rvander68

Now time to get all the ancillary items in that are required for fuel injection.....fuel filters (pre and post), fuel pump, fuel lines, pressure regulator. This required design and fabrication of some mounting brackets. Luckily, the oil cooler was mounted on the bulkhead and the shelf that holds it made for a great mounting location for the fuel pump and post filter. The pre-filter stayed in the same location as the fuel/water separator when I was running the carb, except I upgraded to a 1/2 NPT head so I could run -8 supply lines to the pump and -6 from the pump to the rails and return line. Also needed to make a bracket to mount the MAP sensor, IAC motor, and MAT sensor. A convenient location was at the back of the motor. Here you see how the MAP and IAC are connected to the bulkhead connections running to the vacuum log.

rvander68

I went with the Holley HP EFI computer system (thanks Alex!!). This was ordered with the universal wiring harness. After deciding to mount the ECU on the bulkhead under the rear bench I ran the harness back to the motor. Since I didn't want a mess of wires I ended up redoing most of the harness to get the connectors to come out in the right location to keep every thing as clean and as neat as possible. This took the better part of a day to redo; any splices I used heat shrink marine grade connections. Also, you can see in the last picture I opted to go with a MSD small cap HEI distributor so I could control the timing with the ECU (really slick). In the first picture you can see I was lucky in that my tank had two fittings (one was just plugged when the carb was used so I just opened it up and used it for my return line). A nice thing about the Holley is that the ECU is fully potted and USCG approved.

rvander68

Here you can see I routed the fuel lines (I used the USCG approved low permeation fuel lines) and also installed the thermostat housing that I ground the casting numbers off of and painted cast aluminum so it looked nice sitting on the intake. Also mounted all the water hoses and dressed up the ends a bit with chrome. In the last two pictures you can see the fuel pressure regulator mounted with the fuel pressure sensor mounted to it. Getting close to starting it! One last thing was to make the flame arrestors for the stacks. I modeled these after a standard carb flame arrestor using the same screen schedule (multiple layers of various size mesh). I designed the shape to ensure no loss of air flow since the various screens do cut down on the area quite a bit. The last pictures you can see one in progress (my Dad came up with a clever way to form and make these). Screen cuts really well with industrial scissors. Finally the motor was complete.....but will it run? Stay tuned - I'll post the rest when I get more time.

seafordguy

Wow - very cool...........

trannyjoe

looks rear good ....still working on my project I feel your pain

kvogt

very cool

yschmidt

WOW!
You and that Haxby guy did a great job. I am excited to see how it runs.

rvander68

Thanks guys. Alex has been a tremendous help! He answered my rookie EFI questions, walked me through setting up the base map, and helped me troubleshoot some things when I started it for the first time (probably the second time, maybe even the third time, an even when I had it on the prop dyno! Yes - I had a number of questions!). Most of the issues I had were between the seat and the keyboard so to speak since this was the first time I ever set one of these up. I must say now that I am a little more familiar with it, the Holley software is really good. Now if I can figure out how to insert a video link I'll let you hear it run on the hose and then with me in the back seat on the laptop while my Dad is driving....

rvander68

Here it is on the hose after learning in just in the idle area of the fuel map (set the AFR, O2 sensor is providing feedback and the computer is automatically making pulse width corrections to maintain the target AFR). I was trying to dial-in the idle before launching it for the first time. What I learned with the 8 stack is that they flow like crazy and the smallest of butterfly opening (thousands of an inch) will feed air and it will idle high (this is where I wish I had spent a little more time on the bench adjusting the butterflies and linkage). I had it set fairly good here with it idling around 850-900. I did buy a synchometer to check the airflow for each cylinder and I had two that were flowing just a tad more than the rest. When this occurs, you get a lean idle pop in those cylinders from time-to-time. I was able to add a touch more fuel to bring that down here, but ultimately I adjusted those butterflies to so they are flowing the same as the rest and it goes away. Unfortunately right after this video was taken I burned up the O2 sensor. The first picture shows where NOT to locate an O2 in the tailpipe. When I had the tail pipes made last year I had them put in an O2 sensor not knowing how important the location was. Dumb! Anyway, I learned it should be mounted between 10 and 2 to prevent condensation from collecting on the sensor and shorting it out. BTW - this causes the O2 sensor to report a full lean condition and the computer compensates by trying to richen the motor, black smoke then starts to come out the exhaust, and then the engine dies. The second photo shows a brand new O2 in a better location (at least it hasn't shorted since).

Some observations:
1. The 8 stack really smoothed out the idle - it's not as lumpy as it was with the carb. I don't know if that is a result of the EFI or as I'm told because there is not a large common plenum the cylinders aren't cross-referencing each other. Regardless, it is different.
2. Throttle response is insane!


http://www.youtube.com/watch?v=aLItJChhvlA

rvander68

After getting it running again with a new O2, I decided before dropping it in the water it would be better to build out the MAP (learn) on a prop dyno and make sure I don't burn up another sensor. The dyno session went real well with me making several pulls under various loads and rpms to facilitate the computer learning. This culminated in a few WOT pulls and needless to say I was quite surprised by the power this thing made (keep in mind this is just a 468 that started life as a Merc 420 - nothing crazy). After the dyno my son and I pulled it a couple of hours and dropped it in the lake. Here I'm in the back seat on the laptop monitoring the motor and watching it continue the learn process while my Dad is driving. We have not held it WOT much at all yet but I can say it is wickedly responsive through the mid-range. To say I am happy so far with how it turned out is an understatement.

http://www.youtube.com/watch?v=wwoobucp6PQ