SD22 piston rings 5 vs 3

[NopeNaw720]

hello i am currently overhauling my 81 720 pickup diesel (SD22)

my question is can i use the overhaul kit for the forklift motor (5 piston rings) to replace the 3ring pistons & liners i took out??? 

why do forklifts have 5 piston rings? different loads and rpms? 

coworker suggested putting only 3 rings on a 5 ring piston and that doesn’t seem right. 

im searching for a overhaul kit on ebay. anyone have good experience buying from alibaba? 

 

[Stoffregen Motorsports]

Alibaba is supposed to be legit, but I have never actually bought from them.

 

So your pistons have 3 rings? or 5?

 

Are you replacing the pistons? If so, why? If you can re-use the 3 ring pistons, I'd go that route.

 

5 ring pistons are oooooooold tech. They were obviously concerned with compression loss and oil consumption, and that makes sense in a forklift. I use a gas powered forklift in and around my shop, and man, that thing really stinks up the shop.

[datzenmike]

My info shows STD SD22 ring set as 5 rings 12033-R8112

STD piston and pin set as............................... 12010-36W10

Sleeves as........................................................ 11012-76200

 

[NopeNaw720]

i am looking to replace the pistons with new liners because thats all i can find for overhaul kits. i am overhauling this engine because it was burning oil bad with constant blue smoke. good idea to just look for a set of std rings. all the bearings are std aswell as liners (that are completely glazed) when i purchased the truck the previous owner had installed a racing air filter and was spraying ether into it in the winter months 🤦 

[NopeNaw720]

My pistons have 3 rings

[datzenmike]

Can't find any oversize pistons and rings listed for the SD22 so liner replacement allows you to reuse the stock pistons and rings, no need to over bore it.

 

I know nothing about the 3 ring set up as stated, my info shows 5 rings. You could simply replace the liners and switch to 5 ring piston.

[Stoffregen Motorsports]

I guess I'm missing something. Are the liners bad, scratched, scored, pitted, groove on top? If not, they can be ball honed to clean them up. New rings will seat against the old liners, if the surface prep is done correctly.

[datzenmike]

Then back to 3 vs. 5 rings and how to find 3s.

 

I suggested replacing the pistons with 5 ring because available.

[NopeNaw720]

i want to replace the liners/sleeves with the pistons and rings so as to have a “fresh start” against burning oil and blue smoke. to ball hone i would need oversized piston rings and those are hard to find. versus replacing everything while its all completely torn down and out of truck body. i just want to know why the forklift has 5 ring pistons and the truck has 3 ring pistons? is it an era thing? different manufacturers? when i inquired on a kit from alibaba they asked if i had 3ring or 5ring pistons. i was nervous to purchase that kit because of dealing with import fees. its hundreds of dollars i dont want to waste so im attempting to “do research” here. 

[bilzbobaggins]

5 rings for a natual gas forklift?  shot in the dark

[wayno]

My guess is that forklift parts are easier to find than 720 diesel engine parts, they are also likely cheaper.

 

I had a SD25 engine start smoking after the engine was overheated, it always smoked after that and it had no more power than an average running SD22 engine after that either, the overheated engine also smelled weird like unburnt fuel(like the white smoke when first started in cold conditions), I tore it down and looked at the pistons/cylinders, I did not chase it any further as one of the rods had been compressed and it was slightly shorter and I could not find another rod for it, I could likely have used lighter duty SD22 rods but decided it would be a parts engine as I have 3 other SD25 engines.

 

I do not really know if the compressed rod caused it to smoke so bad or if it was because of the overheating of the engine, I added water to it to get home and it did not boil over, but a hose on the side of the head split while driving one night and that night the dash lights quit working so I did not know there was an issue until I left the freeway and came to a stop and seen steam coming out from under the hood, it was never the same after that event, I never felt anything happen that would have made me think a rod had been bent either, I suspect it had been bent before I owned it.