What cam? What heads? What manifold?

[blykins]

I think I paid $247 for my Comp hydraulic roller cam....and $300 for my Comp hydraulic roller lifters....

[Dennis Kelley]

I run the AFR 165 heads and they make excelant power on a 302. I'm at 289 rwhp and 298rwtq. The key to these heads is that they flow well at mid lift and max lift. My secondaries where not opening all the way so I feel that 300 rwhp is not out of the question with these heads. I have a stock 91 short block, crane 2030 cam, rpm air gap (knock off), Holley 650dp. Idles at 800rpm and pulls very well. If you don't plan to stroking in the future stay with the 165 head the 185 head has 2.02 and will require piston notching. If your concerned about the chamber size just mill the 58cc AFR 165 down to 56cc. I think AFR offers this service in house or call Ed Curtis the AFR Man.

later

Dennis

[Dangerous Doug]

Since my Cobra will be my first toy car in about seven years (since my Porsche...), I'm having difficultly putting the rpm into context for my driving purposes.

For example, if you're going to putz around the neighborhood and not scare anyone, I would imagine that you'd have little need for a motor rev'ing up beyond 5500 rpm, correct?

But, for road racing what type of rev's should I be looking at? I would think you'd have to rev up to ~6500 rpm, but I have no V8 context to compare to. Any of you tracking your Cobra's? What rpm's are you hitting at max?

Also, for Autocross, you need a pretty wide power band, but you also need to rev high to reduce the need to shift frequently. What rpm would be applicable here, for a SB Ford?

[blykins]

DD,

You're right in your conclusions.....With road racing, it's nice to have a higher revving engine for the straights....that way if you run out of gear, you still have some revs left to turn.

In autocrossing, you're generally only running in one gear...usually 2nd. So in that case, you need a broad torque curve to pull you out of any curve that's necessary....

You have to remember though....you're driving a 2200-2300 lb car. This isn't a Chevelle. It doesn't take much torque to get it moving.

What would I set the powerband at ? Probably 3500-6500 for a street car that will see track time. That should be low enough to putz you around town easily....and high enough to give you the extra revs on the race course. If you want a pure track car, the sky's the limit. But at that point, you're making power so high in the powerband, that you need a cam to accomodate that....which will give you poor idle quality and poor low rpm streetability.

My car will take off in 3rd gear by just letting out the clutch slowly. I have max torque at 4500 and max rpm at 5400.

Like I said, you could probably get away with about anything in these cars...they're so light.

[Dangerous Doug]

Looked at the TF Twisted Wedge flow data vs. the AFR 165, and the Twisted Wedge looks better. Intake flow drops off at 0.6" lift on the TF, but so AFR may win for a track-only car.

I'm looking forward to getting my copy of Desktop Dyno so I can play around with some different configurations.

[Dennis Kelley]

DD

Just remember that flow is not the only measure of the head. Port volicity and chamber design mean a lot. You can't beat an AFR head for value.