As a streeter, with a 367/4-speed car, I can tell you that, each of the three cams that have been in my 367, ranging from 223* to 249*@050, were perfect for at least the first summer.
That's almost a 4-size range.
My secret, is keeping the Cylinder Pressure nearly the same between each iteration, and adjusting the starter-gear to match the ever shrinking take-off torque.
Of the three;
I can tell you exactly which one I liked the least, and why. and
I can tell you exactly which one I liked the most, and why. and
I can tell you exactly what changes were needed to the rest of the combo, and why, to get the best out of them.
I have 16 years experience with that same engine, and can tell you that, it went thru 5 transmission selections and 10 different pumpkins, 3 intakes, 5 carbs, and numerous ignition changes. Then, finally, I broke down and bought/installed an overdrive, at which time, all my troubles were over.
What did I learn?
I learned, it's all about the combo; and
if you got a bad combo, yur gonna have to back up the bus and make some changes.
Or, you can pick the combo first, and
make the engine fit it, which is most often, waaaaaaaaay cheaper.
They say there is no perfect cam,
but I do not agree. The combo will pick it's own cam. The part that is not perfect is if a person wants too much from the combo, and is not willing/able to change his expectations.
In my case, right from the get-go, I needed the car to be my DD, and the first cam I picked was way off the DD-path. By the third cam, the car was no longer a DD and that first cam woulddabin perfect.
It's all about the combo.
Once the combo has pointed out the cam, optimizing the engine for the cam, is relatively straight forward.
If I learned one thing from that experience it was this;
get an overdrive before you start, so you can optimize the Second-gear hit. Until I had second gear dialed in, I was never happy with any of the iterations.
Now, afterwards, I realized that I had waaaaay more engine than I needed. It's all about the combo. If the combo wants 4.30s, you gotta get some 4.30s. If you gotta drive a lot of hiway, you gotta get an overdrive. If the combo wants a 2800 stall, you gotta get one. if it wants a 3800, well get one. If it has to run on Premium gas, well yur stuck at every filling station, emptying your wallet. Can't afford it? Then you got the wrong combo.
And so on.
Once the combo is settled, picking a cam is the easy part. The next hurdle is optimizing the engine-build for the selected cam, which is usually a one-time deal.
If you, at a later date, want a different cam, it changes everything. Well except if you have an overdrive, that is a one-time selection and she will never outwear her welcome. Same for a 2800 stall. Even if it's off a few hundred, on the street it will not be a problem, once you have an overdrive that allows crazy rear gears.
So the overdrive puts you ahead of the curve, and more or less cements the stall and rear gear, within a two or just maybe, a three cam-size window. So you aim small, using a thick headgasket running on the upper edge of the Q-window, knowing that if you upcam, you can get some pressure back with a thinner gasket, until yur Q gets to be too small.
BTW,
almost all SBM street cams are gonna run in about a four/five cam-size window of about 210 to 238 degrees @050. Honestly, IMO; beyond this window, is too hard, or too expensive, or too low-perf, or too hi-perf, to successfully install. These 5 cam sizes represent the power curve moving about 1000 rpm from say 4500 to 5500, having shift points of between say 4800 to 6000. Not many of us are gonna dare to shift regularly over 6000 on the street and you cannot usually get to 6000 in Second gear anyway, unless you risk losing your driving privileges, cuz with street gears 6000 could be over 90 mph in second gear.
And we all want more than 5000, lol. So that cam-size range pretty much covers it.
Throwing out the high and low, yur down to a range of three sizes, with an intake Ica window of say 14*, so now you are out of range for keeping in the Q window for all three cams, if wanting to do it with headgasket thicknesses. So now you are trying other things to prevent detonation. Those are the things that I learned.
All that to say;
Get the combo nailed down, then build the engine once. This is ESPECIALLY important, if you cannot afford an overdrive.
Merry Christmas
BTDT
