[Jeff Higgins]

I looked at the Mod S grind for my cams, and decided they simply do not have enough lift for a warmed over 3.0 liter, and way too much duration for the rpm range in which I wanted it to make power.

The Mod S runs .470"/.440" lift on intake/exhaust, and 266/249 degrees duration @ .040" lift. This profile is meant for a smaller, higher reving motor, and works quite well in one. It also requires (according to John Dougherty) racing valve springs with higher seat pressure than stock. Once you go with the heavier springs, you must also go with stronger aftermarket rocker arms. The stock ones are meant to break in any valve/piston contact, saving the rest of the works from greater damage. They will also break if rev'ed into the mid 7,000's with a high lift cam.

After speaking with John Dougherty, we settled on what he calls his "GT2-102" grind for my motor. Specs are .485"/.470" lift, and 254/238 degrees duration @ .040" lift. One of the key aspects of this cam's design is its gentle ramp angles, which accelerate the valves more slowly than the Mod S and similar cams. So, even though it has more lift than the Mod S, the valves actually open and close slower (they spend less time all the way open), allowing stock springs to control them just fine. The ability to run a stock valvetrain (other than the cams) was important to me.

These cams make peak power at 6,000 rpm and peak torque at 5,000. Mod S cams will make peak torque and horsepower much higher; peak hp will probably come at whatever you decide will be redline. In other words, hp will climb as long as rpm's climb, well above where it sounds like you would like to rev it. It will feel slightly peaky, and give up a lot of mid range punch - I disagree with your builder on that point. Yes, the Mod S will give more mid-range than a stock 3.0, but there is so much more to be had...

My horsepower numbers are nothing to write home about - somewhere between 245-250 at the crank. It's the torque that makes this motor, peaking at 230-235 foot pounds, and laying down over 200 foot pounds from just 3,000 to over 6,000 rpm. No Mod S cam will do that; no way, no how. The 3.0's I've seen chronicled here with Mod S, normal S, 964, 20/21, GE or DC 40's or 60's, etc., are lucky to make 210 foot pounds peak.

I started out with the later SC heads as well. I had the intakes opened to 38mm, or 1mm smaller than the early large port heads. That's pretty close to what you came up with John's formula. This port size does seem to work to help make some monster torque numbers, as long as intake velocities are kept high enough through the mid range. I don't think the Mod S will do that.

I typically shift somewhere between 6,500-7,000 rpm. That shift point is not determined by where the power is, but rather by where the next braking zone is. With ARP rod bolts, and the lower end carefully balanced by Monty at Redmond European, I'm sure it is mechanically safe to go several hundred rpm higher than that. There is simply no reason to, though, with peak power at 6,000 and such a flat torque curve. Shifting at 6,500-7,000 neatly splits its peak power in each gear; in other words, that's just about as much above peak power rpm-wise as it drops below, rpm-wise, when I shift. And if I find myself in the "wrong" gear, it can certainly grunt its way out of a corner from quite low in the rev range. I think that would be an advantage in autocross - it certainly is on the street, and on the track.

Anyway, those are my thoughts. Call John Dougherty, or email him, and talk cams. He was a huge help to me, taking the time to understand what I wanted, and finally making an outstanding recommendation. He even custom ground these for me (I'm not sure, they may even have been the first set), and since then, at least two other Pelicans have built or are building 3.0's with these cams. I love 'em - they give this motor its personality, one with a surprising amount of punch.