Smoking #1 cylinder on My Ford 3000 Diesel

[mtodd101]

The rings are measured in the cylinder and in your case near the bottom where there is no wear.
Insert the rings 1 at a time into the cylinder and use the piston to square them up and push them towards the bottom of the bore, then measure the ring gap there.
Can you measure the piston dia. So we can determine if you have the correct pistons?
The piston is measured ｽ ~ 1 from the bottom at 90deg from the wrist pin.
Oversize rings cannot be put on standard pistons.
90cummins

Hi Cummins. I wasn't able to get the ring tool. Had to order it, will pickup tomorrow morning. I did measure the pistons already. I had to use calipers and then mic the gap. I measure across the center of the wrist pin. That's where the manual said "is the datum from which bore clearances are calculated". I did it a couple time because it wasn't the most accurate method and got between 4.18-4.19. The manual says 4.1927 for a standard bore assuming "grading Diameter" is what your asking. Ring gap for the oil ring is.013-.033 and the gap for the top comp ring is .012-.038 and the gap for the intermediate comp ring is .010-.035. So I'll do the 3 compression rings and the 2 oil rings(2 rings in the same groove separated by a wavy ring). Do I measure the wavy ring also?

Anyway I'll be reading the manual and try to figure out how much it would cost to do it right. Thanks again for the help your giving. Time is a valuable thing. I appreciate you give me some of it as well as the others that have helped. Matt

 

[ptgdigger]

Before you take those rings off would you be able to take another picture of all 3 pistons together, what i'd like you to do is roll all the rings so the gaps line up on all 3 pistons, put them on a table side by side with the gaps facing you and take the best closeup / high resolution your camera can handle. Something seems a little off with that #1 piston/rings but I just can't pin it down when switching between that and the other piston you posted, maybe side by side looking at the gaps will reveal some clues.

I see you mentioned wanting to pull the rings to measure ring gap , I would really like to see those numbers as well. As for the blackening on the pistons that are burning correctly , when the fuel ignites and the piston is forced back down the bottom of the connecting rod swings well off center with the crank , this allows the piston to be forced towards one side of the bore creating a tiny bit of slack at the other side, as the crank swings past bottom dead center the rod goes the other way the piston will bias to the opposite side and the exhaust stroke will complete , i don't know if your "staining" is occurring on the power downstroke or the exhaust upstroke but it doesn't seem out of line for an engine as "experienced" as yours. The piston you showed has the staining stopped at the second ring so the rings seem to be sealing that bore at least.

Ray

 

[mtodd101]

Before you take those rings off would you be able to take another picture of all 3 pistons together, what i'd like you to do is roll all the rings so the gaps line up on all 3 pistons, put them on a table side by side with the gaps facing you and take the best closeup / high resolution your camera can handle. Something seems a little off with that #1 piston/rings but I just can't pin it down when switching between that and the other piston you posted, maybe side by side looking at the gaps will reveal some clues.

I see you mentioned wanting to pull the rings to measure ring gap , I would really like to see those numbers as well. As for the blackening on the pistons that are burning correctly , when the fuel ignites and the piston is forced back down the bottom of the connecting rod swings well off center with the crank , this allows the piston to be forced towards one side of the bore creating a tiny bit of slack at the other side, as the crank swings past bottom dead center the rod goes the other way the piston will bias to the opposite side and the exhaust stroke will complete , i don't know if your "staining" is occurring on the power downstroke or the exhaust upstroke but it doesn't seem out of line for an engine as "experienced" as yours. The piston you showed has the staining stopped at the second ring so the rings seem to be sealing that bore at least.

Ray

Hi Ray. Thanks for the reply. I haven't pulled the rings yet so I took the pics you requested. Not great. I will take some in the daylight tomorrow, but here's the ones I just took. Thanks again. Matt The pics go 3,2,1 piston left to right

 

[90cummins]

I would like to make a correction, you can install oversize rings in a standard (or smaller) bore but you need to hand file/grind the rings to attain the proper end gap.
Those oil rings don't look right to me. I would expect to see an expander in there or a larger gap for more pressure on cylinder wall.
There needs to be adequate pressure for the rings to follow the cylinder wall; on the other hand the cylinders have a lot of wear (taper) so maintaining contact will be difficult.
Is it possible to obtain another set of rings so you can compare the oil ring inner expander???
The cylinders have a lot of wear and may just be beyond what standard rings can handle.


90cummins

 

[ptgdigger]

I think the 2 top rings on # 1 have issues , they show a lot more wear than the other rings on #2 or 3 (for maybe 10 hours of use), they have much larger relaxed gaps. I believe if you were to put the #1 rings on the # 2 or 3 piston that you would move the oil problem to those cylinders. I realize you have some cylinder wear issues but the measurements you gave don't add up to #1 being any worse than the other 2.

Ray

 

[duroc]

Matt wrote:

I know the best thing to do would be split the tractor and bore and sleeve it. My concern is then I end up doing clutch work and who knows what else and I have a large and costly summer project. I already have more work than I'll get done the summer, so I'm feeling the heat so to speak.

Hi Matt, I bailed out of this discussion because too much info can be confusing and very frustrating, and besides, some of the others were offering good info. Here's my opinion for what ever it's worth..... Instead of throwing lots more money and time at this repair, why not do it right this time around. Sure, it will take some time to get things where they need to be, but right now you're still chasing your tail (so to speak). Just my opinion, but even if you do cobble this job enough for it to work, you'll still have a motor that's iffy.

 

[ptgdigger]

Whether you bore it or sleeve it at this time or not I still think it is worth doing enough detective work to find out why #1 is oil soaked, if there is a ring problem , maybe poor quality or soft/twisted rings then you don't want to buy more sleeves/pistons or rings from that source, same with the ill fitting valve seals , I'd be looking for another supplier.

 

[mtodd101]

Hi guys. Got around to measuring ring gaps and they are huge. I measured the rings about .5" from the top of the cylinder because the top and bottom of all cylinders were the same @ 4.233". All compression ring had the same gap @ .162, give or take a thousandth. The oil rings on all 3 cylinders did NOT touch the wall and had a rough wall to ring gap of .010 - .020. I joked about the oil rings falling out the bottom in an earlier post. I didn't think I would be right. Holding the oil rings in my hand I measured the gap and it was between .015 and .020.

I still have no idea why 2 cylinders with worse numbers seated the rings and #1 didn't. There was some wear on the bottom of some of the rings. Not sure what to make of it. Anyway still waiting to hear back from the machine shop on cost of rebore. Can anyone give me an idea what cost i'll run into other than the rebore, sleeves and unknown thing. I'm thinking about clutches and bearing, turning the crank. I have a small fuel leak somewhere behind the injector pump that needs some attention also. I saw rebuild cost of about $ 700 so you see where my problem is. Money... I think it's money.

Hi Digger.

Your right on the rings, some thing isn't right. I think I bought the rebuild kit on Ebay. Won't do that again. I saw YT has parts for sale and I could go to the dealer. Any one you trust for your parts?

Hi Bill.

Yeah I'm pretty overwhelmed with this. I'm very mechanical but I just didn't think to check the cylinder diameter cause we've had this tractor for ever and it was never bore. Well I'll still make mistakes in the future but not this one.

Hi Cummins.

I honestly don't think the oil rings touched the cylinder wall on more than one side at any given time. The rings literally fell down the cylinder. I'm going to order an .030 over set of rings and see what they look like and how the fit. I do believe a expander ring should be behind there somewhere.

Thanks for all the help from you guys. Much appreciated. Here's some pics from today. Thanks Matt

 

[duroc]

.
Hi Bill.
Yeah I'm pretty overwhelmed with this. I'm very mechanical but I just didn't think to check the cylinder diameter cause we've had this tractor for ever and it was never bore. Well I'll still make mistakes in the future but not this one.

We all make mistakes, what really matters is if we learn from them. Obviously you have, so that's a good thing.

Whichever way you decide to do your rebuild, take the pistons, along with the block to the machine shop and have them bore/hone the cylinders to fit with the proper clearances. As for the crankshaft, it may not be necessary to do anything with it. Check for scoring, and mic it before you make a decision to have it turned. Same thing applies to all the other parts/components. And most of all... Good luck and have fun getting your tractor up and running! It will be an experience that will live with you forever.

 

[the old grind]

Don't remember what/whether you said your piston clearance was, but I still think your bores were done .030"-over at some past time (before you owned?) with ~ .010" of cyl wear since. Gaps should be more like .016" give or take, and your rings seem to be std size, so those oil rings might be fine in a std bore without add'l expanders. (They don't usually require the same tension as compression rings & they're open-spaced to hold a bit of oil between upper & lower 'wipers' and keep the bore lubed without leaving too much of it there.)

Guess the oily-or-not thing WAS a red herring ....

Bore taper is somewhat typical with extended wear since rings don't sweep the bore's full length. (Wrist pins don't go below cyl bottoms at BDC & rings are above them) 'Side gap' allows combustion pressure to get behind them to assist compression ring sealing, with more wear possible toward the cyl's top over time.

IMO a rebore or sleeve job would be wise & worth your trouble in the long run, tho' this won't be V-twin easy. Be sure you're given the right pieces, and measure like you've been doing to match 'em up. Matt, you're 'on top of this' now! :thumbsup: