Engine replacement, 3.0 - Pre Alpha

[CableGuy1978]

Hello,

I am currently looking for a replacement engine. The one I have is a 3.0L with Pre Alpha drive system. The only missing piece is an engine serial number. I have looked everywhere on this engine after reading some of the earlier posts about where to locate it. So this may make responding a bit more difficult if possible at all.

I have come across some replacement options while searching some online trading sites. Specifically, I have found one that claims to be late 80's, dressed and ready to drop in the boat. I'm assuming that it cam from a Alpha I set up. My question is are there major differences with the inner transom assemblies over various years that may make this engine not mount properly?

From what I have read so far from various sources is that Pre Alpha will fit with Alpha I stuff, but after that things are different.

Another option is that I may be able to use my parts to dress the engine. In that case, if I can find a serial number on the replacement, is there a resource that would tell me if my parts would even fit on that particular engine. Have these engines evolved and changed over the years as the drive systems have?

This part of the Mercruiser puzzle is new to me. The only experience I have with the engine itself so far is regular maintenance, and removal to replace a coupler. Any info or direction is always greatly appreciated.

Thanks again.

 

[achris]

Re: Engine replacement, 3.0 - Pre Alpha

"Pre-alpha" is not a useful term in this thread. The Alpha One appeared in 1986, so by what you are saying your engine is anything before 1986. Between the first incarnation of the 3 litre engine (as a '140' in 1968) and 1986 there were a huge number of changes, making it very difficult to know if what you propose is possible.

If you can find a serial number of the drive we can help narrow down the year. Also look for a serial number on the transom assembly.... That would also be useful.

 

[CableGuy1978]

Re: Engine replacement, 3.0 - Pre Alpha

As I mentioned, I haven't been able to locate the serial on the engine itself. I couldn't see anything in the inner transom plate or outdrive. I did see 87356 stamped on the gimbal ring, which suggests that it is between 1965 and 1975, according to this site:

http://www.mercstuff.com/oldgimbalrings.htm

My outdrive looks like the one from this thread: http://forums.iboats.com/showthread.php?t=229637, only mine has no decals left anymore, and the cavitation plate is more rounded than the one from that thread.

The guy I picked up this boat from was in no way the marine mechanic he said he was - long story. So with that I won't rule out that many pieces of this engine and drive assembly may have come from various places - ie the blue manifold with OMC on it. That is the only OMC part, everything else is Merc.

Thanks for the response so far!