piston rings

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martin53

martin53
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How hard is it to change piston rings. I'm thinking of pulling the engine and swapping rings. Getting oil in plugs

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not that hard. gotta pull the motor, pull the head and the pan. get a ridge reamer to take down the ridge at the top of the cylinder. from there pull the pistons one at a time making sure you pay attention to their orientation in the cylinder. pull the old rings off. be carefull you dont want to scrape any of the aluminum off of the cylinder. clean the ring lands well, make sure the holes in the oil ring are clear and re install the new rings. they can go on more then one way but there is only one right way to put them back on. if you do it wrong you will still have smoke and oil in the cylinder and low compression. get a ring compressor and tighten it down on the piston and tap the piston back into the cylinder carefully with a piece of wood or i like to use a wood handled hammer. a good safety tip is to put some rubber line on the connecting rod bolts so they dont nick the crank. snug them up and move on to the next cylinder. i get them all snug then go over all of them and torque them down once they are all done. make sure you put the caps back on the connecting rods the way they came off too. otherwise your bearing will spin.
 
not that hard. gotta pull the motor, pull the head and the pan. get a ridge reamer to take down the ridge at the top of the cylinder. from there pull the pistons one at a time making sure you pay attention to their orientation in the cylinder. pull the old rings off. be carefull you dont want to scrape any of the aluminum off of the cylinder. clean the ring lands well, make sure the holes in the oil ring are clear and re install the new rings. they can go on more then one way but there is only one right way to put them back on. if you do it wrong you will still have smoke and oil in the cylinder and low compression. get a ring compressor and tighten it down on the piston and tap the piston back into the cylinder carefully with a piece of wood or i like to use a wood handled hammer. a good safety tip is to put some rubber line on the connecting rod bolts so they dont nick the crank. snug them up and move on to the next cylinder. i get them all snug then go over all of them and torque them down once they are all done. make sure you put the caps back on the connecting rods the way they came off too. otherwise your bearing will spin.


Great advice.

I just want to add;

Check to make sure that all of the new rings are free spinning in their grooves before installing the piston.

Make sure that the ring gaps for the two compression rings and two small oil rings are at least 90° apart from each other. (180° is best).


Posted via my desktop at home...
 
If you're gonna pull it for new rings, maybe get a ball hone at NAPA and clean up the cylinder walls....










Posted via my desktop at home
 
That was my next question. Would I have to hone cylinders walls even if their in good shape. Is it necessary. I was just planning on putting it on a stand just to change the rings and maybe the head.

Posted via Topify on Android
 
You will be dismantling pretty much every piece of the engine in the process of doing this. If you don't already have a Factory Service Manual you need it for all the specs. Not much diff in the years, but there are some. The FSM has details for complete engine rebuild. Also go to slantsix.org. In particular - look under 'articles' for manifold install and main seal/oil pan install.

Many manuals are available at http://www.mymopar.com/index.php?pid=109
 
good call on staggering the rings and making sure they spin freely. odds are that you will break a ring or two taking the old ones off. you can use the pieces to clean the ring lands if there is a lot of built up crap in there. otherwise a little gas or gum cutter will work well. DO NOT HONE. your motor has had xx,*** miles to polish the cylinder wall. you will not get that back until you drive that many miles again. there is no need to hone with cast rings. when i did them in my motor i was skeptical because it goes against everything i ever learned about the subject. i was pleasantly surprised to see the rings seal in under 200 miles. no smoke no blowby just a smooth clean running motor. fsm is a good idea too.
 
Simple re-ring job are getting rarer anymore. With bore and piston wear, it usually does not work for that long.

Ring grooves: It is more than free spinning of the rings in the grooves. Ring grooves get worn and dirty. They have to be cleaned, and then the ring side clearance in the grooves has to be checked. If the grooves have worn wide, the new rings will flutter in the grooves and wear rapidly. At that point, time to at least put in new pistons.

Hone: I would not bother re-ringing without a hone job. Doing it in-car, and then cleaning out the grit takes a lot of care. Glazed walls are a problem for new rings ever sealing; I'll humbly disagree with the above opinion on this matter.

Pulling: To pull the pistons, you need to pull off the head, and then pull off the oil pan. (Plan on partly lifting or jacking up the engine for this.) Then you can unbolt the rod caps and carefully take out the piston& rod assemblies.

Bore check: Once out, you need to check the bore wear. Check #1 most closely; #1 tends to wear more in inline 6's due to being at the front and cooler. If worn too much, piston rock will wear the new rings pretty quickly. Time then to pull and bore.

Ridge removal: Taking out the ring ridge in a /6 is not the most trivial job since the top ring is so far down in the bore.

OTHER OILING ISSUES: Aaaaand, before you go tooo far.......Your plug oiling may not be due to rings at all. It may simply be worn valve stems and valve stem seals. New seals can be installed easily; all you have to pull is the valve cover and use the right tools and techniques. I would definitely do the valve stem seals first to see if it clears up the plug oiling. New seals costs $15 or so, plus a new valve cover gasket. Even better, just take the head to a shop and have the valves and guides all gone over, do a valve job, and all of that will be known good.

You can usually detect bad valve stem seals by:
- Drive around and back off the throttle completely and come to a stop from medium speed and idle for 20-30 seconds.
- Then start out normally. If you consistently get a cloud of bluish oil smoke when you accelerate after decel and idling, that is usually valve stem seals.

You also may have sticking oil rings; that will show up in erratic clouds of oil smoke. Have you had much fuel contamination in the oil due to a carb leak or a leaking fuel pump diaphragm?

You can try loosening up sticky rings; may work or may not. Get a pint of Sea Foam or Rislone. Idle the engine and than take it to a fast idle by hand; dribble at least half of the pint of fluid veeery sloooowly down the carb while modulating the throttle by hand to keep it running. It will take a few minutes to work a half pint of this through the engine. You will get a huge storm cloud of smoke in this process; it might loosen up a stuck ring, or not if it is really bad, but the smoke part is fun. It will clean intake valves pretty good. Then put the rest in the crankcase and run it. Stuck rings can loosen if not bad, but if they are really badly varnished, there is not much hope.
 
First thing to do is a proper compression test and/or a cylinder leakage test. Find out what's causing the problem before taking things apart.
 
honing is a matter of opinion. way back when it may have been a necessity but not so much these days. do your own research and make your own decision.
 
Where is the oil coming from.??

Looking at the deposits on the spark plugs should tell you if it's rings or hopefully valve guide seals.

Pull the plugs,, and if oil is accumulated on one side of the electrodes,, then its possible you just need valve guide seals..

Oil evenly coated on the plugs,, would indicate rings..

Google "how to read spark plugs"

A vacuum guage reading, along with the "green tab" samples at this link may also be helpful in determining your problem..

http://www.secondchancegarage.com/public/186.cfm

cheers..
 
cast iron rings needed to be lubricated by the familiar cross hatch pattern a hone (dingle ball or stone) to seat properly. Chrome rings needed a smoother bore and finally moly rings needed the smoothest (ie. seasoned motor polished) and they required almost no break in time, maybe 200 miles. If you get new rings and dont want to scuff the walls with a hone, get chrome or moly rings. I reringed my smoking tired 2.0 mazda truck without honing, installed moly rings, checked valve seals (they were good) and started it right up. No more smoke, more power and I have put 16000 miles on it without a sign of smoke. Iron rings needed the roughest surface to seat, chrome was smoother and moly is almost polished. Id do valve seals first, then wouldnt hesitate to rering the motor with it still in the car, especially a slant. Easiest motor to do with exception of the oil pan rail almost sitting on the frame. Stuff some poly rope in the spark plug hole, bring piston up to TDC and use valve spring compressor to pop retainers off without losing the valve, R&R the seals and give it a drive. Much easier than a rering. About every LA head I dealt with had rock hard seals and 50% were always missing, Id find the pieces in the pan.
 
That was my next question. Would I have to hone cylinders walls even if their in good shape. Is it necessary. I was just planning on putting it on a stand just to change the rings and maybe the head.

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You don't have to hone it to change the rings, but while you have it torn down, you may as well get a ball hone and "scratch the cylinders"...

It puts a good surface on the walls so the rings seal better....
 
Hastings recommend 220-280 grit hones for all 3 ring types. Other recommendations are for low 200's for iron and high 200's to low 300's for moly faced. see here:
https://www.hastingsmfg.com/ServiceTips/cylinder_bore_refinishing.htm

The OP is likely to end up with moly faced rings for this engine (not full moly). Keep in mind that the 2nd ring will be cast iron. The Hastings rings that come from EngineTech are not a full moly top ring; there is a moly 'insert facing' in the top ring with cast iron uppper and lower ring edges.

A lot of what is being forgotten is that cylinder taper and roundness have lot to do with a re-ring job sealing. I will be that the guys who have put in rings and ended up with success with or without honing had good round bores with little taper. So any of us just saying that a re-ring with or without a hone job will work out well is not complete adivce; the bores need to be checked first. I have done one engine with bore tapers in the range of .003" to .008" and it ran, but it was not ever right; I was a poor student at the time.
 
Hastings recommend 220-280 grit hones for all 3 ring types. Other recommendations are for low 200's for iron and high 200's to low 300's for moly faced. see here:
https://www.hastingsmfg.com/ServiceTips/cylinder_bore_refinishing.htm

The OP is likely to end up with moly faced rings for this engine (not full moly). Keep in mind that the 2nd ring will be cast iron. The Hastings rings that come from EngineTech are not a full moly top ring; there is a moly 'insert facing' in the top ring with cast iron uppper and lower ring edges.

A lot of what is being forgotten is that cylinder taper and roundness have lot to do with a re-ring job sealing. I will be that the guys who have put in rings and ended up with success with or without honing had good round bores with little taper. So any of us just saying that a re-ring with or without a hone job will work out well is not complete adivce; the bores need to be checked first. I have done one engine with bore tapers in the range of .003" to .008" and it ran, but it was not ever right; I was a poor student at the time.


True, but if he just wants a quick "refresh" it will still benefit as it should seal better than it did with the old worn out parts....

It's not "by the book", but it is better than waiting until it gets worse before fixing it....
 
Always hone the cylinders when doing a ring job, and wash the cylinders clean w/ soap & water until you get no stone residue on a white cloth. Also change rod bearings, since in there and cheap. The main bearings tend to wear less, in my experience. I pull one main cap to check one and if looks new, don't touch them. I think you can do it w/ engine in car. I did my 383 that way and didn't have to crawl underneath too many times. In my 64 slant, I must jack the engine up a bit to remove the oil pan. The K-frame might block access to a front cylinder in a slant. Change the rear crank seal while in there and remove and clean the oil pickup.
 
Washing the cylinders with soap and water in-car would not be wise IMO....; it'll get into the mains. Use ATF saoked into paper towels and go over and over each cylinder until no more grey color shows up on the paper towel. It usually takes 3-4 cleaningss with ATF to get it that clean; ATF will really suck the crud out of the grooves.

And, BTW, I have seen plenty of reference to Moly rings using a hone grit in the ranges of 300-400, especially for full moly top rings. But the Hastings/EngineTech moly top rings for the /6 are not full moly tops.

The one issue that really would give me pause for honing in-car is the grit getting all over the crank; the honing fluid will wash it down into the oil passages in the rod journals if you do not plug them and will also wash the grit into the edges of the mains. How well the oil pressure in the mains will push that out, I can't say. But then the grit will go into the pump. So that is is one good reason to not hone in-car. That all adds up to why I don't bother to do anythingbut pull the engine; you get aroudn all these issues. Easy to do since I have an engine hoist and stand!

So OP, are you just rolling your eyes by now? LOL
 
Is the engine burning oil? Do you have the drool tubehead? If you arent using oil and have a drool tube around the plug, you may be fine.
If not, I still agree with making certain the rings are the source of the oilfouled plugs. I would do a cylinder compression test and a leak down test first and make sure it isn't valve seals, which would be a far easier fix. It you do have to replace the rings, you should consider some other work to do while the engine is dismantled.
 
Definitely test the engine before deciding you need new rings. Many people here jump into pulling the head, then find the head gasket was fine (not reason for their over-heating, like Billy-Bob told them), cylinder walls look new, then wish they had checked compression first. First, just turn the engine over by hand, tugging on the fan belts, and feel for each cylinder (3/rev). If all feel strong and you hear them hiss down, your engine sounds excellent.

If you do re-ring, many people do that w/ block in car. I have, but never a slant. I always flow new oil thru, using a little pump-up garden sprayer in the oil switch hole. That way clean oil flows out the bearings, washing out any water or grit, plus primes the engine. You don't want any stone grit from honing left on the cylinder walls, so clean thoroughly by whatever means.
 
I'll check the compression first. I got 4 plugs that have foulers the other 2 are good. The engine was sitting for 2 years I got it from a guy down the road its a strong engine but the just knowing I have could plugs bothers me. Hopefully I just got to change valve seals. I got a intake manifold gasket I'm going to replace it when it warms up a little. Is it really that difficult to change the manifold gasket every thread I read it seems like a long process. Thanks for the help guys
 
I'll check the compression first. I got 4 plugs that have foulers the other 2 are good. The engine was sitting for 2 years I got it from a guy down the road its a strong engine but the just knowing I have could plugs bothers me. Hopefully I just got to change valve seals. I got a intake manifold gasket I'm going to replace it when it warms up a little. Is it really that difficult to change the manifold gasket every thread I read it seems like a long process. Thanks for the help guys

It seams that most of us take the manifolds all apart. Clean, paint, do carb.... IF you are not doing any of that, I see no reason to separate them. Never done one that way, but should be able to take the whole thing off and back on as an assembly. Doing it that way it's just a matter of getting your washers back in correct place. If you disturb the studs, use sealant when putting back in. If it's a stock gasket now and it's not leaking, you should be fine to put back with same. Many of us go to Remflex or Aussie gaskets for a bit of insurance of not having to do it again.
My earlier post referenced info on rebuild. Doesn't mean you need to do it, but along with tips here, at least you can have the info to make more informed decisions what needs done as you get into it. I don't think you ever said what the year or mileage was. Or what your intended use is. That would all play into my decision of how far to go with it.
 
The manifold is not a long process but there are the right placement of washers and fasteners to learn and checks of gaps, and the best procedures. Once you learn it, you can R&R the manifolds in <1 hour (assuming they are not warped and you have your gaskets, sealants, extra studs just in case, etc.).

BTW, any oil coming past bad oil rings can oil-up the compression rings and make the compressions read pretty good. Make sure you do it after it has set at least overnight and not been started at all, to let as much oil as possible drain off the rings.
 
Read the article on www.slantsix.org before removing the manifolds. Valve stem leaks cause oil to be sucked past when idling (high vacuum) a long time, like sitting at a stop light. When you drive away, you get a puff of black smoke. Leaking rings typically give a blue smoke under hard acceleration. Have someone drive behind you, preferably looking thru the exhaust into the sun as you step on the gas.
 
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