SA 250 Perkins question

[JFwelder]

Hey everyone... New to the forum. I searched around but couldn't locate anything for my question. I just bought a 1988 sa250 with the 3 cylinder Perkins motor in it. It ran and welded great except I knew it had blow by. It was getting back pressure and coming out of the dipstick port and breather tube. I was told it probably needed new rings. So I bought new pistons and rings. Broke the top end down and pulled the old pistons. Two cylinder sleeves have pretty decent scars in them where a piece of the old ring ground into it and the piston. I had planned to have the motor done and the machine in my truck already so I could go back out and make some money.

So my question is if I don't pull the block and have it re sleeved or bored out enough to get rid of the indentions and just hone them and slap in the new pistons and rings what will be the result? Will it change the amount of blow by? Not blow by at all? Or work good for a while and then fail?

If it will last me a year then eating the 300.00 for the new pistons/rings getting ruined isn't that big of a deal to me.bc the sleeves are already bad anyway. If it won't then I'm throwing the money away for no real gain. So I'm torn on what to do and this is the first time I've ever taken an engine apart so not sure what to do at this point with time being an issue. I know that it should be re sleeved yes... But can I get away with it like it is is what I want to know.

Any help or advice would be greatly appreciated.

[smokin_dodge]

IMHO... by just replacing the rings you are only putting a temporary fix on the problem. I take it this is a work rig, so any down time is lost money. This is where its time to do a little acounting...

I would first calculate the time and cost to just re-ring the engine and compare it to a full rebuild. It is very possible that by just replacing the rings you can "theoretically" get another year out of the engine, but is not a definite. Odds are it will be cheaper to just re-ring the motor....or are they??

So then you have to start asking yourself what if...
what if the rigs blow out in 30 minutes after installing them? was your time worth re-ringing the motor and just wasting 30 minutes?

What if the motor runs great and you go out of town on a job and the motor blows, then you have to add the cost of getting another machine (either a spare you own or a rental) and add that time and other costs to the bill of the rebuild, more money possibly wasted.

Im sure there are hundreds of scenarios that you can play out in your head, but I suggest rebuilding the motor correctly, this way you can address all of the potential problems at once, instead of slowly repairing things as they come up. In the end, I find it much more cost effective to repair everything at once then little by little.

[JFwelder]

Thanks for the reply.. I went ahead and ordered sleeves this morning. Going to replace that along with pistons and liners. The only problem it had before I tore it down was the blow by. Which was from everything I'm replacing. She ran like a top and welded great other than the blowby. So once I get the new stuff in I should be ready to rock and roll.

[smokin_dodge]

Post up some pics when your finished.

I don't know too much about perkins engines, but I've worked on a few in forklifts and they run like champs. I worked on one a while ago that had well over 10,000 hours. Just a quick tune up and ran like a champ.

[76GMC1500]

nevermind