In a message dated Thu, 28 Jun 2001 6:20:24 PM Eastern Daylight Time, mbstartech@juno.com writes, among other things:
<<
Engines, except marine types,
usually rotate clockwise, when viewed from the radiator end. Marine engines rotate counter-clockwise, why, I don't know.
It's the Correolis Force of course....we're in the northern hemisphere. If they went the other way, they'd get sucked right into the water. (kidding!!)
unless there has been some sort of industry change that I am unaware of, Standard rotation marine engines turn the same way as auto engines, that being counterclockwise facing the flywheel. It is the PROPELLOR SHAFT which turns clockwise,(commonly called a "right hand screw or wheel") in a single screw boat, as the marine gear reverses the shaft rotation through the gear set.
What complicates the issue is that a lot of older marine engines coupled the reverse gear and transmission to what we normally term the front of the engine, so that the flywheel faced forward. The ubiquitous Chrysler Crown and Ace flathead series is one example. Crusader, Interceptor, Flagship, Gray, and others also favored this configuration at one time. To further complicate things, twin screw boats, whose props rotate so that the tops of the props spin outwards, usually come in counter-rotating pairs. One engine is standard rotation and the other is opposite rotation. This requires a different cam, starter, sometimes distributor and associated gearing, etc. If one has a single screw boat with a forward facing engine (same as in a car) and it turns clockwise when looking at the flywheel, then one has an opposite rotation engine, probably a swap from a pair out of a twin screw boat. Note that this then also requires the fitting of a left hand prop, or the boat would be going !
backwards all the time. The fina
l obfuscating example is that Palmer Marine Engines (based on IH engines) sold an engine series that was called the "Palmer Space Saver". Most of them were six cylinder overhead valve engines based on International's 265 cu in six. While the 265 was in itself a venerable old mill, this particular modification was bizarre to be sure. The engines were sold in counter-rotating pairs for twin screw applications, and were configured so that the block layed over on its side, with a side slung oil pan and articulated pump pickup, and a very nasty explosion prone Holley cast iron updraft carburetor. The kicker was that the standard rotation engine had a standard bellhousing to accept the Paragon marine gear, while the in the opposite rotation unit the whole engine was was REVERSED, and had the transmission mounted to the engine crank snout. Thus, the front mounted transmission required a special adapter, and due to clearances when installed, also required that the distributor be moun!
ted to that same adapter, with s
pecial gearing for timing on that side only. The engines were good performers generally, and were limited to boat designs in which the depth of the engine well was limited by hull design. I once owned a steel hulled Striker brand boat that was equipped with such a pair.
This merely proves that rules of thumb are made to be broken!
Regards,
Jack
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