Engine Overhaul Kama 554

[Brad_Blazer]

Way to go Rob!
Thanks for a great thread with a lot of universal good info as well as specific stuff for us KM554 owners.

Did you put one of these on your list for Santa?
Sy-Klone International: Series 9000 Models: Dimensions, Airflow, & Hood Clearance

 

[Diamondpilot]

Very nice Rob. I am glad you got it running. Nothing like doing it yourself. Chip really came through for you also. Nice to have such a good dealer network here.

Chris

 

[3RRL]

Thanks all, you have been super supportive!

Jim, Chris and PAGUY,
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.

IH3444,
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.

 

[doxford jim]

Hi Rob,

Just to be sure that the oil pressure reading you have is correct, I would double check that pressure. If you have a mechanical pressure gauge, connect it to see what readings you get and compare - you wouldn't be the first guy to have a transducer to fail and give you false readings. With a bit of luck you will find that the transducer has gone and needs replacing - a lot cheaper and faster than the rebuild

I would also check the pressure adjusting valve for the lube oil. I know on my tractor there is a pressure adjusting valve to adjust the main oil pressure - right by the regulator on my engine. It could be the spring in that is starting to fail in it and needs to be replaced - again a lot cheaper.

Cheers

Jim

 

[IH3444]

Jim is right on the money with that comment. The spring may have lost a bit of it's spring tension, and a slight adjustment will put you back up in pressure. The rule of thumb is 10psi per 1000 rpms. I think you maybe ok. Plus the rod never "hammered" so a slight thunking, caught right away, me thinks no damage, or measurable wear. Glad it's purrrrrrrrring for you Rob.

 

[SPIKER]

Jim is right on the money with that comment. The spring may have lost a bit of it's spring tension, and a slight adjustment will put you back up in pressure. The rule of thumb is 10psi per 1000 rpms. I think you maybe ok. Plus the rod never "hammered" so a slight thunking, caught right away, me thinks no damage, or measurable wear. Glad it's purrrrrrrrring for you Rob.

I agree gas engines the rule is 7 psi per 1000 rpm, so not sure if the diesel is more or not?

I have same problem in my old cougar after the harmonic balancer was thrown in the middle of the night driving from South Dakota to Kansas, I was pulling the boat heading home in Nebraska corn field, I had to keep going back then no cell phones. ended up wearing the rear main bearings... lost oil pressure after warming up from then on... warm pil pressure is/was only about 35psi Bearing was worn into the copper but no crank scoring. I had to put it back together that way as I had to get the car moving out of the shop they closed it on me, (military support auto shop) base closed the shop completely for lack of interest... I was in that shop probably 40 times in the 2 years I was there. I pulled front clip off engine ^& trans out, rebuilt front suspension and painted frame rails inner fenders all suspension parts after sandblasting them all. and when I pulled the engine apart they said I had to put it back together by Friday as it was the shops last day. the car was still in pieces... This was on a Tuesday after work... I had heads off & apart porting & polishing them long with the new alum intake. had full Elderbrock kit/system setup for it. I pulled the main caps to find well polished journals chamfered already & crank was marked .01 under. I didnt know and the bearings I had ordered ahead of time were too large... had to put it back together with the old bearings. left the rest of the bottom end alone but got all the top end done new cam & lifters & rollers into the ported & polished heads.

still ran great but the plasti-gauge told me my rear main was out to max spec. I just didnt have the time to re-assemble engine & front of car in 3 days..

Mark

 

[3RRL]

Guys,
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.

 

[ToadHill]

Looks like the fuel gage is trying to tell you something.

 

[greg_g]

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.

Pg2 of your engine manual shows the 495T output rating is 44.1KW @ 2500 RPM. That green mark on the tach just indicates the engine RPMs necessary to produce the correct number of turns at the PTO. I guess it's just the way the linkage is designed. Cuz I too still have quite a bit of throttle left at that point. I get about 2650 outa mine. Comes in handy to be able to get more throttle when the mower gets bogged down.

//greg//

 

[greg_g]

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.

Pg2 of your engine manual reflects the 495T output rating as 44.1KW @ 2500 RPM. So your 60hp guess is pretty close. That green mark however, just indicates the engine RPMs necessary to produce the correct number of turns at the PTO.

I guess it's just the way the linkage is designed, because I too still have quite a bit of throttle left at PTO revs. Wide open, I can get about 2650 outa mine. I like the capability to have reserve power underfoot when the mower starts to bog down.

//greg//