730 Diesel Ring Gap

[deereboy4020]

Working on a 730 diesel with a blown head gasket. We decided to go ahead and pull the pistons to check the rings. It’s been bored .045 over and the pistons and bore are in spec. When I checked the ring gap I’ve got .164 gap on the compression rings. There isn’t a spec in the JD service manual for ring gap but that to me seems excessive. Just wanted to get some feedback from some of the JD diesel guys.

 

[Powered By IH]

I can't help you but you've really got a nice lineup on your profile there. Stellar tractors!

 

[used red MN]

Per the common rule of thumb spec of .004" per inch of cylinder diameter. That would be excessive, using that spec plus adding you over bore the min. gap would be 0.025". Your quite a bit over an 1/8"(.125"). I'm by no means a JD 2 cylinder guy, so best if one chimes in to agree or not.

 

[rustred]

I have never heard of anything other than .003-.004 for every inch of cyl bore. Red , Green, orange or yellow it’s still pistons and rings. Would not be the first time I have seen overbore pistons with standard rings. Lol

 

[JOCCO]

I have never heard of anything other than .003-.004 for every inch of cyl bore. Red , Green, orange or yellow it’s still pistons and rings. Would not be the first time I have seen overbore pistons with standard rings. Lol

I have to agree with you on all that. He should get new rings and test them in the bore, check end gap with feeler gauge.

 

[rustred]

Exactly , standard procedure. Never have to worry about end gap when you go the ATF overhaul.

 

[used red MN]

when you go the ATF overhaul.

ATF must not be “alcohol, tobacco and firearms” which is a US crime bureau, must need a Canadian translation? Everybody is not in your back pocket or wants to be for that matter.

 

[rustred]

ATF must not be “alcohol, tobacco and firearms” which is a US crime bureau, must need a Canadian translation? Everybody is not in your back pocket or wants to be for that matter.

Are you getting the knife out again ? Or having a bad day today ? Mechanics actually do know what ATF is , you know that red oil that a couple people use here to put in engine cylinders instead of Automatic Transmissions where it actually belongs.

 

[used red MN]

Are you getting the knife out again ? Or having a bad day today ? Mechanics actually do know what ATF is , you know that red oil that a couple people use here to put in engine cylinders instead of Automatic Transmissions where it actually belongs. View attachment 145457

Actually I had a brain fart and momentarily forgot about that “ATF” haven’t been enough posts by old to keep it fresh in my mind. I suppose it was partly because I am not sure how that correlated to his issue. By the “boy” in his username I would give him the benefit of doubt and not pull out the “idiot” card right away. From his fancy line up of green paint in his avatar I could draw other conclusions but I won’t open that up here.