Here's what I'm thinking of doing to my '84 Mustang 302 HO for my 1951 Mercury truck: I'm looking for a great torque and good horsepower with mainly stock components for a daily driver

1984 302 block
D94E cylinder heads fitted with GT-40 valves (1.84 Intake and 1.54 Exhaust)
Flat top pistons to bump up the compression to 9.0:1
1988 Mustang HO EFI intake with 19lb injectors (Already have)
1986 Mustang VR1 5spd Speed Density Computer (Already Have)
1990 AOD (Already have)
Sanderson shorty headers with 2.25" dual exhaust

I'm disappointed with the cam choices for the speed density engines so I came up with a grind on Desktop Dyno 2000: (all specs are in seat to seat)

Lobe Separation: 118'
Intake Duration: 260'
Exhaust Duration: 285'
Intake Lift @ Valve: .450 (1.6 rocker ratio)
Exhaust Lift @ Valve: .450
Valve Overlap: 36.5'
IVO: 14'
IVC: 66'
EVO: 82.5'
EVC: 22.5'
ICA: 116'
ECA: 120'

The Speed Density computer should have no problem running this cam since the lobe separation is above 114', right? I know just getting GT-40 heads would be easier but are rare in Saskatchewan. I will be grinding the thermactor bumps in exhaust ports. I've included the Desktop Dyno graph and chart. I'm happy with the torque curve and if you look at the volumetric efficiency, you can see at 4500 rpm I have 95% efficiency. I know a 351w is better for torque but I already have a good 302 and I like the Mustang EFI better than the F-series EFI. What do you guys think?

 

Interesting. Why not E7 heads with the GT40 valves? Those '79 heads are rated to have 69cc combustion chambers, so I seriously doubt you'll get 9:1 compression. I have cc'd the chambers on my heads to 65cc, and that gives me about 9:1 runing flat tops with eyebrows.

 

Well to find some decent E7 heads would cost me about $200-300 cdn. 90% of these engines also have over 200 000 kms on them. The E7 might make 5-10 more horsepower than the heads I have now.

Did some calculations and I would require domed pistons. I can get some Keith Black pistons with a -2.60cc from Summit that will put my compression at 9.2:1.

I'm mostly wanting to know if my cam specs will work with the factory Speed Density computer?

 

lob seperation is key with SDensity but i am unsure if any of those other specs would throw things off. Have you called compcams or Crane to see what they may have. you could also call cammotion for custom grinds they have done in the past.

 

Will a SD computer and 19 lb injectors even support a 300 hp motor? Are you using the stock flow data for the heads?
I doubt it will do over 270 HP at the flywheel with those heads even if they are ported.
I'd think you would get more bang for the buck going to mass air and cheaper cam instead of spending the $ for a custom grind.
Just a thought.

 

All that's needed to take 19lb injectors to 300hp is an adjustable FPR. A close friend of mine got about 275hp out of his 5.0HO naturally aspirated, the heads were untouched.

 

It would cost more to convert to mass air than to get a custom cam grind.
$150-200 CDN for the computer and $150-200 for the mass air flow meter compared to $300 CDN for a cam which I like better than what Comp or Crane offers. I would also have to rewire my harness.

I know I probably won't hit 300 hp (probably only make 95% of what Desktop Dyno says) but I'm after torque since I'm building a truck not a show car. I've tested the E7 and GT-40 heads, I lose some HP but gain more torque which is fine by me. I currently have it set with the wedge/stock ports and valves.

I've revised my cam specs a little to increase the dynamic compression ratio and managed to pick up some more HP and TQ.
(All specs are in seat to seat)

Lobe Separation: 115'
Intake Duration: 255'
Exhaust Duration: 285'
Intake Lift @ Valve: .450 (1.6 rocker ratio)
Exhaust Lift @ Valve: .450
Valve Overlap: 40'
IVO: 12.5'
IVC: 62.5'
EVO: 77.5'
EVC: 27.5'
ICA: 115'
ECA: 115'

I would have about a 7.4:1 dynamic compression instead of 7.25:1. This cam profile should work good with the stock speed density and still get 93% Vol. Efficiency.

 

I'll pm you a link to flow data for Ford heads. You can plug it into Desktop dyno and get a better result for your motor.

 

Thanks!