dongfeng tractor with y385t wont start help

[reelnative]

well went out and pulled piston no2 in the center that had 455psi comp and guess what all the rings were all good, but theres more, the piston was broke in between ring 1 and 2 so it deff was a good idea to change out all three or i would of been doing this all over again, what do you tighted the rod bolts down to when putting it all back together, Thanks again guys

 

[reelnative]

does anyone know the gap of the rings when i set one in the cyl to test for tightness, i have a T snap gauge and micrometor but the micrometer only goes out to 3in but the cyls are around 3.25in so i have to drop a new ring down the cyl and ck for tightness that way with a feeler gauge, Thanks guys

 

[reelnative]

heres some pics of the broken pistons and rings that were in the 385 and the new pistons

 

[reelnative]

well i got the new pistons and rings put on the rods today and got the liners out and had enough time to hone 2 of them, before it started to rain hard with a lot of lighting and theres no were better to be then in a 1000sq ft metal barn so I called it a day, ill post some more pics tomorrow, I know there prob the same but the new pistons said y385 inside of them and the ones that were in the tractor said 485 inside of them also I dropped a ring into both of the sleeves before and after honning and there was almost zero gap in the ring opening is this ok or should there be a small gap

 

[Rich Waugh]

There should be a specific ring gap - the engine owner's manual should have the specs for it. If not, call Tommy at Affordable or Ronald at RanchHand Supply and they can give you the correct gap. If the rings are too tight when you put them in, they'll expand when the engine warms up and then they'll either score the cylinders or break or seize the engine. You may need to stone off the ends of the rings to get the gap correct, but it is very important to have it right. It is also important to put the rings in with the right side up and the gaps rotated so as not to line up. The manual should tell you how to set them up correctly.

 

[reelnative]

There should be a specific ring gap - the engine owner's manual should have the specs for it. If not, call Tommy at Affordable or Ronald at RanchHand Supply and they can give you the correct gap. If the rings are too tight when you put them in, they'll expand when the engine warms up and then they'll either score the cylinders or break or seize the engine. You may need to stone off the ends of the rings to get the gap correct, but it is very important to have it right. It is also important to put the rings in with the right side up and the gaps rotated so as not to line up. The manual should tell you how to set them up correctly.

hahaha yea rich i know its very important or i wouldnt be asking hahah ,before i installed the rings on the pistons today i called affordable tractor and spoke with harold and I asked him about ring gap and also about what side is up on the rings, and ring placement he told me he didnt know about ring gap but did tell me these rings didnt have a up or down side but the 2 black rings go on the 2 and 3 slot and the shinny ring goes on top, and also the oil ring goes on the bottom, I looked at the rings very close and cold not see any angles or marks on any side s of the rings, so i put them on as he said, I would think that there needs to be .010 or .020 gap for exp of the ring when it gets hot, im going to search this site to see if i can find out what the gap is if no one answers back, im not going to button it back up until i know the specs

 

[reelnative]

ok for anyone that wants to know in the series y85 diesel engine operation and maintenance manual, it states on page 5-3 that the ring side with a sign up should face the top of the piston, ok i was told differant so ill go ck again tomorrow, but i swear i didnt see any up sign, and also it states the end gap should be 0.2 to 0.4mm and side clearance between the ring and ring groove should be0.07 to 0.102 for the first ring and .05 to 0.082 for the second ring, what about ring 3 now this is the info i needed but theres one problem this book is talking about a piston with 2 fings and 1 oiler ring the pistons in my eng have 3 rings and 1 oiler so are these good readings or did they change the eng, seeing that now there are 4 rings are the rings diff then when they had 3 rings, any help would be great guys hahahha, its getting to be hair pulling time

 

[quicksandfarmer]

I know there prob the same but the new pistons said y385 inside of them and the ones that were in the tractor said 485 inside of them

The 385 is the 3 cylinder version and the 485 is the 4 cylinder version. They use the same pistons.

 

[Bob Rooks]

ok for anyone that wants to know in the series y85 diesel engine operation and maintenance manual, it states on page 5-3 that the ring side with a sign up should face the top of the piston, ok i was told differant so ill go ck again tomorrow, but i swear i didnt see any up sign, and also it states the end gap should be 0.2 to 0.4mm and side clearance between the ring and ring groove should be0.07 to 0.102 for the first ring and .05 to 0.082 for the second ring, what about ring 3 now this is the info i needed but theres one problem this book is talking about a piston with 2 fings and 1 oiler ring the pistons in my eng have 3 rings and 1 oiler so are these good readings or did they change the eng, seeing that now there are 4 rings are the rings diff then when they had 3 rings, any help would be great guys hahahha, its getting to be hair pulling time

Piston ring end gap: .020". I'm sure you know you need one of these to do the job correctly (or take them to NAPA):
ProForm 66785 : Proform Manual Piston Ring Filer.

Usually the top compression ring will have different tolerances than the intermediate rings, and the intermediate and oil rings will have the same tolerances. Sometimes the top ring will be a keystone type, and the intermediate rings will be a barrel type. Ring placement on piston should always start with the top ring gap in line with the crankshaft, and for three ring pistons, ring gap at 45 degree from each other working your way down. For four, five, and six ring pistons, same orientation for the top ring but ring gaps at 30 degrees.

 

[Rich Waugh]

The end gap and groove tolerances should be the same with the extra ring - like bob said, the top one is usually different and the lower ones are the same. Since you have new pistons and rings, the side clearances should be OEM correct - they don't usually expect you to have a lathe to re-cut ring grooves. (grin)

That's a cute little ring filer, Bob. And here all these years I've just been filing them by hand using a wooden bench pin and a diamond file. I'll probably do it that way again if I ever have to (hope not), since our local NAPA store isn't going to have one and I'm too cheap to buy one for just one job. Heck, I still file my saw chains by hand, too. Us poor folks gots us some poor ways, but we do get by. :thumbsup: