Engine Rotation

[Jeanmardn]

1978 Carver 3396 Mariner. Hello. I really need some help with this. I believe that my boat has twin 351 Windsor engines and according to my research, they counter rotate outboard. I fully understand what that means however, the engines are backwards in my boat. So the front of the motors are facing aft. So would that mean my STBD motor rotates left or right? I have the original owners manual and ive looked everywhere online and I cannot find clarification on that. Thank you. Also, neither engine is running currently so I cannot start one to find out.

[bud37]

Welcome to the forum.....if the starters still work, you could bump them over and take note of the direction. The firing order is another way. My guess here because of the "V" drives, would be the stbd engine is reverse.

Sometimes if you are real lucky, there will be still the rotation labels on the engine or someone has marked them to remind how things go.....cross fingers here....

[km1125]

Those engines should still have timing marks on them, so you can reference them as a clue.

Here are mine from the 454 Crusaders:

crusader_timing_marks.jpg

You might also check the flywheel end of the engine. Some have tags like this:

crusader_flywheel_timing2.jpg

[buster53]

Assuming the boat is in the water, any way you can jump in and take a look at the props? That is a dead give away to the engine rotation.

[Viper]

KM is correct and is the easiest way to tell at a glance. There are other ways but check that first and let us know. Hopefully the markings are still legible.

You can also tell by the firing order; Standard rotation (LH) for your engine I believe will be 13726548 and the counter (RH) will be 18456273. I believe both distributors on those will rotate CCW. With that in mind, follow the plug wires starting with number one cylinder to get that reference on the distributor, then see which is the next to fire as the distributor rotates CCW. Remember that unlike GMs, Ford's #1 cylinder is on the front RIGHT side of the engine when you're standing behind the engine and facing the flywheel (the marine way). If you stand in front of and face the front of the engine (the automotive way), it's the first cylinder on your left. The head on that side will protrude further forward than the other bank. Confused now?!! When we're dealing with v-drive applications, we have to be careful with our wording as the location of the front of the engine isn't the front end of the engine compartment.

Source of the post......any way you can jump in and take a look at the props? That is a dead give away to the engine rotation.

Not always the case in v-drive applications as the output of some drives is the reverse of engine output.

Except for some high performance applications, standard prop rotation on a pleasure craft is right hand on starboard side and left hand on port side. They turn outward from the center line of the boat. You can assume that this is the way yours is set up unless a previous owner changed that in the past or someone screwed up.

[Legacy33]

Mine has 350s starboard is reverse rotation