Engine Overhaul Kama 554

[dfkrug]

I have found that using a cordless drill on the end of the handle and alternating directions every 5-10 seconds or so is much faster than spinning by hand and does a good job.

That's almost how I do it, too. I thought, "there has to be a better way", once when I did my first 32-valve engine. First coarse compound, then
fine.

You can barely see my drill in this photo. I chuck it up around the valve
stem, instead of using the wooden rod with suction cup.

 

[3RRL]

Hi guys,
Got back yesterday from my 2 day a week job down South.
I wanted to start checking the everything that was mentioned above but Loretta had me put in a gate to her garden. At least I got some seat time on her Jinma and the post hole digger.

Chip is sending me the new sleeve liners and they should be here late today.
I will check the valves to see how good the guides are. As I recall, when the valve is almost closed there seems to be very little or no play, but I will check it again. I'll also blue-off the valves into the seats before lapping any more of them. After checking the blue off I figured on using a drill motor like you guys do to finish seating them. I have plasti-gage and several different kinds of impression blue in my tool boxes. I use that stuff all the time to check shut-offs on the plastic injection molds I build. I remember when I was an apprentice back in the sixties, I was working for an old journeyman top moldmaker. He used to light cigarette paper under the mold inserts and use the soot as impression blue off (black) ... pretty cool.

I've also decided to grind the valves to length to obtain the proper rocker arm geometry.
I have a set up in my surface grinder to do that. I can also grind a radius on top of the valve stems so that the rocker arm only hits closer to the center point of the stem. It won't be a full radius, I was going to leave about a .050"/.100" flat on the center of the stem. Right now the valve stems are just squared off. My plan is to measure the new valves with gage blocks and indicators. I have to determine an average over-all length. I presume since they are stock, I could use that length as a standard? Then, depending on how much deeper the valve sits in the head (than spec) I will kiss grind that amount off the valve stem. Looks like from what you guys have said, that should make the rocker arm geometry real good again (closer to spec).

Is that piston cracked?

You know I haven't check it close enough.
Good eye! But that is also the piston with the that broken ring and the first ring groove has doubled in width. So I ordered a new one and it will be replaced anyway. I'll take some photos of the new components later today and any progress I make.

BTW Dave, yes that is a direct injection engine.
I too was paranoid at removing those sleeves, but like I said they came out nicely.
IH3444, Indeed I was lucky to only be a short distance from the barn. I was already cringing at the thought of even driving it that short distance to the barn, but I had to.
Mark, Jim, kernopelli, Chris, Tom (and anybody else I missed) thanks for all the technical input and support. With all your help, this DIY project should come out real good in the end.
I should have more stuff to share later in the week.

 

[SPIKER]

Hi guys,

I've also decided to grind the valves to length to obtain the proper rocker arm geometry.
I have a set up in my surface grinder to do that. I can also grind a radius on top of the valve stems so that the rocker arm only hits closer to the center point of the stem. It won't be a full radius, I was going to leave about a .050"/.100" flat on the center of the stem. Right now the valve stems are just squared off. .

3RRL:

Not sure on the valve to rocker geometry on this engine, the radius probably is not needed as it will take away form the contact area of the rocker to valve stem and may cause some additional wear on the rocker or the stems. adding a very small chamfer to the very outside edge is OK to prevent any sharp edges but not .100 worth of flat left. You can break the edge with a stone is all it should need to remove any sharp edge that was left after grinding. Also note you may not need to take much off as noted prior by several people there is more than likely enough adjustment on the rocker stud mount to compensate unless you have really hogged down the valve seat...

Mark

 

[3RRL]

Thanks Mark,
I'll just grind a tiny radius on the stems then.
In fact I have done 2 valve adjustments so far, and each time there was very little adjustment to do. My thought on grinding the valve stem was because those valves in the head already sat low from when I bought the tractor new. So I was thinking maybe I should grind the length to compensate? But if I don't need to, time saved and a little less work to do.

What I'll do is check the length of the old valves vs the new set.
Maybe they have already been adjusted (ground before)? When I check the length I'll know better which way to go. I don't mind having to grind them, and if indeed they are all the same length, then I probably will. If the old set is shorter than the new, then I won't.

I really meant to get more done on the rebuild today, but Loretta and I got caught up in putting up more fence posts for her garden. We had to drive down to Visalia again to pick up more stuff which took up the rest of the day.

 

[doxford jim]

Hi Rob,

Seems like you are getting just as good service from Chip, for your Chinese tractor as some people get for home produced machines.

When I rebuilt the engine on my JD450, I was held up for over a month waiting on engine parts and they had to be ordered three times before they got it right. I even had to point out to the John Deere parts people what they were doing wrong and I am sure I had to pay a restocking fee for their faux pas. A long story but finally got 'er together and tried it out and it fired and ran the first time I tried it. Sure was good to see it running clear with no exhaust smoke or blowby from the head valve cover vent pipe. Oh, and the old sleeves on my engine pretty much fell out - the O-rings were shot and two of the four liners had impingement erosion (pinholes in walls) from previous owners running without the inhibitors in the coolant (like final charge etc.).

I think you will be very impressed with the way that engine runs when you are through with it. Gives ya a good feeling knowing it is all done properly - in your case, the whole bloody tractor now

Cheers

Jim

 

[3RRL]

Thanks for the vote of confidence Jim,
Chip at Artrac has given excellent service. And more importantly, because most of us do it ourselves on these Chinese tractors, he gives clear and accurate advice how to do it. But this is not the first time. Even though I did not buy my tractor from Chip, I've been buying parts (and getting advice) from him going on 5 years now.
Very admirable indeed.

BTW, along with Chip, there are Tommy and Ronald who have also given the same service and technical advice over the years. I feel the Chinese tractors are very well represented and supported by these dealers in particular.
The myth about not being able to get parts or service is something I have yet to experience.

 

[dfkrug]

The myth about not being able to get parts or service is something I have yet to experience.

I am interested in what you have to give for things like new pistons, liners,
etc. I am sure the prices will look stunning next to what I have paid for
many many factory Kubota and JD parts.

It is great that you have been able to get all those parts. What about
service? You do all your own service, as far as I know. What if you had
to get service for your machine?

 

[3RRL]

I am interested in what you have to give for things like new pistons, liners,
etc. I am sure the prices will look stunning next to what I have paid for
many many factory Kubota and JD parts.

It is great that you have been able to get all those parts. What about
service? You do all your own service, as far as I know. What if you had
to get service for your machine?

Hi Dave,
Yes, I do all my own service.
I planned on it when I decided on the Kama. If you're lucky enough to live near a dealer, then you could bring it in. I bought mine cross country and at the time, there were no dealers here in CA.
Example of cost:
New piston: $60
New liner: $65

 

[dfkrug]

New piston: $60

Sweet!

That is less than half what JD costs per piston (complete with rings).

 

[3RRL]

I measured all the valves ... old and new.
Turns out that the old valves are the same length as the new. In fact, the old valves measured within .002" and the new valves, one was about .009" shorter than the rest. After depth mic'ing the all the valves, I found that only the very first one was sitting deeper in the head than the others. That was the one I based my judgment about having to grind the ends of the valve stems. Turns out all the other intake valves were only slightly deeper than spec, from .003" to .008" deeper. And all the exhaust valves are within spec (.027/.044 deep).



With that in mind, I decided not to grind any of them. Instead, I replaced that first intake valve with a new one which sits closer to what the other intake valves were. I also tested each valve when it was almost all the way in for play or slop. All of them except one exhaust valve had almost zero movement. So the valve guides were all good. I tried a new exhaust valve and it seemed to fit tight in the guide, so I decided to put a new one in that 2nd cylinder.
That means I only replaced 2 valves ... intake on cyl #1 and exhaust on cyl #2.