The Steamboating Forum

Mike
The Portland is Stbrd 90deg ahead of port, but if I think the Preston is the other way around. You could check that out on your way back to the island.

Dave

I'll ask Frank Orr in Anacortes. He's downtown every day.

For balance on a twin you can't beat a 90deg. opposed V configuration- they only require one crank so there are zero dead spots and as the engines are pushing in slightly opposed directions they cancel out each other's reciprocating mass. There have been successful v-twin simples and compounds made and are a very compact smooth-running engine.

In conventional layouts, a three cylinder crank makes the most balanced arrangement as cranks are 120deg. apart, with 6 power strokes per revolution- the stem equivalent of an inline 6 cyl. IC engine.

Greg

gondolier88 wrote:For balance on a twin you can't beat a 90deg. opposed V configuration- they only require one crank so there are zero dead spots and as the engines are pushing in slightly opposed directions they cancel out each other's reciprocating mass. There have been successful v-twin simples and compounds made and are a very compact smooth-running engine.

In conventional layouts, a three cylinder crank makes the most balanced arrangement as cranks are 120deg. apart, with 6 power strokes per revolution- the stem equivalent of an inline 6 cyl. IC engine.

Greg

Since a double acting steam engine gets two power strokes per revolution and a four cycle Otto engine gets a power stroke every other revolution, I think a three cylinder double acting steam engine is like a V12 IC engine in terms of power strokes/rev, if not in terms of balance.

- Bart

barts wrote:

gondolier88 wrote:For balance on a twin you can't beat a 90deg. opposed V configuration- they only require one crank so there are zero dead spots and as the engines are pushing in slightly opposed directions they cancel out each other's reciprocating mass. There have been successful v-twin simples and compounds made and are a very compact smooth-running engine.

In conventional layouts, a three cylinder crank makes the most balanced arrangement as cranks are 120deg. apart, with 6 power strokes per revolution- the stem equivalent of an inline 6 cyl. IC engine.

Greg

Since a double acting steam engine gets two power strokes per revolution and a four cycle Otto engine gets a power stroke every other revolution, I think a three cylinder double acting steam engine is like a V12 IC engine in terms of power strokes/rev, if not in terms of balance.

- Bart

Yes, that is true.

The above posts may well be correct , indeed I'm sure they are but although I love steam I think I'd prefer the V12 ic engine and the Ferrari that goes with it .

Regards , Edward .

"V12 ic engine and the Ferrari "

We all have toy diversity, probably.

Diversity indeed!

Anyone want to buy a rust-free '64 Buick Riviera? Not quite a Ferrari, but still ahead of its time in styling!

Lopez Mike wrote:Weird thing about steam locomotives. All over the world, the right side runs 90 degrees in advance of the left side. No exceptions as far as I know EXCEPT the Pennsylvania R.R. in the u.s.a. which was left ahead of right. I have no idea why. Historical stuff I suspect

The Strasburg Rail Road owns a Porter locomotive that is left hand leading. The Virginia & Truckee #2, the "Lyon" was left hand leading (you can see through to the other side in one of the existing photos), and so the reproduction that is nearing completion is as well. The third example that comes to mind is the Climax geared locomotive that was being restored at Cass WV has left hand leading on its crankshaft. I'm sure that there are others out there.

I suspect that most locomotives were right hand leading in that quartering machines (specialized machine tools used to turn both crankpins on a wheel set simultaneously) were built right hand leading, so the railroads standardized as well to save on buying a second quartering machine. That could be a chicken and the egg deal, I suppose.

Herreshoff's steeple triple-expansions had 3 cranks and they weren't at 120* speration