Bravo One Vs. Alpha?

[eb0248]

I recently acquired a 1981 Wellcraft 210 Nova with trailer for next to nothing; floors/hull are good, my mechanic says when he gets through with the 260, it should have around 300 hp. The original outdrive is about shot, and I have a line on a good-condition Bravo One 1:50 with transom, Gimbal , etc. What are the pros/cons of using this outdrive instead of an Alpha? I've asked several shops, they all tell me the Alpha runs hotter, the Bravo is heavier, but none tell me anything about what to do with the boat. Help?

 

[HT32BSX115]

Re: Bravo One Vs. Alpha?

All you have to do is jerk the Alpha outta the bot and bolt the Bravo in.

Depending on which model Alpha you have you may have to drill 2 additional holes in your transom.

I did the same thing except I removed a Very High tecknologee OMC 460 King Kobra and installed a 454/Bravo III. I had to drill 2 additional holes and relocate the engine mounts for the 454.

While you have it out you should inspect your transom for rot and water intrusion.

Uh....tell me more about what your "mechanic" is doing to get 300 hp out of that smallblock engine. If he's putting some sort of a "trick" cam and high compression pistons you might not be completely satisfied. You usually have to turn the engine pretty fast to get that claimed HP. Stern drives don't really like to turn much faster than 5000-5500 RPM or so.

Also, if you're a lake boater, you might have to bring your own fuel (or octane booster) since a lot of lakes (not all) only have 87 octane regular gasoline.

In a boat that size, I would put in a big block.....but that's just me...

Mercruiser gets 300hp from EFI in theirs at lower RPM (which is far more efficient for propellers)

Is this shop going to dyno the engine before you pick it up or are they just claiming you'll get 300hp?

Cheers,


Rick

 

[JustJason]

Re: Bravo One Vs. Alpha?

not going to be much difference between an alpha 1 and a bravo 1 except that the bravo is a beefier drive, and can put up with more punishment. Both drives will pretty much perform the same. The bravo will shift better/smoother because of the clutch that it uses vs the alpha. And that's about it really. You won't notice any difference except for the shifting untill you go to a bravo 3. With dual props there are major differences in performance.

 

[HT32BSX115]

Re: Bravo One Vs. Alpha?

Oh....yeah.

When I had the 460 (340 rated crankshaft HP) with the single prop drive my boat was always a little slow out of the hole. (in fact it was a DOG, especially if loaded up with people and "stuff")

My brother bought this boat new and told me it was always that way. It did do 60mph flat out though...

When I put the Bravo III in with the 454 (rated at 300 PROPSHAFT hp) It lost about 3 mph (57 gps speed) but now just ROCKETS out of the hole regardless of load by comparison.

So in a boat that big for all around perfornamce you might consider a Bravo III


Cheers,

Rick

 

[eb0248]

Re: Bravo One Vs. Alpha?

HT...that's exactly what he said he wanted to do...cams, etc...what I didn't know was if it was worth the trouble playing with the existing engine, or if another engine would be a more efficient option. The transom looks great, I couldn't tell you much about engines, other than routine maintenence.

 

[Mkos1980]

Re: Bravo One Vs. Alpha?

I'm running in the neighborhood of 380 HP and my Alpha 1 and have no issues so far. Spinning to 5400 RPM's I'd stick with the alpha for now.

 

[eb0248]

Re: Bravo One Vs. Alpha?

Jason, that's what I thought, as no one can give me a good answer yay or nay for either one at the shops. I was thinking of just finding a decent old alpha, I'm just running it to the islands, after all.

 

[eb0248]

Re: Bravo One Vs. Alpha?

Mkos, thanks for the input, I think that's what I'm going to do.

 

[QC]

Re: Bravo One Vs. Alpha?

Be aware . . . yes an Alpha can handle more than 300 bhp, but the issue is for how long. If you are careful with the throttle, and rarely run at WOT, then maybe you'll be OK. The Bravo was designed specifically because Alpha's were not living at ratings above 300 bhp

 

[mkast]

Re: Bravo One Vs. Alpha?

Get the Bravo, leaves room for expansion (horsepower).
Money being the deciding factor, price the rebuilt big block,
lots of them on the market.
Then the 383. In a 21 footer it doesn't matter. I think the stroker will cost you more.
Some people will side with the stroker. It will save a quart of fuel every time you take the boat out.

 

[eb0248]

Re: Bravo One Vs. Alpha?

I saved a chunk of money on the boat, the Bravo outdrive is reasonable, so what engine be suited? Pardon my ignorance, but what is a "stroker", and where would I look?

 

[eb0248]

Re: Bravo One Vs. Alpha?

Just googled "stroker". Do I look for this engine online, or do I get mine rebuilt?

 

[mylesm260]

Re: Bravo One Vs. Alpha?

A "stroker" is a 383.

I'm not 100% sure, but I believe the recipe is:

A Gen I or Gen II Chev small block 350.
A Crank shaft from a small block 400.

The 400 has a longer stroke than the 350, when you put the 400 crank in the 350, you end up with more displacement and a higher compression ratio.

The higher compression ratio allows you to run a hotter cam, but it means you need to run higher octane fuel.


The extra displacement and compression ratio gives you more torque across the board. I understand they're good setups for boats, as it helps both your hole-shot and your top end.

Personally, I would much rather have a Gen III or GEN IV Chev small block with all original internals.


As far as Alpha VS Bravo, I'd say this:

If you plan to have more than 300 HP, go with the bravo. If you are going to have 300 or less, go with the alpha.

Basically:

Small block --> Alpha
Big block --> Bravo

It seams that heavily modified small blocks running in excess of 300HP (some as high as 350-400 HP) still run okay on alphas. It would appear that Alphas can handle High RPM horsepower, but not HIGH torque HP.

A 383 for example could make 350 HP @ 5400 RPMS. That seams okay on an Alpha.

But, a 454 Might make 350HP @ 4100 RPMS. This is too much torque for an Alpha.

HP = Toque @ RPMS / 5252 So for those examples:

The 383 would be making 340.4 Ft/lbs @ 5400

and

The 454 would be making 448.3 ft/lbs of torque @ 4100

Having said all that, keep in mind that wear = RPMS Squared. All things being equal, you're wearing your drive and engine MUCH faster @ 5400 RPMS than you are at 4100.

 

[eb0248]

Re: Bravo One Vs. Alpha?

Thanks for the reply, Myles. I was on the phone with a guy telling me the 383 was gonna run about 5 grand in drop-in condition...

 

[mkast]

Re: Bravo One Vs. Alpha?

Thanks for the reply, Myles. I was on the phone with a guy telling me the 383 was gonna run about 5 grand in drop-in condition...

A tad more expensive than the big block.

 

[TilliamWe]

Re: Bravo One Vs. Alpha?

Myles hit the nail on the head, in his post. Alpha drives can handle 300+ horsepower, but they can't handle the TORQUE of a big block. At least not for long, if you like to hammer the throttle from a standstill, get airborne over waves, and stuff like that.
With the company SEI selling complete Alpha One drives for $1195, don't worry too much about tearing up your existing drive with a small block.

 

[180shabah]

Re: Bravo One Vs. Alpha?

I think we need to slow down here for a minute.

With the new engine what are your goals? How much power did the old engine produce, and how did the boat perform with it?

Once we determine where you want to go, we can then select an engine, THEN decide on the drive. Also, be wary of hp claims by small shops unless they include dyno sheets. There claims are oftem very optimistic, and even when they are verifiable, the hp is usually rated at the crank at 5500-6000 RPMS. What does it produce in the 4500-5000 range then subtract about 30hp to account for loss through the drive and we can compare propshaft hp to propshaft hp.

 

[wca_tim]

Re: Bravo One Vs. Alpha?

as above, a lot depends on our goals. I seriously considered putting a bravo 1 in my current boat. Right now I'm running a 383 (385) stroker that was built with all forged components by a shop that does a good business building engines for circle track and the offshore racing community. If you decide you want to go with a stroked smallblack, it is a very viable and relatively inexpensive proposition. It will also easily make more horsepower than most stock bigblocks if built right.

the biggest advantage of a 383 over a 350 small block is that is is very doable to make a lot of torque from idle to 5000 or 5500 rpms, make 350-375 or more horsepower, and maintain good idle quality, good power off idle, etc... To get the same kind of power out of a 350, you're generally talking a larger cam, and moving peak horsepower up over 5500 rpms as mentioned above. The worst part is that you can't idle down as far... which is really important to be able to shift an alpha drive into gear.

On the alpha vs bravo thing. in a nutshell my decision to stick with my alpha (at over 400 hp) was based on the following:

Alpha drive is a couple hundred pounds lighter... in my 17 1/2 foot sub 2500 boat that's a ton of weight right in the ***** end of the boat.

Alpha has a little less power loss

In the scheme of things an alpha is very inexpensive to replace...

IF I had a bigger boat and was going to buld more engine for it, I would definately go with a bravo. They can handle being shifted into gear at a little higher rpm, can handle a good bit more power and are much better for a heavier boat (it's the torque that will trash an alpha drive in a hurry...)

 

[HT32BSX115]

Re: Bravo One Vs. Alpha?

Alpha drive is a couple hundred pounds lighter

Howdy Tim!

I am going to have to disagree with you a bit on the weight difference....


The weight differences between the gimbal, transom plates are insignificant.

The actual drive weighs less than 20 lbs more than my previous OMC King Cobra drive. I had to weigh it to ship it to the east coast last month.

I picked it up (by myself) and placed it on a bathroom scale to measure 110lbs. (I used my legs, not my back by the way)

I also have picked up my Bravo III (by myself too). In fact when I removed it (by myself) was able to "muscle" it over to where I wanted to lay it down.

I had an Alpha GEN II off a boat last summer to swap the raw pump and I would say it's definitely lighter, but not by "a couple hundred pounds"!!

30 lbs maybe.... + one more SS prop.......OK, 40lbs!!


My 87 Liberator could have been ordered with a 454 + Alpha new.....and there's still a lot of them out there in original condition....running with the Alphas.

Even if mine was an Alpha I'd still do the Bravo if I had the opportunity.



Cheers,

Rick

 

[180shabah]

Re: Bravo One Vs. Alpha?

Shipping weight on an alpha is 86lbs.