IF memory serves, look at the rear slinger on a crankshaft, the grooves go one way to keep the oil away from the seal... (i'm working from 15 year old memories)...

If they didn't alter that for reverse rotation, there'd be lots of oil in the bilge...

I can't imagine machining the grooves the other way added a significant amount of cost to the crank... unlike the cost of the cam.

And remember, these weren't automobile engines, they were marine engines.

Anyone running twin 427's had enough money to pay the extra few $100 for the reverse motor

 

It's true the hatch /////// marks went the reverse direction on the marine reverse rotation crank. Wish I still had them here to show you. My bud took the reverse rotation crank and smoothed the //////// oil slingers till smooth. Then used the newer rubber seal vs the older rope seal. It still leaked LOL. He changed out the seal for a rope one and was worse. Then put another rubber seal in and lived with it. This has to be well over two years ago by now. G.

 

Think about it. if the grooves they put on all cranks back then were angled to pull oil back in toward the inside what do you think would happen as soon as they fired up a reverse rotation engine? They would have to reverse the angle or have oil spraying outh the rear of the block. Common sense goes a long way.

 

He should have used a small ID seal, because the crank was now under sized.

 

Sometimes common sense it the enemy of logic and reality. I understand about the hash marks, but I just don't see how effective they would be.

 

O.K., Go out and find your self a reverse rotation crank . Throw it in your engine and see just how effective they really are.
Short of that I don't know what else to tell you.

 

About 10 years ago a friend got a good deal on a running 427, we installed it in his F250. Wouldn't start, bumped it rolling backwards in 3rd gear it started. He had 4 speed reverse and one forward, fan blew air forward. Changed cam, dizzy and intake, ran great for years but always had a weeping rear main seal leak even after three seal changes, rope or rubber. If you think the hash marks are not important why did Ford make them for different engine rotations, enjoy your oil leak.
.....=o&o>.....

 

What I'm saying is that if you are trying do do something as a money saver, a different crank isn't the smart way to do it. I didn't say the hash marks don't work. However if you are feeding pressurized oil to the rear main brg (they do) and the seal should retain that, why would the hash marks improve that, even a rope seal?

 

I remember reading something about this on Net54. IIRC it's the same crank with a minor variation in the same machining process. I think Ford did that as an oil control measure-move oil away from the rope seal.

It's all trivia to me. It's not likely that I'll ever see one, much less own one.

 

I suppose you could, but since nobody in their right mind would want a reverse rotation cam sitting around, unless it was for a boat, they're cheaper that way. The boat cams, by the way, are basic RV truck cams, lots of torque, rpm max is 4000 rpm, torque is 438footpounds at 2700 or something like that. I posted the 427 marine specs on the boat web site I host, in case you're interested in seeing the stuff. http://www.network54.com/Forum/424840

INTERCEPTOR made a marine 427 that had 300, 330 and 400-hp. I think the 300 hp version was the same as the Chris Craft version, but not really sure.

P

 

You're right, it is the "identical" crank, except there are some embossed grooves that are intended to "wipe" oil back into the motor. So if you get one of those reverse rotation cranks and you don't machine those embossed marks out, the standard automotive rotation will be wiping oil "out" of the motor.

regards, P

 

The pressurized oil coming from the bearing doesn't directly spray toward the seal. The oil slinger ring cast into the crank blocks this. The hash marks pull the oil that does end up near the seal, away from it, as to keep too much oil from puddling and getting pulled thru the seal by the crank. I've looked at a marine 351W crank ( also a rev. rot. crank) and you're right , it is the same as a std. rot. unit, the only difference being the hash marks near the seal surface facing the opposite direction from a std. rot. unit.