Reversing Engine Rotation?

RH = CCW reverse rotation

LH = CW standard rotation.

BW tranny is always index opposite of engine's rotation.

it isn't CC's terminology it's the marine industries terms. You can get about any brand marine engine in standard or reverse rotation just go look at a big cruieser with duel engines.

79nautique wrote: rmcdonald wrote: Engine Rotation: This is determined by looking at the front of the Engine as in the Water pump. Clock Wise is CW or RH Counter Clock Wise is CCW or LH. this is completely wrong and ass backwards. long story short if you own a correct craft and it has a 1:1 transmission then you have a reverse rotation engine RH from the factory, If it's an older model with an I/O or you have a 1.23:1 transmission then it's conventional rotation LH or automotive rotation.

I agree with '79, except he forgot to mention that the Nautiques with 454's were conventional LH engines mated to 1:1 trannies and turned LH props

Hi All
I hate absolutes!
My main purpose for posting on this site is to gather information for myself or give out relevant information, which allows people to determine the right solution for themselves

Since 79nautique made his comments, I have done some research.

Borg Warner refers to Engine Rotation in the way I describe.

The Chrysler Marine Manual, which is also available from this site refer to Engine Rotation the way I describe it. ( Page 59 & 60 if any one is interested )
Yes I have a Chrysler 383 V8 in my boat.

Yet if you look up Marine Engine Rotation on the Internet Some Manuals describe it the way 79nautique describes it looking at the Fly Wheel.
The Fly wheel Rotation is a bit hard to determine when the Bell housing and the Gearbox is attached to the Engine and installed in the boat.
Unless they have a View point on the Bell Housing
They say to look the front or forward end of the Motor.
This is also mentioned by the Marine Engine Manuals that 79nautique describe.

As I said Earlier my main point of my posts.

Prop Rotation cannot be changed by reindexing hydraulic pump on the front of the gearbox.

I just want people to get it right the first time, by understanding the concept.

However you look at it, this is how it is, 79nautique please comment if you disagree.?

Looking a the boat from the Stern to the bow of the Boat.
LH prop
Gearbox pump indexed RH or -->
Fly Wheel LH or CCW.

RH prop
Gearbox pump indexed LH or -->
Fly Wheel RH or CW.
---------------------------------------------
Looking at the boat from the bow to the stern of the Boat.
LH prop
Gearbox pump indexed RH or -->
Harmonic Balancer RH or CW.

RH prop
Gearbox pump indexed LH or <--
Harmonic Balancer LH or CCW.

Regards
Rob McDonald






Prop Rotation cannot be changed by reindexing hydraulic pump on the front of the gearbox.