I have a 360 on the stand I'm building solely as a tosser. It'll probably sit there assembled until I decide to sell something and don't want one of my other engines to leave. It's a clean block, good at STD. I could just slap it back together stock and call it good, but I want it to be a decent engine in case I need it at some point.
So, you could say I have a vested interest in what you're doing to some extent. I'm just doing it on the lowest budget with which I'm comfortable.
I'm foregoing all the expensive machine work based on its budget nature. For something I wanted to keep I'd definitely get the block decked (to 9.58"-9.600") and have the boring done with deck plates at the very least. The 340 block for my Challenger is fully blueprinted; that's a four-digit expenditure before even buying the first part.
My shortblock recipe is pretty simple: I'm using stock 340 rods because I have them and I don't have to press pins. I probably won't bother resizing them; if I do I may go ahead and use the press-fit 360 rods since they'd already be at the machine shop. The pistons are Speed Pro H116CPs, which have a compression height of 1.670". At TDC on a "perfect" 9.600" deck height, they're .012" down the hole. As much as I detest hypereutectic pistons, the price was right and this engine isn't a darling to me. If I didn't have a dozen other more important engines, I'd have bought forged (SRP forged are .018" down the hole, if memory serves).
Anyhow, I know I don't have a 9.600" deck--it's taller, almost without question. I'll measure the pistons at TDC once the block is assembled, which will give me a milling number for the heads, if any (I'd rather not pay for that, though I will have them resurfaced). For a slap-together, I'd be OK anywhere over 9:1 and quite happy at/above 9.5:1. The crank is gorgeous so it's not getting machined. I have .001" under bearings; I'll measure with those and standard and use the better clearance.
Using the pistons I've got and your calculator (which I like), I ran some variations. Worst-case scenario with those pistons would be finding the deck is, say, 9.625" (.037" down @ TDC) and the chambers (open, probably use smog heads) are 72cc. Using a .042" gasket, I'd end up with 8.84:1. Far better than stock, but I want more. Simply resurfacing the heads should drop the chamber by 1cc. That and a Mr. Gasket .027" head gasket gets me up to 9.24:1. In my case, success! It'll live forever with 34° total on garbage pump fuel. If the deck height is a more-realistic 9.615", I'm closer to 9.5:1--approaching "joy" territory.
Here's what you'll want to remember: If you build it for higher static compression, you don't need (or even want) a cam that maximizes dynamic compression. You'll simply land in detonation territory. Spark timing is more important than compression. If you've got an 8.2:1 dynamic CR but can't run it higher than 29° total without spark knock, you lose. It'd have more power on 7.2:1 DCR and 34° timing, period.
Because I was bored last night (the dog didn't feel like talking) I ran some rough simulations on the following engine: 68cc heads, .042" gasket, 9.600" deck height. Static CR was 9.75:1. I used generic X/J/308-type flow numbers with 2.02" valves and a basic dual-plane intake. Headers, 700CFM carb, and 34° of timing, all in by 2,700RPM. Simulated exhaust was 1-5/8"-primary headers into high-flow mufflers. I ran several similar hydraulic cams I either own or for which I have accurate card info through the simulation, along with the Whiplash in the video you posted.
The Whiplash
was the HP winner--by a whopping 2HP.
However, it lost to the
Lunati 10200702 Voodoo and
Howards 711451-08 on average HP, average torque,
and peak torque. More importantly, the Lunati and Howards both did the job with lower DCR, knock index, and lift, as well as less duration. The Lunati also did all of it at a slightly-lower RPM, probably since it has a much wider LSA (112° v. 107°). The wider LSA also translates into better cruise economy, with the Lunati showing dramatically better BSFC in that RPM range. The Howards cam is very nearly the Lunati's equal in overall performance, but the Voodoo does show a slight edge. I'm not surprised, since the Voodoo line consists of former Ultradyne grinds. Both are fast-ramp designs, a.k.a. "real Chrysler cams".
The Whiplash
barely beat the long-gone Crane 698301, which is a design from the 1970s that I happen to have lying around. The difference was 3HP peak and 1lb/ft peak, 4HP and 5lb/ft average. The Crane has slightly-lower @ .050" numbers than the Whiplash (a degree or two) but only .467"/.494" lift. It had the lowest DCR, knock index, and lift of the bunch. It also has the widest LSA @ 114°, so it's more efficient at low RPM. The discontinued Crane and the Lunati will both clear factory valve guides.
All of the cams I modeled showed peak HP at 5,500RPM or less. Sweet. Peak torque hovered between 3,750 and 4,000, meaning a modern 3,800-stall converter and 3.91 gears would be a blast.
"Just for fun" side simulation: The tiny MP P4528346 solid-lifter shaft (276°/.490") clobbered all of them in every department, though the Crane had a slightly-lower DCR.
Since these were simply a rough simulations, the peak numbers aren't important (and are probably optimistic). It's how the cams
compare on a realistic Bob/Jass shortblock.
By no means am I recommending a cam--I still suggest you call a company that engineers cams for that (not one has "hug" in their name). Testing with even larger cams for which I have specs pushed the peak numbers up the RPM scale without dramatically increasing average numbers. That tells me it's probably near the limit of head flow.
My takeaway? The Whiplash is
not a particularly well-designed camshaft. Every other cam requires less-violent valvetrain motion and is less likely to detonate, yet performs better overall. Do they
sound as gnarly? Maybe not, but I don't build engines for sound, either. I'd probably be calling Lunati or Howards
for a recommendation. I certainly would not call an engine builder who can't properly install an RB rear main seal and doesn't know the intake side of the head requires attention after milling the deck surface. Hughes is all hype; there are better options.
I have both the old Crane and the Howards cams lying around. Neither of their intended engines exists anymore, so I may as well use 'em up. The Crane doesn't require guide clearancing, but the choppier idle of the Howards might help sell a car. I don't know which I'll use, but it'll be one of those two. I'm not buying another cam just for this half-assery!
