Time to bore out?

northernredneck · #1 02-25-2018, 11:21 PM

Pulled the head off my k241 that I had put together 2 yrs ago (quick and in a hurry) never had the bore checked out then put new stock sized back in. Skip to now I finally have the time to tear it down and do it right this time. So I pulled the head and it seems as though I can see more of the rings then I should possibly should? Is my bore all wallered out and in need of a bore job? Short of having it mic checked is there any way to visually check maybe. I attached a pic so that it maybe help. Any help is appreciated.

DieselDoctor · #2 02-25-2018, 11:32 PM

Unfortunately the science of engine rebuilding requires measurements taken with something more accurate than the human eye. If you don't have the tools to take a precise measurement, take the block and piston to a machine shop and have it done. This is your second tear-down and you mentioned you want to do it right. Also looking at a picture is far different than looking at the engine in person. If you think you can "see" a lot more of the rings while looking down on the piston crown, it probably is worn, but to know for sure it needs to be measured with a bore micrometer.

J-Mech · #3 02-25-2018, 11:35 PM

No, you cannot "visually" see if a bore is .004" of an inch out of round. You have to use the proper measuring tool. Inside mic, bore gauge, whatever. You can "feel" scratches that are in the cylinder walls and you can likely see them, but unless you have superhuman eyes, or at the very least very well trained ones, (as in you are a machinist) then you can't see cylinder wall wear with your eyes. (Even an experienced machinist and mechanic can't "see" how much wear is actually present in a cylinder.)

Are you having an issue with the engine? If it's not burning oil, and it runs fine, then put it back together and leave it alone.

ol'George · #4 02-26-2018, 07:57 AM

Quote:

Originally Posted by J-Mech

No, you cannot "visually" see if a bore is .004" of an inch out of round. You have to use the proper measuring tool. Inside mic, bore gauge, whatever. You can "feel" scratches that are in the cylinder walls and you can likely see them, but unless you have superhuman eyes, or at the very least very well trained ones, (as in you are a machinist) then you can't see cylinder wall wear with your eyes. (Even an experienced machinist and mechanic can't "see" how much wear is actually present in a cylinder.)

Are you having an issue with the engine? If it's not burning oil, and it runs fine, then put it back together and leave it alone.

plus 2

northernredneck · #5 02-26-2018, 09:43 PM

Alrighty no doesn't burn oil at least a noticable amount in the last 2 yrs. I guess I'll run her till I get more problems if any come up. Just figured since I had the more rare k301 block only bored to 10 h.p. and had wiggle room if need be. Thanks gentelmen I appreciate the advice.

J-Mech · #6 02-26-2018, 10:54 PM

Those aren't that rare. I have a few.

Yep, let 'er be until it's wore out. No reason to bore it out until it needs it.

dodge trucker · #7 02-27-2018, 07:41 PM

Yup I just dropped off a k321 at a machine shop that the previous owner had partly disassembled because of oil usage, which probably was why he bailed on the machine, but when I got it the rest of the way apart it was obvious that it had previously been blown up, by the marks on the crank, the chip out of the bottom of the bore and the aluminum smear on the inside surface of the block. If it doesn't come back as junk im doing it right. I ain't doing it twice.