jleonard
Guru
- Joined
- Jun 25, 2008
- Messages
- 5,067
BW velvet drive at 1.9:1
No. They aren't. Just that the Twin Disc guys like to flaunt it and rest of us are green with envy, grovelling away in the background keeping our mouths shut.....
....snip.....
Jim
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How many hours on those beasts?nmuir; said:Cummins 555's
Drop center refers to the output shaft being below the input shaft. The alternative is the two shafts being inline (at the same level).
Ted
How many hours on those beasts?
Twin disc MG509 2.47:1 on Cummins 555's, 2" shafts
Kanzaki KM4A...but not sure what the gear ratio is. The engine, service, and parts manual are all at the boat, but I haven't found any notation of the gear ratio yet.
The PO squeezed the 100hp Yanmar 4JH2-UTE into where a 65hp engine once sat, so I can't get a good look at what the information plate says. Can you decipher it from the photo below or have an educated guess?
If I recall right, those 555's were below square - like 4.5" bore by 4" stroke, which is the opposite of most of the traditional marine diesels which are long stroke/high torque.
Can you comment on any noticeable characteristics or your engines in particular?
Fascinating, thanks Ski.Not uncommon for V-block engines to use under square bore/stroke ratio. Long stroke means long conrod and distance between head and crank gets pretty far. On a v-block this means a really wide beast, and that cramps lots of installs. So they cheat a bit. Tall is easier to handle than wide.
Nothing really wrong with undersquare, a little more heat loss per displacement. Torque goes up with bigger bore, too, so long stroke is not the only way to do it.