Vortec heads on a mercruiser / EFI conversion

[dcg9381]

I have a 1987 Mercruiser 350ci motor that's in a 1989 Glastron.

So this is still in the "theory" stages, but I've done EFI conversions on 3 different street vehicles. I've done research on the megasquirt forums regarding the practicality of going EFI on a marine motor.. Several people have done it.

My question is this:
I strongly prefer port injected EFI (MPI) over the old school style of TBI injection. TBI injection is cake, but doesn't have all the benefits of MPI.
I know you can bolt vortec heads on to these motors, but is there a "marine" lower manifold that can be used with an MPI setup of some type? The lower manifold design is typically what prevents me from using the standard automotive stuff.

I'm aware that flame arrestors and saftey are concerns when going auto->marine usage.

 

[Bondo]

Re: Vortec heads on a mercruiser / EFI conversion

Ayuh,.........

I Believe that Mercruiser,+ possibly others are/ have done Alot of MPI motors based on the SBC with Vortec Heads.......

Why Reinvent the Wheel,..??..??..........

All you gotta do is Find the Parts............

 

[tommays]

Re: Vortec heads on a mercruiser / EFI conversion

affordable-fuel-injection.com




There the DIY place BUT thee are issues they use and auto ECM that is NOT waterproof and you have to somehow protect

And they use a return line back to the fuel tank which NO other marine approved system uses at this time


Or
Holley Marine Commander 950 MPFI Systems


ALL the aftermarket systems ignore all the R&D Merc and Volvo put into resolving the problems with them living in a marine environment and leave that part up to you





Tommays

 

[dcg9381]

Re: Vortec heads on a mercruiser / EFI conversion

Ayuh,.........

I Believe that Mercruiser,+ possibly others are/ have done Alot of MPI motors based on the SBC with Vortec Heads.......

Why Reinvent the Wheel,..??..??..........

All you gotta do is Find the Parts............

I'm sure an MPI stand alone system is $$$. I like the flexibility of the system that I use. The question is - where do I get the MPI parts - there has to be some sort of aftermarket for these things... Or is there an auto equivalent manifold that I can adapt for use with marine style cooling.

I'm familiar with the afforable fuel injecton and the holley system - both are TBI.. Affordable fuel injection says they have MPI, but I haven't seen the manifold.

 

[rodbolt]

Re: Vortec heads on a mercruiser / EFI conversion

Marine power has an MPI setup that returns fuel to the tank, they will even sell the fitting to cut into the fill hose at the tank.
your asking way to much sugar for a dime though and wont relly see the bennies without a cam change as well.
the auto ECM will have to be scrapped in favor of a marine unit do to calibration issues.
autos use a feed back from the O2 sensor for finetuning the fuel curve and marine does not use an O2 sensor,yet.
autos tend to go into an open loop mode at WOT and marine is programmed to run at or near WOT.
most marine MPI setups on the SBC run a single intake. some of the older marine power stuff ran a two piece and most all big blocks ran a two piece.
so while its fun to theorize, its not a practicle conversion.
vortec heads are not mandatory as GM ran MPI long before the 8 bolt vortec intakes.
the injectors and fuel rails and such were mostly standard GM AC/Delco stuff.
the marine part comes in the form of fuel coolers and approved plumbling and a remapped ECU. after that its all easy.