omc sterndrive conversion questions

[rbunk13]

OK so I have a 1976 20' Formula with an omc 235 and omc sterndrive. The motor is locked up. I have a good 1981 mercruiser 260 that I want to use. Does anyone know if it is possible to bolt my merc 260 to the omc sterndrive? I can't use the merc outdrive because of the transom hole size difference. Please help me!!!

 

[cr2k]

Re: omc sterndrive conversion questions

If they are both same blocks i.e. Ford or GM you can use the bellhousing off the boat on the other engine. If not you will need a Merc bellhousing to for the other engine and may have to deal with front engine mounts. If one is a 6 cyl. you will need to change drive gears anyway so probably not cost effective.

 

[Bondo]

Re: omc sterndrive conversion questions

1976 20' Formula with an omc 235 and omc sterndrive. The motor is locked up. I have a good 1981 mercruiser 260 that I want to use

Ayuh,... 235,..?? That's the 351 windsor Ford ain't it,..??
So,...
Not only yer tryin' to mix OMC, 'n Mercruiser,... It's Ford, 'n Chevy too..

No way in 'ell it'll swap....

Fill in the transom, 'n go Full on Mercruiser.... It'll be less work in the short, + long runs...

 

[rbunk13]

Re: omc sterndrive conversion questions

Yea it's a ford 351. Want to use my chevy 350. Thats what I was afraid of. From what I've read it's a tough job to redo the transom though.

 

[Howard Sterndrive]

Re: omc sterndrive conversion questions

yep. but it's not like you have a lot of options.

cheapest might be to sell the mercruiser/chevy stuff and buy a 351 or fix the one you have

making the boat mercruiser propelled adds value, but your gauges/steering etc are OMC so lots of work and parts as well as the transom rework to make it mercruiser

 

[wire2]

Re: omc sterndrive conversion questions

Yea it's a ford 351. Want to use my chevy 350. Thats what I was afraid of. From what I've read it's a tough job to redo the transom though.

I don't think so. It took me a couple weeks of spare time, after I removed the rotten transom plywood.

http://forums.iboats.com/showthread.php?t=225270

The steering cable bolted right up, gauges (including trim) all worked fine, (although I kept the original 5.7). I used the dash mounted tilt switch for "Trailer", the throttle/shift lever switch for "trim".

I did have to modify the coupler to fit my smaller flywheel, but it has been running great since I completed it.

 

[Howard Sterndrive]

Re: omc sterndrive conversion questions

I don't see how his trucourse drum would connect to a Mercruiser drive.
did the OMC cable unit stay in place?

or you had power steering? think they had that on 800's as an option in 81-on

 

[wire2]

Re: omc sterndrive conversion questions

I don't see how his trucourse drum would connect to a Mercruiser drive.
did the OMC cable unit stay in place?

or you had power steering? think they had that on 800's as an option in 81-on

Mine wasn't TruCourse. My OMC cable fit the Merc p/s actuator section, was the same thread size/pitch, the nut just did up and it worked perfectly.
I even re used my OMC throttle & shift cables, (I did have to make a new plastic nut for 1 of them, from delrin).

All OMC V8's in the mid 80's had p/s as standard. I found that out when I ordered a new '84 Glastron in the fall of '83.

 

[Howard Sterndrive]

Re: omc sterndrive conversion questions

OP's is a 1976... don't think they had power steering on stringers then.. not sure

 

[zbnutcase]

Re: omc sterndrive conversion questions

It has been a long time since I looked at one of those, but I seem to recall that some of those stringers had a dual bolt pattern housing the would take either a Ford or a Chev....

 

[rbunk13]

Re: omc sterndrive conversion questions

Just fyi my '76 does have factory p/s on it.

 

[justchange]

Re: omc sterndrive conversion questions

OP's is a 1976... don't think they had power steering on stringers then.. not sure

Mine's Tru-course.

 

[Howard Sterndrive]

Re: omc sterndrive conversion questions

Just fyi my '76 does have factory p/s on it.

neat. 76 must be the first p/s stringer option
the parts book for 1976 235 shows "over under" steering as standard on the four models with 235HP,
and then it shows optional "trucourse"

must have been too rare for the parts book or a late model year option