King Cobra to Mercruiser/SEI

[Noe de la Garza]

Hello everyone, well I spent a couple of hours at the boat shop today and we have come to a conlucion. We will not throw any money at the King Cobra cone clutch on my 1991 Four Winns 200 Horizon with a Ford 351.

Talking to the mechanic here are my options, but wanted to run them through you guys. (He is also going to look into this deeply since it is rare has not confirmed anything yet, so in other words what we are going to try and do)

The 351 is in awsome condition (Would love to do 350 but not enough money at this point to do both) The Fourwins transom cutout should should be ready to fit an Aplha 1 Gen 2 assembly except for drilling the 2 holes and SEI drive should mount on this assembly. With that said and now the tricky part is how do we get the motor and drive to couple together.

1) Water Pump (We eliminate motor pump and use drive pump, we can get creative on Plumbing)

2) Exhaust (This is the tricky part and is what makes me doubt and what will determine if we go that route once we start to measure)

3) We searched online and it seems we can get a coupler and flywheel for this project. The older Ford/Mercruiser had them and some parts are still available. This is what gives me hopes, this set up has existed in the past so I do not think it is impossible.

What do you guys think?

Ohhh ALso forgot to mention. Might need a New Control Box for shifting.

Thanks

Noe

 

[Don S]

Re: King Cobra to Mercruiser/SEI

Merc hasn't used the 351 since the 70's. So trying to hook a 351 to an Alpha I Gen II drive and transom shield is going to be an uphill battle all the way.
I think you are going to find it a very expensive proposition.
You better start looking at things like exhaust manifolds, and risers, adapting them to the Gen II Y pipe on the transom shield, the flywheel covers for the motor mounts and the couplers.

 

[Bondo]

Re: King Cobra to Mercruiser/SEI

Merc hasn't used the 351 since the 70's. So trying to hook a 351 to an Alpha I Gen II drive and transom shield is going to be an uphill battle all the way.

Ayuh,... For starters, the rear motor mounts are 6" different between the old Ford flywheel covers,+ the Gen.IIs...
I Think you'd need a MC-1 transom assembley, but then your limited to the Alpha 1 drive...
Not the Gen.IIs...

I'd Sell the 351,+ use those funds for a Merc. dressed 350....
Simpler,+ Cheaper by the time yer Done...

 

[Noe de la Garza]

Re: King Cobra to Mercruiser/SEI

Those are details we are getting into because as he (Mechanic) admitted very rarely has this been done.

Is having only the Alpha 1 as option bad vs Gen 2?

Most likely we will look at both options

1) Getting all parts to the conversion. He is going to take a quick dive in his network to see how much parts would cost.

2) Getting a Mercruiser engine. Might take time to find one for the right money. Also How much money would go into adapting the engine> Mounts etc?

As mentioned I would get some money back by selling what I currently have, which is a plus. How much have you guys seen a 305 or 350 average for?

Or does anyone know of any other options besides these?

Thanks

Noe

 

[Noe de la Garza]

From The SEI Web page forum

From The SEI Web page forum

08-14-2006, 09:43 PM
cmac
Junior Member Join Date: Aug 2006
Posts: 1


Ford 351 Mercruiser w/ Alpha One Drive - Gear Ratio

--------------------------------------------------------------------------------
I just purchased a complete drive unit from you with a 1.47 ratio. I was told by a boat mechanic that it would work OK, even if the ratio is not the same as the original drive of 1.32. Will the new drive unit work OK, or are there potential damages by doing so? Do I need to change my prop to compensate for the ratio difference? I would appreciate any help or guidance you can provide.

cmac
View Public Profile
Send a private message to cmac
Find all posts by cmac
Add cmac to Your Buddy List
#2 08-15-2006, 12:59 AM
Technical Support
Administrator Join Date: Nov 2003
Posts: 336



--------------------------------------------------------------------------------
You will definately need to change the prop to make up for the ratio difference. I 1.32 ratio is definately stronger, but you should be okay with the 1.47 ratio.

Tech Support
__________________
Brunswick Corporation is the original equipment manufacturer (OEM). Sterndrive Engineering, Inc. (or SEI) is not affiliated with the Brunswick Corporation and is not authorized to sell or service Brunswick products.

 

[Don S]

Re: From The SEI Web page forum

Re: From The SEI Web page forum

08-14-2006, 09:43 PM
cmac
Junior Member Join Date: Aug 2006
Posts: 1


Ford 351 Mercruiser w/ Alpha One Drive - Gear Ratio

--------------------------------------------------------------------------------
I just purchased a complete drive unit from you with a 1.47 ratio. I was told by a boat mechanic that it would work OK, even if the ratio is not the same as the original drive of 1.32. Will the new drive unit work OK, or are there potential damages by doing so? Do I need to change my prop to compensate for the ratio difference? I would appreciate any help or guidance you can provide.

cmac
View Public Profile
Send a private message to cmac
Find all posts by cmac
Add cmac to Your Buddy List
#2 08-15-2006, 12:59 AM
Technical Support
Administrator Join Date: Nov 2003
Posts: 336



--------------------------------------------------------------------------------
You will definately need to change the prop to make up for the ratio difference. I 1.32 ratio is definately stronger, but you should be okay with the 1.47 ratio.

Tech Support
__________________
Brunswick Corporation is the original equipment manufacturer (OEM). Sterndrive Engineering, Inc. (or SEI) is not affiliated with the Brunswick Corporation and is not authorized to sell or service Brunswick products.

I have no idea what all of that is about, other than it's over 4 years old.

 

[Noe de la Garza]

Re: King Cobra to Mercruiser/SEI

I had found it on the posts and saw that at one time someone had the setup I am talking about. Pretty much it.

I have been doing a lot of digging.

 

[Don S]

Re: King Cobra to Mercruiser/SEI

Dig all you want, but don't always expect those old post where someone had 1 post to be anything close to fact.

If you are expecting anyone to say this is going to be easy and/or cheap, forget it. It's not going to happen. No one uses fords. and the MARINE parts are getting rare.
You bought into a problem, and it's not going to get any better. You will have a Frankenboat here soon at the rate you are going.

 

[Noe de la Garza]

Re: King Cobra to Mercruiser/SEI

So assuming I find the 350 for the adaptation. Are the mounts differently positioned from the 351? I assume yes. How different and how much work?

I Like the Frankenboat expression. Do not want to end up with one. So will go with 350.

So whats the big difference between Alpha 1 and Gen 2 drives?

Thanks

Noe

 

[Howard Sterndrive]

Re: King Cobra to Mercruiser/SEI

Your best option imo would be a complete donor boat.
A Ford powered Mercruiser with a frozen block would probably be very affordable and allow you to use your engine that you know is good.
But you would really need to inspect a purchase well for condition of gimbal and transom shield parts.

So whats the big difference between Alpha 1 and Gen 2 drives?

nothing you'd notice performance wise, just updated housing shapes and mounting dimensions mainly. The uppers use the same gearsets.

I think most techs would tell you the Alpha 1 Gen 1 is just as good of a drive as a Gen II

 

[Don S]

Re: King Cobra to Mercruiser/SEI

Yes, installing a 73 to 77 Mercruise engine and drive into your 91 boat will sure increase it's value. People are begging for 10 year old boats with a 25 year old drive drain.

A donor boat is great, but at least make the whole thing newer than the boat, either Mercruiser or Volvo. Don't even think OMC. Those 3 letters is what got you into this mess to begin with.

 

[Howard Sterndrive]

Re: King Cobra to Mercruiser/SEI

his boat is a 91, so Alpha 1 Gen 1 is period proper.

He can still throw a brand new $1200 SEI drive on it.

The value is irrelevant if the boat isn't for sale.

It'll certainly be worth many times what its worth now.

Lots of options with the cutout in the transom.

Want to get the current stuff out of there and evaluate the hole/hull.

Volvo used some Ford engines into the 1990's so another donor option might be a VP 5.8 powered boat with cracked stuff...

 

[Lou C]

Re: King Cobra to Mercruiser/SEI

sorry duplicate post

 

[Lou C]

Re: King Cobra to Mercruiser/SEI

I think you have to consider what your plan for this boat is...run it a few years and sell or keep it longer...if its keep it longer...honestly I'd bit the bullet and go with a 350/Alpha with a good used transom assembly and an SEI drive...mixing and matching always leads to details that have to be worked out...exhaust...steering...belt driven stuff...etc...start with a combo designed to work together...the time saved is worth money...and if you sell the boat...well there is no downside to the most common I/O package out there...

But before you do any of this...check that boat REALLY carefully for ROT...I sure as heck repaired a lot of it on my 88 FW....and...it was NOT FUN....just did the last spot I found...bulkhead in front of the gas tank...

I found in my rebuild that FW's construction techniques were not that great then...for example...stringers dimensional lumber not plywood...not glassed on top at all...not glassed up the sides...thin skim coat of glass on the deck...deck stapled down with no adhesive (easy to rip up though!) rusty nasty staples each caused a rot spot...then my pet peeve...carpet everywhere...holds moisture that rot spores love....so be careful before throwing a lot of money at the powertrain...The way the weather covers were made on many of them...the bow cover did not cover the anchor locker up front...so water went from there...into the ski locker...laid in there and made the inside nice and moist...perfect conditions for rot...when I re-did the bow cover I had the canvas guy make it cover the anchor locker...the newer H-200s have a drain but water can still get in there...and it lays up against the gas tank bulkhead...which is why I had to replace mine...

Having said all that...these H-200 hulls were great running boats...they are very stable and bigger inside than the newer ones....and there's none of that molded in fiberglass around the engine compartment that gets in the way of working on the engine...so in some ways I like em better than the newer ones...
Check out this pic of the engine compartment...when you slide the rear seats foward and remove the divider panels...you can get at most stuff pretty easily...starter replacement 1/2 hr job...no need to lift the engine...oil filter (non remote) can be reached without a problem, just use a cap wrench...Chevy small block distributor way in the back...there is a panel you can remove just above it...so no problem there either. I look at some of the new I/O boats at the boat shows and imagine the cuss words spewed out by the poor mechanics who have to work on em....

 

[krisnowicki]

Re: King Cobra to Mercruiser/SEI

I did this swap last year on my Liberator, I did a OMC 454 ( thats was thirsty so it drank som salt water) to Mercruiser 350 mag.
I found a donor boat and sold all my omc stuff to make up some cash. I got 1100 for the transom and hydraulics, you can use your omc pump on the alpha rams, and I got about 1000 for the drive. I just sold the omc coupler for 200 on ebay.

So there is cash in your set up that can recoup the outlay for a donor boat.

The best way to go is find a donor and swap. Mix matching will drive you case and broke.