The 284/484/108hydro, Is IMO, not very streetable in a 318, unless you have mega compression and aluminum heads. Even at 11/1Scr/175psi, it is only making a VP of 129, just a little better than a stock 360.124,IIRC.
And the 284/114 version is yet worse, but at least you can put iron heads on it.Also at 11/1 the pressure might be 165psi, but the VP looks like 115, about what the teener makes with all stock parts;114VP,IIRC
but, with a more typical 9.8 Scr, this falls to 152psi@112VP with the 284/108 cam.
So to make this 318,fun; the 108LSA cam needs about a 2800 and 3.73s,
while the 114 probably is the one needing a 3000TC and 3.91s. I would never install one of these 114s in my teener. It really needs about 11.5 Scr to make 175psi@ a meager 121VP, just a tad less than a stock 360. Sure, it idles nicer with just 56* of overlap, compared to the 108 at 68*, but the loss of bottom end is very disappointing, not to mention the atrocious fuel consumption.
And the primary nail in the coffin, for either cam in a 318,is trying to make the Scrs of of 11 and 11.5. This is very expensive.
And then;
4000 rpm with an automatic, and 3.73s is about 35mph. IDK about you but I can't wait that long for the engine to wake up. With 3.91s this comes down to 32mph,and; I can't wait that long either. Of course, if it's spinning anyway, then I have no choice.
I'm guessing in a 318, that 284/108 cam is gonna peak around 5400, perhaps a bit more. For low ET with an automatic, you will have to rev it about 800 to 1000 rpm over the peak, to drop in at 3670 to 3800, for a powerband requirement of 2600. To do that, and hit 60 mph at the peak in second gear requires 4.56s. Now if you can make that stick, you will get a low ET because your average power is two full pulls.
With 3.55s, your rpm will be [email protected], then you shift, and the Rs drop to 3660, and the little teener has to pull from there to just 4030 to finish at 60mph. So that's the slow way.
With the A999. She will hit 6200 at 49 mph now, and the Rs drop to 3485, 175 rpm lower: and finish at 60= 4280,250 higher. Can't say which would be quicker.
Now 4.56s is probably not that great an idea, but neither are the 3.55s. A better idea is to bring the power down to a lower rpm, and have more of it down there, and then regear it to peak with 2 full pulls again.
How about the A999 with 4.10s. This would make 60~5000, and so a power peak of about 4800. That requires a cam of about 3 sizes smaller or 262 advertised. That cam on a 110LSa has an ICA of 60* and so at 9.8Scr (easy to make with a 318) makes 162psi and a VP of 126. Compare that to the 284s 152psi/112VP at the same 9.8Scr. The smaller cam looks like 126/112= plus 12.5% more performance below say 3000. That 126 VP allows you to run less TC and Less gear should you chose to. But for low-ET, the 4.10s could quite possibly out perform the 284/108 with 3.55s....... from zero to 60mph. In any case, the power below 3000 will be far more suited to a streeter.
Now, the 268/110 cam has been installed by many, and the happier fellows also pumped up the compression. The guys with the 8/1 teeners are the first to talk about the bottom-end softness.