How do I change engine rotation direction?

[botel joe]

Hello, I have a right-hand rotation 454 and I want to use it in a car. How do I change rotation direction? Is it even possible?

 

[Scott06]

cam,distributor, and flywheel

thats it i believe. Flywheel i think you can move/ replace the ring gear for an automotive block mounted starter if you are using a manual trans, if auto you need a flexplate anyways…
of course exhaust manifolds are different between marine and automotive.

 

[kenny nunez]

The pistons also have to be turned the other way on the rods. Front and rear crankshaft seals should also be replaced.
I am sure there are some other issues will be needed to correct.

 

[Scott Danforth]

Cam, timing hardware, ignition, pistons and the crank.

The knurling on the crank main seal areas is different for RH VS LH MOTORS WITH A 2-piece RMS to control oil. While the motor will run, you will effectively pump the oil out of the rear main seal and the front cover. BTDT, bought the tee shirt

Much cheaper to buy what you need vs convert

 

[Bt Doctur]

starter too

 

[QBhoy]

oil pump too perhaps ? Not an expert though

 

[Scott06]

oil pump too perhaps ? Not an expert though

The reverse rotation camshaft and distributor have the gears such that the distributor turns the same way thus driving the oil pump the same direction

To the OP if you peruse this subject on Offshore only there are a few threads on this subject, of course giving somewhat cloudy info....

 

[QBhoy]

The reverse rotation camshaft and distributor have the gears such that the distributor turns the same way thus driving the oil pump the same direction

To the OP if you peruse this subject on Offshore only there are a few threads on this subject, of course giving somewhat cloudy info....

of course !

 

[achris]

In the earlier Mercruisers (inboards), reverse rotation was achieved by changing the cam timing chain to a cam timing gear. Thus most other components remain the same, including the distributor and oil pump. The engine was just spun the opposite way (with the starter) and the cam turned the 'normal' way. The dissy cap was plugged differently, but it is the same cap. The front and rear crank seal was different, so the oil was pushed back in and not out, the pistons are the same, but swung 180 degrees so the thrust side remained the thrust side. The hoses are swapped on the engine driven water pump too (not the circ pump, that's bi-directional).

Here's a picture of the cap, with the STD and REV cylinder numbers on it.


Chris........

 

[nola mike]

the pistons are the same, but swung 180 degrees so the thrust side remained the thrust side.

Confused here, are the piston pins offset from center on these?

 

[Bt Doctur]

pistons have a small notch in them, this shows you where the oil squirt hole is in the con rod to oil the underside of the cam lobes.

 

[Scott Danforth]

same pistons, however thrust side is swapped.
same crank casting, however the knurled oil control grooves go the opposite way
gear drive for cam so the cam spins the same way which drives the oil pump
depending on year, cam may have different grind for cylinder balance

if the BBC is going into a car anyway. the cam should be changed and the motor rebuilt however unless the motor was something special, a run-of-the-mill 454 is nothing special.