Engine Overhaul Kama 554

[3RRL]

Well, in fact I do have an update for you. I performed the leak test early this morning.
The 2 new valves passed the test 100%. The test is to pour kerosene (I used diesel) into the intake and exhaust ports .. fill them up and watch the valves for leaks. The valves should not leak for a minimum of 3 minutes. I tried to take some photos to show the fluid in the ports along with the valves. There was no leakage or seepage at all on the new valves so they passed with flying colors!
First photo is the new intake valve and second one is the exhaust valve.



Sorry to say only one of the old valves passed the test (barely 2 min 45 seconds).
The others leaked within 45 seconds. I decided to use the rest of the new valves including replacing the marginal one. That meant starting over taking all the valve springs off again, and of course all that meticulous cleaning to do after lapping and bluing every one of them off, let alone the extra leak tests. Anyway, I figure I had a better chance of lapping them in correctly than chasing the old valves.
Plus the all the new valves seated within that depth tolerance better.

After I got the all the new valves completed and installed, I re-checked them with the leak test. Guess what, 2 intake valves still did not make the 3 minutes. I had to remove them ( a couple times) until I got all of them to pass the 3 minute no leak test. I'm glad I did and I'm proud of myself for taking the extra time to change them out even though I was tempted to say ... "ok, that's good enough". Especially after re-lapping and bluing those intake valves several times until they sealed 100%. Now I KNOW for certain they are all leak proof. But I also smell like a diesel fuel truck.
Photos below show leak if you look close, and second one of all the new valves installed.

 

[SPIKER]

We spend most major holidays together either at her place or ours or one of the kids' place. It's a great time because all the kids and grandkids get together with all their "parents". My Ex's first Ex also comes to all the get-togethers when he's in town. Loretta's only son is also in on all the fun every chance he gets.
You know, the alternative could be a lot worse!

That is really great to be able to have friends & family all together!

Merry Christmas and happy new year, You will have that Kama back together real soo to help keep the GRIN on you face going!

Mark

 

[3RRL]

Thanks Mark,
I called the Ex and the kids to let them know I would not be coming down for work this week. I took a couple days off so I could finish up fencing Loretta's garden (again) and also to do a little more work on the Kama.

I was pretty excited about the valve job coming out so good.
Next was to check the crankshaft journals and connecting rod bearings for roundness and proper clearance. It took me a little while attaching them and taking them off again, but it was worth doing to be sure they were not shot. I got some red and green Plasti-gage. The green is .025-.076mm(.001"-.003" and the red is .051 to .152mm(.002"-.006"). I also installed the new journal bearings onto the connecting rod. Shown are old ones out and new ones in.

 

[3RRL]

Regarding the journal bearings...
The photo of my manual shows the clearance needs to be between .04~.098mm(.0015"~.0038").



I used the green hoping to fall within the acceptable clearance written in my manual.
I put a length of Plasti-gage diagonal (with a dab of grease to hold it) on top of the journal and inside the connecting rod cap. To read the plasti-gage scale, you compare the squished width (after tightening) to the scale on the paper package. Whatever width matches up is the amount of clearance you have. I had to crawl underneath and tighten the bearing cap while Loretta held the connecting rod in place.



After removing the connecting rod from the crankshaft, I could see the Plasti-gage on top of the journal had squished down a little wider than the .001" mark on the scale, but I think it moved a little upon removal. So I think it's abut as wide as the .001" mark. The bottom side was right at the .001" width but no pic of that because it was too hard to get a photo upside down.



So I figure I have a total of .002" clearance or less in those journal bearings.
Looks like I'm right in the middle of the clearance tolerance. Next on the agenda is to prepare the new sleeve liners for installation into the engine block.

 

[IH3444]

Good to go......you'll be firing that puppy up shortly.

 

[3RRL]

Man, I hope so!
But before reinstalling everything I have to clean it up really good, so that takes a little time. When I took it apart I just took the parts and laid them on a bench.

Today I focused on installing the new sleeve liners.
Before doing so I wanted to be sure that the bore in the engine had a nice lead in so the "O" rings would slide over without shearing. When I removed the old sleeves, I saw several had sheared so I wanted to avoid doing the same thing. I took a little dremel flapper wheel and ground a 45 degree lead in on it. I went into the bores and smoothed out the rough sharp edges. Then took some 320 wet and dry and hand worked it. Sorry, the bottom of the bore didn't come out so good in this photo below.



After that I started to measure the counter bores to see if they were all the same.
I also mic'ed the head thickness on each sleeve. Then I measured the step above the head. What I was trying to do was make sure all the steps would sit the same distance above the engine block. I don't know how good the head gasket will seal if they are different heights so I thought it was a good thing to do...maybe it was unnecessary?, but when I build molds that have counter bores and inserts with heads like that, I grind them all alike or one will keep the others from shutting off.

 

[3RRL]

What I found was interesting.
One of the counter bores in the engine was .009" shallower than the other three. Well, that cant' be good?
The head thickness on the sleeves were all identical so that was good. But on one of them, the little step was .003" taller than the rest.

What I wanted to do was to reduce the head thickness by .009" on the one sleeve to fit that shallow counter bore.
That way, the top of the sleeve would end up the same height as the others. Then reduce the little step to be equal in height as the others.

I figured there was nothing in the bottom holding the sleeve from dropping into the crankcase, so the heads are what keep the sleeves from sinking deeper. But when I set up the on sleeve in my lathe, I couldn't get both the diameter and the face (of the head) to come in to zero. So I decided that the diameter was more important, since that's what fits the bores in the block. I indicated it in to zero and machined the head concentric and parallel to diameter. That meant kissing the underside of the head first, then cutting the top of it to establish the new head thickness. You can see the dykem (red) that was partially machined when I took a kiss pass on it.
Then I machined it to the new head thickness.

 

[3RRL]

When I finished checking size, I added some chamfers before unchucking it.
Took it over to the surface plate to check the little step and it was right on the money.



So now all the sleeves will (should) protrude above the engine the same amount...and they did.
The head gasket will have a better chance to seal properly and evenly. When I put the sleeves into the bores, the "O" rings went past the top part easily, but they were pretty tight going into the bottom part where they seal off. I had polished that lead in and also greased the "O" rings so they would "slide" past that point. I can see how the original ones got sheared.

Instead of pounding the soft cast sleeves in, I actually took the head itself and placed it gently on top of them all. I used the head bolts to seat the sleeves by evenly tightening them until the sleeve heads hit the counter bores.

There was no way I was gonna take the engine block and machine that one counter bore deeper! I presume they all should have been the same depth, right?
BTW, what do you guys do with the head gasket?
Do you put a gasket sealer on both sides of the gasket? Or is it not necessary? I was going to add a gasket sealer on both sides of it.

 

[3RRL]

Before I stopped for the day, I fit the rings into the new sleeves.
I wanted to check the ring gap to be sure it was within tolerance. I measured the gap with a feeler gage. An .011" went in and a .012" did not. The tolerance for the top ring is 0.30mm~0.45mm which is .0118" ~ .0177", so the top rings were at the low end of the clearance. The other rings were toleranced 0.25~0.40mm which is .0098"~ .0157". The .011" feeler gage went in those as well.

After checking, I then installed the rings onto the pistons.
They are ready to go back into the engine tomorrow. The new piston is on it's connecting rod. I had to heat the piston up to slide the wrist pin in. And all of the connecting rods have new journal bearing in them now.

I'd still like to know about using gasket sealer on the head gasket, or not.

 

[Diamondpilot]

Your work is amazing Rob. I would give Chip a call on the gasket. Some require sealant and some do not. Many of the Chinese gaskets also take a sort of shalack called something like "Indiana Head". Maybe Greg G will know?

Chris