fuel injection time
 

I now have 3 guys ready to switch over to fuel injection from carbs. I have been on line to holley and elerbrock talking to them about there systems. One has a kit to have throttle body and one has multi port with a new intake. My guestions are has anyone try to do this? Is it worth the switch? Two of them are charter guys and need the better fuel economy. Any info would really be great. thanks again dan

I believe,None of those sysems have any knock protection. I would rather have carbs with proper instrumation than have efi with no knock detection because if any piece in the system goes bad you have a trashed motor.One fuel injector bites the dust, time for a rebuild. If one map sensor bits the dust, time for a rebuild. Just to many pieces to an efi system not to have knock protection.
Allen

I don't think there would really be much of a fuel economy increase over a properly tuned carb, how many gph would you have to save to offset the cost of switching over?

I believe in fuel injection BUT for the 2500-4000 per motor you will spend I doubt you will ever recover a savings. You can bolt fuel injection on just about anything, I am putting a hybrid /home brewed efi on a 1974 Pontiac 455, I used a Edelbrock intake and rails, high impedance injectors and a ram jet 502 /zz502 efi harness and Mefi-4 controller. You can buy the controller and harness fairly cheap from GM but I still have close to 2500$ in the efi stuff alone, Smitty

Holley's HP system is excellent. I've done a half dozen of them this year with zero complaints. They have knock protection and anything else you can think of. There are a lot of reasons to convert to EFI but like Smitty said, for that application the fuel savings alone won't cover the cost. There are other good systems out there but the Holley ecm is waterproof, vibration, and shock proof like the MEFI.

How about driveability ??? Can't touch fuel injection in that area. My motors idle the same, whether 65 or 95 outside. Just tap the key and go...

unless you have some sort of magic carb, the only knock protection you have with one is the sound the pistons make when they hit the hatch cover...

you don't go to efi for economy altho that will be a meaningful and significant benefit. you go to efi for the advantage of having exactly and precisely the correct fuel curve for every single condition... so no fuel in the oil, no rich/lean anywhere at any revs. no carb made on this planet can do that. the motor lasts much longer , makes better power and has a much wider usable power band. assuming it is executed properly at installation and calibration, then there is no downside to it what so ever and the upsides are very significant.

Thanks for the help and support guys. The charter guys are the ones hurting on fuel economy. The one guy owns 2 - 30 ft sportcrafts one inj one not. On lake erie from vermilon river to the border and back the carb boat uses almost 20 gals more in a 36 miles round trip. Both are well maintained and both run side by side. In his case saving about a 125.00 a trip it might pay for itself quickly. thanks again dan

If at all make sure you go port injection.

You may want to look into using a GM speed density system.
Fairly cheap and parts are readily available.
You'll get closed loop fuel control and knock retard.

I've switched my Donzi over to this and it is nice.

Jeff

Not, true, the Holley system can do it. The sensor does not come with the kit.

I have been using the Holley MPI system for about 7 years. It starts better, quicker, faster and better fuel economy. If you make changes to the engine you get out the laptop and retune. No need to change jets or carbs. Be sure you get the wideband O2 option, much better than narrowband. I use the DUI distritutor with electronic control. The timing, fuel maps, startup, accelaration, ect... are all adjustable. No soot on the transom and no exhaust fumes from the exhaust when you start it up. They are expensive, I have about 4k in mine with wideband, upgraded 42lb injectors and AN hoses and fittings. I have seen the kits in CP performance, Eddie Young also deals in Holley, I am sure he could help you out.

Efi
 

I just switched to EFI from carb. No more pumming the throttle to start these. Just turn the key and let the computer take over. I am making 685HP and 720LBS of TQ with my 604CI EFI set up. I also have one extra computer in you need one.
Ken

Is there a big difference between the throttle body or multi port? The one is a small block chevy and 2 are bbc. I have seen a big price difference for sure.

Fuel economy is achieved with timing curve and fuel curve, EFI systems will set them correctly if a Wide band o2 sensor is used same is true for a carb if you know how to tune them according to what the o2 is telling you , but an ignition system that will simulate vacuum advance with the use of a map sensor is needed for best economy. The carb has to have adjustable air bleeds and power valve restrictor channels among other things. The idle circuits are always to rich and the high speed bleeds to lean causing an impossible tuning solution with the main jet. This is why most boat run fine at wide open throttle and suck every where else yes efis also, I've seen plenty of 1075s huffing black smoke at idle and pipes black as the ace of spades and owners wonder why the oil smells like gasoline and so on. So if Holley's efi system uses the same calibration as their carbs plan on putting the tech line on your speed dial. I'd save your guys some money and just get a portable wideband o2 unit so you know what the engines really want to run correctly. If you choose to go efi get a sophisticated system that does everything for you. big$$$

Funny my Blowen 600 with carbs do the same thing? :) :)

It is possible to get a bit more torque from Port injection due to injector timing. It is more expensive though.

Jeff

My Innovation Marine 500EFI uses the Holley system(with MEFI) and I get far better gas mileage at cruise than my friend's with carbed 330hp 454s.

I've seen good and bad from both....lots of factory EFI boats soot the transom up bad..run weird at certain RPMs, some work great no issues...but have had carb boats run great thru out and do well on fuel...so ???? getting it dialed in is the key...now just figure out which is easier..

You might look at the Fast, EZ tune and XFI 2.0 with self tune. http://www.fuelairspark.com/

Has anyone tried Projection system? I like what I read about it, but have not found anyone that has any real world experience. There is a Projection 3 plus in the works with built in knock/spark control. Very interesting.