K321 rebuild?
 

Was going through some files last night and found a PDF printout of the ad the PO posted for my 1450, the ad said the engine had been rebuilt and bored 0.010 over, now that I think of it someone had written 0.010 on the engine tins before I painted over it. When I took the head off last winter though the piston said STD on it. I'm not too familiar with these things, can you use a standard piston and just use bigger rings or did the rebuild never happen? Engine runs fine, just curious.

No it should have had a .010 over piston installed too.

If the cylinder was opened up .010 the std piston would be very sloppy in the bore.
Possibly someone was mistaken?? or you were given a line of B.S.
Happens all the time, the term "it was all rebuilt" is about as misunderstood/misleading as "if you don't like you can return it" @ a restaurant:biggrin2:
Then there are some ppl who think a couple of gaskets and some spray paint describes the term also.
possibly the bore was in decent shape and it got new rings?
Did you actually measure the bore? That is the only way to really know what you have.
But if you are happy with the performance,no problem.
Some service manuals state a bore if round, it can be as much as .008 oversize and still use Std rings, I don't like that much clearance.
:beerchug:

Yeah no the ad specifically said "bored 0.010 over", also that the crankshaft was ground 0.010 under. He pointed to the writing on the tins to indicate it was rebuilt when I went to take a look at it. I don't remember if he said he had it rebuilt, or if the PO had it rebuilt, but obviously somewhere there was some BS. The piston was fairly snug in the bore when I took it apart. Who needs special equipment when you can rebuild an engine with just a marker :biggrin2:? Oh well, it runs fine so no big deal , caveat emptor I guess.

just because he said it don't make it gospel. probably half the parts tractors
I've bought I was told "it was just rebuilt 3 or 4 years ago" I pretty much ignore it unless there's receipts to back it up

What he could have done is turned the crank. Honed it put 10 over rings on a standard piston and called it rebuilt.

If he lightly Deglazed it, and file/hand fitted .010 over rings properly, ok.
but if he used a power hone to go oversize to fit the .010 rings with std piston, it would rattle like a diesel on a very cold day!

I wouldn't call that ok..... a .010" over set of rings in a lightly de-glazed std. hole will egg enough not to seal. Maybe if he took it to .008" it would seal after it ran several hours. (Like over 100hrs) But like you said, then it would knock bad.

I don't think the rebuild ever happened, someone just wrote 0.010 on the tin and that was that. Whether it was the person who was supposed to do it or PO, I don't know. I guess is there any way to check next time I pull the head? Measure the inside of the bore? What tool would I need?

One that you don't want to pay for just for the satisfaction of knowing. If it runs good and doesn't burn oil as fast as gas..... let it go. Don't worry. Just enjoy your machine! :beerchug: