efi

[Cheesy]

Originally Posted by gonzo

O2 sensors are not needed on marine installations as much as automotive. The load variation range is very narrow. All major manufacturers have been experimenting with 02 sensors on wet exhausts without success. You guys are re-inventing the wheel. Used marine fuel injection systems are not that expensive, and are already properly designed. The injectors are different too, they are heavier weight (more flow).

It's not really re-inventing the wheel, a used marine system is only going to work optimally on the engine it came from, it will have different cam timing, different inlet and exhaust manifolds, different pistons and combustion chambers as well as different port shapes. All of these variables alter the internal VE table of the ECU, which in the case of a used system cannot be changed. An aftermarket system can be tuned pretty easily to whatever engine you have. The only time you need an O2 sensor is during the tuning process, and then it has to be a wide band sensor which cannot be used long term in any engine.

[gonzo]

A used injection system will come with the intake manifold. Exhaust manifolds are not that critical in marine engines. The same injections system runs with a variety of manifolds. The injection and ignition are run by the same computer. Timing is controlled by a knock sensor. All this has already been developed and tested at great cost. Doing it all over again is what the expression "reinventing the wheel" accurately describes.

[Cheesy]

Originally Posted by gonzo

A used injection system will come with the intake manifold. Exhaust manifolds are not that critical in marine engines. The same injections system runs with a variety of manifolds. The injection and ignition are run by the same computer. Timing is controlled by a knock sensor. All this has already been developed and tested at great cost. Doing it all over again is what the expression "reinventing the wheel" accurately describes.

Well from the start, while the exhaust manifold may not be critical it will alter the engines volumetric efficiency, the ECU calculates the required fuel based on the MAP sensor, the engine speed and the volumetric efficiency. The additional signals such as air temp, engine temp and TPS alter the amount of fuel that is originally calculated. Now different engines may well have the same injection systems and ECUs but the ECUs will have different VE tables in them, making them not interchangeable. The timing is controlled in a similar manner to the fuel, there will be a table of sorts that the timing is interpolated from based on speed and load, the knock sensor is signal is just a modification to the calculated timing and realistically if there is decent fuel and it programed properly the timing should not be pulled at all, the engine should not knock.

[whitepointer23]

Originally Posted by zerogara

Based on the powerband available whatever the use the load has to match the output. Why would you have more gas flow if the engine can't breathe more air? The only difference is that you can run a higher state of tune as you have ample cooling, but that is compression and different cams.

Anyway, the guy was talking about late model V8s, I thought someone mentioned OHC engines, now he is asking about a 79. The blocks may have been the same for many years but the heads are different so you still may need some adopting to do.

Are 351 Clevelands still around in Aus.? I hear they made them till much later than in the US.

there are plenty of clevelands still around, they stopped production in 1984 with the last ones coming out in the xe falcon. my engines are windsor motors. what about the holley marine tbi kit, do you think they are any good.

[zerogara]

An XE Falcon hey?

[whitepointer23]

mad maxs holden van, that is not a falcon.

[whitepointer23]

hi everyone, i have decided to go diesel, started a new thread, toyota 2h

[351EFI]

I realize that this is an old thread, and the original poster has changed his interest, but I believe the original question was to the effect that "is there an after market conversion for an automotive EFI set up to marine?"

If you do a search, the name Holley comes up, perhaps one or two lesser known sources, but I think the most important thing for anyone to do when considering a marine EFI conversion is to ask yourself "what have I got and what do I hope to accomplish by changing it?"

There is no doubt that a properly set up and tuned EFI system is superior to conventional carb and mechanical distributor in every way. Mercruiser, Volvo Penta and some other engine marineizing companies offer EFI controlled engines. This is turn key stuff. All the engineering and tuning has been done, all you have to do is put fuel in it and go. These are normally very reliable systems. The downside is when something does break you are at the mercy of the supplier because a lot of the components and even troubleshooting equipment are proprietary.

The only other option is programmable EFI. This involves a lot of time and effort, and not a small amount of money. Bolting the hardware on is the easy stuff, it's the tuning that really separates the men from the boys, so to speak, and tuning is everything.

There is very little serious interest in EFI marine conversions, and there is a lot of misinformation on the subject on the forums, probably due to the limited amount of people with practical experience with it. It can be done, safely and successfully, but it's no small commitment. Whether it's worth it to you or not depends on what you've got, what you want to accomplish, and the amount of time, effort and money you are prepared to spend to accomplish it