Engine Overhaul Kama 554

[bradblazer]

My little engine manual doesn't have those torques. Here is a chart Larry posted a while back:
i7.photobucket.com/albums/y299/GuglioLS/Misc/TorqueValues.jpg

[3RRL]

Thanks Brad,
I had that chart and decided to use it.
I torqued them down to 40ft/lbs. I was afraid of the cast head stripping.

I put it all together tonight and started it up. Here's some photos.
-Set the valves
-Filled it with oil
-Filled the radiator with Fleet Charge
-Filled the diesel tank
-Put the hood back on



And fired it up.
I cranked it for about a minute with the decompression lever. I also used the hand pump on the injection pump just prior to that. It wanted to start but maybe there was not enough fuel in it yet. So I waited a couple minutes and did the same thing.
It caught and started running ... very smooth too.
I am jazzed!!!



I went through the recommend start up...
5 minutes low rpm
5 minutes medium rpm and
5 minutes full rpm

Looks like I got my Christmas present early.
I want to thank ya'll for helping out wo much with this project. It's all done now. All I have to do is put on the fel and I can start working on the pond project again.
Many thanks and Merry Christmas!!!

[rayh]

Congratulations on a job well done!!! Very nice when every comes together and it runs well. I think the blowby will be far less now.

[bradblazer]

Beautiful!
I think this thread deserves to be a sticky. Thanks for turning your misfortune into a super tutorial on rebuilding a Diesel.

I figured my torque post was a little late - little did I know you already had it running! There shouldn't be much danger in stripping the threads in a casting even with high strength bolts because the engagement length is usually much longer than a typical nut.

Merry Christmas,
Brad

[3RRL]

Thanks all, you have been super supportive!

It was certainly worth the effort when it fired up and ran as well as it did.
The fel will be not sweat to put back on. I don't know if you picked up on it or not, but I removed that blow by tube I had made going to the air intake. I put a regular breather on the Kama. That was the first thing I checked at all running rpm. Man, there is hardly any blow by at all ... I mean hardly anything. So the ring and valve job came out super good.
I am very pleased with that.

I didn't check the weight of each piston and connecting rod either.
But nevertheless, it ran a lot smoother and quieter than I remember from before. My manual told me about it but I neglected to do it. Next time I will.

Brad,
I found the problem with my air filter.
I found that the air filter did not shut off against the rubber seal. Apparently there needs to be another nut on the stem to push the filter completely against the cannister. I saw Loretta's Jinma had this extra nut which does that. It must have been that way from delivery and I never knew the difference until I was putting it back together again. So I added a washer and nut to keep the filter sealed against the back of the cannister. Now the air MUST go through the filter. I'll bet that's what caused the premature ring damage in the first place?

One thing I did see after running it the 15 minutes.
Towards the end of the high rpm run, I saw the oil pressure go down to about 30/35psi. I figure that one connecting rod journal where the bearing was squished was not perfect. When I plasti-gaged it, it measured good...easily within the clearance tolerance. But there was a slight bit of scoring on that bearing journal. Now I wish I would have ground that journal on the crankshaft. I did run some 600, then 900 then 1500 paper on it to smooth it out best I could. Since there are no over sized journal bearings available for my Kama, I guess hard chrome plating and grind back to size would be the solution?

Save that for next major service.
For the time being I'll keep a very close eye on it. With everything I've learned, I'm not afraid to do it again. The total cost for doing everything myself and only buying parts was minimal. For the next time, I'd have to send that crank out though. I have no means to do it here in the barn.
Rob-

[bradblazer]

Maybe the oil pressure just dropped due to thinning as it warmed up? As long as no metal was proud of the surface a little scoring of the journal shouldn't hurt. With hydrodynamic lubrication the surfaces don't actually touch each other.

I'm glad you found the air filter problem! Man - that was a costly little defect! I still think a precleaner is a good idea for your dusty conditions.

[3RRL]

I agree with you Brad.
I'm looking into those links you provided and would like to get one.
But nevertheless, the air filter should be working now...lol...at least better than before.

You know I do have a mechanical oil pressure gage.
It was installed earlier this/last year when the OEM gage stopped working. Only to find out it was not grounded correctly. You can see both the dash OEM gage and the mechanical gage in that first photo. I decided to take another set of photos after my last post.

The engine started right away and ran very smooth.
At first, the oil pressure was OK ... close to 50psi. So I don't think I need to adjust the oil pump. It should be set ok as is. After I let the motor warm up at low rpm, I ran it at medium and high rpm again and I snapped these photos below. The medium rpm photo is after about 15 minutes. The high rpm photo is after 25/30 minutes.



BTW, the engine runs great and easily reved past the green "rated speed" on the tach.
This engine is rated to make 55hp @ 2300rpm, so I figure it's getting all of that or close to 60 @ 2400rpm. Generally I don't ever run the rpm that high since I don't need all that hp. I usually work the tractor at 1800 up to maybe 2000 rpm. 1800rpm is about 150rpm over the max torque (made at 1650), so if it bogs at all, it surges back to 1800 as the max torque kicks in.

You can see the rev meter, the temperature gage is near 78C and the oil pressure on both gages.
The OEM gage has a "green" range which I presume is acceptable oil pressure. The readings are confirmed with the mechanical gage. At higher rpm, and when the engine was completely warm, the oil pressure dropped to 35psi? But it's still well in the "green" zone on the OEM oil pressure gage.

Later I ran the tractor for about 1-1/2hrs dragging my 1000lb boxblade and graded the road.
Towards the end, the oil pressure dropped even further down ... close to 20psi, but never going out of the "green zone" on the OEM gage. Still, it scared the crap out of me. With that in mind, I think the oil gages and oil pump are ok. I think I need to fix that one bearing journal because I don't remember the oil pressure ever getting that low since I heard that "bang".

What should I do?
Could I remove the crank shaft and send it out to be reground? Would they do just the one journal or would they end up doing them all to "balance" things out?
Are there over-sized journal bearings (smaller ID to fit a re-ground journal) available? Or would I need to have the journal ground down, then hard chrome plated, then re-ground to size again?
Or will I have to buy a new crank shaft and new bearings for everything?
Chip, do you have one?

I think the top end is alright, except I might balance the pistons and connecting rods for weight.
Need help here... I don't want to run it like it is.

[bradblazer]

I don't have much experience troubleshooting low oil pressure but I did find this link:
www.aa1car.com/library/us1097.htm

I know you are worried about that one journal but it might be good to investigate all possible causes.

It looks like undersized bearings are fairly common. I wonder how common our rod size is?

www.summitracing.com/search/brand/Federal-Mogul/Product-Line/Federal-Mogul-Connecting-Rod-Bearings/?autoview=SKU

[3RRL]

Wow, great links Brad!
I always amazes me how quickly you find information like that.
I bookmarked both links. I can use the Engine manual for the journal sizes (they are given plus tolerance) to see if any of those bi-metal connecting rod journal bearings would work. I saw there are many available in .010" to .040" undersize.

I'll also read about the low oil pressure causes and remedies.
I've been advised to at least check the oil pump and perhaps adjust it so that the oil pressure at working temperature is acceptable (and stays there). I'll have to look into doing that next week. I have Wes (my youngest) this weekend so I will be goofing off with him. It's been a while since he's come up to stay with me.
Thanks again,.
Rob-

[rayh]

Rob
What oil are you using? Real light oil (5W/20) will cause oil pressure to drop when heated. In your warm climate, use 15W/40.
Best of luck
RayH

[3RRL]

Dec 26, 2009 17:43:32 GMT -5 rayh said:

Rob
What oil are you using? Real light oil (5W/20) will cause oil pressure to drop when heated. In your warm climate, use 15W/40.
Best of luck
RayH

Ray, I use Mobil Delvac 1300 15w/40 Diesel oil.
In the super hot Summers (in the past) I used Mobil 1 Synthetic 20w/50. But I have stayed with the Delvac as of the last year. I use it in Loretta's Jinma and also in my 2500HD Silverado Duromax. Photos are of pouring the Delvac in (posted earlier). Others show the temperature variation I get between Summer and Winter. That thermometer is in the shade.
It gets hot and cold over here.
rob-

[Rich Waugh]

Rob,

Years back, a diesel rebuilder buddy of mine gave me some advice about oil pressure when I had concerns regarding an old heap I was rebuilding. What he said was that I needn't worry to much about the actual pressure as long as I had enough to move the oil through the engine and the filter, and I should worry more about the oil temperature.

According to John, as long as the oil was moving through the bearing surfaces and the filter, it was serving it's purpose - look at all the splash-oiled engines out there (no "pressure" at all). What he said was the real culprit in killing engines was high oil temps that destroyed the additives in the oil and thinned it to the point that it couldn't resist interface pressures in the bearings/journals. He made the point that often times, in water-cooled engines, the oil temperature could be a hundred degrees higher than the temp gauge was reading, due to differences in specific heats of water and oil and radiant cooling ares, among other things.

What John advised doing was installing an oil temperature gauge so the oil temp could be monitored and, if necessary, installing an oil cooler. This was when I lived in Phoenix, so the oil cooler was pretty near mandatory and really did the job.

John also told me that one thing to watch out for was excessive oil pressure, which could result in such high flow velocities that the oil actually eroded bearing surfaces instead of acting as a bearing film.

The short answer was, "don't sweat the pressure as long as you have some, and worry much more about the temperature." Seemed like damn good advice to me and so far it's worked on every engine I've dealt with over the years. Something to think about, at least.

Rich - who ain't much of a mechanic but has known some really really good ones over the years.

[affordable]

Rob,I would run the tractor,even at 20-30 psi of oil pressure it should still be oiling to the top of the engine.Have you tried to adjust the oil pressure at the filter head ?I have oversize rod & main bearings for the Y385 and the TY395 engines .25,.50.I'm sure Chip can get them too,


Tommy
Affordable Tractor Sales

[3RRL]

Thanks Rich and Tommy,
I haven't tried to adjust the oil pump pressure yet.
I'll give a shot later this week when I get back. I've been avoiding doing that since I know too much pressure can be just as bad as not enough pressure. The other reason is when I first start the tractor, I have 50psi showing on both gages. Then, as the tractor warms up, it starts to get less and less. So I know the oil pump is working well. I just haven't adjusted it for more flow. Maybe a little more flow would result in a little better (higher) oil pressure once the tractor is fully warmed up?

I put a couple hours on the tractor since the rebuild and the result is the same.
However, even though the oil pressure is low, it's still in the "green zone" of the OEM oil pressure gage. The mechanical one says it's 20psi or even a little less. My fear is if I keep working it, and as it gets hotter, the pressure will dip even lower to "out of the green" range. I will surely wreck something then? One reason I've been running it, was a rule of thumb (not cast in stone, of course) says you can live with 10psi for each 1000rpm. So even when the oil pressure is down to 20psi and I am working at say 1600~1800 rpm, that rule (if true) still gives adequate oiling. Maybe that's why the green zone goes down so low?

I am still interested in fixing it though.
If adjusting the oil pump doesn't result in higher oil pressure, I will need to fix that journal. If I can get 25~30psi (when hot) as the lowest oil pressure I would be happy and leave it alone. Even between 20~25psi but no lower. Once I have the crank out, I might as well get new bearings for the mains and rods etc. And since I'd need to get the crank ground anyway, I might have them grind everything so I know it's 100% concentric and true. I'd get undersized bearings for all. Then for sure it would be back to "like new" or maybe better?
What do you think about that?
Does anybody know what it would cost to have the crank ground (approx)? I would do all the dis-assembly and re-assembly myself.
Thanks, Rob-

[rayh]

The actual grinding of the crankshaft is quite reasonable ($250-$300). (In Canada) The big job is to remove and replace the shaft in the engine. The tractor has to be split and the timing assembly and bottom completely dissassembled. BIG JOB

GOOD LUCK
RayH