Upgrading my Motor Outdrive Combo. Need better knowledge

John3

Petty Officer 2nd Class
Joined
Jun 17, 2010
Messages
136
Fwd End2.jpgFront Mount Stringer2.jpg

My Boat is a 23 Ft Dorsett Cabin Cruiser, built in 1967. It has a 165 HP Mercruiser I/O with a straight 6 Chevy block.
The lower unit is ?Toast?. The Outdrive has ?Power Tilt?, they didn?t make many of them, most had Power Trim & I can?t find a New/Used Lower Unit or Complete Outdrive with Power Tilt. Power Trim won't work, no downlock in reverse.
I figure, as long as I must do something drastic, I?d like to re-power with a small V8/OD combo. The Boat?s always needed more HP anyway.
The attached photos show the engine compartment & how the angle iron that the front of the motor is attached to the stringers.
A new V8 will be shorter than the present straight 6. I worry that moving the angle iron aft and re attaching it could be missing something vital. Anyone have experience doing something like this?
 

oops!

Supreme Mariner
Joined
Oct 18, 2007
Messages
12,932
Re: Upgrading my Motor Outdrive Combo. Need better knowledge

yes....lots of us have done this.....

ok.......no problems with the v8 swap.
the out drive is another story.
i think you are currently running an omc drive.....
(if its a mercrusier, they all have tilt and trim, you are describing an omc with no down lock in reverse.)
i would look for a newer alpha one gen2 drive and transom/bell set up.
you are in californina......and there are tons of them around.
you might be cheaper buying a doaner boat. then buying the parts independently...
you can buy a brand new sei (merc gen2 alpha 1)drive right here at i boats for just over a grand, but you will need to change the bell/transom and coupler.

please post pics of the back end of this thing so we can see what you have...it really sounds like an omc, not a merc
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: Upgrading my Motor Outdrive Combo. Need better knowledge

View attachment 107295View attachment 107296

My Boat is a 23 Ft Dorsett Cabin Cruiser, built in 1967. It has a 165 HP Mercruiser I/O with a straight 6 Chevy block.
The lower unit is ?Toast?. The Outdrive has ?Power Tilt?, they didn?t make many of them, most had Power Trim & I can?t find a New/Used Lower Unit or Complete Outdrive with Power Tilt. Power Trim won't work, no downlock in reverse.
I figure, as long as I must do something drastic, I?d like to re-power with a small V8/OD combo. The Boat?s always needed more HP anyway.
The attached photos show the engine compartment & how the angle iron that the front of the motor is attached to the stringers.
A new V8 will be shorter than the present straight 6. I worry that moving the angle iron aft and re attaching it could be missing something vital. Anyone have experience doing something like this?

Ayuh,... Find yerself a runnin' boat, with the driveline you Want, buy it, 'n junk it...
That way you have every single piece it takes for the refit,...
No missin' Expensive pieces to go find...
Alpha 1s will be the cheapest, Bravos the Best...

Forget yer old angle iron,..
You'll be glassin' in a new motor bed...
You'll also be redrillin' a few of the transom holes, maybe tunin' the keyhole abit with a grinder...
 

ingalp01

Petty Officer 1st Class
Joined
Sep 11, 2010
Messages
357
Re: Upgrading my Motor Outdrive Combo. Need better knowledge

Bond-O is the master, and just what I was thinking scrap the angle iron, grab the full donor boat and go for it. I managed to pick up a full transom assembly, bell housing gimbal ring, trim rams, etc... from Craigslist for $150.00 bucks, so wayyy cheaper to find donor parts that way...

There will be Fiberglass work, carpentry work, and engine / outdrive work, but nothing that can't be accomplished with some searching and knowledge seeking and questions. You are in the right place for knowledge, that's for sure!

Also agree with Oops, send some more pics, so we can all "See" in more detail what you are working with... Good luck and keep us posted...
 

John3

Petty Officer 2nd Class
Joined
Jun 17, 2010
Messages
136
Re: Upgrading my Motor Outdrive Combo. Need better knowledge

Outdrive Attachment2.jpg
This is a picture with the Out Drive Removed. The boat started life (1967) with a 160 HP "MERCRUISER" with "POWER TILT". I bought it in 72, after a few years I had to replace the OD with a 165 HP, also with "Power Tilt". That's the one I'm replacing now. My problem is they didn't make many Power Tilts & I can't find a replacement.
Yesterday I found a Pre Alpha I OD (Made for Power Trim). It looks like it will fit except I will only be able to raise it manually, for trailering. In use I'll lock it down so that it won't kick up in reverse.
The OD didn't cost that much. If I can find a good, used V8 with OD, Transome plates, Controls, etc at a reasonable price, I may make the change.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: Upgrading my Motor Outdrive Combo. Need better knowledge

View attachment 107432
This is a picture with the Out Drive Removed. The boat started life (1967) with a 160 HP "MERCRUISER" with "POWER TILT". I bought it in 72, after a few years I had to replace the OD with a 165 HP, also with "Power Tilt". That's the one I'm replacing now. My problem is they didn't make many Power Tilts & I can't find a replacement.
Yesterday I found a Pre Alpha I OD (Made for Power Trim). It looks like it will fit except I will only be able to raise it manually, for trailering. In use I'll lock it down so that it won't kick up in reverse.
The OD didn't cost that much. If I can find a good, used V8 with OD, Transome plates, Controls, etc at a reasonable price, I may make the change.


Howdy, you can put whatever you want in your boat! (I removed a 460 King Kobra from my 87 Four Winns Liberator and replaced it with a 1997 454 Bravo)


That boat should perform nicely with a V-8!

You'll have to build/modify the engine mount pads though and carefully inspect your transom and rear stringer area for rotten wood.

You can find transom mounts on ebay but your best bet might be to find a damaged "newer" boat that you can remove the entire engine and drive from. That way you get everything you need.


Regards,


Rick
 
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