Ford FE block swapping, and rotation issues

Reversing the direction of the FE motor.

The FE (Ford/Edsel) motor series includes the 332, 352, 390, 427, 428 and the 361 and 391 FT (Ford Truck) series, among other variants too. These engines are all identical in external dimension and appearance, save a few differences in manufacturing such as intakes and valve covers, etc. between model lines. Thunderbirds came with rounded valve covers, Fords with pentroof valve covers, etc. You get the idea.

When it came to marine motors, however, many boat manufacturers used an opposite hand rotation in a single motor application, and why this was done is still a mystery to me. Naturally, all twin engine cruisers of the day used a standard rotation and opposite rotation application to offset torque and improve efficiency.

The FE motor series will spin in either direction just fine. There are some issues, however, that MUST be dealt with if you are converting a standard rotation motor from automotive rotation to the opposite hand rotation for marine use.

Naturally the camshaft must be different, and the gear on the bottom of the distributor must be changed too. By doing so, the distributor will still rotate in the same direction as it’s neighbor, even though both motors are spinning different directions. The distributors will spin clockwise when viewed from the top).

The crankshaft on a FE motor is NOT interchangeable from one rotation to another UNLESS the embossed directional grooves are polished out. Grooves are installed to help “wipe” oil back into the motor at the main seal. If the grooves are not polished out of a standard rotation motor, and the crank is placed in an opposite rotation motor, it will run just fine, but it will leak oil like it’s going out of style, because the opposite direction will be trying to wipe oil OUT of the motor. It will be a major leaker.

A machine shop can lightly polish these embossed grooves out, and you can use a non directional main seal to do the job. It’s been done before, hopefully if you do it, it will also work for you. It is better, however, if you really want a dry engine bay, to use the proper rotation crankshaft in the proper rotation motor when it comes to big block Ford FE motors.

I've long thought the 390 FE block would be a good alternative for the 427 block, in the event someone had to make the conversion. All manifolds, transmissions, etc., would bolt up to the 390 just fine, and externally they look identical. There is no problem making the same power out of a 390, and unless you really ran it long and hard, I personally don't think the two bolt 390 would suffer from not having the cross bolted mains of the 427 (anyone contemplating doing this, should get another opinion too).

I know a friend who has done this conversion with good results. He runs his (Trojan) boat at moderate speeds, and the engines give every appearance of being able to wear out 3 or 4 new owners into the future. 390 blocks, rebuilt shortblocks and longblocks are available for a song, and they may well be a viable alterntive. There are some flycut bosses that are specific to the marine motor, for mounts, etc., and those would have to be duplicated on the 390 block.

The crankshafts of the 390 and 427 are identical, so there are no clearance issues there. The FT series has a larger end snout, and they can also be used for marine service if this is known and dealt with. The FT motors are beautiful and heavily reinforced web designs, that are basically heavier built versions of the automotive blocks.

I hope this outline helps clarify some of the issues about swapping cranks and changing rotation within the FE series. They're great motors right out of the late 50s and all through the 60's, and they're very well built for the long haul.

Sincerely,

Paul Pletcher
Forum moderator and FE motor fan