DjMikeyC

iTrader: (1)

Looking for some info on the mercruiser reman 400HP 383 stroker scorpion, option R61... the one with the CMI headers. Is anyone running one of these? Looking for impressions.

Thinking of replacing a 350 Mag MPI with one of these in a 22 Apache. The 350 Mag MPI is rated at 300HP at the prop shaft... the stroker is rated 400HP at the crank and will spin to 6000 rpm, anyone think it is worth the upgrade?

The Apache has a Alpha SS drive but merc says the 383 stroker will only work with a Bravo setup. Anyone know if this will bolt up to an Alpha SS drive? What would be needed to change the 383 to bolt up to the Alpha SS?

Here's the link to the engines info from the merc reman site... check out the link to the pdf on the bottom called "383 Stroker Scorpion Bravo sell sheet"

http://sites.mercurymarine.com/porta..._schema=PORTAL

firehawkcat

What kind of boat is it going in? New engine and drive will cost you plenty and thats if you do the work yourself

FIXX

iTrader: (2)

the only reason they say bravo is because of the ss drive hp rating..that drive should handle 450 hp with no problem as lons as you are easy out of the hole..their are several guys running the ss with lots of hp over at donzi.net..
their is also a gut scott over their who just put that engine in his mint donzi bench seat hornet..he said the boat should do 73-74 mph..

http://www.donzi.net/forums/showthre...ch+seat+hornet

Bartel22

I put one in a 21 or 22 ft ( cant remember) Baja Hammer. Removed the water filled 454mpi and put the 383 in. Picked up almost 7 mph. Topped out at 73mph, and the boat sat a little higher in the stern wich was nice.

DjMikeyC

iTrader: (1)

Firehawkcat - thinking of putting it in a 22 foot Apache Scout. I'm planning on keeping the Alpha SS Drive so it would be just an engine swap. Doing the work myself is not a problem and selling the 350 mag mpi will help offset the cost a little.

mrfixxall - I was hoping that is was all about HP and not some weird reason that it will not bolt up. Thanks for the tip on the Donzi.net forums as I never thought to check there as if I remember correctly quite a few of the mid to late 80's Donzi's came with Alpha SS drives.

Bartel22 - Sweet! This 22 Apache I want to drop this motor into originally had a custom built 383 stroker back when it was originally rigged at MRD and supposedly ran mid 70's.

HTRDLNCN

I think its because the 400hp isnt setup for the shift interrupt you need to shift the Alpha,basically the engine shuts off when you shift to allow it to go into gear. Bravo engines dont have that feature.

As for power its torque not hp that kills drives, a 400hp 383 will have less torque than
an equal BBC,, I ran a 310hp/454 in front of my Alpha for over 200 hours, wasnt till I upgraded to a 502 that I finally broke it. You should be fine if your drive is in good shape.

FIXX

iTrader: (2)

Read your first line,,so when you up graded to a 502 which has more torque and horse power and that's what killed the drive??

they kinda go hand in hand.. i have blown a few alphas on a old chris craft with a 260 hp,,it depends how you drive it..

Also he can use his existing shift mechanism which the motor he is looking at does not come with unless he bought the whole package..

HTRDLNCN

Correct, the stock 454 was 310hp/450lb tq the 502 is actually a 509" with custom cam,hp500 heads,intake and carb with Drake exhaust so its around 500+hp 600+tq
That was defiantely over the top for the Alpha, still lasted a full poker run and a couple weekends before it blew up though!

Mbam

Htrdlncn has it right. The biggest problem is there is no provision for shift interrupt. And the Alpha water pump is not adequate but all you need is to add a pickup as the engine has a pump. There are a couple of work arounds on the interrupt.

FIXX

iTrader: (2)

If the alpha water pump could feed a 454 and a 502/509 then why wouldn't it be able to feed a mouse motor?