Merc OPEN CLASS fuel injection
 

I always loved the old Merc 900 Open Class engines with stack fuel injection (Crower?). Does anyone know if that was EFI or mechanical? I would love to adapt a set on my engines. It is mostly an asthetic thing for me but it would also idle much better than my twin dominators (if they were EFI).

Pics would be great also if anyone has them.

Jody,

the IR stack injection on the Open Class Merc's was EFI. The quality of the idle depends on the electronics you use, and of course the cam. If my memory serves me well, the manifold was made by Kinsler.

What kind of heads do you run?

Andreas

Andreas,

I have Dart Big M heads on Donovan aluminum blocks, 705ci. I currently run a Dart tunnel ram with large spacers between heads and block. Pair of 1050 dominators. Idles OK but wish it was better. Cam is conservative for this size engine.

Would love to get a couple sets of that stacked Merc EFI and reprogram for my application. Think that would work well or is this application out side the capabilities of the Merc EFI?

Thx,
Jody

Jody I sent you a couple pics. Systems were EFI. Kinsler supplied the intake manifold. Merc supplied the remaining parts and electronics. A few of the parts are NA. TPS switch for one as I recall. They did start nicely though! I ran the FAST CPU's which is programable and uses 02 sensors in exhaust. Great system. Should probably set it up initially on dyno. Bob

Bob,

Thanks for the info and the pics. Those are beautiful engines. Just what I wanted to put together. Very dissapointed to hear that these EFI systems do not work well in a non-racing environment (partial throttle applications). That kinda kills my aspirations. Thanks for saving me the headaches.

Here a pic of my engines with tunnel rams. Looks they they'll stay this way.

Jody

Jody165, definetly some nice motors! The setup I had did not work the best. There are newer setups out there that are probably better than th 1994 equip I had. Perhaps a smaller flowing setup would be more user friendly at lower rpms. When you get 8- 2.100" throttle plates working together it doesn't take much to effect the a/f ratio. But.....it does look neat! Good luck!

Bob,

Found another pic of an aftermarket system on another boat. Looks really nice. I'll call this guy to see how well it worked.

Thanks again for the advise.

I have a pair of open class (stacks)intake manifolds in my vast supply of bbc parts I have in my garage.I'm using the EFI engine control & data system on a pair of supercharged engines that Tommy at Chief's is building for me.But if you are interested I'd part with them.

Jody,

sorry for my late reply. Don't get discouraged, and overlook the many negative comments! Most people don't have the experience, the patience or the budget to get involved with EFI. As with everything in life, if you don't do it right, you probably should not have done it in the first place...

EFI is the way to go for most applications, IMHO. It is expensive, or at least more expensive than a carburated setup, but I believe the benefits offset the costs.

The electronics are very important. The old Merc CPU could not be reprogrammed. My 588 c.i. motor is running EFI Technology electronics. Laptop programmable, instant starting, good idle, great throttle response...

I would never go back!

Andreas

I would say that majority of the marine engine builders out there have no clue about fuel injection. It is much better than carb, more expensive yes. Go with a Fast system or Motech are the top two for real high performance systems. DFI is not bad also but limited.