318 Camshaft Selection

[70 Challenger Lover]

I'd like to warm up my 318 but the choices of cams can be dizzying. I want to keep my numbers matching motor and I don't want changes that take away from the stock appearance such as headers. I've narrowed my search to a few from Lunati and a few from Comp. I'm open to other brands but I prefer that it be off the shelf rather than some custom grind and it needs to use stock rocker arm and pushrod set ups. No rollers. I have a set of adjustables from a 273 but don't want some .480 lift cam or something with a high ramp rate that will create noise and wear.

Essentially stock 318 with 302 heads and thinner gaskets. Hoping it will be around 8.7 compression. 3.23 gears. Dual exhaust with 340 hp manifolds. I'm open to the original 2 barrel or bumping up to a small 4 on a Performer manifold.

Really want the most low end torque I can get without changing pistons. I get that gains will be modest and I won't win races. The most important thing to me is to not overcam it which I've done too many times over the years.

[headejm]

I'd ask @Chryco Psycho what his opinion is.

[70 Challenger Lover]

Thanks. If he doesn't chime in soon, I may be forced to just guess.

[Chryco Psycho]

Don't guess 
Don't bother with Comp you are throwing away power .
Lunati i better designed for the wider Mopar lifter
Using exhaust manifolds & low compression the cam choice is critical !
So you want a 112-114* CL higher is better , duration in the 220* @ 50 range & get as much lift as possible , lift helps breathing & costs noting as far as idle vacuum & low end power goes  .
This should narrow it down & I can look at what you find close to that .

[tparker]

How are Hughes cams? That's what I ended up getting. I liked that they seem to specialize in Mopars and figured they know their stuff. But I haven't heard anyone else recommending them so I am kinda second guessing my choice. LOL. In any case, I didn't guess, I called and they where great with their recommendations. Took a few minutes on the phone.

[70 Challenger Lover]

The only one of my picks that come close is the second voodoo cam with a CL of 112. How does LSA play into it? The voodoo one seems tighter than the others. Is that what gives it the rumble they're trying to advertise in this series?

[Bullitt-]

  LSA question from https://mgispeedware.com/camshaft-calculator/

What is valve overlap and why is it important

Valve overlap is mostly a function of duration and lobe separation angle (LSA), and to some minor degree valve lift. If the LSA remains the same but you increase the duration, the amount of overlap will also increase. Overlap is the span (measured in crankshaft degrees) when the exhaust valve and intake valve are both open.

For normally-aspirated engines, overlap generally improves engine performance by starting the intake cycle before the exhaust cycle has finished. As overlap increases, this tends to make the engine idle quality more erratic or lumpy, while improving mid-range and top-end power.

So it appears the smaller the LSA # the more overlap there is, everything else remaining the same, which adds mid to upper end power

[70 Challenger Lover]

Looking at it again, I was mistaken on the voodoo cam having a cl of 112. That was lsa. I don't find anyone making a cam that. If I find centerline of 112-114, the lift and duration are close to stock so no improvement.

Anyone know of an off the shelf 318 cam like that? I've tried the big manufacturers but keep striking out

[Chryco Psycho]

The 112* LSA traps limits the time both valve are open & traps extra pressure in the cylinder & moves the powerband down .
With headers you get added scavenging / vacuum behind the exiting exhaust , with manifolds you don't get this so closing the intake valve sooner helps more , the factory cams used 114 LSA with manifolds

[70 Challenger Lover]

It doesn't look like I will have many to choose from. I find nothing with an lsa that high and cl seems to be 112 ar best. If I do find cams with lsa and cl that high, the lift and duration are very similar to the original 318 specs.

[Chryco Psycho]

So I would look at the saller Lunati VooDoo grinds with the 112 * lsa