads.

Depending on your ability and provide the engine is still together to do so you can use a compression gauge to run a compression check on your engine by pulling the spark plugs. All cylinders should read above 100 lbs. on a good engine, but more importantly, should read about the same on each cylinder, if they don’t that usually indicates valve leakage problems.

All that being said, and depending on your budget and ability, it’s probably better to have the engine overhauled including rings, rod inserts, main bearings , cam bearings and a valve job on the heads. The reason being is that the valves and rings work together to seal the cylinders for good compression and cylinder pressure. also you have to disassemble the engine to get to the rings
Hope this helps
Jms58vt
 

 

I wish I had paid more attention to your information given, at 29,000 miles and oil blowing out the vent you have excessive blow by. Blow by is caused by the fuel explosion blowing past the compression Rings filling your crankcase with pressure. The only escape for this is the vent. New engines have excessive blow by until the rings seat, that usually happens in the first few minutes of operation. Dyno operators tell me they see the blow by stop before the second pull on a dyno test.
With 29,000 miles you may have fractured a compression ring or two with detonation or poor cylinder hone has worn out your rings.
IF the engine was built to factory specs they may have used Cast Iron rings or Chrome or moly coated Cast Iron rings. Although these work pretty well in standard engines they don't like detonation and can fracture if exposed to detonation. These old engines use high compression and run near detonation all the time, if you used cheap fuel or had a little advanced timing you may have fractured the top rings in one or more cylinders.
When you pull it apart the rings will fall out of the ring lands in pieces if this has happened.
If the piston ring lands were not damaged by the detonation just re ring the engine ( 29,000 mile ) and run it. Assuming the engine was assembled correctly to start with.
Upgrade the Top rings to Ductile Iron moly faced rings and you will not fracture any more rings. At this low mileage I would not even hone the cylinders. Modern Rings are pre lapped at the factory and work on a smooth cylinder perfectly and don't need a new hone to seat in. ( GM has recommended this for years now ) Moly faced rings have been the ring of choice at OEM's since 1984 or so. Cast iron top rings leave a lot to be desired.
Modern rings will run 300,000 miles without wearing the cylinder or burning oil in a well tuned engine.
If this 29,000 mile engine was not honed correctly on rebuild and they used Cast Iron rings a rough hone can wear out the rings to the point it causes this type blow by.
This type wear will leave the top and second ring worn flat accross the full face of the ring, normally they are angled. All second rings are cast iron so you can always read the second ring even if the top ring was a Moly Ring. Moly rings are barrel shaped on the face while cast rings are angled. At 29,000 miles the second ring should show a wear pattern on the face with the angle worn about 1/3. The cast rings are coated so the worn area of the ring face angle shows shinny steel where it has rubbed on the cylinder wall and grey to flat black where it is still beveled and not yet touching the cylinder wall.
At 100,000 miles you may see the second ring worn 80 to 100% on this same ring face but at 29,000 miles it should be no more than 1/3 worn. This is a simple way to read your rings and see how they are working on your cross hatch.
Detonation happens when the fuel charge lights off before the spark plug fires, this happens when hot spots in the chamber start to glow red and can fire the fuel charge early. This early ignition of the fuel charge try's to blow this piston back down as 7 other pistons are trying to push it up. Detonation creates cylinder pressures that can exceed 3,500 to 5,000 PSI while normal wide open throttle PSI in these engines is 600 to 900 PSI. Detonation is what breaks rings, blows head gaskets and can break pistons. These hot spots can be caused by cheap fuel, advanced timing or a lean fuel mix. Hope this helps.