350 Mag MPI upgrade questions
10-26-2012, 04:10 PM
#1
Registered
Thread Starter
Join Date: Dec 2009
Location: West Monroe, LA
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
350 Mag MPI upgrade questions
2000 Scarab w/ twin 350 Mag MPI and Bravo 1's
Was wondering what bolt on upgrades work well with the 350 mag mpi's. If this were an automobile 350 I'd know, but new to the marine upgrades. For instance I don't want to spend the money on headers if they aren't going to do much in the way of performance over the manifolds. Things I'm interested in are headers, roller rockers, intake/throttle body, ect. Also are there any budget minded heads out there that perform better than the stock mercruiser heads, such as maybe the Vortec heads pulled from a chevy 350 (assuming they would work in a marine application)?
Was wondering what bolt on upgrades work well with the 350 mag mpi's. If this were an automobile 350 I'd know, but new to the marine upgrades. For instance I don't want to spend the money on headers if they aren't going to do much in the way of performance over the manifolds. Things I'm interested in are headers, roller rockers, intake/throttle body, ect. Also are there any budget minded heads out there that perform better than the stock mercruiser heads, such as maybe the Vortec heads pulled from a chevy 350 (assuming they would work in a marine application)?
10-26-2012, 08:45 PM
#2
Registered
Join Date: Mar 2009
Location: Beaverton Or
Posts: 386
Likes: 0
Received 0 Likes
on
0 Posts
hat boat engine has a lot going for it already such as the intake
http://www.pacificp.com/forum/viewtopic.php?t=317
If you take the valve covers off id bet youd see 113 heads which are vortec however they should have srewed in studs..nice little shortcut when installing 1.6 rockers
Great cam
http://www.compperformancegroupstore...Category_Code=
http://www.carcraft.com/techarticles...pring_upgrade/
Nice little tutorial for building up heads without a ton of money
Thru the hull exhaust..y pipe is a bit of a restriction
2000 model yr is probably a mefi 3 ecu give these guys a call http://www.obd2allinone.com/sc/detai...?item=mefitune There very competent
http://www.pacificp.com/forum/viewtopic.php?t=317
If you take the valve covers off id bet youd see 113 heads which are vortec however they should have srewed in studs..nice little shortcut when installing 1.6 rockers
Great cam
http://www.compperformancegroupstore...Category_Code=
http://www.carcraft.com/techarticles...pring_upgrade/
Nice little tutorial for building up heads without a ton of money
Thru the hull exhaust..y pipe is a bit of a restriction
2000 model yr is probably a mefi 3 ecu give these guys a call http://www.obd2allinone.com/sc/detai...?item=mefitune There very competent
Last edited by Pliant; 10-26-2012 at 08:56 PM.
10-26-2012, 09:25 PM
#3
Registered User
Platinum Member
iTrader: (1)
Join Date: Aug 2012
Location: Charlotte Mi.
Posts: 614
Likes: 0
Received 0 Likes
on
0 Posts
Weiand 177's cheap reliable power! depends on your comp. ratio how much air you can cram in there. My cal it getting two of them for christmas this year
10-26-2012, 09:33 PM
#4
Registered
iTrader: (2)
Join Date: Aug 2005
Location: Between A Womans Leggs in IL
Posts: 6,306
Likes: 0
Received 1 Like
on
1 Post
you did say mpi.then theirs nothing if you have the 555 ecm..or you will need to loose the efi or switch to a mefi so you can tune in what ever you do..the 555 ecm is non tuneable and i dont think anyone but merc or whipple can do it..
10-26-2012, 10:14 PM
#5
Registered
Join Date: Mar 2009
Location: Beaverton Or
Posts: 386
Likes: 0
Received 0 Likes
on
0 Posts
http://media.channelblade.com/EProWe...ng%20horns.pdf
It should be a mefi...actually it could be a 2. Depends on the yr of the engine. 555 started in 01
350 MAG MPI 1995‑1998 0F415189 0L339999 MPI MEFI 1 & 2 4
350 MAG MPI 1999–2001 0L340000 0M299999 MPI MEFI 3 4–5
350 MAG MPI MCM 2001–current 0M300000 Current MPI ECM 555 6
350 MAG MPI MIE 2001–current 0M310000 Current MPI ECM 555
There are serial numbers on your ecu a simple post will make it evident..
It should be a mefi...actually it could be a 2. Depends on the yr of the engine. 555 started in 01
350 MAG MPI 1995‑1998 0F415189 0L339999 MPI MEFI 1 & 2 4
350 MAG MPI 1999–2001 0L340000 0M299999 MPI MEFI 3 4–5
350 MAG MPI MCM 2001–current 0M300000 Current MPI ECM 555 6
350 MAG MPI MIE 2001–current 0M310000 Current MPI ECM 555
There are serial numbers on your ecu a simple post will make it evident..
Last edited by Pliant; 10-26-2012 at 10:17 PM.
10-29-2012, 11:41 AM
#6
Registered
Thread Starter
Join Date: Dec 2009
Location: West Monroe, LA
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
Yeah, the boat is tucked away at the moment, but I will try to crawl in there and get the serial number off the engine. I have had to mess with the electronics when I first got it and I am pretty sure its the Mefi 3, but will confirm with the serial number.
10-29-2012, 01:16 PM
#7
Registered
Thread Starter
Join Date: Dec 2009
Location: West Monroe, LA
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
03-04-2013, 11:31 AM
#9
Registered
Join Date: Feb 2011
Location: Brookfield Wi
Posts: 769
Likes: 0
Received 0 Likes
on
0 Posts
1999 mpi 350
Thinking of doing cam's, valve springs, exhaust valves and port the heads soon on my Active Thunder Savage with twin 350MPI's. Nothing crazy since I don't want to loose the idle...completely. Having Stainless Marine exhaust already, may push this a little. Anyone do something like this already on a 300HP MPI? What cam did you use? Results? Will i have to reprogram? Probably going to install an air fuel ratio gauge on before I start to have some comparisons.
