Eppa Hunton asked in another discussion on July 3, 2013:

Can anyone give me a definition of an "F", a "Q" and compare to a Marine Power engine?  Marine Power was the engine division of CC and sold replacement engines to CC and other dealers. It would be useful to know if a discussion about a "Q" or "F" was applicable to my Marine Power.

 

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Its pretty simple. F is the standard installation with the flywheel near the strern of the boat and Q is what we call flywheel forward. A lot of boat/engine manufacturers did this in the 60's and 70's not just Chris. Graymarine was another biggie. Today there are still many flywheel fwd installations but they have V drives that still bolt up on the fly wheel where as the Q has special adaptors and castings and a special timing chain cover to allow the manufacturer to bolt a conventional trans to what we know as the front of the engine.
Lee Dahlen . www.glassicboatworks.com 704-287-3914

The later Chris Craft K (flywheel aft) motor series eventually became Marine Power sometime in early 80's. 

I have a 307g from 1975 and a 307k from 76. The 75 says Chris Craft and the 76 Says Marine Power on the exhaust manifolds. I believe that was the year CC sold the motor division to Marine Power.

Thanks Lee. You always have the most authoritative answers and can clear the air.

Hope you had a great 4th.

Eppa

Lee H. Dahlen said:

Its pretty simple. F is the standard installation with the flywheel near the strern of the boat and Q is what we call flywheel forward. A lot of boat/engine manufacturers did this in the 60's and 70's not just Chris. Graymarine was another biggie. Today there are still many flywheel fwd installations but they have V drives that still bolt up on the fly wheel where as the Q has special adaptors and castings and a special timing chain cover to allow the manufacturer to bolt a conventional trans to what we know as the front of the engine.
Lee Dahlen . www.glassicboatworks.com 704-287-3914

Does any one know why they went back to the flywheel forward. I know in the old days they did that to turn a car engine right hand. I also heard that they got more horse power driving off the front of the engine, 327Q/230 hp. 327F/210hp

The real reason for flywheel forward engines is their lower height profile, allowing lower cockpit floors and/or engine boxes. Remember, inboard engines normally sit at a 7 - 10 degree back angle. When you visualize a side profile of the engine, it becomes apparent that moving the flywheel to the forward area really reduces height. As to getting more horsepower by driving off the front of the engine, that's pure fallacy. From an engineering standpoint, the front of the crankshaft, being much smaller in diameter than the rear flange, can't transmit nearly as much torque & horsepower as the rear can. Fortunately, the front snout is still strong enough for the power a normal engine develops. The bad thing about the most popular flywheel forward engines club members encounter (the "Q" series) is the whole bunch of very special parts Chris designed and manufactured to turn a normal small block Chevvy into a flywheel forward Q. Many of these parts are getting very rare and hard to find, most notably the special low profile intake manifold and distributor. As to the horsepower rating of the 327Q at 230HP vs. 210 HP for the flywheel aft 327F, the real reason for the increased horsepower was a higher compression ratio for the Q. The F engine was 8:1, while the Q was increased to 8.8:1.

The Q's are good engines, but they have a whole bunch of hard to find special parts when compared to the normal Flywheel aft engines.

Thank you, that sheds alot of light on the situation. my engines are freshwater cooled (antifreeze) but my daughters are raw water and intakes and flywheel covers are an issue.

Dick Morland said:

The real reason for flywheel forward engines is their lower height profile, allowing lower cockpit floors and/or engine boxes. Remember, inboard engines normally sit at a 7 - 10 degree back angle. When you visualize a side profile of the engine, it becomes apparent that moving the flywheel to the forward area really reduces height. As to getting more horsepower by driving off the front of the engine, that's pure fallacy. From an engineering standpoint, the front of the crankshaft, being much smaller in diameter than the rear flange, can't transmit nearly as much torque & horsepower as the rear can. Fortunately, the front snout is still strong enough for the power a normal engine develops. The bad thing about the most popular flywheel forward engines club members encounter (the "Q" series) is the whole bunch of very special parts Chris designed and manufactured to turn a normal small block Chevvy into a flywheel forward Q. Many of these parts are getting very rare and hard to find, most notably the special low profile intake manifold and distributor. As to the horsepower rating of the 327Q at 230HP vs. 210 HP for the flywheel aft 327F, the real reason for the increased horsepower was a higher compression ratio for the Q. The F engine was 8:1, while the Q was increased to 8.8:1.

The Q's are good engines, but they have a whole bunch of hard to find special parts when compared to the normal Flywheel aft engines.

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