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1965 Kohler 6.5R22 to be Placed into Service

Motorhead

Subscriber
Age
67
Last Subscription Date
07/09/2019
Looks good Keith. Funny to see the crank main bolts safety wired. What did Kohler expect, the bolts to back out at a whopping no load 1860 RPM?
Personally, If you have it this apart, I would pull each piston to check the rings and making sure they are not worn or worse yet, stuck. I would at least lap the valves.
The engine reminds me of the little 134 ci flathead in my 1939 Willys pickup.
 

Vanman

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Last Subscription Date
06/10/2020
Yes, I agree about checking the pistons and rings. I can check the wrist pins for looseness at the same time. I want to look at the bearings and crank anyway.

It was making 18 lbs oil pressure at cranking speed right before I took it apart so I'm cautiously optimistic that the bearings are all fine.

I'm a bit nervous because I *thought* I *might* have heard a slight knock the last time I gave it a good run. Between the carbon build up and the crap in the water jacket it may have just been a little spark knock.

The wired bolts are pretty funny. I've never seen that in person before. Only in pictures of aviation stuff. But I'll put them back. :D
 

Motorhead

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Age
67
Last Subscription Date
07/09/2019
Plastigauge the rods and mains. You can check the journals for roundness with a good micrometer. Look over the cam lobes real good and see if any of the followers are dished out where the cam meets. If you have to remove the cam, make sure you keep each lifter with each cam lobe.
Flathead, water cooled engines will sound a little "Knocky" when running. They were built with more clearances than late model engines.
 

Bent Trigger

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Last Subscription Date
06/15/2020
Keith, that pan and motor internals are gonna need some cleaning.:D Good job on getting it apart with no damage. Chris
 

Vanman

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Last Subscription Date
06/10/2020
Made some more headway tonight, and made some somewhat disconcerting discoveries, but could be worse.

Pulled the pistons, rods, and crank. The crank looks pretty good, and mics pretty good too. The center main is maybe borderline.

Considering the condition of the #1 and #4 rod bearings, the corresponding journals look great! :shrug:

I wonder if these bearings are a common, standard part. :shrug:

I'm thinking to micropolish the crank and throw in a new set of bearings.

I haven't checked any of them for clearance yet, and they all look good other than those two... If they're expensive I'd check the others and see about keeping them I suppose...
 

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Vanman

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Last Subscription Date
06/10/2020
The first photo is the #1 rod journal. This bearing is the worst looking one, though #4 is bad too. Don't mind the bug stuck in the oil...

The second photo is the #2 and center main. The bearings for these look good, and I think the journals would look good too, with just a micropolish.
 

Attachments

Vanman

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Last Subscription Date
06/10/2020
I think it was water in the oil. When I bought it the oil was very milky, and the seller had demonstrated it running. I changed the oil after I got it home, but evidently that was too late.

All of the other bearings look good. I'd better look at the cam and it's bearings too.

I was hoping to find that Kohler used off the shelf bearings, but I have yet to find any cross reference to the Kohler part number.

Beyond that, what to do? Pour babbit I guess... :shrug:
 

Vanman

Subscriber
Last Subscription Date
06/10/2020
Here's a video sort of summarizing what I've done and found thus far.

Take a look at those bores. That's a pretty odd wear pattern. :shrug: Looks sort of like a circumferential groove around ~1-1/2" down from the top. It has me more concerned than the bearings did. It was hard to get good still shots of it, but it shows up very well in the video.

https://youtu.be/AVwZaw2gN8Y
 

Motorhead

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Age
67
Last Subscription Date
07/09/2019
Looks like where the oil ring traveled to and wore the cylinder?
 

Vanman

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Last Subscription Date
06/10/2020
I'm not sure. I was planning on taking some measurements to see what it lines up with. If the compression rings don't go past it, maybe I'll just run it. :eek: But the stroke is 2-3/4", so I think all of the rings are going past it. :( It doesn't look that far down to me. Maybe it is a point where the piston has been rocking back and forth ~mid stroke. :shrug:
 

G Sams

Registered
Although far from ideal, since it has good compression I'd use it as is with the grooves.
You'll want to install a thermostat to control wear and for heat.
 

Bent Trigger

Subscriber
Last Subscription Date
06/15/2020
Hi Keith, after looking at the video I would say the indentations in the cylinder walls is not going to be a problem for this non-Nascar motor! :cool:
Being EXTREMLY CAREFUL REMOVING THE RINGS!! (Ask me how I KNOW)With the rings off the piston place them in the cylinder and measure the gap. Should be .007 to .017, the manual specifies the same number for all three rings, top middle and oil. I think this motor even with the bearing looking this way will function for a long time. The grooves in the bearings are from something in the oil being pumped into the journals. There are no noticeable grooves or scratches on the crank surfaces? Not changing the oil or as you mentioned the guy started it with milky oil. With a very good cleaning I think it will continue to function without heat build up at those bearings. I also think that is a last resort. Try to find some bearings or check google for a bearing manufacturer. They are cheaper than you think in some aspects. (PEICE OF MIND) Chris PS HAPPY INDEPENDENCE DAY!!:salute:
 

Vanman

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Last Subscription Date
06/10/2020
Thanks guys, you're making me feel better about it's prospects.

I found the bore gauges, but I'm not sure about some piston ring pliers... There've been so many moves and rearrangements lol. I guess I can buy some cheapies to get me by for now. I'm a little nervous about breaking the rings...

It reached 112 today, and it's *down* to 110 right now, so it's going to have to wait. :brows:
 

Motorhead

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Age
67
Last Subscription Date
07/09/2019
Thanks guys, you're making me feel better about it's prospects.

I found the bore gauges, but I'm not sure about some piston ring pliers... There've been so many moves and rearrangements lol. I guess I can buy some cheapies to get me by for now. I'm a little nervous about breaking the rings...

It reached 112 today, and it's *down* to 110 right now, so it's going to have to wait. :brows:
Over at the coast from you in the Paso Robles area, it is 110*. My JB ready to go if the power goes down. Must have the AC.
 

Newoldstock

Registered
I'm not sure. I was planning on taking some measurements to see what it lines up with. If the compression rings don't go past it, maybe I'll just run it. :eek: But the stroke is 2-3/4", so I think all of the rings are going past it. :( It doesn't look that far down to me. Maybe it is a point where the piston has been rocking back and forth ~mid stroke. :shrug:
The human eye can detect a defect in a surface finish down to the 1/10,000.
Sometimes what see is much worse than what you think

Try these Keith, I have used them with good success. Although there are only 2 sets left of the rings .Chris
If you email a ring manufacturer often they can match a set.
Rings sets are more standard than we often realize.

I remember this Lister my old man had.
You could net get rings for it from LP, he matched up a set like that. ( this is back in the day before the internet and he talked to a real person on a real phone how quaint eh ? )
I think he had to get ring lands recut on the oil control for some reason because they were a different design but it all worked out in the end...
 

Vanman

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Last Subscription Date
06/10/2020
Got a little break from the heat, and a little time this afternoon to look into the cylinder grooves. Here's what I have found.

1) They are present in all cylinders, and all are around 1-1/2" down from the top. This is right close to 1/2 of the 2-3/4"stroke, the place where an inline four will always naturally stop. I think water sat in the bores for a while, and this is the rust line. :(

2) The most prominent grooves go all the way around the cylinder circumference, and are around 1/4" wide.

3) I don't really have very good tools for measuring bores, especially small ones, but I measured the worst looking one at around 2.631", .006" over.

4) Measuring the cylinder near the top puts it pretty much right at spec at 2.625".
 

Bent Trigger

Subscriber
Last Subscription Date
06/15/2020
Keith, if you cant find the oversize, what are you going to do? I would get it running and check all other things. After 6-8 hrs of run time pull the head and re-measure. If it can run for 6-8 hrs I would call it good. It will be unlikely that it will die from a little oil or loss of compression for a loooong time. In the mean time you can source another motor possibly. When I get a used bike I try to make it perfect in the piston ,bearings and seals. This is not always possible (unobtainable). Move forward and don't sweat the stuff you cannot fix. A generator in a million pieces is a waste. Any motor that runs is better than a wish that locks you down. Your time and energy are worth more than the search and rescue of a generator. These problems can take a long time to remedy. As always take what I say with a grain of alcohol. :cool: I Have!!Chris
 
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