Cams galore......again

[moper]

CP, we both do a decent amount of work...you probably more than I. I attribute the improvements that come about to getting a cam that works better for the combination or owner, more so than just changing brands.

[Chryco Psycho]

Agreed
 last year a friend brough his 440 Duster to me as he was disappointed in the performance ,it made 270 RWHP on a Mustang Dyno & used a custom Comp solid grind cam , I pulled the heads off & touched up the porting to improve it slightly & swapped to an UltraDyne fast ramp cam & we went back to the dyno with no other changes & gained 71 HP at the rear wheels with 341 RWHP so having the best cam is critical to the build
 the Duster was running 13.8 which is why we took it ot the dyno as a good 340 should run that when we finished it was running 12.0 -12.1

[Hot_Rodder]

My '69 Charger R/T that I had, I went and put in a .509 Purple cam, and installed a Summit Racing Double roller timing chain with billet steel gears (seemed like a nice piece, esp. with a 9 way crank key....).. And the Holley Street dominator intake, 1" 4-hole aluminum carb spacer, Moroso Blue Max wires, Accel plugs, MSD Blaster 2 coil, Mopar Performance electronic ign conversion (Orange Box), mechanical f.p. with Holley regualtor (had to put this on), Barry Grant Speed Demon carb (rated 750 cfm with electric choke), and a 14x3 drop base air filter. This car had a most certain "idle" to it, until I idled it up some..... The previous owner installed straight pipes on it, unsure of the muff's that were on it. I had to change the factory starter out, and ran a Power Mater XS torque starter, man oh man what a change.... Anyway, I'm not going to sit here and say anything bad about anything, well, I will one thing, I hate that Carter AVS that was on there when I got it, man that thing was shot..... And the Holley 3310 that I had on there for a little bit, and still have it... well, I found myself adjusting that thing quite some bit . I praise the Demon b/c of I've had no problem, and have heard none, but that's another topic later.... The Mopar Cam that I installed, ran great while I had it, after I sold it however, the new owner, wiped a lobe out, dunno how, but he did. He said he installed another cam, little smaller, he said the 509 was too big for his liking?....? The tran's that I built, with CRT's help and the folks over at dodge-charger.com when it was there, he says it hurts him b/c of how hard it shifts , I told him I built it with performance only in mind, and that's what it is... But anyway, as fas as cams, I say each cam is ground with an engine in mind. Some cam manufactures do look more toward certain motors like chevys, fords, ect.... As far as comp, I think they do focus more on Chevy than any others, want proof? Look at the new Thumper series lineup, right now there are only 3 grinds, but all 3 are for chevy. I like the sound bites they have of them, but still, it's chevy... Don't help me out any. Anyway, Mopar cam's, from what I've heard and seen, are old grinds, and there are better grinds out now. IMO it would be nice if they'd do some new grinds, but to each there own. The things I've heard about Crane are from a buddy of mine that runs....chevy.... Not a whole lot of Mopar in this immediate area . There are a few around here, but nothing out in the open... Anyway, I've been thinking about a Lunati VooDoo for a 383 build for a freind, later post. But as far as the Stroker build, when I talked with Indy, they said they will install valve springs matched to the cam, hince this post. They said the SR heads should be able to handle 600 plus horse power. For a street car, in this case a '70 Duster, I've decided on a manual trans unless someone changes my mind... For a bad boy street car that want be driven a whole lot, maybe more like a weekend here and there, what would be an ideal #? To me it seems like 600 maybe a bit much, then again... You can never have too much. I've been leaning toward the fast ramp design mechanical flat tappet because you can get a close to roller cam performance with out the required for a full roller setup. The 440/505 Stroker uses the Fast Ramp design, but it over a .600" lift, and the duration to go with it.... Big ol' cam. Anyhow, I didn't set any numbers, so cam spec's are at a hault right now, I'm just trying to figure out what everyone thinks about different cam companies, and what kind of problems they've had with them, and what pro's that they've had with them. I know CP has built god knows how many motors, and I do look to him for info, once again thanks CP. Moper has a lot of info too, and seems to have built a motor or two also, so thanks for the info so far, and keep it coming, maybe this will become a posted topic for people to look into. Hmmmm, how about this question:
How do you determine the best cam for your motor?
And no, I'm sorry to say, hoping online and coming here and posting every little and large detail about your whole car, and what you want it to do on each build doesn't count What I'm getting at is, something we can use as a guide line to specifing a cam. There's a lot involved, but it would be nice... And cam deisgn, the break down of a cam, for those who don't know. I'll hush now.

[dimples]

Me?

Lunait, ISKY, Engle.................

I wouldn't put a "new" comp cam in one of my motors if you gave it to me. I like ISKY because they custom grind me stuff.

[Chryco Psycho]

It is not easy to pick the "BEST" cam for any engine , the biggest factoer is the power band, the Cam must work with the intake , stall speed on the torque converter etc to get all the parts working together , next is lift , I basically port heads for every build I do so more lift is good , if the heads are not ported any lift over .480 results in no gain , also you need to watch piston to valve clearance , too much lift can get the valves too close to the pistons  , next you need to look at over lap , an engine with manifolds will not benefit from increased overlap but higher rpm engine especially with headers definatly like more overlap , next is cam design most street engine will use a hyd cam , these are the cheapest & do not require adjustable rockers , next is hyd roller which generally works great for great power & emissions in newer enines but are not high performance cams but can perform very well , these are typically very costly to set up , next is solid flat tappet , I use these the most , they are very reliable , relatively cheap to buy all the needed parts , can last for decades , low mainainence , the last choice is solid roller , these usually have very agressive profiles & are by far the most expensive to set up & maintain but will make the most power too 

[Hot_Rodder]

also you need to watch piston to valve clearance , too much lift can get the valves too close to the pistons

in this case you might end up with some very unwanted piston/valve slap... Then you may just end up:  . 

[moper]

What goes into picking a cam... That's akin to asking how is world peace made.  

I start with the engine's owner. What do they want out of it? How much can they spend? How much can they do in terms of maintenance?

Next, I look at cylinder head design, piston design, and stoke. Displacement changes thru stroke increase will make better use of larger cams, shorter strokes the opposite. I'll get into "larger" later. Aluminum heads, and/or tight chambers, and/or piston dishes/domes will all effect quench and cylinder pressure. The cam MUST be able to make the right amount of pressure, at the right rpm.

Next, the rpm range the engine needs to make power in. Steady state running (road racing) needs stable valve train, and a long flat torque curve. Street or street/strip needs this too. Drag raceing needs peak power to be high, and can sacrifice some torque number for it.

Next, how is the block being built up? Can it take the stress of big numbers and/or big rpm? If not, dont spec a cam for that.

Next, What support systems are in place? Is the intake a factory casting? Is it exh manifolds or headers? Does the car need to run thru quiet exhaust? These all come into play when you get into talking about lobe seperation angles, centerline, and overlap, and things liek ram tuning and scavenging.

Last is what type of cam fits the bill and who grinds it? Hydraulic? Solid flat tappet? Roller?

Brand doesnt really figure in until I have an idea of what I want. And then it's who makes one that fits my spec and still gives me accuracy. Crane is one of my oldest and dearest. They tend to have more low end, and very strong midrange to their grinds, with better idle and vaccum levels. But, they are almost as old as MPs grinds in most cases. I'll rate quality and accuracy as 1-5, 5 being the worst. Crane is a 3. Comp Cams poors a lot of $ into research. More than most. Any lobe that works on a Chevy (notice I said lobe, not camshaft) will work on an AMC, a Caddillac, or a Mopar. They have a new line of asymmetric lobes that sounds very promising. Their XE line has consistently been very good at delivering what's expected, in Mopars and others. As a side bar, if you order a cam from Scott Brown, or Porter Racing Heads, you are buying a cam ground to their specs by Comp Cams. Quality at Comp is a 1.5. MP has some grinds that are very powerful, but IMO, most were developed for drag racing, and sacrificed a lot of driveability to get performance. Times change, and customers dont want ragged idles and power bands that start at 4K and need static ratios that are not supported by pump fuel. With little new development in LA or RB cams in the last 20 years, they are way behind. They altered the lobe seperation angle on the 484 and 509 cams, but that's a bandaid that doesnt work real well, and too little too late. Quality from MP is a 5. I have run Wolverine, Sealed Power, and Summit brands, and they are all decent replacement cams. I dont run a lot of them, but I'd say quality in the 3 range. I have not ever run Lunati, Racer Brown, or Isky. More that they were hard to get, and now not in my habit of looking. So I cant comment. UltraDyne and Engle to me are close together. The new lines of lobes Engle has (the KV and the EP) look very promising, and in fact, the 505 has a cam I designed with the KV lobes. Quality for both is easy 1.5.

Cam choice is more critical than any other single part or system. Because it either effects, or is affected by, all others. Get it right, and get it made wth quality, and you're a hero. Get it wrong, or get one that was ground on a friday at 4:30, and the engine build is a waste of money. It's a science all it's own.

[dimples]

I think he was asking Brands................


My brain is smoking..........

[wart1de]

Quick question. Which cam makes more power under 6k? A solid flat or a hyd roller?

[moper]

The RIGHT cam profile...
As I said, brand really doesnt matter. Any hydraulically adjusted lifter cannot make the same power as a fast ramp solid. But, they are smoother, and they are quieter, and you dont have to adjust them. That's similar to asking "which blue car is faster?" Without details, there is no answer.

[dimples]

However, I can say a mech flat tappet would rev higher than a hydraulic roller. Buuut, you can lift the valves open faster with the roller cam.

[Chryco Psycho]

not nessisarily , if you open the valves to fast with a hyd roller  lifter the lifter will collapse under the load

[moper]

not nessisarily , if you open the valves to fast with a hyd roller  lifter the lifter will collapse under the load

Buy that man a beer

[dimples]

But where do you draw the line between collapsing the lifters, and slower ramp rate of a mechanical flat tappet?

I don't know, solid flat, or solid roller for me...........

[moper]

The fast rate solid flat tappet will raise the valve off the seat faster than many hydraulic rollers. The hydraulic adjuster basically acts as a Rhodes type lifter on real fast ramp speeds. The solid flat tappet doesnt, but can run the risk of flattening the cam lobe if things are not done perfectly.