goofy engine stuff CW vs.CCW Rotation

[Clayton]

Ok..I'll try to be concise; but.....

I am restoring a '56 17ft CC Cavalier Utility #v17 757. It was shipped from the factory "less engine". It is equipped with a 312 Y-block Ford of 1957 vintage. It was more common to Century boats, but I am assuming that it was powered this way upon delivery, since the transom is set up for dual exhausts. I understand that all CC single screws had CW(right) forward rotation props, and starboard steering to help compensate for engine torque. This prop. is CCW (left) and though I haven't started the engine, I have turned it over, and from the output end it will turn CCW, although I can't see rotation at the tranny output due to no oil pressure, I assume it will turn the same direction. Anyway, it looks like this was set up backwards.

I am now to my questions:)

Does the output of the tranny(appearently a Dearbomatic) when in forward gear, match directions with the output of the engine?

Can the Y-block rotation be reversed? I have a starter rhat would spin it the right direction; and all the parts to mate up to a Velvet Drive. I assume the cam would be wrong and firing order would be reversed. I am thinking of switching to a Velvet Drive if I can spin the engine the other direction. What else am I missing???

Would love to get some input on this one........Thanks

Clayton

[brian.cunningham]

you'd need a special camshaft and of course the wires on the distriutor need to reversed.

This is a common thing to due with marine applications.

Just make sure it's not handled in the transmission. turn it over in gear, with a rachet, and see which way the prop goes.

[Bob Adams]

That boat turns a small wheel and should not be adversely affected by prop torque. I'd fire her up, see which way is forward and install the appropriate wheel.Most marine transmisions do indeed turn the same way as the engine in forward, there are a few exceptions, mostly on larger transmissions, Twin Disc 506 ect.

[Concordia..41]

A 312 was known as the police interceptor in the 1956 Ford. My Dad bought one new in 1956 because it could climb this steep hill on the road to where we lived with out shifting into second gear. It was a very fast car for it’s time as most family cars were six cylinder.
I would first get the engine started and see how well it runs. There are still places that sell parts for older engines if you decide to rebuild it. Back then most of the engines could be rebuilt just by honing the cylinders, new bearings and a valve job. Unless a ring had broken and damaged a cylinder, the oil rings were the first to go and was the reason you normally could get by without boring the engine.
I would also check out the transmission to see if it can be repaired. If the present transmission is bad and you must replace it then I would use a velvet drive. I’m not sure of the velvet drive model number, but I believe it is model 72 that you can reverse the out put just by rotating the front pump 180 degrees. You would also need to know what the reduction gear ratio is on the old transmission. Most were 1 to 1 on small speed boats back then. Here again the velvet drive has an advantage as the reduction is in the tail shaft. Probably the hardest thing would be to find the adapter plate to mount the velvet drive to the engine.
If I remember right, it’s been years since I rebuilt the 312 I had, the oil pump is driven by the cam shaft. This would also have to be changed if you decided to reverse the engine direction. There use to be a parts place call J. C. Whitney out of Chicago that had parts for older cars.

Dave

Sun over the foreyard

[brad9798]

On a single engine boat, it's not really something I would consider critical.

As long as the prop is a counter-rotating prop, who cares?

Certainly, it ran for years and years with that set-up.

You'll just pull to starboard with a counter-rotating engine ... everyone else will go to port.

Am I missing something here? Seriously! I wouln't worry about it.

Brad

[nedL]

Recently I've noticed some brand new single screw inboards with left hand props on them. I've seen left hand props on competition ski boats like the Correct Craft Ski-Natique, and on a 45' - 48' trawler type of pleasure boat. I have no idea, I kind of like to think I would know which way the stern will 'walk' when I drop her in reverse, but with today's boats who knows? If I were you I'd probably leave well enough alone unless there is a reason.

[Clayton]

Wow....thanks guys......sounds like the consesus here is to see what happens...

The only reason I would mess with it is that I'll probably rebuild the engine anyway, as it has signs of leaking oil. I have heard the Dearbomatic is hard to get parts for, so hence the Velvet Drive idea. (I do have the proper bellhousing, flywheel and damper)
Hadn't thought of the oil pump.....so finding one of those may be a trick...and the cam too for that matter....

Anyway.....love to learn more about this beast if anyone else has any thoughts.

Thanks again,

Clayton

[Gordon Bartlett]

My old Pacemaker had twin Chevy small blocks. The one that turned backward had its cam driven with a pair of meshed gears rather than the normal sprocket/timing chain arrangement. In other words the cam rotated in the opposite direction from the crankshaft. This allowed the use of a standard distributor and oil pump. Of course the cam was specially made for the reversed firing order and the distributor wires were arranged accordingly. I don't know if any of this applies to your Ford engine.