Wet up top IIV

Hi All,

The latest battle with the bloody KH! More rings, more hones, more pistons, more money, more oil.....I started it up and ran about tree miles, and when I got back it was smoking as much as it ever has since I have owned it. It usually does not smoke so much, so.....

I pulled the heads, and there is a ton of oil up top. When I lift the intake valve there is a bit of oil in there, but that is not where I think all this oil is coming from. I think it is going right past the rings as usual. I checked the breather timing by rolling the engine over and checking when the compression is relived through the breather tube. It is about 8 to 12 thirty-seconds after TDC of the front piston. Seems just where it is supposed to be. Of course the rear develops the pressure in the cases before this, but it has to get presume from somewhere to blow the oil out. Looks like I will pull the engine again and redo the pump seals, and check to see that the breather tower's bottom plate is the flattest one I have, that is in good shape.

Looks like all the work to make plates, changing the oil pump, sealing up the side oilers, and putting in Total Seal rings was not the answer. I just can't figure why this thing will not seal up. The best results I have ever had was with Total Seal rings with the Hastings three piece lower ring, and not the one piece HD style that is now in it, as Total Seal changed their supplier.

Do any of you use valve guide seals on your guides? I see that on the NOS parts page they list them for Pans and K models as the same part number, but I have never heard of using guide seals on a Flat Head.

Any advice is always welcome. This time I only had about three miles on it, but it was smoking far more than it was when I pulled it apart last time. The compression was very high though, and was hard to kick over, but when I pulled the heads and the rear was very wet, and the front was pretty wet. The rear it was a seriously puddling in the cylinder on top of the piston, and spread out all over the head. The front had less oil, but was still wet up top.

I am thinking now about moving the breather one tooth forward, and then running it until it has no compression, and then work on the whole thing again. Really tired of this circus.

Barry55KH

Barry have you drained the crankcase after you run it. It would be interesting to know what quantity of oil you get out of the bottom end.
Mike

Hi Mike,

I had so much trouble getting the drain sealed that I had them weld it up. I could drain the tank and tip it over on the crash bars, but I had all bud drained it when we changed the pump to the early 14 tooth drive gear pump, that should put out less volume than the '72 one we took off. The oil is getting past the rings, though I have run it before with the same rings and new hone, and I could not see it burn it. Now there was big white clouds. That is why I pulled the heads. When I checked the lower end before, when I still had the drain, it was about 3 to 5 ounces depending on how hard it was run. I plugged up the side oilers this time thinking that would help also, but to no evail....

Thanks for the idea.
Barry

Barry
3 to 5 ounces is in my opinion to much. The critical things to consider are to high oil pressure, scraper clearance oil viscosity and breather timing. These are roller bearing crank assemblies and as such do not need to be flooded with oil. If you over oil a roller it skids instead of turning and skidding causes heat. On our race KR I welded up the scraper and re-shaped it to close up the clearance. I run 15-40 Delo 400 and never get more than 1 to 1 1/2 ounces out of the crancase after a race.
You mentioned that your problem is worse in the rear cylinder, this is classic symptom for a v-twin wet sumping as the rear cylinder
is the cylinder that gets the majority of the oil carried and flung off the flywheels.
Mike

Barry, I'm just speculating but this may be a possibility, has anyone altered the pinion shaft oil feed to the bearings to full time oiling by grinding either a channel around the shaft to the feed hole or modifying the bush internally in a similar way. Also, is the scavenge return line blocked or restricted.

Well All,

I think I have it figured out! It has no scraper! I will still have to pull it apart to check, but I beleive there was no scraper from the factory! They just did not put it in on a run or missed it on this one, and since it looks like it should not be there, every one that has been in there has figured that that was just the way it was made, and that is the way it should be.....

At the same time I'll pull the engine and fix the pump leaks,,,. I'll also pull the trans and change the slots in the shift guide so that I don't have to shift to second to get it into first gear. It's an aftermarket transmission from our friend "Taiwan Ted". Thanks for the Trans, but I wish it could have been correct in the first place. OH Well, they must have copied a bad one.

I will let you know! It will be a while before I can get in there.

Thanks for all the help! I think Patrick and Mike 100m may have hit on it when they talked about scraper tolerneces.

Thanks guys!
Barry55KH

scraper clearance is very inportant. also clearance between oil pump tower and body. i have welded many k kh kr xlr sportster xr 750 and remachined. pocket behind scraper is important. oil pump timing should be degreed in rather than relying on marks. cam side of engine case can be reworked for better oil return. oil ring seal as u know is very important. scraper angle can be rewowked to slove lot problems. and pocket behind scraper. seems to work best to degree oil pump timing rather than to rely on marks. there r other case mods that can help also. i worked for tom sifton he was the master when it came to oiling pboblems.

XLR, working for Tom Sifton must have been quite an experience, i find your tips intresting, what oil rings do you prefer on the side valves, 3 pc. or 1 pc. cast iron ? Not clear on what you welded and re-machined, the tower slots ?

HI SENT U A PM. THANKS