-just wondering on the history of the early 3 cylinder engines, were they reliable, durable engines with few issues etc..

Absolutely, ran them for hours and hours no probs. There were hundreds of them here in Wheat country.

My first ride on a antique Cat was with Alan Smith on his 3 cylinder Diesel 35, pulling a 5 bottom plow in 4th gear , he had made some HP improvements and said it was close to 100 HP, not sure how that was estimated but it pulled that plow with ease and sounded cool.

I hope they're good engines. I'm about to start a Diesel Forty restoration.

Here's a good explanation of them:

Is the three cyl. also known as the 9K and was it also called the D6100?

- i notice John Deere has a new series of Diesel engines...3 cylinders...maybe they work after all:tape2:

Ford backhoes have had three cylinder engines for years, good little engines.

The old diesel-powered Lincoln welders run on a 3 cyl. Perkins. Maybe the new ones do, too.

"Fat wrote:

Is the three cyl. also known as the 9K and was it also called the D6100?

Only hit I get on a search for 9K here on this site is the #12 grader with the D4600 4.25” bore 6 cylinder engine so no connection to the 3 cylinders

The D6100 was the 5.25” bore 3 cylinder that was used in the early Diesel tractors (35 and 40??). I’m not sure on this era of machines exactly when the changeover to the D6600 occurred. But for a long time now, I think most of the D6100 engines have had to be overhauled using the 5.75” bore sleeves and the block modified as needed to fit them.

The D6600 was the 5.75” bore upgraded 3 cylinder and I believe it was first used in the RD6/D6 as well as some of the graders.

Got a couple little JD utility tractors here with a 3 cylinder diesel. One’s a fairly recent (within the last10 years) import from India I think. It’s a really simple tractor without any frills and it shakes pretty badly from the engine. JD has had little 3 cylinder diesels for 40 years or so but I’ve never driven one of the really old ones, just seen them around. We do have one about 15 years old that was a domestic production tractor assembled in Georgia and it seemed to be balanced pretty well. It ran just like any of the other small 4 cylinder tractors, so I know it’s possible to design the engine or tractor or both to run smooth as far as the operator perceives things.

Ed Porter of Salinas Ca. had a 3 cyl diesel 40 Which included a detailed diary kept by the operator beginning at year 2 that documented 40,000 hours of service including all of the repairs made over time. That's good service.