yup, mostly Tecumsehs, not hp, but block size. their "bigblock" 5hp was so overbuilt it looked like a 7 or 8hp. It is a big heavy bad ass engine, some were made from cast iron. Performance built, it puts out a lot of reliable power, and the exhaust sounds really cool.
nowadays, some of the OHV engines, larger than 6.5hp are called bigblock.
nowadays, some of the OHV engines, larger than 6.5hp are called bigblock.
I wrote it in response to FOMOGO's question and I can't find it!!!:laugh: I offer only what I know.. [MENTION=5969]markus[/MENTION] is probably the most knowledgeable about Tecumsehs and their various iterations.
So, here goes: Tecumsehs are divided into several engine groups:
Small frame H (Horizontal) S (Small) and are engines beginning with H25, H30, H35, HS40, HS50. the 25, 30, 35 are early iterations, hence no HS designation. These are all aluminum blocks and some may have steel sleeves and bearing crankshafts depending on the model. The number denotes horsepower (2.5, 3.0, 4.0, etc).
Medium Frame engines are referred to as Big Blocks. Models include H50, H60, H70, HM (medium) 80 and HM100. Models can be bushing crankshafts, bearing crankshafts, steel sleeve and some may even be cast iron sleeve (Markus knows better than me). They are medium duty because they are aluminum blocks. These engines can be found on minis, small garden tractors and tillers. Number also denotes horsepower (5.0...10.0).
HH engines are heavy duty, cast iron engines. HH engines start at HH50 and go up. These are not suitable for minis due to their weight and are designed for fixed rpm operation (they will run for days on end). Wheel Horse used these engines.
HSK engines are 2-cycle snow blower engines found on single stage blowers.
HMSK engines are 4-cycle snow blower engines and are nearly equivalent to H and HM series engines. We adapt a lot of these for mini use.
There are still more variations, but my brain is failing....
So, here goes: Tecumsehs are divided into several engine groups:
Small frame H (Horizontal) S (Small) and are engines beginning with H25, H30, H35, HS40, HS50. the 25, 30, 35 are early iterations, hence no HS designation. These are all aluminum blocks and some may have steel sleeves and bearing crankshafts depending on the model. The number denotes horsepower (2.5, 3.0, 4.0, etc).
Medium Frame engines are referred to as Big Blocks. Models include H50, H60, H70, HM (medium) 80 and HM100. Models can be bushing crankshafts, bearing crankshafts, steel sleeve and some may even be cast iron sleeve (Markus knows better than me). They are medium duty because they are aluminum blocks. These engines can be found on minis, small garden tractors and tillers. Number also denotes horsepower (5.0...10.0).
HH engines are heavy duty, cast iron engines. HH engines start at HH50 and go up. These are not suitable for minis due to their weight and are designed for fixed rpm operation (they will run for days on end). Wheel Horse used these engines.
HSK engines are 2-cycle snow blower engines found on single stage blowers.
HMSK engines are 4-cycle snow blower engines and are nearly equivalent to H and HM series engines. We adapt a lot of these for mini use.
There are still more variations, but my brain is failing....