D8H 235 vs. 270HP

Provided they have the stock air cleaners it is easy to tell them apart, the 235 has a vertical air cleaner and the 270's is stuffed under the hood at an angle. Horsepower changed around 1966, OM will know exactly

Went to 270 hp in 1966 at s/n 12885-up.
FLRPM went from 1240 to 1280 rpm
Rack went from 0.270" to 0.365"
Boost went from 26 to 33 in. hg.
There were internal parts changes as well. Some day I'm going to make a list of all the part number changes.

HP went to 270 in June 1966, UK built tractors 68A1229 and 22A1250.

The D8H is a very interesting tractor to follow through from the first built to the last built. For example in the 46A series they started at 225hp and fuel converter, then somewhere about 3,000 they went to oil converter and 235hp, then at 12885 to 270 hp. My gut feeling is a handful of the last may have even been 300hp even though Caterpillar only ever rated them at 270. Many many improvements were made, heavier final drives, transmission case updates, radiator nose cones, radiators, starting systems, exhaust systems, blade configurations etc. If it was possible to put 46A001 beside a 46A33,000 tractor some of the external changes would be seen very easily, as well an incredible performance/production difference.

For me the D8H was the flagship of the Caterpillar crawler line up, even though they were also producing D9 tractors, it was the D8 that you mainly saw on projects and was the darling of contractors.

Definitely my favorite model. Someone can correct me but I also think that a water-to-air aftercooler was added sometime during the 270hp run. Given the hp rating did not change, how did Cat describe what impact that addition had on performance?

The D8H is a very interesting tractor to follow through from the first built to the last built. For example in the 46A series they started at 225hp and fuel converter, then somewhere about 3,000 they went to oil converter and 235hp, then at 12885 to 270 hp. My gut feeling is a handful of the last may have even been 300hp even though Caterpillar only ever rated them at 270. Many many improvements were made, heavier final drives, transmission case updates, radiator nose cones, radiators, starting systems, exhaust systems, blade configurations etc. If it was possible to put 46A001 beside a 46A33,000 tractor some of the external changes would be seen very easily, as well an incredible performance/production difference.

For me the D8H was the flagship of the Caterpillar crawler line up, even though they were also producing D9 tractors, it was the D8 that you mainly saw on projects and was the darling of contractors.

Definitely my favorite model. Someone can correct me but I also think that a water-to-air aftercooler was added sometime during the 270hp run. Given the hp rating did not change, how did Cat describe what impact that addition had on performance?

[quote="Wombat"]The D8H is a very interesting tractor to follow through from the first built to the last built. For example in the 46A series they started at 225hp and fuel converter, then somewhere about 3,000 they went to oil converter and 235hp, then at 12885 to 270 hp. My gut feeling is a handful of the last may have even been 300hp even though Caterpillar only ever rated them at 270. Many many improvements were made, heavier final drives, transmission case updates, radiator nose cones, radiators, starting systems, exhaust systems, blade configurations etc. If it was possible to put 46A001 beside a 46A33,000 tractor some of the external changes would be seen very easily, as well an incredible performance/production difference.

For me the D8H was the flagship of the Caterpillar crawler line up, even though they were also producing D9 tractors, it was the D8 that you mainly saw on projects and was the darling of contractors.[/quote]

Aaaah, the 46A was power shift from the beginning. It's the 35A that had the fuel converter.

No mention of an intercooler or aftercooler in my 46A24433 to last built Parts Book.