Dave's 1650 Project

[Sasky]

Originally Posted by _DX3_

Yep, those bearings won't last very long and will be an expensive boo boo.

They need to be open to get oil:

If they are only shielded on one side put the shielded side to the outside.

[CC1650Dave]

Huh, that was unexpected feedback. That's the original bearing reinstalled - I probably shouldn't have taken it out in the first place but when I disassembled it, I thought bearing replacement would be a standard part of rebuilding.

So regarding them not lasting very long, they've run since 1978 anyway. And the manual does specifically say "If using a shielded type bearing, install with shielded side facing toward inside of block."

I'm OK with removing it if it's not needed, though. Does it just pry out of there?

[_DX3_]

Originally Posted by CC1650Dave

Huh, that was unexpected feedback. That's the original bearing reinstalled - I probably shouldn't have taken it out in the first place but when I disassembled it, I thought bearing replacement would be a standard part of rebuilding.

So regarding them not lasting very long, they've run since 1978 anyway. And the manual does specifically say "If using a shielded type bearing, install with shielded side facing toward inside of block."

I'm OK with removing it if it's not needed, though. Does it just pry out of there?

WOW, I have never seen a bearing like that installed, but, I admit there's a lot I haven't seen before with these things, LOL. When you took it out, was the shielded side facing into the motor? I just can't figure out how it's getting the supply of oil it needs to lube the bearings. Are there slots in the shield?

[CC1650Dave]

Here's a pic of that bearing on disassembly. The shielding is slotted.

Originally Posted by CC1650Dave

[CC1650Dave]

Guys, I think I found a major problem. I'm going to hold off on getting really, really angry for a moment until some of you have had a chance to look at it.

While getting ready to reinstall the camshaft, I noticed that the block had a piece missing where the camshaft pin goes through, on the tappet side.



I reviewed my pictures from engine disassembly, and it was there when it was disassembled but I did not notice it. I was worried that I may have done it when I drove the pin out, but the bolt I used to drive it was on the other end of the pin. Here is the pic from July 18th:




And another one from July 18th showing that the piece was missing then:



Perhaps it happened as a result of that badly stuck exhaust valve? The scrap yard did start the engine with starting fluid when that valve was stuck, and maybe the extreme pressure that was put on the camshaft trying to move that stuck valve caused this? I don't know.

I didn't find a large metal fragment during disassembly, but that doesn't mean it wasn't there. I could have missed it.

So, the $64K (or at least several hundred dollar) question: Is my block JUNK? If so, I wasted $105 and a lot of time on getting it machined, and now I'm looking at big bucks for a replacement.

[JOHN SCHUTTE]

Dave, it looks like that is an old break. How much "meat" is left from the break to the outside of the block? I would try to sand/debur the edges down to prevent and more cracking. As long as the camshaft rod is tight when reinstalled I think it would be ok. Don't forget to lube the camshaft rod with oil to prevent camshaft damage at start up. Hang in there!

[CC1650Dave]

The block is about .810" thick at that point, and the chip extends down about .160", so there's .650 of decent block for the shaft to sit in. I can't see any further cracking in the hole.

But the inside edge, where the break is, is missing about .400" of surface. Those shims and the camshaft would have to run on a surface missing that chunk.

What would indicate that it was an old break?

[JOHN SCHUTTE]

Originally Posted by CC1650Dave

The block is about .810" thick at that point, and the chip extends down about .160", so there's .650 of decent block for the shaft to sit in. I can't see any further cracking in the hole.

But the inside edge, where the break is, is missing about .400" of surface. Those shims and the camshaft would have to run on a surface missing that chunk.

What would indicate that it was an old break?

Very good and important point Dave. I forgot about the camshaft shims. I would think the shims would be in bad shape if it was old damage.

[Sasky]

Originally Posted by CC1650Dave

Here's a pic of that bearing on disassembly. The shielding is slotted.

After looking the pic again I don't think that is a shield it's the bearing cage, it should be fine the way you installed it.

[CC1650Dave]

Another consideration is that my K341 has the "short" camshaft pin, so you have to recess it .300" on the bearing plate side (the side that's missing the chunk) so the shaft will be sitting in about .340" of solid hole. <edit> It's not the short shaft, it's the long one. But by the time you drive it flush with the PTO side, it's still .300 into the bearing plate side, so this is still a valid observation</edit>

The shims didn't appear to be in bad shape. One was .010 and the other was .005. And I'll need another .010 of shimming on this to get it to Kohler spec. I wish they'd include things like this in the rebuild kit.

Another thing I noted is that the Kohler manual (on disassembly) tells you to drive the pin out from the bearing plate side to the PTO side, and I did it in reverse when I disassembled it. I wonder if I *did* cause this break. <EDIT 8/24/11 - on second review, I DID remove it correctly. It's supposed to be tapped out from the PTO side TO the bearing plate side, as I did.</EDIT>