Old pistons...new rings, or not?

[RobertH]

Hi all,

I am working on my JD engine, which partially seized on me last winter, due I suspect to bearing wear, dirty oil, maybe partially plugged oil filter. Anyway I pulled the engine and all is apart.

The kicker is that there is no aftermarket rebuild kit for this engine, (type 4219 GT) which is gas. There is one for the diesel version. Among other things the pistons are different. Nevertheless I have sourced most of what is needed to rebuild it from different suppliers, including a new (used) crank and all the usual bearings, gaskets etc.

I am hung up on what to do regarding pistons, liners and rings. JD does have liner kits available, the problem is the cost, $403 per cylinder and I need 4.
What really floored me was the cost of just a ring kit, $132 per cylinder!

So, what to do?
1 mortgage the house and buy four new liner kits (really a stretch to find that much $$) OR
2 Re-use the old pistons, rings and liners OR
3 Old pistons with new rings

Or maybe something else, new pistons and rings in old liners perhaps. I am not sure what.

I had thought to put new rings on the old pistons and just hone the liners a bit. However I understand that if the old pistons are too worn in the ring grooves this may not be a great approach. I would appreciate insights from anyone with more experience.


Rob

 

[dieselknudt]

Are your pistons or liners damaged?
If you don't have serious pitting on the liners you should be able to hone them out.
Same the the pistons, the rings are doing the sealing.

 

[bigdeano]

I'd measure the liners and pistons and compare the clearance you have to what the manual says is allowable. It will help you decide what to do.

 

[doxford jim]

The engine you quote - is it a 4 cylinder, 219 cu in engine ? If so I had the equivalent diesel in my JD450 crawler loader but in the diesel version.
Those prices don't seem realistic and I would advise on checking the after market sources further. I rebuilt the engine in my JD450 and found the parts much cheaper after market. I did buy JD piston kit and liners though, which were pricey.
The cylinder liners in my engine were actually holed through the cylinder walls by cavitation. I also had bad seals between the liner and block.
A hard call on your situation, but needed. My mix of parts ended up costing me around $4,500 all told plus $500 plus on a head rebuild.
Whatever you do, it will probably be expensive. Good luck in your search.

 

[doxford jim]

OOops - a mistake on my figures. It should read $2,500 all told including around $500 for the head rebuild. Sorry about that though it won't make it any easier for you as JD like to charge a lot of money for their parts.

 

[RobertH]

Thanks to each of you for the feedback.

My existing liners are reasonable, no bad pitting, cavitation etc, however at least 2 of the pistons had cracks, so I will replace them all. I have found a source of good used pistons.

I will check the clearances for sure as part of the triage process.

Jim in BC, for sure I agree the prices are not very reasonable but the choice appears to be JD or nothing for a new liner kit, as aftermarket options do not seem to exist. I have checked all ways and had a local machine shop check all their 'inside' sources as well with no luck. I would really prefer to put new liners and pistons in, but at some price point it gets impossible. As such I have to decide which combination of alternatives is best.
cheers

Rob

 

[whis]

I know it's a lot of money but if half way do it you will be doing it again. check with some more dealers and buy the new liners you will be money ahead in the long run. How do you know the old liners are not egg shaped?

 

[jaydee325]

Back in the day, Perfect Circle was the go-to outfit for pistons and rings. They are now owned by Mahle. Google either. Hope this helps!

 

[doxford jim]

Can't help you on the after market parts supplier as I have since sold the JD450 along with the manual and extra info I had in it. I did google the supplier quite accidently but it proved quite worth while. All I can tell you is that I bought from an outfit in Saskatchwen and had the parts sent to me by Greyhound bus (quickest and cheapest back then).
One thing I would advise is to renew the two balancer shaft bearings while you have the engine apart. I found mine (shaft bearings) quite worn and probably contributed to low engine oil pressure. When rebuilt and with the engine warm etc., I got 45psi oil pressure. I also installed a new oil pump and replaced the oil pressure regulating valve and spring.
HTH

 

[franklinute]

Is this rare for a gas tractor to use liners? Is this due to just the way it was done on older tractors?
I was thinking that a sleeve could be installed and cut the bore to fit the piston. There are businesses
that specialize in obsolete engine parts sometimes they are hard to find.