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1redTA
10-17-2009, 04:51 PM
I have a buddy at work who believes a mid 90's fuel injection set up from a f150 with a 5.8 would be an easy swap for my 81 351 with a 600cfm holley 4 barrel. I am inclined to believe him but I am a lt1/ gm guy. So would the swap work well for a marine set up? Let's leave cost out of the equation for now please thanks art

TMCNo1
10-17-2009, 06:56 PM
I have a buddy at work who believes a mid 90's fuel injection set up from a f150 with a 5.8 would be an easy swap for my 81 351 with a 600cfm holley 4 barrel. I am inclined to believe him but I am a lt1/ gm guy. So would the swap work well for a marine set up? Let's leave cost out of the equation for now please thanks art

You'll probably have to find a marine computer to run it and who knows what else type /amount of additional wiring. Contact these people, http://bpi.ebasicpower.com/, they may be able to help with the electronics and/or even the EFI unit itself.

dummy
10-18-2009, 11:31 AM
I donít see why you couldnít, but I was having this discussion with my buddy about his 5.8L Ski Nautique and I kept coming around to the point that itís just sorta easier to sell your carbureted boat and buy an injected one if thatís what youíre after.

Regardless, youíd need to crack open your fuel tank to install a high-pressure in-tank pump and run high-pressure fuel lines to and from the engine (I think from - canít remember if the Ford system is returnless or not). I know the 5.0L Ford truck engines were Speed Density systems in the 5.0L Ďtill about í95, so Iíll assume the 5.8L engines were Speed Density as well. Iíd say youíd probably be better off converting to a Mass Airflow setup (computer and MAF meter from a Ď89-í95 Mustang, or there are lots of companies including Ford Motorsports that offer the conversion). Reason is the fuel and spark tables for the 5.8L Speed Density system will be built around the EFI engine, which Iím pretty sure uses a different camshaft profile and sports different volumetric effiecieny than your carbureted engine. The Mass Airflow system directly measures incoming airflow and can adjust itself more widely to compensate for differences in exhaust backpressure, camshaft lift/overlap, cylinder pressure, intake volume, etc. The Speed Density can only adjust for so much outside of the factory-designed paramaters, which were programmed for the truck, car, whatever chassis/configuration. Donít forget about converting over to the electronic igntion and all the other injection-specific acoutraments you can pull off the donor engine. Lotsa sensors - CPS, MAP, Coolant Temp, etc all need to go in somewhere.

It all may be a moot point, however, because Iím not sure if thereís any way of getting around the need for an O2 sensor in the exhaust stream, which thereís no cheap way of doing in a wet marine exhaust manifold. To my knowledge, both the MAF and SD systems use a O2 sensor to provide feedback to the ECU. Without it, youíre talking about a custom MEFI- or other-type marine computer programmer as TMCNo1 suggests, which really defeats the purpose of a cheap/easy swap using factory components.

That brings you to the aftermarket for something like an old Holley Marine Pro-Jection setup like this: http://www.holley.com/700-21.asp

Again, itís usually just easier and sometimes more cost-effective to upgrade to a newer injected boat and be done with it.

1redTA
10-18-2009, 12:06 PM
That is what I thought about doing the swap. I really don't think I would see a worthwhile difference over the carb. Thanks art