Possible engines for an 87 Alpha 1

[Razgriz81]

So here it goes.... I'm new to the whole boat thing. I inherited an 87 Marlin Cudy with an Alpha 1 out dive. Now please bear with me. If this is in the wrong section please move it and acept my apologies.
So on I would like to put a BBC in her, but from what I have been reading is that I should get a Brovo 2 for it. I don't think that the 350 that is in my boat is any good. I have a sbc 400 that I could use, would it mate to the Alpha 1 without any reliability issues? I even have a BB 400 that I would love to use but finding a Brovo 2 might be an issue right now. Any info would be great.

 

[Scott Danforth]

Your existing 350 is a 1-piece rear seal motor with brass core plugs, marine cam, and marine head gaskets. Your 400 sbc and and 402bbc are both early 2-piece crank seal motors which would require a different flywheel and coupler in addition to brass core plugs and marine gaskets and cam. The cam in the 402BBC is not marine friendly

The alpha drive is rated at 300hp. While plenty of people have put 383 strokers in front of them, generally a BBC requires a Bravo. You would be so much farther ahead either fixing your existing motor, or finding a 350 out of a 1986-1995 truck and using the longblock (after installing brass core plugs, marine head gaskets. The cam is close enough to use.

Switch over the intake, carb, dizzy, starter, water pump, alternator, windage tray, oil pan, and dipstick from your marine motor to the new longblock

 

[wrench 3]

I agree with Scott. You'll save yourself a whole mess of problems if you stick with what have so that all the hardware etc. fits. The 400 small block wasn't a good engine to start with. A lot of problems caused by the siamezed cylinders.

 

[thumpar]

You do swap the drive you would want a Bravo 1 or 3. The Bravo 2 has a longer lower unit to allow for large props on large boats.

 

[Razgriz81]

So the 400 SB would be a no go if I had a flywheel for it? I had no issues with the motor when it was in my car, but it was an idea though. As for the bbc it was out of a suburban, which I have been doing some reading and kinda figured that going to a Brovo would be my best bet on going bb. Would it be best to find a dual prop Brovo or are they pretty much all dual?

 

[Bondo]

So the 400 SB would be a no go if I had a flywheel for it? I had no issues with the motor when it was in my car, but it was an idea though. As for the bbc it was out of a suburban, which I have been doing some reading and kinda figured that going to a Brovo would be my best bet on going bb. Would it be best to find a dual prop Brovo or are they pretty much all dual?

Ayuh,.... Welcome Aboard,... The 400 is doable,.... The coupler on yer motor now is probably flywheel mounted,....

If so, a standard Chevy cast iron flywheel will use the pressure plate bolt holes,....

Was the 400 "Hot Rodded", seein's it was in yer car,..?? Big cams are No-goes in boats,...

The BBC was used ahead of Alphas for 2 years, with dismal results, Bravo came out then,....

The Bravo I is a single prop drive, same size props are the Alpha series,...

The Bravo II is a tugboat/ houseboat drive with a HUGE prop,...

The Bravo III is the duo-prop drive,....

 

[Razgriz81]

The 400 sb wasn't hot roded out to much just a different came mostly. It was a stock replacement for my 350 that went to crap. But besides that, if i was to do a bb would it be better to go with the Brovo 3 then with the dual prop?

 

[Bondo]

if i was to do a bb would it be better to go with the Brovo 3 then with the dual prop?

Ayuh,.... Of course,....

 

[thumpar]

The 400 sb wasn't hot roded out to much just a different came mostly. It was a stock replacement for my 350 that went to crap. But besides that, if i was to do a bb would it be better to go with the Brovo 3 then with the dual prop?

For a boat you want a truck or rv cam not a car came. You can have reversion and you won't have the torque curve you need for a boat with a car cam. Even a stock car cam is not right. Best thing to do if you use the 400 is to buy a marine cam. They are very close to a truck or rv cam but slightly different.

 

[Razgriz81]

Ok sweet thanks for the info and I guess I have a few more things to get for the BB swap.

 

[Scott Danforth]

if your going to go BBC, I personally would start with a 454 mark IV (1978-1990) or Gen VI (1996 - 2000+). pull a running motor out of a truck from a pick-a-part yard. you get forged rods on these, the Gen 6 is a roller motor. clean up the stock heads (casting flash, port match the exhaust and intake. you will have about 400hp easy.

However, I would recommend a complete new rotating assembly, build either a 468 or a 496, use the same small chamber - oval port heads, minor clean up, 270 degree roller cam and edlebrock air-gap intake and you have yourself a torque beast to put in front of a Bravo drive. Feel free to read what I am doing here http://forums.iboats.com/forum/engi...rds/10101672-bbc-build-don-t-tell-the-admiral