Reply to "Stroker Motor Questions by Dave F #5972"

> We did not have to modify the engine management system at all.

That combo is still within the limitations of the basic EEC tables.

> The engine management system employs adaptive software, which gives it the
> capability to create new curves (tables) in response to changes you make to
> the motor.

but there are finite limits. We ran outside what the Mustang Cobra EEC-IV
could compensate for early on and run a piggyback controller that gets tuned
on the dyno and with a wide-band. Also, don't make the mistake that just
because something starts and runs smoothly that the air-fuel or spark tables
are anywhere near optimal. I tuned a Cobra over the weekend with my wide
band O2. It ran great on the street and ran an 11.88 second 1/4 mile but was
dangerously lean everywhere in the RPM range. He's been running it that way
for a long while so I hope he hasn't hurt the pistons but only time will tell.
I got him in the right ballpark and we'll head back to the dyno for final WOT
tuning.

> As I have a stock 351-CJ (I think!) a junk yard EFI system is an attractive
> idea. I ran my Sunbeam on a $10 junk yard electronic ignition system for
> years. It could be a cheap way for me to better fuel economony without
> sacrificing any bhp (I'm happy with the 308bhp I have).

If you keep the CJ cam, you should be within the limitation of the tables.
You might be pushing the limitations of the 19 lb/hr injectors though you
can always try them and see. With the mass-air EEC's, installing larger
injectors often means either re-calibrating the mass air sensor or
tweaking the conversion in the tables. Most upgrade to a larger throttle
body and mass air unit that is matched to the injectors they choose to run.
There are specific EEC-IV's calibrated for 24 lb/hr injectors (the Mustang
Cobra processor) but most are 19 lbs/hr. The standard 5.0L HO SEFI Mustang
was 225 HP and all the components are sized for that. Larger throttle bodies,
EGR spacers, mass air meters, intake manifolds, injectors, fuel pumps are
the norm when you up the power. It's all available but the cost can add up.
The intake manifolding won't work on your 351C. You can modify a carb intake
or try to adapt the 5.0L stuff using adapter plates or mill and drill a
351W lower.

> Does the EEC-IV system control the sparks too or just the fuel?

It controls the spark too. You set base timing with the distributor but
lock out the advance. The spark tables can only be change with an aftermarket
tuning device.

> Unfortunately Mustangs of any type are pretty rare in the breakers yards in
> the UK (I'll check out ebay).

Be aware that very similar looking systems were used on a variety of Ford
5.0L engines. Some were SEFI, others were not. A friend attempted to
swap in an Explorer 5.0L in for his truck 5.0L only to find the truck had
bank fire and a different firing order. Also, some were speed density and
others were MAF.

Dan Jones