Forum | Stupid question about efi technology

Yeah, MAD may make it sound like a simple conversion but there's key words in their litature such as "dual EGT's" that ya' really got to pay attention to. Without the egt's there's no good way, short of melted pistons, to know when you have it "too" lean. Of course EGT's aren't part of their package nor or the guages nor the installation.

Box stock efi – low cost(or at least lower cost) little maintainence, economical.

Speaking of box stock…. there's probably a good chance of finding a new non-current model at a fairly decent price if you're flexiible on mfg and/or hp.

Thanks mad isnt clear about the injectors,yet it does asay everything inc then lists stuff like fuel rails etc.

Going to have to get a psi checker,may not be as much damage as thought,plastic melted in places thats about it as for his psi check of 60 each cyl hard to get an accurate reading with a 1/4 water imlet hole open,water could not get to motor as both ends the one on bottom of the block and the top where it goes into thermostats both open melted or broken,so 28 psi (that hose was ok) means nothing wasnt going into motor,bottom one threads stripped top one melted due to bottom not connected duh.Try reading tire pressure with a 1/4 in hole in it.Doubt if it will be pristine but more than 60 lol.

Thermostats definately toast as have a plasitic flapper valve,currently in open position,nor do I understand their function as water goes thru cold as well just not as much,unlike a car not using it for heat.

Net goal would be less gas consumption may need to even chuck the mota and go stock,at least stock powerhead.Merc 200 stats do look nice weight,gas consumption and hp wise lol im thinking dark thoughts.

Nope the carbs have to go away. EFI is not direct inject. It still injects fuel into a manifold pretty the same as the carb models do. Thus you have to have an efi type manifold to mount the efi injectors.

I think I know what you're thinking of though. GM first came out with TBI which was Throttle body injection. And in that application it had what were esentially carbs incorporating an injection system where by fuel was injected into the system vs the venturi draw system of the carb. The TBI system didn't hang around long.

 Then they when to the MPI which was "Multi-Point Injection" and that is where the manifold changed to accept 4/6/8 injectors but still in a manifold structure. Direct inject on the other hand uses no manifold for fuel(manifold is required for air). The injector of the direct inject system injects fuel directly into the cylinder it's associated with. One of the reasons for the additional weight of DFI engines is these things ain't small like a EFI injector. The EFI injector opened(called pulse width) and from a common high pressure fuel rail, fuel was injected into the manifold. On DFI engines there is no "fuel rail" each injector creates the fuel pressure at time of injection. They also inject at much higher presssures than the common rail efi systems which produces better atomization leading to better efficiency, requiring less fuel and reduced emissions.

DFI or as I've seen it refered to as GDFI(Gasoline direct fuel injection) is making it's way into the auto industry. This should prove interesting. Because DFI directly injects fuel into the cylinder it would appear in a 4 cycle engine w/DFI there would no longer be a need for an intake valve. Does that mean on 32 valve v8 engines instead of 2 intake and 2 exhaust valves per cyclinder they can now create 4 cycle engines with 4 exhaust valves per cylinder????

In the picture below the OMC MAD EFI you can see the fuel rail for each set of injectors at the bottom of each air horn. If you look close enough you can see one of the injectors on the left side air horns at the bottom connected to the fuel rail. They don't have the braided fuel line installed running from each air horn back to the fuel manifold though.