Converting engine from Bravo setup to Alpha setup
#11
Registered
Gold Member
Thread Starter
Also not opposed to running the bravo impeller pump on the alpha if it's possible. What would need to be changed other than the inlet hose mentioned above? I'm also assuming you have to remove the impeller from the housing within the alpha itself
#12
Yeah remove the impeller in the alpha and route a non collapsable hose from the transom to the sea pump intake.
Also need to use the shift interrupter from the alpha setup. The older ones ground the coil, newer one may be different, cant remember, but you will need it.
Also need to use the shift interrupter from the alpha setup. The older ones ground the coil, newer one may be different, cant remember, but you will need it.
#14
Offshoreonly Advertiser
Offshoreonly Advertiser
Okay, on Genuine Mercury & Mercruiser parts. WATER PUMP AND FRONT COVER they list 3 different belts. 1 is for Alpha and 1 is for Bravo and why a 3rd ? However, it doesn't say which belt is for what drive.
Cruising thru other look-ups:
Loks like #57-861758A1 is for the Alpha equipped.
Looks like #57-861757A1 is for the Bravo equipped.
Looks like #57-861049A2 is for 4.3L v6 boats...why this is on that page as an option I don't know.
So....I did this quickly and it's your boat not mine, so please do your homework still and don't 100% go by what I found.
Cruising thru other look-ups:
Loks like #57-861758A1 is for the Alpha equipped.
Looks like #57-861757A1 is for the Bravo equipped.
Looks like #57-861049A2 is for 4.3L v6 boats...why this is on that page as an option I don't know.
So....I did this quickly and it's your boat not mine, so please do your homework still and don't 100% go by what I found.
__________________
Marc
www.mercruiserparts.com
www.go-fast.com
www.bammarine.com
www.cyborgtransmissions.com
It's not alive -www.BoatStuffExpress.com - temporarily retired
Marc
www.mercruiserparts.com
www.go-fast.com
www.bammarine.com
www.cyborgtransmissions.com
It's not alive -www.BoatStuffExpress.com - temporarily retired
#15
Offshoreonly Advertiser
Offshoreonly Advertiser
The bravo version does not, that is one of the obstacles. Mercury does offer a 350 MPI Alpha engine as part of the reman program.
__________________
Marc
www.mercruiserparts.com
www.go-fast.com
www.bammarine.com
www.cyborgtransmissions.com
It's not alive -www.BoatStuffExpress.com - temporarily retired
Marc
www.mercruiserparts.com
www.go-fast.com
www.bammarine.com
www.cyborgtransmissions.com
It's not alive -www.BoatStuffExpress.com - temporarily retired
#16
Registered
iTrader: (1)
#17
Banned
iTrader: (9)
If you are going to use an ALPHA GEN 2 outdrive you can NOT use a bravo impeller set up unless using a water pick up instead of the drive water inlets.
., And for all --- the Gen 2 Alpha impeller and housing is more bullet proof than any bravo housing and impeller. The alpha gen 2 impeller is called a floppy vane impeller and I have seen people never change it with the darn engine still pumping water like crazy. The longest alpha gen 2 impeller and housing ( in which is heavy duty stainless steel with a pretty thick wear plate on the bottom ) in use was 12 years straight. I could not believe it if I did not see with my eyes. I do not recommend ever doing that period. Just saying.
The Alpha impeller set up does not pump as much water volume as the Bravo set up,
., And for all --- the Gen 2 Alpha impeller and housing is more bullet proof than any bravo housing and impeller. The alpha gen 2 impeller is called a floppy vane impeller and I have seen people never change it with the darn engine still pumping water like crazy. The longest alpha gen 2 impeller and housing ( in which is heavy duty stainless steel with a pretty thick wear plate on the bottom ) in use was 12 years straight. I could not believe it if I did not see with my eyes. I do not recommend ever doing that period. Just saying.
The Alpha impeller set up does not pump as much water volume as the Bravo set up,
Last edited by BUP; 07-25-2017 at 04:54 PM.
#18
Registered
Gold Member
Thread Starter
Lots of good info here. Thank you everybody. I did find the Alpha and Bravo versions of the 350 Mag Mpi on mercs reman website. To me, it seems easier just to buy the engine for the correct application instead of trying to change things and make it work. If decide to do it I'll keep everybody posted through the transition process. Now for the most important question, how much speed will be gained from the old engine to the new? Boat currently runs a best of about 57mph with a carbed 350 Mag.
#19
Registered
iTrader: (1)
The interrupter switch can be added to use the Gen 2 provided your using the EST distributor. Need to change the switch from a NO to a NC switch. If motor has the HVS distributor, don't think it will work, but might, I would need to dig some more.
As for speed, it takes a lot of HP to increase above boat efficient plane speed, and will leave that to others
As for speed, it takes a lot of HP to increase above boat efficient plane speed, and will leave that to others
#20
Registered
iTrader: (1)
Play with this, it has been quite close for a few boats I work on. Single engine.
Desired Speedē / Current Speedē = Y
Y x Current HP = HP needed to go Desired Speed.
Desired Speedē / Current Speedē = Y
Y x Current HP = HP needed to go Desired Speed.