Stern Drive Motor in a straight inboard boat?

[Mike Feuti]

Hello, I have a 1986 Silverton with two Merc 4.3 vortec engines. One is on the way out. I'm considering replacing it with a rebuilt engine with low hours but am only finding engines from a stern drive boat. From what I can find it seems I can use this engine in my boat but I wanted to check with people more knowledgeable than I as to what it would take to do so. Thank you.

 

[7228sedan]

As long as you use a vortec 4.3, the long block will be identical. Everything will bolt on. Are both of yours standard rotation? That is would be the only concern. All stern drive motors are standard (LH) rotation.

 

[Barry]

As long as you use a vortec 4.3, the long block will be identical. Everything will bolt on. Are both of yours standard rotation? That is would be the only concern. All stern drive motors are standard (LH) rotation. When viewed from the front

Since you usually cannot see the flywheel with the engine in the boat it can also be determined from the front of the engine. If you are looking at the front of the engine at the belts and pulleys, clockwise would be Left Hand, and counter-clockwise would be Right Hand. ALL I/O ENGINES ARE LEFT HAND!

BELTS & PULLEYS TURN CLOCKWISE

 

[7228sedan]

Since you usually cannot see the flywheel with the engine in the boat it can also be determined from the front of the engine. If you are looking at the front of the engine at the belts and pulleys, clockwise would be Left Hand, and counter-clockwise would be Right Hand. ALL I/O ENGINES ARE LEFT HAND!

BELTS & PULLEYS TURN CLOCKWISE

Not to completely confuse the OP but Stern drive motors are LH rotation when looking at the rear. The image in Barry's response is correct. When you view that motor looking at the flywheel, it would be spinning in a counter clockwise rotation. The front end of the motor spins in a RH or clockwise rotation as indicated in the arrow.