chatting with another mopar guy about cams,well i explained i was considering a bigger cam(something from hughes)I went on to tell him my cam was a comp 21-224-4 xtreme energy,he suggested this comp cam
21-672-4 street/bracket cam

how streetable will this be and will my 2800 stall be enough?

Can you post the actual cam specs?

From the book.

21-224-4, 1000 to 5200, XE256H, 256/268 adv, 212/218 @ .050", .447/.455

21-672-4, 3000 to 6500, PP292H, 292/299 adv, 247/254 @ .050", .509/.509, 10:1 comp, 3500 stall recommended, the recommended valve springs will require machining the cylinder heads.

The 21_224_4 is very close to my MP 268/272 .450/.455 cam Its in my 340 under a 6 pack. It has a nice lope at idle and pulls great.. I built a 350HP 360 for a friend of mine useing that same ca. In the 360 the lope wasnt as noticeable but pulled great in that car also. for his 73 Duster

the bigger cam would like more convert but the 2800 should work. It will give you more rpm, so it should pull longer giving you a longer "powerband" The 455 is a tiny cam for a BB. I'd think you'd pick up a good deal of "uumph"

That will be a nasty cam (I'd like it :-))
Will need to be installed at 102 (101 to 103) to work with a 2800.
You will need light advance springs in the Dizzy with timing 38 deg all in by 1200.
5.5 power valve
That said it will kick butt.
But if you lack cam, carb and distributor tuning skills like most hear you may want to pass and go with something like the hughes whiplash.

What is it your really looking for??
What gears you got!
and so on

That's a huge cam for the street.

If you're really an old guy and don't want to spend your driving time trying to keep it from stalling at idle it is worthless. I'm an old guy and recently went through gyrations trying to keep my $500 ford pickup running long enough to get it to a shop and back again, and I didn't like having to keep one foot on the gas while the other foot tried to work both the clutch and brakes. I'd rather be able to drive and enjoy the powerful feeling. Having a power band that comes alive at 3500 rpm doesn't get it.

If you want more cam but still want to be able to drive your car on the street, keep in the same family and move up two steps to the XE268. Or jump over to the Lunati Voodoo, something with about 222 degrees intake duration at 50 lift. Or call Hughes and talk to them directly. They can be pains in the butt to deal with, I'm told, but they know their stuff. And they'd never make as lame a suggestion as you already have.

R.

If you actually read this post dogdays, I didn't suggest this cam!

I'm changing to 3:55 gears,2800 stall,440 approx 475-500hp,street car

It'd work fine, although the VooDoo 533 might work a little better. The cam has good street manners. Buddy runs on in his 68 RR Similar build 9ish:1 440, e-heads, headers, M1 intake 770 Street Avgr carb, 2800 stall and 3.54 dana. Car runs has run 12.48, usually in the 12.50-55 range.

If for street,why don't you look and Hughes' Whiplash cam? It's not just sound,it works! Great street cam.

Rule of thumb a cam size change is 5 degrees in duration. The new cam is 5 sizes (!) bigger. Totally different animal from what you have. It will be very rough and lopey. It will want more convertor or may actually be slower in normal driving without. Other components (carb, rear gear, manifold even compression) may need to change to "make it right".

If you want to step it up without completly changing the character of your engine, suggest 2 "steps" or about 10 degree increase in duration.

I actually read the post. I never thought for a moment that you had MADE the suggestion. I wouldn't have been so harsh if I had thought it was your idea.
I did get distracted by heyoldguy's name. You're probably not an old guy.....

The new cam's intake duration is 35 degrees at 50 bigger than what you are running. That's either 6 or 7 steps hotter than what you have. Add to that the fact that the cam has very low lift for the duration and I feel confident to say there are at least a dozen cams out there that would be better. It appears to be a clone of the old MP 509 cam about which I have the same opinion.
You really need to talk to someone who will sift through the information and get you much closer to your desired result. Hughes, Scott Brown, Dwayne Porter, any of these would be better than anyone from a major cam manufacturer who you'd get on the phone.
One last thing...Most stock 440s made a real 335hp on the dyno. Don't get caught up in horsepower inflation.

R.

That looks like a lazy cam for the lift vs duration. I wouldn't run it with less than a 4.10 rear and 10-11:1 compression in a 440.

All of you lift/duration guys...why would u want more lift...when stock heads are done (more or less) by .450??? Assuming they are stock heads...

As usual on cam posts, I'll go against the grain and say that I have no issues with that cam....It will need more than 2800 flash..3500 at least...

With some flash speed it will work with 55s...although not optimal.

If you are stuck with the 2800, back the 050 duration down 10 degrees or so....

BTW, dont let them scare you...the cam you listed is VERY streetable, et...with the right carb, vert, etc. I ran the .509 MP cam when I was 19 and couldnt tune a radio...It would idle all day long..

I do wonder if some of the naysayers have ever ACTUALLY ran some of the stuff you knock????


I agree that you should call a cam guy. Porter or Bullet, IMO...skip the others listed. Not saying the others grinds wont work...but Porter is the man...by a long shot. Bullet is decent as well on their Mopar grinds. That ought to get the

The port flow doesn't increase over a certain lift, so why would you want to go over that lift? Is that the question? Used to be a popular topic among Pontiac owners and bench racers.
Area under the curve is the answer.

Let's start out by assuming you get maximum flow at 0.450 lift. With a cam with a valve lift of 0.450, you are at maximum flow for maybe ONE DEGREE. All the rest of the time you are at less than maximum flow.

Now use a faster acting cam that goes through the 0.450 lift number earlier and stays above that number for 10 degrees before coming back down through the 0.450 on its way to zero. That port is now at maximum flow 10 times longer than the first cam. That doesn't translate into 10 times the flow, but you must be able to see that it could translate into more total flow.
That's the reason to get the valve opened and closed quicker.

R.

As a couple of other guys have stated, not much lift for the duration. The overlap on that cam will reduce vacuum signal to the carb and will be somewhat lazy under about 3000 with 2800 stall & 3.55s, and will bleed off some CR, compared to something with less duration. I would think something in the 220-230 range with .510-.530 lift and a fast ramp would be a better match for your car. I'll take throttle response over a big-duration drive-in cam any day.