Gotta pull the Head

[Selkirk_D]

No crack there. Machined edge of depression for injector as #40fan pointed out. I’ll post pix of cleaned up chambers later. Pistons are coming out, I’ve got rings, rod bearings, and rod bolts on order. There were no issues with overheating or coolant loss before I tore it down, so I doubt head is cracked. I’ll check everything closely for sure though.

 

[PoTreeBoy]

You may want to check the piston deck height before you pull them, in case a rod is bent.

 

[Selkirk_D]

So got the pan off today, moving front axle was the easy part. I just jacked up front of the tractor until wheels were about 2” off the ground, removed the 6 bolts that held it in place, and lowered the axle with a floor jack until tires were on ground. Some of the bolts were a little tough to get to , but I figured it out. Hardest part was getting pan gasket to let go. Also I didn’t realize pan weighed a ton since its cast iron.

 

[Selkirk_D]

Pulled all the pistons/rods today. #2,3&4 all looked great. # 1 though was another story. While the piston & rings looked fine, the rod bearing was toast. It had been hammered to the point that the the bearing material was squished out the sides and the shell was practically welded to the rod . Lower shell was less hammered but had no crush left. The welded upper shell only thing that kept it from spinning. Fortunately crank appears ok other than a bunch of bearing material being stuck to it. A real mess, hopefully I can salvage it. I’ll break out the bore gauge and mikes tomorrow and see how things measure out. Pretty sure Rod needs replacing as opposed to resizing. Maybe this catastrophe was caused by bad #1 injector that the dealer replaced? Funny thing is, the engine didn’t knock and ran great.

 

[#40Fan]

I've never seen a bearing like that and the crank not needing some work.

 

[North Idaho Wolfman]

Pulled all the pistons/rods today. #2,3&4 all looked great. # 1 though was another story. While the piston & rings looked fine, the rod bearing was toast. It had been hammered to the point that the the bearing material was squished out the sides and the shell was practically welded to the rod . Lower shell was less hammered but had no crush left. The welded upper shell only thing that kept it from spinning. Fortunately crank appears ok other than a bunch of bearing material being stuck to it. A real mess, hopefully I can salvage it. I’ll break out the bore gauge and mikes tomorrow and see how things measure out. Pretty sure Rod needs replacing as opposed to resizing. Maybe this catastrophe was caused by bad #1 injector that the dealer replaced? Funny thing is, the engine didn’t knock and ran great.

Ouch that is bad.
Hope the crank can be cleaned up, but I wouldn't count on it.

 

[Selkirk_D]

I've never seen a bearing like that and the crank not needing some work.

I hear you. But we’ll see once I get the bearing material cleaned off and I measure the journal. At least there was no steel to steel contact. Also, I noticed that the torque needed to remove the rod bolts was way less than the others, like maybe half. This tells me that the rod big end was badly distorted , I was headed to a “ how do I fix the hole in my block?” Thread for sure. Good thing the rods are forged.

 

[North Idaho Wolfman]

I hear you. But we’ll see once I get the bearing material cleaned off and I measure the journal. At least there was no steel to steel contact. Also, I noticed that the torque needed to remove the rod bolts was way less than the others, like maybe half. This tells me that the rod big end was badly distorted , I was headed to a “ how do I fix the hole in my block?” Thread for sure. Good thing the rods are forged.

https://www.fridayparts.com/connecting-rod-17311-22010-for-kubota-v1500-v1702di-v1902di-engine?gad_source=1&gclid=Cj0KCQjw16O_BhDNARIsAC3i2GBXk4N_VqAUPww0VlWDYp57UB6MSNkblYckqPnt27hijkEXropORZcaAuuyEALw_wcB

 

[Selkirk_D]

Well I think I saved the rod journal thanks to some hillbilly machining. I discovered that 3-m double sided foam tape is about .010 thicker than the rod bearing shells and 220 wet-or- dry sandpaper is another .010. So I decided to use a good rod as a polishing mandrel using the tape and wet-or-dry sandpaper.

View attachment 151926

I installed rod upside down on the beat up #1 rod journal with a little oil and tightened the cap screws. It’s a little tight at first but the foam compresses to the size of the rod and gets easier as you go. I began swinging the rod back and forth from under the engine, with the journal a bdc, I could manage a 90 degree arc. I’d polish for about 100 swings, remove rod, then measure the journal. Rinse and repeat. After I polished as much as I dared, I switched to the shoestring method with 320 grit and then 400. Not perfect but journal is round and straight across the journal according to my mitutoyo micrometer. Still has some minor imperfections but I only gave up .001 more clearance, which I can probably partially make up with selective use of rod bearings. I could probably clean it up more but the trade off would be more bearing clearance. I’ll see if I can go further once I get the new bearings. Factory clearance spec is .001-.0034 with a limit of .0079.

# 4 journal for comparison

 

[#40Fan]

Pics of the rod journal?

 

[Selkirk_D]

So started working on the head today. Checked block and head decks for straightness. Block deck is totally flat, head has about .002-.0025 variance. Not sure it’s worth resurfacing because it would potentially change compression and injector timing. Guides are good, Valves looked ok, #1 intake lapped in just fine, # 1 exhaust was another story. There was carbon build up on the valve seat and valve face. I cleaned them up, but lapping the exhaust showed divots in the faces where the carbon was pounded in. This is where #1’s compression was escaping. I had a new exhaust valve on hand but I’m going to have to touch up the seat with my trusty valve grinder to get the valve sealing back.

 

[ruger1980]

So started working on the head today. Checked block and head decks for straightness. Block deck is totally flat, head has about .002-.0025 variance. Not sure it’s worth resurfacing because it would potentially change compression and injector timing. Guides are good, Valves looked ok, #1 intake lapped in just fine, # 1 exhaust was another story. There was carbon build up on the valve seat and valve face. I cleaned them up, but lapping the exhaust showed divots in the faces where the carbon was pounded in. This is where #1’s compression was escaping. I had a new exhaust valve on hand but I’m going to have to touch up the seat with my trusty valve grinder to get the valve sealing back. View attachment 152211 View attachment 152212

i would recommend removing the injectors from the head before doing any more work on it. You should have removed them before cleaning but it's a but late for that. Injector nozzle should not be cleaned with a wire brush, a hard or abrasive tool.

The journal does not look too bad but will need cleaning and I would recommend turning the crank so the oil hole faces down and flush it out with brake clean. by micing the journal you should have a pretty good idea of the clearance you will end up with.

 

[North Idaho Wolfman]

So started working on the head today. Checked block and head decks for straightness. Block deck is totally flat, head has about .002-.0025 variance. Not sure it’s worth resurfacing because it would potentially change compression and injector timing.

Milling the head does not change the timing only milling the block does that.
Milling the head might up the compresion a very small amount like 5 lbs which wouldn't affect anything

 

[Selkirk_D]

Thanks, I was contemplating pulling the injectors, just wasn’t sure if I’d have to replace any seals . I intentionally stayed away from them while cleaning. I’m going to measure bearings in rods before proceeding on that journal so I know exactly where I’ll wind up on clearances. Got new rod today, still waiting on the bearings.

 

[North Idaho Wolfman]

Thanks, I was contemplating pulling the injectors, just wasn’t sure if I’d have to replace any seals . I intentionally stayed away from them while cleaning. I’m going to measure bearings in rods before proceeding on that journal so I know exactly where I’ll wind up on clearances. Got new rod today, still waiting on the bearings.

Yes if you pull the injectors you will need to change the seals.
Pencil injectors can be a pain.
There is 2 different styles of pencil injectors:
If it's the old style there are 2 seal pieces and they can be a pain to get the seals off or they have also been know to stick in the heads.
If they are the new style injectors then there will be only one seal.

 

[Selkirk_D]

Yes if you pull the injectors you will need to change the seals.
Pencil injectors can be a pain.
There is 2 different styles of pencil injectors:
If it's the old style there are 2 seal pieces and they can be a pain to get the seals off or they have also been know to stick in the heads.
If they are the new style injectors then there will be only one seal.

Thanks Wolfman, I think I’ll just work around them.

 

[BAP]

The amount of work that you are doing, I would pull the injectors and take them to a injection shop or even a dealer and have them put them on a pop off stand and check to see if they are working properly. Doesn’t cost much and can make a huge difference in how the engine performs.

 

[Selkirk_D]

Good suggestion. If I can even find a shop around here that can test them. This area is kind of remote. Basically the burn patterns on 3 of the cylinders look great. The offending injector on #1 was replaced by the dealer with OEM not long ago. Oddly, the tractor started and ran great before I tore it down. I’m pretty confident it will run even better with compression improvements and con rods that plan on staying in the block. I’ll check around and see if I can find someone.

 

[North Idaho Wolfman]

The amount of work that you are doing, I would pull the injectors and take them to a injection shop or even a dealer and have them put them on a pop off stand and check to see if they are working properly. Doesn’t cost much and can make a huge difference in how the engine performs.

Most shops can't pop tests pencil injectors.
And they are not rebuildable.

 

[Selkirk_D]

Turns out I can buy a set of “rebuilt” oem injectors with new seals for the same cost as just the seals from messicks.