Which EFI system would work best/be the most simple
 

Looking for a relatively simple EFI swap (if possible) on my set-up.

My #1 question to figure out however if if my camshaft is mechanical and will work with EFI anyway. It is a Crane #268761.
The engine is 505ci with eagle rotating assembly, Merlin Intake, Camshaft noted above, Dart Pro 1 heads, Quick Fuel Carb, Lightning Headers. Makes 610hp/613tq.

Not doing this for a power increase really, just to get rid of the carb and go to EFI for simplicity, turn key and go, etc plus I am not very familiar with carburetor set-ups so when it comes to tweaking them I am just not familiar.

I have seen the FAST EZ EFI, I also see FAST offers a Marine EFI. I know Holley offers the HP system, etc.

With this, if my cam is compatible, my other question would be what to do for the O2 sensors with the lightning header exhaust, surely we can't get the sensors wet.

Thanks for the help as well as recommendations, will be my Winter project!

I have 2 Cutler MPI systems that came off older 502's. One system is 100% operational. The other has a bad ECM. !00% complete, including fuel pumps. Make offer.

Cant go wrong with Holley HP EFI. You will need 02 sensor in each manifold/header but other then that its "self tuning" for the most part.

I am running the Holley Hp system.

I have run O2 sensors in my Lightning Headers all summer with no problems

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Cam specs: duration @ .050 235 243
lobe lift .3590 .3690
lobe seperation 114.0

I purchased the Holley Hp through Alex Haxby. Alex has been a great help with setting me up with a base tune and helping me with tuning along the way.

You really are not going to get much "simpler" than a carburetor. Fuel injection is a tad pricey and has more things that can break (ie: sensors). It will be turn-key and go, after someone tunes it. Aftermarket exhaust manufacturers can modify their risers to allow an O2 sensor if you really have your heart set on this. And there are adaptor plates that go between stock manifolds and risers as well.

Enjoy.

1st EFI and simplicity should be in same sentence, my .02...ran both..Haxby marine on here will be the best to set you up..but if you are not up to some laptop tuning to get dialed in stay with your carb. Also going to need to add a wideband 02 to get EFI to work, and not a bad idea to use one to fine tune your carb...after do so might find your carb setup pretty simple afterall !!

I did not look up your cam, you can do that, but a mechanical cam is fine with EFI's if they don't have a knock sensor. If they have knock sensors, than you would have more homework to do.

I'm a huge fan of EFI, but I'm glad that I went with a carb on my boat. Today's carbs are light years ahead of the old quadrajets that I had to deal with as a kid, and the corrosion issues on a boat make me keep it as simple as possible.

Marine efi is either very basic or very expensive. The underlying speed bump is a wet exhaust system OS sensors don't play well so your left with speed density..... Which means a carb jetted properly is going to do just as well at about 1/5 the cost......well pretty close to that.

I have done several of the Holley HP systems..... Haxby, was the most influential role in guiding me through the first, tune... Mostly the navigation of the software, if you know how to tune a carburetor and map out timing curves, you'll find a EFI the most tunable.. Some things are just not possible with a carburetor and a basic timing curve, your only other option on timing is use the Daytona CD-1 Marine, you can Map it as a EFI, the software is just a little primitive in comparison to any EFI.
Let Me be perfectly clear; just installing the EFI and running it in closed loop, isn't tuning for power... You need to do it on a dyno and have your base MAP, that way you can adjust fuel and timing for performance, then you can move that into the boat adjust from there, this will be done in closed-loop-learn..
You may have to adjust low speeds and idle, shifting into gear from your laptop into those cells which need adjusted. That isn't always determined by A/F numbers, it's by experience and what the engine wants or doesn't want.

I'm currently, building 2 525 EFIs different cams, modified TB and upper intake plenums, these are also being converted over to the Holley HP...Different heads, would have been great, but not in budget, so let's see what the stock 525s will do with port matching and a bowl blend, with a better valve job... Marine Kinetics, my dear friend Bob, put together the valve train for me as usual, expecting good results from the cam profiles. These packages are 6000 rpm, will see if there's anything left in the heads with those 3/8 valve stems......LoL

I hope; I helped with your question..... didn't mean to :hijack::hijack::hijack: just wanted to share