Other than oil pans... will it work?

[mikeeyre74 289]

Is there any Kohler big block engine that isn't suitable for use in my c120? Are they all capable of taking sideloads like that from the PTO, or are some different than the rest? If so, how do you tell what's good and what's not? My 120 smoked a rod and if it's a good deal on a 12hp from the guy down the street, say, how can I tell if his Kohler motor is going to be good for my wheel horse? Hypothetically speaking.. I haven't located the replacement engine yet, but I need to start looking. 

[953 nut 60,204]

Most, if not all, 12 HP horizontal shaft Kohlers will bolt on to your existing oil pan, measure the bolt centers on yours for comparison.

[rmaynard 16,340]

Also check the diameter and length of the PTO side of the crankshaft. The original C-120 engine had a 1-1/8" diameter crank. 

[mikeeyre74 289]

I understand the crank diameter and oil pan issues. I had to swap the oil pan from my 12hp onto this 14hp a while back for the bolt up issues. My main concern, and this  might be totally unfounded, is with sideload. As I understand it, some engine intake side loads, while others cannot.  What I mean by that is, the pressure of the PTO that the wheel horse has pushes in along the axis of the crankshaft… As opposed to just spinning a shaft and not having a forward or backward load. Does any of that apply to Kohlers? Or are they all capable of this sort of loading?

[tbarnhart 240]

AFAIK, all the cast iron Kohler singles have the same ball bearings that support the crankshaft and can take the same side loading. As stated above, the differences are in the oil pans and block designs, and the specific crankshaft dimensions. The rod dipper can be different as well between the different pans, so changing pans without addressing that could be problematic. There were other differences such as cable hookups etc. that can generally be worked around. Kohler also had two different starter arrangements on the big blocks, and the low starter may interfere with the battery on a C-120. I'm not sure of the details there, but it's something to keep in mind.

[JAinVA 4,638]

The crank diameter on most WHs is as mentioned 1 1/8",but there also were some that were 1".The drive pulley for the transmission and  pto sleeve were exactly the same except for the inside diameter.To keep my future options open I bought said parts for the 1" crank and they are sitting on a shelf in the shop.Those parts can be had used and may help if you get a good deal on a 12Hp with the 1"crank.

                                   JAinVA

Edited October 4, 2016 by JAinVA

[pfrederi 18,703]

As mentioned K series singles had ball bearings. Where you have to be careful is with the K series Twins. (KT 17 and KT19).  Many big users (John Deere/Cub etc,) didn't ask for ball bearings or thrust bearings going with only sleeve bearings.  The sleeve bearings have only a very small lip on one end and it cab take the normal stress but when you push on the end of the crankshaft as a WH Manual PTO does you are putting a lot of stress on a very small surface area.

 

For Series 1 KTs only 4 variations out of 75 spec numbers had ball bearings.  For Series II there were no ball bearings at all.  Instead they used a roller thrust washer to handle the end loading, but out of 40 some spec numbers only 1 variation used it (Wheel Horse of Course.