Virtually all automotive engines turn counter clockwise. Clockwise looking at them from the front you are facing the engine, mirror image. The reason some marine engines spin clockwise is because they run twins and need to even the torque twist. No idea why they spin backwards in a single engine boat...???...lol. Has to be something with the V-drive. The engine sat backwards in the boat. The engine had a factory Mallory dual point distributor. Now, I am really confused as to whether the crank is actually the same..  :/  Perhaps a different cam grind with the same oil pump, distributor, etc...or a different crank? If the camshaft rotates the same direction on both engines the oil pump and distributor would be the same in automotive and marine engines, but I guess if you switched the firing order you could leave the cam alone and just rotate in reverse...hhhmmmm. I will have answers after speaking with my uncle the GURU at the Christmas party this weekend!...

A single engine using a Vee drive doesn't spin the other way either.
The boat just uses a L/H or R/H prop depending on the set up


Gary - 1958 Star Customline and 1940 Ford Deluxe Hotrod

the reason dual engines turn different directions  is to make the boate more stabel and easeyer to steer..modern dual engine aps both engines turn clockwise ,but revers gears change the direction so propes turn oposet to each other.

take a look at teds post,page2,picture worth a 1000 words. cliff

Snowcone, this one does.

After more thought on the matter, if the crank is turning reverse rotation, with gears the cam is turning the same direction as it would be with a chain on a normal clockwise rotation motor. That would make the cam, distributor and oil pump turn in the normal rotation. The only thing changed is the plug wire firing order to put each cylinder to fire on the compression stroke for the reverse crank.
Does this make a little more sense?
Now the reason for the reverse rotation in single engine boats, which most I have found are reverse rotation is unclear. Either they had an abundance of reverse rotation drives, props, or they just plain steer better in that rotation, Don't know, good question?

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Bill, 
         Boats with twin engines use one in reverse rotation to even the thrust out. The props are different. In the singe engine version I think you're right, lotsa gear drives.



Frank/Rebop

Bristol, In ( by Elkhart) 

This boat sounds pretty neat. Any photos of it. If I could swim I might even ask for a ride in it when it's done !!!

Larry Short

Some of the following has been already mentioned but some of this is new.  The RH engines I’ve seen are stamped “RH” on the left front of the block.  The RH crankshafts (reverse rotation) are different from the LH engines in that the hash marks for the rear seal are angled the opposite direction so that the oil isn’t pumped to the outside of the engine at the rear seal area.  Other differences in the RH engines includes the cam timing set (gears instead of a chain) and the camshaft which simply accommodates the reverse firing order although the camshaft still turns clockwise as seen from the front of the engine.  Distributors and oil pumps are the same for both the RH and LH engines.  If the oil pan is off, look for the most rearward counterweight to be painted yellow as that should designate the RH crankshaft.  If the engine has been rebuilt to the point where the crankshaft has been reground, the yellow paint could possibly be gone.

Here’s a picture of a 312 RH crankshaft that has been turned into a 3.600” stroker crank for a 292 block.  In turning the 312 mains down to fit a 292 block, the rear seal area is also turned down which removes the reverse direction rear seal hash marks found on the RH cranks.
  

Here’s a couple of pictures showing both the RH and LH camshafts.  The RH camshaft is on the bottom in both pics.  Cylinders 1 & 6 lobes match each other on both camshafts while the remaining cylinder lobes are different to accommodate the reversed firing order for the RH engines.  The cut for the distributor gear is the same allowing the same distributor rotation to be used for each.
 
 

Lorena, Texas (South of Waco)

Ok, the camshaft and the hashmarks and timing set are the only "real" differences. NOW this all makes more sense!....I would love to do the boat but it's just too far gone. This engine will power something nostalgic or end up under the hood of a square body Ranger just for the WTF???...factor.