Piston rings

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rob1miles said:
The bores look very worn, we are looking at how soomth they are, they should be slightly rough to hold the oil, all of that has worn off. We are also looking at how big the step is at the top. the bore above the point where the rings stop wears very little so it give a measure. The bores also wear oval, more side to side than front to back because the con-rod/crank angle pushes the piston to the sides. If you get a inside caliper and some feeler gauges you can measure it. Clean the top 5mm of the bore and set the calipers to that, then move them down the bore and use the feelers to measure how much bigger it is. Remember it all started the same size. The rings will be very worn and not springy so there will not be enough pressure to fire the diesel. With a petrol it would run but burn a lot of oil. You may be able to fit new rings, but if you do you MUST cut back the ridge at the top - get a "ridge reamer" from an engine repair shop. If you do this you will need new rings and new big end shells, its the cheapest fix for an engine to keep it running. If you do not cut back the ridge the new rings will hit it and break. The vidoe of the measuring has a fancy tool but old fashioned calipers and feeler gauges work ok.

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Very helpful, the first video explained well the problem with the ridge on top of bore. I think it shouldn’t be a problem to get a ridge reamer nearby.
I will try to measure bores, I understand if they are too oval, the bores should be rebored. Right? What is the wear limit?
Also, why it is necessary to replace the big end shells?

jamesmartin said:
cranking speed and pump pressure a worn pump can often not reach injection pressure at cranking speed,timing etc ,did you get any smoke from exhaust
theres a defined ridge were rings reach the top of the stroke and you can see were 2nd and finishes and bores have that extreme polished look ,ive done enough of those engines to tell just by looking
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I have some smoke from exhaust when cranking. Once it almost started.
Not sure about the cranking speed. Cranking sounds same as on my other series, but than again, I could be wrong here. Is there a way to measure the cranking speed?
 
DefenderScout said:
Very helpful, the first video explained well the problem with the ridge on top of bore. I think it shouldn’t be a problem to get a ridge reamer nearby.
I will try to measure bores, I understand if they are too oval, the bores should be rebored. Right? What is the wear limit?
Also, why it is necessary to replace the big end shells?


I have some smoke from exhaust when cranking. Once it almost started.
Not sure about the cranking speed. Cranking sounds same as on my other series, but than again, I could be wrong here. Is there a way to measure the cranking speed?
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dont bother with a ridge reamer you cant polish a turd,in any case you can get top rings called ridge dodgers they have a chamfer on top edge but new rings wont help ,it needs a re-bore and new pistons, the measuring isnt to prove its worn thats obvious to to see what plus size piston would be correct,if your doing the block youd fit crank bearings as a matter of course
 
Alternatively, get a replacement engine and save yourself a load of bother. J M is right, your engine is worn but I reckon you could get it running without much expense. The trouble is, it will lack power and smoke like a good un. These engines are indestructible and will still run when all others in similar condition wouldn't. It just a question of getting the fuelling right.

Col
 
When i tried to get ridge dodger rings I couldn't find any, got the feeling they were seen as a "thing of the past", pity, but that's why I got a ridge reamer.
 
rob1miles said:
When i tried to get ridge dodger rings I couldn't find any, got the feeling they were seen as a "thing of the past", pity, but that's why I got a ridge reamer.
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i wouldnt use either, i guess it would be specialist suppliers now,they were never an lr replacement part
 
Thank you for valuable advise. I made my mind. I will just assemble everything back together and try to crank again as is. If no luck, I will sell the truck as is - I have more series to play with and for an engine rookie like me this would just be to much of a job right now :)

I have 5 more engines sitting in the barn, so to learn working on engines I might take one on the work bench and start working on one which is outside the car.

I will keep posting how the cranking goes. Yesterday I replaced the starter for a better one and cleared earthing cable connection points on chassis.
 
DefenderScout said:
Thank you for valuable advise. I made my mind. I will just assemble everything back together and try to crank again as is. If no luck, I will sell the truck as is - I have more series to play with and for an engine rookie like me this would just be to much of a job right now :)

I have 5 more engines sitting in the barn, so to learn working on engines I might take one on the work bench and start working on one which is outside the car.

I will keep posting how the cranking goes. Yesterday I replaced the starter for a better one and cleared earthing cable connection points on chassis.
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That's what I would do too. There are some talented mechanics on here who would think nothing of removing an engine, stripping and rebuilding it just for fun. I think they are perfectionists, nothing wrong with that but I'm more your big hammer merchant and the method seems to work for me. Whatever you do though, don't let it get addicted to easy start spray. When I worked on the buses as a mechanic, and I use the word loosely, if we had an engine that was a difficult starter, we would hold a burning rag close to the air intake whilst someone cranked the engine. Worked nearly every time. I'm not suggesting you do this unless you are willing to strip the head off to remove all the ash. Nowadays, I'd use a blow lamp. For short term solutions, a bodger trumps a perfectionist every time. Good luck.

Col
 
The point about the ridge reamer or ridge dodger rings is that new rings can give a worn engine a new lease of life. Its not the same as a rebore, new pistons and new rings, but it can work suprisingly well especially if the engine is doing low mileage and it can all be done with the engine in the vehicle. The big end shells wear faster than the main bearing shells and the wear in the big end shells is usually what determines the oil pressure, more wear = less pressure and as they are cheap and you have to take the big ends off to change the rings it is standard practice to change them at the same time. By the time you have the pistions out you have done 95% of the work of changeing them so its "no brainer" to do them while you are there. When you take them off they will have numbers on the back, you are looking for std -010 or -020 or the same in mm or some numbers you can look up on the web. I would take the pistons out in your engine, in my expreince when an engien is that worn the rings can loose all their spring and be doing nothing.
 
rob1miles said:
The point about the ridge reamer or ridge dodger rings is that new rings can give a worn engine a new lease of life. Its not the same as a rebore, new pistons and new rings, but it can work suprisingly well especially if the engine is doing low mileage and it can all be done with the engine in the vehicle. The big end shells wear faster than the main bearing shells and the wear in the big end shells is usually what determines the oil pressure, more wear = less pressure and as they are cheap and you have to take the big ends off to change the rings it is standard practice to change them at the same time. By the time you have the pistions out you have done 95% of the work of changeing them so its "no brainer" to do them while you are there. When you take them off they will have numbers on the back, you are looking for std -010 or -020 or the same in mm or some numbers you can look up on the web. I would take the pistons out in your engine, in my expreince when an engien is that worn the rings can loose all their spring and be doing nothing.
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At first I was keen to the idea.. I took of the sump and then I reconsidered. This is the 2.25 with 5 bearings and it has a somesort of cover above the sump, therefore I chose not to proceed.

BUT WHATS IMPORTANT!! I assembled it all back together with a good starter and earthing redone aaand.. it runs! I heated the plugs for about 30 seconds, cranked for 5 seconds and it started :) I was actually surprised by the sound - doesnt sound that bad at all.

I am now going to work on the electrics and clutch. I will keep this tread updated

Thanks guys!
 
Now I am stuck again. Clutch...
Master cylinder and slave cylinders ale both new. Cant seem to bleed the thing.

What is the best method for bleeding clutch on a series 3?
 
bleed nipple at the top, have you any fluid at all at the slave, if not remove pipe at master and use your thumb over the hole as a valve to bleed master up first
 
When I was having trouble bleeding mine, I parked it so the front was facing uphill and wedged the clutch pedal down with my hammer and left it for a couple of days. It seemed to do the trick. I use the same method for bleeding my bike clutch, I clamp the clutch lever back to the grip and leave it for a few days.

Col
 
Done. With the right approach I managed to bleed the clutch in few minutes and without a partner.

The approach that worked for me was reverse bleeding.

Under pressure of approx 1bar I got fluid into the bleed nipple of slave cylinder. On the spare master cylinder cap (see picture 1) I fitted a hose to see what is coming out from the tank. While under pressure I made few very slow pedal strokes. After 5 minutes and about 1liter of fluid I got the system fully bled.

Now brakes - I have a servo assisted dual circuit system, these are also pain in the A to bleed. The only method which worked for me was to undo the hubs and rotate the brake assembly plate into a horizontal position. Today I tried to slack off one bleed nipple and it broke :/ so plate out anyway..
But first, all wheel cylinders will need an overhaul.

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CC868889-7AB5-42C2-AE02-DB6AA519291C.jpeg
 
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