Re: [OMC-Boats] Sportsman 155 Engine Replacement

From: Lee Shuster <Lee.Shuster@...>
Date: Wed, 17 Feb 2010 12:40:56 -0700


One thing I forgot to mention about re-powering options. Your particular OMC boat's physical engine housing constraints should always be considered.

Your 1967 Sportsman has a top deck that was derived from the original 1964 Sweet-16 outboard deck. They simply added a engine hood and a bulk-head/seat to move from outboard to sterndrive. But Beginning in 1968 the Sportsman got a new top deck mold that integrated the sterndrive engine "dog-house, " as outboard versions were long gone.

I mention this because the longest engine that was originally designed to fit you boat was the Chevy in line 4. The Buick V6 is only "3-cyl" long and is shorter than the 4. So obviously the only way to consider the L_O_N_G Chevy 6 (which is almost twice as long as the Buick V6, is to intrude much further into you available passenger floor space, which would require chopping a big hole in the bulk-head. and somehow protecting your passengers from sticking their fingers into the rotating water pump pulley.

Because the small block Chevy V8 is roughly only as long as the inline four, I was able to (just barely) fit it under the existing 66 Sportsman engine dog-house. Performing this trick on a 1968-1970 Sportsman would be made more difficult by the integrated deck design.

So for future planning, I'd keep my eye on the 153 Chevy II four and not worry about the long inline 6. But they are both great engines especially in marine applications.


From: omc-boats-bounces@... [] On Behalf Of Don Mandelas
Sent: Tuesday, February 16, 2010 7:38 PM
To: Evinrude & Johnson Boats of the 1960's and 70's; bchowk@...
Subject: Re: [OMC-Boats] Sportsman 155 Engine Replacement

I have a Question,

Does a 1967 GM-Buick V6 225 Engine mount to an 1967 Evinrude Sportsman boat floor at exactly the same locations on the floor as a GM-Chevy in line-4 153? or a GM-Chevy inline-6 230 ?

Will an inline-4 or inline-6 use the same bolt holes on the floor as the V-6?

Or do modifications have to be made to a boat's floor in order to accept either of these 2 example engines and their floor mounting hardware?

I know of two older boats in my area that are currently not being used.
One has the inline-4 153 with an OMC sterndrive.
the other has an inline-6 with an OMC sterndrive.
I would like to know for future planning.


From: Lee.Shuster@...
To: bchowk@...; omc-boats@...
Date: Tue, 16 Feb 2010 09:40:18 -0700
Subject: Re: [OMC-Boats] Sportsman 155 Engine Replacement

Actually if you want to stay with OMC sterndrives and OMC exhaust manifolds you have the following engine choices:

V6- 196-225-231-252 (the 231 was available in both even and odd-fire, the 252 is only even fire)
V8- 300 (it might be possible to use the 340/350)

Inline-4 153-194
Inline-6 230-250
V-8 265-283-307-327-350-400

British Ford Inline 4 (Kent)
V-8 289-302-351-W

Besides the issues that B.C. mentioned you also need to pay attention to sterndrive gear ratios when swapping engines.

From: omc-boats-bounces@... [] On Behalf Of BC Howk
Sent: Monday, February 15, 2010 9:10 PM
To: ohnoitsnexi@...
Cc: omc-boats@...
Subject: Re: [OMC-Boats] Sportsman 155 Engine Replacement

Hey Nexi,

Yep, I have some ideas about this...if you are looking for a straight up replacement you need a buick 225 odd fire, if you are talking about the 155 in NC then you SHOULD be able to reuse the manifols (exhaust and intake), hopefully rebuild the rochester 2G, the trick being finding a marine water pump...I understand that they are built with different impeller material that stand up to lake water better (I gather an automotive pump would work but would not last like the marine version) CAN get the manifolds still but they are not the cheapest items you'll ever find, just be aware....

OK, so the trick about looking for an odd fire BUICK V-6 is that they were NEVER put into BUICK's, LOL...they were put into JEEPS and OMC you are either looking for an OMC 155HP v-6 (again odd fire 225) or a "DAUNTLESS V-6" put in 60's era Jeeps (I know 69 jeepster FOR SURE as I used to own one :-) again the key is ODD FIRE 225

here is a site that has long blocks, I have never purchased from them myself but if I ever decided to replace my 225 here is where I would start...

OK so the next stop in the geneology is a 231 EVEN fire is some history to tell you what they would be in

SO......a 231 is a less striaght forward swap, you'll need to be sure your intake and exhaust manifolds still fit and you'll need a new destributor (good news is an HEI unit should be pretty easy to come by)...also if you REALLY wanted to step up you have more options for hot rod stuff (like the HEI, cams, edelbrock makes a 4bbl intake specifically for it, etc)....I hesitate to mention this option...I would like to do it myself but currently HAVE NOT so I cannot be sure if there are any hidden "gotchas" in there...however from what I underdand an early 70's even fire SHOULD bolt right in with your ODD fire manifolds and work just fine...I think there are a few people here on the list that have even fires, although am not aware of anyone who has done the swap personally..

AND of course if you really want to do the MAC DADDY swap (particularly down at sea level) you must stop by and take a look at Lee's site....he put in a good ol' fashioned chevy small block.....gotta say, if you gonna do it, go big and put in a V-8, 350 would be SOOOO sweet and forget about any kind of parts availability issues (at least as far as the engine is concerned) lot's of aftermarket upgrades too.

Hope this is helpful...


Heya BC...

Wondering if you know off hand what kind of engine I could drop into a sportsman 155. Don't know if I need to look for specific years or what not.

- Nexi

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Received on Wednesday, 17 February 2010

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