replacing a 305 with a 350 engine

We'll need some specifics... what year make and model outdrive are we talking about?

All single engine I/O applications are standard LH rotation engines (same as a car) as far as I know. In fact, I thought that if a counter rotation was needed in a twin engine application; that was accomplished in the outdrive not the engine. RH rotation engines are more of a straight inboard item.

 

It's far better to do counter rotation in the engine, as the acceleration rotation momentum of the engine parts and the flywheels then also counter each other.

 

In a traditional inboard maybe... However for the sake of parts availability alone, reverse rotation engines are all but obsolete.

There are no new reverse rotation gas engines. All counter rotation application handle it in the gears. For the OP's purpose this is of no consequence as it's a single engine stern drive.

 

Single drive here yes, but far as I remember the possibility of RH vs LH was mentioned to be checked for when looking for used replacement parts on the market.

 

BTW, as a matter of fact, I don't think LH vs RH rotation was mentioned at all on this thread.

However I did mention it to be checked on the thread: Crusader 454 XLI MPI motor information → post #3

 

Your thread was hijacked by this post :

Hello everyone, I figured I would not start a new thread for this as it is just another step in this process that I hope you all can help me with.

I am in the process of "rebuilding" a 305 for a coworker's boat. I was just able to get it just about all torn down to just the block. The reason for this teardown is that the engine was not winterized correctly and cracked the block on both sides (just above the engine mounts). The block is a complete loss and at this point, I think it might be better to just find a 350 and put the intake, fuel pump, exhaust manifolds, and other marine specific things on the replacement engine. That all being said, on another site I am reading that some of these engines were designed to run reverse of a car engine, as well as the marine cam is different than a car cam.

The boat is a big old cabin cuddy (I'm a high school shop teacher, not a marine person)? Has a Mercruiser of some type. If I get a different engine do I need to figure out the other firing order to achieve reverse running, and change the cam as well? I know I am asking a lot with almost no information but hopefully, someone can help me.

Thank you,

Also, who would I talk to about OMC sterndrive things? I made a mistake and bought one a couple years ago...


Thank you again,

Ian Schilf


I was responding to that, sorry for the confusion!

 

No problem, post #1 here is by Mrostkow, and I see now you're referring to Ian's post #30, with is indeed another topic.

 

Lined up makes clear that post #31 looks to me like a correct response to the below quoted part of post #30...

For anyone wanting to do further elaboration on Ian's questions, please see and quote his post #30.

I think it would indeed have been better and more clear if Ian had started a new thread about this, the confusion on my part was caused because it coincided with the change from page #2 to page #3 of this thread, while post #31 didn't have a quote, and post #30 was already a few weeks old.