engine compatibility with mc1 outdrive

[thestigmach1]

I have a 1969 boat with a 160hp straight 6 and mc1 outdrive. I'm wanting more power so I want a v8. If my research on gm engines serves right my engine and small block Chevys will bolt up all the same except for the front engine mounts and of course exhaust. I plan on running through transom exhaust anyway so I'm not worried about that. Is that right as far as the bolt up? Ive been told that they used Ford 351 Windsor with these outdrive as well. Is that true and can I keep my bellhousing and output shafts with that motor. I know a chrysler 318 la was never used with this outdrive but does anyone know if it can be bolted up? I have one of those and would love to use it if I can. Thanks

 

[Bondo]

I have a 1969 boat with a 160hp straight 6 and mc1 outdrive. I'm wanting more power so I want a v8.

Ayuh,... There were many changes in the MC-1 from '69, til the Alpha came out in the early '80s,....

Yer's, bein' older ain't to condusive to what ya wanta do,.... 'n the gear ratio is very wrong,....

If ya want a V8, buy a rotten donor boat, with the driveline ya want, 'n transplant it into yer hull,....

Also, Chrysler was never used with a Merc,...
It would have to be Custom built,... no parts available, no where to do such a thing,....

 

[thestigmach1]

I know that I'll have to change the gearing to the 1.5. I tried finding a donor boat but everything I find around here is way to expensive for a boat I'm going to gut. That's why I started looking at automotive engines. Of course I'll have to Marinize them but oh well. But will the chevy and Ford v8 bolt up to what I have?

 

[Bondo]

But will the chevy and Ford v8 bolt up to what I have?

Ayuh,.... But with alot more parts than ya have now,....

By the time ya buy all the parts, 'n pieces ya need, you'll be up to the price of a donor boat,....

What's yer Budget for this anyways,..??

 

[thestigmach1]

Around 500-600. I found a 283 with a 4 bolt main for a few hundred. I found a set of manifolds for a 5.7. But they should bolt up since most of the sbc stuff on the auto side are interchangeable. With the 283 I should be able to run with my current gear set and a two barrel carb for a while. They run around 210hp like that, I believe the mc1 6cyl gears were rated for 200hp so as long as I take it easy it should be fine. then upgrade it to a four barrel and upgrade the gears to get the 260+hp. Any boat I find with a v8 in it is over 2000. People around here are very proud of their stuff, even when its junk. At that point it would be better to spend 3000 and get a boat that is ready to go, but I like my boat and don't wanna do that, nor can I afford that. It seems like a sbc should bolt up to the bell housing and output shaft that I have since they used my engine on the th350 trans same as the 283 and 350. I'd have to change the front engine mounts I think.

 

[Bondo]

Around 500-600.
Any boat I find with a v8 in it is over 2000.

Ayuh,... Good luck with that budget,.....

When We buy a donor boat, up to $3500. is reasonable for a solid runnin' V8, 'n ALL the pieces to make it work,.....
All the hardware,...
All the wirin' harness,....
All the bracketery,....
All the tiny pieces, that Cost boatloads of money, for each tiny piece,....

Yer dreams are Way bigger than yer budget,.....

 

[thestigmach1]

Like I said spending 2000+ on a boat that I'm going to gut is counter productive to me. I'm rounding up parts from various places just no one has the entire thing. It's going to be a Johnny Cash song by time I'm done, but as long as the sbc will bolt up to the housing and output shaft I have then the rest will follow fine.

 

[thumpar]

The price of changing out just the gears is enough to blow your budget. To marinize an engine you will need to change the core plugs, carb, distributor, alternator, fuel pump, starter. You will need Merc exhaust manifolds and elbows. The flywheel will need to work with the coupler. In the end you will spend more than the $2000 donor boat to try to piece it together. You would be better off selling the boat and getting something with the engine you want.

 

[ihc1470]

I think projects like this boil down to what you want to do. As you have said most SMC items interchange so that probably will not be much of an issue. As several have pointed out you will run into all sorts of things that will nickle and dime you as you make the change. I have worked with powered units of some sorts most all my life, cars, truck, tractors etc. Been in on quite a few swaps be it engines, transmissions or transfer cases etc. I have always maintained and still do if you want more power, or a 5 speed instead of an auto, V8 instead of an inline go buy what you want you will be much happier in the long run and will have more coin in your pocket at the end of the day. As has been said the best would be to find a donor, yet what you are thinking of doing is possible also. I think what it will come down to is how well do you really like your present boat, how much time do you have for this project, how willing are you to work through all the issues that will come up, are you willing to put more money into this when you run over budget and most likely you will, and when your done will the final project be what you want and will it be safe and reliable. Do you have the time and expertise to do this type of thing? Have you done something like this before or will this be a total new experience? And finally would you rather be working on this for who knows how long until finished or would you rather be out on the water enjoying your time. Only you will be able to answer most of these questions. Best of luck to you.

 

[Scott Danforth]

you can do if for 5-600 if you do exactly as follows:

sell your 160hp I6 and MC1 for $400. Take the $400 cash and add $1000 - $1100 cash so you have between $1400 and $1500 dollars. go buy a donor boat with a rotten floor, stringers and transom for that price and pull the complete driveline, controls, gauges, etc. install in your boat.

Now take the donor boat, strip it down, sell everything you can on ebay and craigslist for about $200 (you will get the most money for old windshields, etc.)

take the donor boat hull to the dump (or cut up in little pieces)

sell the trailer the donor boat came on for $300

Net result to your pocket is $500-600 spend. not to mention about 100 hours worth of work.

BTW, you could not even get your 250 cubic inch motor refreshed for $500-600, or the gears and seal kit for your MC1 for under $400

 

[harleyman1975]

thestigmach1, The place that your going to run into problems is things like the C.O.G. and the C.O.B. will change and this will affect the way your boat handles. the 6 cyl gears will allow the v-8 engine to over-rev some so new prop for sure if you don't re-gear the out drive. you will have to possibly make additions/changes to the engine stringers. I have heard that the input shaft is different from an 8 to a 6. Your likely going to only see a few mph more out of a small v-8. ford requires a different bell housing than a chev so that's not cost effective. This stuff in not at all friendly to mix and matching. You are not going to find much support for your endeavor I'm afraid. Most guys are thankful just to keep their boats running in stock form. I know of one guy who pumped up his horsepower by like 100 hp and only got a bit more out of the hole and basically nothing top end. Sometimes its more hull design than it is h.p.

 

[Bondo]

Most guys are thankful just to keep their boats running in stock form.

Ayuh,... I'm ALL for Mixin', 'n matchin, 'n Hot Roddin' a boat,...... But,.....

I've learn from experience that what might seem counter productive, or counter intuitive, actually is the Right way to get the job done,.....

I've done piece-meal builds, 'n donor builds,...
'n I can tell ya, Donor builds are ALWAYS Cheaper,....

Considerin' I'm a hoarder who's into boats, believe me, if anybody can throw together a piece-meal build cheaply, I'm him,.....

One of the Sweeter builds I've done is a '79 Slickcraft 195SS,....
Pulled the original 120hp/ MC-1 drive out, dusted, 'n polished the hull, 'n dropped in a late '80s 350/ Alpha 1, outa a $3,000. donor,....
It's a barn-find cherry hull, 'n handles the power quite well,...
It's the kinda ride, that if ya want, the adrenalin buzz don't wear off for 10 minutes once ya get to shore,.......

 

[harleyman1975]

We all know you aint "most guys" Bondo As for me, I don't want to open the hatch 'cept to check the oil before I head out.

 

[achris]

... I don't want to open the hatch 'cept to check the oil before I head out.

What, open the hatch? Isn't that what the pressure gauge is for?

 

[harleyman1975]

Well you know what I mean achris. The local guy around here won't touch an engine that has been modified. He says how do you "set it to spec"? What is spec for an engine with a hot cam and a re jetted aftermarket carb with an msd ignition box ect... Not to say O.P. is talking modifying his engine...just the idea that now it aint what it is supposed to be...wiring altered, fuel system rearranged, exhaust boogered up, ect...

 

[Scott Danforth]

Well you know what I mean achris. The local guy around here won't touch an engine that has been modified. He says how do you "set it to spec"? What is spec for an engine with a hot cam and a re jetted aftermarket carb with an msd ignition box ect... Not to say O.P. is talking modifying his engine...just the idea that now it aint what it is supposed to be...wiring altered, fuel system rearranged, exhaust boogered up, ect...

if you have a hot cam and rejetted carb, you dont need your "local guy" as you already know your motor better than he does.

 

[harleyman1975]

Looks like we have more interest in this thread than the O.P. LOL

 

[thestigmach1]

Been busy with all the thrills of life, or burdens I should say. My goal here isn't to build a boat that is to spec, or even looks professional when you open the hatch. I want it to look good and correct though. My goal is make something that is mine, built by me and completely different from what everyone else has. Everyone has a 350merc or a v6merc. I want a 283 Chevy in mine. Why? Because it's special. The 283 bolts up all the same as a 350 so there shouldn't be any problem there, exhaust will be interesting but I'll just straight pipe it out the transom and put some chrome tips on for good meausre. Of course I'll have to change prop, but my prop has been beaten up by the PO anyway and needs replaced badly. As far as speed goes, according to a website if I get my hp up to around 250 from 160 my speed should go up to around 55 compared to 30ish. That's based on all the current variables of prop, rpm, hp, hull type and I think a few more. If I can 55 I'd be happy. Honestly just the fact of a 283 in a boat and the wonderful sound they make would make me happy. The good thing abut the 283 is in stock form it'll make around 210, which is right above the threshold of what my current gears can hold ideally. Then after a bit I can change out the gears and put torqer2 heads and a 4bbl with edlebrock tunnel ram on it, maybe a mild cam, and it'll make closer to 280hp or so. I'm slowly compiling a parts list and based on selling my i6 for 400, which should be doable it's a solid motor, I should be able to hit 600ish.

 

[thumpar]

I think you are a little high on what you can do HP wise. You will need a truck cam or risk reversion. The most you could probably get out of it without issues is more like 220. You can go for unique but there is a reason "everyone" has the same motors. You might run into flywheel and bellhousing issues trying to run that motor.

 

[K-2]

You can't put big valve heads on a 283 the bore just isn't big enough. You can use 2.02's with a low lift cam but why risk it and why choke your engine like that.
If the 283 block has NO side motor mount bosses , 3 per side it is a 1957 block, probably worth some money.