I have a K321 Kohler 14hp here, that I got apart (the rest of the way) this past weekend and took the bare block and crank into the machine shop yesterday, I got the phone call with the "results" of the machine shop evaluation.
This is/was the original engine from my '72 New Holland S14. the most recent PO dismantled it part way before I got the tractor.
debating what to do with it..... go ahead and have it machined out and buy the matching parts to the machining needed, or whether to cast it aside and put one of my others onto it..... I have a good engine on that machine as we speak but it is "only" a 12 hp, I don't like downgrading HP on a machine.
anyways, there's more to the story regarding the block, it's machinable and reusable. no big deal. oversize parts readily available, as needed to bring clearances back into tolerance, easily. both OEM/NOS and aftermarket.
but, this post is about the crank and rod from this engine, and I have a question about it.
This engine has been apart and "rebuilt" previously, and not very well. Definitely it was never measured out and just got thrown together with replacement standard sized parts. done by a past-past owner, before the guy that I got it from, had it.
The guy I got it from did not have this tractor very long. and it ran when he got it, before he dismantled it.
Well I found out today that the crank is already 0.013" under standard size. Machinist wants to take it down to a -0.020".
I know that I can't get a -0.020" rod in an OEM Kohler replacement, and I am still leery of the quality of most of the aftermarket Kohler rebuild parts that are being sold these days. though -0.020 is readily available in aftermarket.
the machinist said that there is an application for a set of bearing inserts like a car engine would use, where he can get as much as -0.040" inserts, if that were what it would take to clean up a Kohler crank. He would bore out the crank end of my current rod to accept those bearing shells. My concern is that this is a splash lube engine, not pressure lube like a car engine.
I have 1 for sure, and I think I may have 2 rods left over from past rebuilds, where I had replaced the rod with a 10-under rod and saved the old rods for him to "play with" I know that Brian Miller offers this service to fit an old rod for inserts for (something like) $25+ postage both ways.
Has anyone here ever used a rod that had inserts in it, on a Kohler single? I like doing a given job ONCE, I hate redo's.
This isn't a competition pulling engine that would come apart several times a season. I would hope to potentially get 1000 + hours out of this rebuild, mowing, blowing towing and plowing. I could see an advantage to inserts on a competition engine. something that would be replaced perhaps after every race weekend, or at least once a season.
I am NOT interested in an overpriced Ebay crank, that will in all likelihood also need to be ground to be usable "the right way"...
I'll put this engine aside and use either my 14hp Magnum or my K341 (16hp) before I pay Ebay prices for a crank.