Tale of 2 K301's or Anyone have a clue??

[dschwandt]

As to when Kohler stopped installing balance gears and changed the style of the crankshaft in the K-301 engines?

Calling all Kohler Gurus here.....

My engine I installed in my 128 (it had no engine when I got it 2 years ago) has no balance gears, has the vertical in block dipstick and a 1/4 x 1/4" wallowed out PTO keyway, and bolt on drive cup w/3'16" woodruff key for the flywheel. This is the upper crank in pic's. This engine has a .010 overbore w/Kohler piston in good shape but for some skirt wear and no obvious cross hatch, and a Kohler rod (w/broken dipper)

The spare K301 (bottom pic) has balance gears, a good 1/4" PTO keyway, a 3/16" straight keyway for the flywheel that is secured w/a nut. Also, this engine has a standard bore w/a no-name piston and rod but has erosion on the top piston land and the crank does not appear to have been turned.

2 questions here....
Why would a standard bore 301 have a no-name piston and rod?

Will these 2 cranks interchange w/no issues other than main journal size for a rod (broken dipper) that will have to be replaced anyway?
I am hoping I can swap the crank into the 128's engine and reinstall.

 

[danderson]

As far as the bolt crank in a block with a vertical dip stick I’d say it was replaced. Older block, newer crank. Just worked on a buddy’s 129 with the original engine and it had a nut. I have a 1974 replacement engine. It has a nut. My 1250 has a bolt IIRC.

 

[hydroharry]

David - if you want the Kohler Guru you better give David Kirk a call. He used to work with the Kohler engineers (as a consultant if I recall correctly). I asked him to check one time for some old Kohler K series blocks and he told me they were all melted into new bath tubs

 

[dschwandt]

I thought of that
I'm hoping he will chime in here.

 

[dkirk]

Morning guys - thanks for the kind words Harry.

David S., the crankshafts should be fully interchangeable with no issues. Just be sure that you shim the flywheel-side end-plate (using the white gaskets) such that there is no axial preload on the ball main bearings.

Regarding the no-name piston and rod, the earlier Kohler pistons were high-pressure die castings and had no identifying marks for the standard bore sizes. The oversized pistons always had numbers stamped into the piston dome indicating the oversize (.010, .020, etc.). As far as the connecting rod goes, there should at least be a part number cast into the rod beam. I don't think I've ever seen a rod without some nomenclature.

Another tip, a little off subject - The K321 and K341 use a full counterweight crank (without the flats machined on the lower radius). If you use one of these cranks in the K301 without balance gears, you'll have a smoother running engine as it brings the balance factor closer to the 50% "ideal".

 

[dschwandt]

Thanks David!
I kinda thought the cranks would interchange, just needed a bit of verification.
I can salvage the wollowed out on by cutting a new keyway on the opposite side.
I'll get a picture of that rod when I can.....
And set the un-bored block aside for a later project, minus the balance gears of course!
Right now, I have to go haul some cement....