Okay guys, I will do my part and start a new thread.
How many of you have reworked your tractors for more power?
My Case 700 diesel has overbore sleeves and pistons and raises the horsepower from 51 to about 65 with a change in timing and injector pump tweaking.
My 1948 Case LA has 1/4 inch overbore raising the displacement to 448 cu. in. plus a LP gas head which raises the compression from 5.7 to 1 to about 8.0 to 1 ratio. Horsepower now is approximately 90 from the original 64.
My 1942 Case VC originally with a Continental F124 is now bored out to 165 cu. in. and showed 27 horsepower on the dyno, up from 21, with no tuning, still set at the static timing I set when I assembled the engine. Hoping for 30 when I get it fine tuned.
The 700 is my main field working tractor, The LA is used at tractor shows to run sawmills and threshing machines and an occasional fun tractor pull. The VC attended its first show 2 weeks ago and will be mainly for show and running smaller belt machines an maybe a few hooks to the sled in lightweight class.

How about the rest of you guys???... Gene

I rebuilt the engine in my little JD model H recently. Bored .125 over, new aluminum pistons and the cam and followers were sent to Iowa and a hot "puller" grind was done to it. Can't say anything about the horsepower gain, but it lopes when idling. Kinda fun.

Dave

I though all 2 cylinders loped at idle:D:D

My family never has believed in modifying anything for more power other than an upgrade in piston designs when time came for a rebuild. Otherwise everything has been kept stock, including the electrical systems. Dad always said he sold enough parts for stock machines that destroyed theirselves by being overloaded. I guess it really depends on how well overbuilt the original machine is. When you look back at our farming history, when a machine was deemed too small to get the job done, it was traded in on a larger machine. Don't get me wrong, not condeming the practice of squeezing out more power--it certainly adds more flavor to a tractor pull!

I know of guys sending off the crankshafts out of JD As & Bs to be stroked. They weld up the rod journals on the rear side up to 1/2" and then turn them to give more stroke. The downside is they have to remove some of the crankcase casting to allow the rods to clear at BDC. Then they're bored big time, cams reground, governor RPM spun up and secret fuel additives used. I haven't heard of one blowing up yet. There is 5 or 6 in this immediate area.

I know of guys sending off the crankshafts out of JD As & Bs to be stroked. They weld up the rod journals on the rear side up to 1/2" and then turn them to give more stroke. The downside is they have to remove some of the crankcase casting to allow the rods to clear at BDC. Then they're bored big time, cams reground, governor RPM spun up and secret fuel additives used. I haven't heard of one blowing up yet. There is 5 or 6 in this immediate area.

I met a vendor at the '07 JD expo who had owned an engine machine shop where he did the stroking you describe for numerous customers. I believe he referred to JD D as a good candidate.  I purchased a JD LA engine from him that he had rebuilt for his own use.  He planned to make a Stretch L to put this engine in.  Before that could happen he sold his business and went to work for the US Gov't running an engine machine shop at a nearby military installation.  He claimed he "tinkered" the LA engine a little, but did not say what that meant.  ??  Someday I will find a use for the motor and hear it run.  I still have to dig up a manifold and carb for it. They were sold separately off his table for $75.00 each.  Hindsight is 20/20.

Charlie V.

Is your engine a John Deere or Hercules? Deere used their engines in the later models. I have 3 of the Deeres, mainly for parts.
Dave

My family never has believed in modifying anything for more power other than an upgrade in piston designs when time came for a rebuild. Otherwise everything has been kept stock, including the electrical systems. Dad always said he sold enough parts for stock machines that destroyed theirselves by being overloaded. I guess it really depends on how well overbuilt the original machine is. When you look back at our farming history, when a machine was deemed too small to get the job done, it was traded in on a larger machine. Don't get me wrong, not condeming the practice of squeezing out more power--it certainly adds more flavor to a tractor pull!

Modifications have been a way of life in our family. We were a large family growing up on a small farm and had to make do with others hand-me-downs. For this reason, we all developed a background for our mechanical experiences. A matter of survival.
Our main tractor was a Farmall H with high altitude LP gas pistons and worked at 38 horsepower for years.
Growing up we all had cars with bigger engines, special cams and carbuterors. Did some drag racing with moderate success. Tractor pulling too.
Brother Gary modified his 1947 Farmall Cub with a Kubota 4 cylinder diesel engine and is a masterpiece of engineering.
One of my winter projects was repowering my Yamaha golf cart with a 18 horsepower Briggs Vanguard V-Twin, repainted bright yellow and built a carrier on the back.
Gary's "Cubota" and my golf cart along with my LA and maybe my VC can be seen at Portland's Tri-State tractor and engine show from Aug 26 to 30.... Gene

Is your engine a John Deere or Hercules? Deere used their engines in the later models. I have 3 of the Deeres, mainly for parts.
Dave

It is a Deere, Dave, not a Herc NXA or NXB. I also have a couple of NXB parts engines.

I bet the "Cubota" is quite a sight! A friend of dad's came into the IH dealership he worked for and told a new guy at the parts counter he needed some parts for a diesel Cub. The guy looked far a while and never found the parts book so he asked the boss. Needless to say the boss wasn't too thrilled at one of his employees being made to look so foolish!

My Dad's Cockshutt 40 would qualify as "powered up" I guess. When he bought it used in 1968 the 40 was found to have a 50 engine installed in it. Since the engines are identical externally it was literally a bolt in swap. Sometime in the past 40 years we switched it back to a 40 engine after the first 50 needed work. It was always a noisy rattling engine, so much that we gave it the nickname of "the rattler". We had another parts 40 and used the engine out of that one so since that day the 40 has been just a 40 with the original sized 230 Buda engine.