Quote:
Originally Posted by twobjshelbys
The cam document says it was used in a 1985+ Mercury 302. It lists a part number of 449571 but that doesn't look like a Ford part number.
First, you've got to remember that the Accel DFI controller is a complete controller. All firing timing and fuel firing PWM are in tables. I had to do two things. They were done by a tuner that had received Accel training.
1. Tweeks to the basic configuration to account for the unique characteristics of the 8-stack throttle bodies (note 1).
2. Properly creating an altitude compensation table.
Note 1: The position of the injector with relation to the butterfly valve in the trumpet creates some unique air flow issues. At lower throttle positions the air flow at the time of the injection fire gives adequate flow and turbulence to properly mix the fuel. This is about 0 (idle) to about 60* attack. As the throttle opens and the blade becomes more vertical the air simply flows straight down the neck. The effect is that there isn't enough air flow against the side of the trumpets to deflect and cause the fuel to mix. The result is that the fuel is show almost directly through and doesn't have a good air mix. So, counterintuitive as it is, as you get from that threshold to WOT you actually need to cut the fuel back otherwise it runs rich and will backfire.
I got to know much more about DFI and the dynamics of the 8-stack than I wanted to 
This is a copy of the cam spec sent to me by Roush
Attachment 28495 |
That cam is a hydraulic roller from Crane.
Interesting to note their quote of RPM, not minimum and maximum, but best operating range. Note that it will valve float at only another 200 rpm.
I would have thought it would float a little higher than that.
A good camshaft though.