SX and Alpha 1 Gen 2 drive questions

[Bigdave196]

Ok, I just picked up a new toy at a deal I couldnt pass up. 1997 Blue Water Monte Carlo with a Volvo 5.7 300hp (F.I.) and the SX drive on it. I have not had this newer boat in the water yet, but I am familliar with it and I have seen it out on the water many times. I own the same boat but a 1995, and I have repowered it from carb'd 260hp 5.7L , to a carb'd 350hp 5.7L and for 2 years and over 200 hours I have never had an issue with over powering the Alpha 1 Gen 2 with my 19* 3 blade Stainless prop.

Hours on the new boat is about 600, and the drive in netural is a little "tighter" to spin at the prop. On my Alpha 1 drive you can easily spin the prop and it spins freely for a second or two before it stops, the SX drive it has drag to it and almost stops immediatly. So here are my questions,

1. I have heard that the SX drives are smother shifting, could this have any relativity due to a form of clutche in the drive?

2. Is this a known issue on prop "drag" for the SX drive?

3. How hard would it be to either fix a suspected issue and if this is a common issue, am I looking at a gimble bearing and U-joints, or ???

4. I have heard that SX drives are stronger than Alpha 1 Gen 2's, Is this true? If so how strong are they and what kind of power can they handle?

5. Are parts hard to get, and are they pricey?

All replies are greatly appreciated and thank you in advance.

 

[Don S]

Re: SX and Alpha 1 Gen 2 drive questions

1. I have heard that the SX drives are smother shifting, could this have any relativity due to a form of clutche in the drive?

Yes, they are smoother shifting, no dog clutch or shift interrupt system like the Alpha drives. No ratcheting into gear if you move to slow. The Volvo cone clutch is what the Merc Bravo drives imitated.

2. Is this a known issue on prop "drag" for the SX drive?

No more than any other drive

3. How hard would it be to either fix a suspected issue and if this is a common issue,

Confusing, Unanswerable question

am I looking at a gimble bearing and U-joints, or ???

Yes, that drive has ujoints and gimbal bearing. Uses the same alignment bar and gimbal bearing as Merc. The drive comes off like easily, and the bellows can be replaced in 1/2 an hour.

4. I have heard that SX drives are stronger than Alpha 1 Gen 2's, Is this true?

True, same upper is used for the big blocks, they could use the single prop lower, but Volvo uses the duo prop with higher power engines. You can also change to the DP drive by replacing only the lower unit.

5. Are parts hard to get, and are they pricey?

Parts are readily available, and major parts are more expensive than an Alpha, more in line with the Bravo.

 

[Bigdave196]

Re: SX and Alpha 1 Gen 2 drive questions

Don, then what could possibly make the prop have resistance/drag when i spin it by hand with it up in the "trailer" position? What is the rated HP of the SX drive?

 

[Don S]

Re: SX and Alpha 1 Gen 2 drive questions

what could possibly make the prop have resistance/drag when i spin it by hand with it up in the "trailer" position?

Bearing preload,and all that is turning. If you are comparing the turning ability to the Merc, DON'T. They turn harder.

What is the rated HP of the SX drive?

Like I said before, the uppers are the same and were used on big blocks (7.4 & 8.1) fuel injected engines putting out more torque than you 5.7 has.

 

[Bigdave196]

Re: SX and Alpha 1 Gen 2 drive questions

Thank you Don. So from what it sounds like when I get the urge to build this one up, I can go past 350hp. Sweet!