Street Demon vs AVS2

I don't like wide LSA cams. But if you have too much compression, sometimes they are the lessor of two evils

I'll show you what I mean.
First; lets pretend that 213/220/114 Voodoo is 252/260/114 advertised, and lets pretend your Scr comes in at 9.6. And that you are at 200 ft above sealevel.
Sooooo,
Static compression ratio of 9.6:1.
Ica of 56* (114LSA installed 4* advanced)
Effective stroke is 2.79 inches.
Your dynamic compression ratio is 8.11:1 .
Your dynamic cranking pressure is 165.42 PSI................ 165
V/P (Volume to Pressure Index) is 162........................... 162
Notice your cylinder pressure here is 165psi, for your application, this is too much pressure, for pumpgas. You will have to reduce the pressure or open the intake a lil later.

Ok so, since the VP is up to a crazy 162,lets just retard the cam-timing to straight up, and I get
Static compression ratio of 9.6:1.
Ica of 60*
Effective stroke is 2.70 inches.
Your dynamic compression ratio is 7.88:1 .
Your dynamic cranking pressure is 159.28 PSI.............. 159
V/P (Volume to Pressure Index) is 151 ........................ 151
So there you go, pressure is down, probably in 89 gas territory, and the VP is still a generous 151.. I made it work.

But with less compression, say 9.0
Static compression ratio of 9.0:1.
Ica still 60*
Effective stroke is 2.70 inches.
Your dynamic compression ratio is 7.40:1 .
Your dynamic cranking pressure is 146.58 PSI. ................... 147
V/P (Volume to Pressure Index) is 139 ................................ 139
Look what happened to the pressure!, and the reduced VP. This ain't gonna work.... Well it will; 139 is the beginning of fun at low rpm, and the 147psi will run on any old gas. But it sure ain't optimum, and won't make the power you were expecting.

so lets put the cam back in at 4* advanced
Static compression ratio of 9:1.
Ica of 56* (114LSA@ 4* advanced)
Effective stroke is 2.79 inches.
Your dynamic compression ratio is 7.61:1 .
Your dynamic cranking pressure is 152.11 PSI. ............... 152
V/P (Volume to Pressure Index) is 147 ............................ 147
Ok so, now we have a tire fryer with the 147VP, but the pressure is down at 152, and yur not gonna get the best mpgs at that pressure.But it will still run on crap-gas.
Remember, this is all the same cam, just messing with the compression ratios and the install.
So by now you should be able to predict what will happen at 10/1 Scr. The pressure is gonna skyrocket and the VP as well, but the pressure even with a retarded cam may be too much.

Lets run it and see
Static compression ratio of 10.0:1.
Ica of 60*,(4* retarded)
Effective stroke is 2.70 inches.
Your dynamic compression ratio is 8.20:1 .
Your dynamic cranking pressure is 167.83 PSI. .................... 168
V/P (Volume to Pressure Index) is 159 ................................ 159
So there you can see the pressure is outta sight! and the VP is ridiculously high.And the cam is already retarded. I can't see this working for you with iron heads
Now, I set this up for the final work-ups.
As you can see, with 168psi, the above combo is ready to self-destruct on pump-gas; but lets change the LSA on that same cam from 114 to 108, and reduce the compression ratio, and see what happens

Static compression ratio of 9:1.
Ica of 54*( straight up)
Effective stroke is 2.83 inches.
Your dynamic compression ratio is 7.71:1 .
Your dynamic cranking pressure is 154.76 PSI..................... 155
V/P (Volume to Pressure Index) is 153 ............................... 153
There you have it; 155psi will cruise on 87E10/15, and the 153Vp is crazy strong bottom end; you can run any rear end you want to; altho you may need 89 or more gas to stay out of detonation, under heavy acceleration.

Lets advance the cam just 2*
Static compression ratio of 9:1.
Ica of 52*, (108* LSA/ 2* advanced)
Effective stroke is 2.87 inches.
Your dynamic compression ratio is 7.80:1 .
Your dynamic cranking pressure is 157.15 PSI. ............... 157
V/P (Volume to Pressure Index) is 158 ........................... 158
Heck yah! Compare the above, to the below; both at 9.0 Scr

Static compression ratio of 9:1.
Ica of 56* (114LSA@ 4* advanced)
Effective stroke is 2.79 inches.
Your dynamic compression ratio is 7.61:1 .
Your dynamic cranking pressure is 152.11 PSI. ............... 152
V/P (Volume to Pressure Index) is 147 ............................ 147
The only difference in these two is the LSA, and the 4* advance
Check out the HUGE VP increase from 147 to 158, this is soooo big, that you could actually run the next bigger cam,
Lets try a 260/268/110
Static compression ratio of 9.0:1.
Ica of 56* (110LSA cam at 4* advanced)
Effective stroke is 2.79 inches.
Your dynamic compression ratio is 7.61:1 .
Your dynamic cranking pressure is 152.11 PSI. ................... 152
V/P (Volume to Pressure Index) is 147................................ 147
Look familiar? It is the same 56* Ica, so the numbers come out the same.... but the power is gonna be up maybe 15 hp..... with no loss of performance below 3000 compared to the 252/260/114cam. And now you know why I don't like wide LSA cams. When properly compared, they will cost you power every time. But worse is that they will also cost you hiway-mpgs every time

So why do people run wide LSA cams?
Because they reduce overlap and make the engine run smoother at low rpm, and if an engine is to run for many miles at very low rpm, like a city car would, then this has the bonus effect of increasing city-mpgs by virtue of mixture control. This is why your old LA318 had like 16* of overlap and 2.76 gears.... and idled around town at 35mph=1250rpm in Drive.
But the 340 had 44* overlap and ran 3.23s with a loose TC and 35mph was maybe 1500 in drive, but most guys were in second, cuz, you know, it's a 340, and we got a point to prove; so in second the Rs were around 2200.
At 2200 the overlap was NO LONGER AN ISSUE.

So knowing that now, lets look at your imaginary 252/260/114 cam, with it's 28* of overlap, and compare it to the 260/268/110 with its 44* of overlap.
As you can see the small cam will idle pretty much like a stock 360, cuz that's about what they had (maybe 24* I forget), and the bigger cam will idle like a 340, cuz it has the same 44*. And like the 340, on the hiway, it will like to be up around 2000/2200 for best mpgs. which is why I picked 2100 for you.
Yes there really is a method to my madness, lol.

OK just one more FYI

here we have the next bigger cam again, a 268/276/108customLSA cam
Static compression ratio of 9.6:1.
Ica of 56*(108LSA at straight up)
Effective stroke is 2.70 inches.
Your dynamic compression ratio is 7.88:1 .
Your dynamic cranking pressure is 159.28 PSI. .................. 159
V/P (Volume to Pressure Index) is 148 .............................. 148
Notice I jumped the compression back up to 9.6
Notice the gas requirement at WOT is back up to probably 91
But notice the VP is up to about the same as the best of the other combos. So this combo will have another 15 or so hp , so now we are up at least 30hp over the 213* cam, but without any loss of low-rpm power. The penalty for this is that overlap is now 56*, and your hiway rpm or speed, may have to be increased to above 2100 to clean up the intake; say 2300, and so at 65mph (still with 28s) you will need a minimum 2.94s. This is the minimum; bigger is Ok. With 2.94s 75mph would be 2650 at zero-slip, which is 350 over 2300 so just a lil buzzy is all........ but a lot easier to engineer the ignition timing curve.

The whole point is this;
the cam and the pressure are like an old married couple, they hold hands in public, but sleep apart because they can't stand each others farts.
You'll get the best results when they are holding hands. If you just slam them together, chances are very good that the result will stink.