Alpha 1 Conversion

[sqzbx]

Can a alpha 1 for a 4cyl boat motor be converted to a run with an 8 cyl motor by changing the gears? Our boat is a 1987 Wellcraft with a V-8 motor. We purchase a alpha 1, and then discovered it was used on a boat with a 4 cyl. We are going to buy an Upper Gear Service Kit for Mercruiser 1.50 ratio if we can convert it.

 

[Haut Medoc]

Re: Alpha 1 Conversion

Can a alpha 1 for a 4cyl boat motor be converted to a run with an 8 cyl motor by changing the gears? Our boat is a 1987 Wellcraft with a V-8 motor. We purchase a alpha 1, and then discovered it was used on a boat with a 4 cyl. We are going to buy an Upper Gear Service Kit for Mercruiser 1.50 ratio if we can convert it.

Yes, it can be done, but.....
The tools as well as the cost of the gear/seal set, will come close to purchasing a new aftermarket SEI upper.....
It is not as simple as throwing new gears on it, there is re-shimming, setting rolling torque, etc....
If it were me, I would sell your upper & use the money to offset the cost of the 1:50 upper, JMHO.....

 

[Haut Medoc]

Re: Alpha 1 Conversion

Oh & welcome to iboats, btw.....​

 

[rad1026]

Re: Alpha 1 Conversion

A similar thing happened to me. I needed to change the gearing and in the process of disassembly a bolt sheared when removing the top plate. I wound up buying a new upper with the correct gearing and selling the old upper on ebay. I guess my point is, even if you decide to work with the existing unit and change the gearing, there are risks in doing so. You are kind of crossing your fingers in hoping the rebuild will be flawless. By the way, I purchased a brand new Merc upper and my re-coup on selling my old unit on ebay was enough to offset the difference in price of the original gear change and the cost of the new unit. Did that make sense?

 

[BAYLINER185]

Re: Alpha 1 Conversion

Is youe existing, already geared upper unit still ok or is that where the peoblem is that is causing you to re drive the boat?

Maby just swap lower units over if your upper is OK, that would be the easiest way to go.

Or am I missing something?

 

[Don S]

Re: Alpha 1 Conversion

Maby just swap lower units over if your upper is OK, that would be the easiest way to go.

Or am I missing something?

Yes, you are missing something. The gear ratio change is done in the upper, not the lower. The lowers are the same.

 

[BAYLINER185]

Re: Alpha 1 Conversion

Don I relise that,What Im suggesting is:

He already has an upper geared for his boat ( his original )

He never said why hes re driving? or why the origianal outdrive is bad. Mabe the problem he has is only in the lower so he can take the New lower and mate it to his existing upper and wa la he has a gear ratio alpha that works.

sure I suppose he would have just got a lower then instead of an entire drive but sometimes you can buy a used complete drive really cheep to as Im sure he did.