Pre-alpha --> Alpha???

Karl1432

Recruit
Joined
Sep 8, 2020
Messages
4
I have taken a MC1(pre-Alpha) power train out. I intended to put it into a 1998 Caravelle 188 Bowrider. The transom plate holes do not match. Using the gasket off of the gimble housing I see that they do not match. Not sure what engine was in the Caravelle to start with though I was told that it was a Mercruiser.

The engine that I have is a 1975 3.7L 165 hp Mercruiser engine. How can I find out what I need in order to put an engine into this Caravelle?

Screenshot of side by side here: http://prntscr.com/udx265 (Couldn't upload the pic for some reason.)
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
51,316
the transom on your post 1991 motor is set up for an Alpha 1, Gen 2

I would sell the 470 off and find a decent motor and drive to put into the caravelle. like a 1996 and later 4.3 with a 4-barrel and the A1G2

it would be sad to put that motor into the caravelle
 

Karl1432

Recruit
Joined
Sep 8, 2020
Messages
4
Thanks for the response. I had one of these years ago. I didn't have any issues with performance. I think the original tri-hull types that it came from was around 1,500 pounds. The Caravelle is 2,500.

Can you be more specific about what your concerns would be?

I know 30-50 gallons of fuel on a long busy day was a wallet buster in my old boat. Bigger engine means more gas too.


-----
What’s behind you doesn’t matter.Enzo Ferrari

Whatsa behind me is'a not important. https://youtu.be/AjGXn249Fc0
 
Last edited:

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
I have taken a MC1(pre-Alpha) power train out. I intended to put it into a 1998 Caravelle 188 Bowrider. The transom plate holes do not match. Using the gasket off of the gimble housing I see that they do not match. Not sure what engine was in the Caravelle to start with though I was told that it was a Mercruiser.

You have an MC1. While it was before the Alpha One, and technical 'pre-Alpha', so were 15 other drives. Saying 'pre-Alpha' is meaningless.

The engine that I have is a 1975 3.7L 165 hp Mercruiser engine. How can I find out what I need in order to put an engine into this Caravelle?

Merc didn't release the 470 until 1976. If the transom plate doesn't match up with the mounting holes form the later model, you have an EARLY MC1 and the mounting holes are different. You need to plug 2 holes and drill new, and also open the cutout about 10mm near the centre.

...I know 30-50 gallons of fuel on a long busy day was a wallet buster in my old boat. Bigger engine means more gas too.

:facepalm: Why is this people default position, when it's just not true! A 'bigger engine' will only use more fuel when you push it to beyond where the 'smaller engine' was able to go. And pretty much all the range below that point the 'bigger engine' will use LESS fuel!

I have 2 great examples.

1. My boat originally had a 4.1L 165 which on a good day, would push the boat to around 30knots. My current 4.3MPI, making 220hp, up to 30knots uses about 20% LESS fuel than the 165, and that's throughout the range. Once I'm over 30knots, yeah, I'm using more fuel. Surprise, surprise!

2. My car. 100 series LandCruiser. Pulled the gutless 4.2L Toyota diesel out and dropped a 6.5 GM Turbo diesel in. Uses less fuel towing the boat than the original engine did not towing.

Chris......
 

Karl1432

Recruit
Joined
Sep 8, 2020
Messages
4
Merc didn't release the 470 until 1976. If the transom plate doesn't match up with the mounting holes form the later model, you have an EARLY MC1 and the mounting holes are different. You need to plug 2 holes and drill new, and also open the cutout about 10mm near the centre.

Any diagrams or something similar would be helpful. I will put the MC-1 stuff up there later and look at it. Thanks for the tip. I would love to not have to sell the MC-1 and hunt down a Alpha.




Why is this people default position, when it's just not true!



:facepalm: I should've known that. I have had this debate with folks about fuel consumption in aviation.
 

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,704
.



:facepalm: Why is this people default position, when it's just not true! A 'bigger engine' will only use more fuel when you push it to beyond where the 'smaller engine' was able to go. And pretty much all the range below that point the 'bigger engine' will use LESS fuel!


Chris......

i don't know that you're comparing apples to apples. Probably less pronounced in a marine application, but more cylinders is more rotating mass, more friction, etc. There's a reason you don't see many v8s around any more. And your examples are not comparing the same technology in the motors. Again, I think it's probably less of a difference when you're under a constant steady load, but it's gotta be there. I went 50 miles on the new motor last week, I'm going to fill it up today, we'll see how it compares to the 3.7
 
Top