i am lost on cams!

[greasydonkey]

sorry for another cam question, but this one's pretty specific at least...

im going through the 440 and am changing the combo, hoping for something a bit milder but still tons of fun on the street. im taking out the 305/525 hydraulic comp cams and am thinking of something like a 290/490, but im lost on the specifics. its a 10:1 452 headed 2.14x1.81 440. its got a holley street dominator and a 3310, but i think the intake is getting chucked too for a dual plane unit. its a 4 speed with 3.70 spool in a 72 duster, and its just a street car but i want a nasty sound and STRONG mid range (2500-5000). I think the 290* will give me the sound and the .490" will give me the midrange. what do you guys think, and would i be better off, with a cam like the one Im thinking of, of going dual plane or staying with the holley single plane?

[dave571]

I like my rpm air gap.

Gives great torque.

My motor has a little more compression.

The cam you are suggesting will be a decent one. Mopar .509 is quite popular, and should respond well with a light car like yours.

I'm using a racer brown ssh 44, 510 lift, and 242 @ 50 duration. 410 gears, 3800 pounds with driver. Still squeeks off 11.70's at sea level

[mhenesian]

Hi GreasyDonkey,

Before swapping cams, try advancing what you have 4 to 6 crank degrees. You have enough compression to make that cam work down to at least 2500 rpm. Also, if you want max bottom end, and aren't too concerned about over 5500 rpm power, go with the Edelbrock Performer (not the RPM !). Also distributor setup has a lot to do with how the car pulls below 3000 rpm. In my 440 4spd Roadrunner, I'm running 16 degrees initial timing with 34 degrees total in by 2500 rpm (MSD distributor). My experience is that 4 spd cars can't take excessive total advance. Also block the vacuum advance if you have one - to avoid detonation. With 3.70 gears in a '72 duster you don't need the vacuum advance. Also, dump the Holley 3310 and get a Proform 650 or 750 double pumper. A 650 DP for max torque. Use a 1" four hole spacer. All this will give your 10:1 440 maximum pull below 5000 rpm. If you stay with the 3310, then you'll need a stiffer secondary spring ( I remember having good luck with the "brown" one).

If all this fails, then change cams to something in the 268 to 284 degree range (225 to 234 degrees at 0.050") - but I don't think you'll be happy, the sound of that Comp 305/.525" is in your ears !

Good luck, Mark H.

(I'm now convinced that the best intake for mild to wild 440's is the single plane Mopar M1 - if you're going to buy only one manifold this is the one !)

[greasydonkey]

the 305/525 is 2* advanced now. the main reason for replacing it is im having trouble with the engine that i cant find and the cam is one thing ive not tried replacing as of yet. it looks fine, but at this point, the motor is out and completely apart and i figure i will swap it out now. it sounds nasty with this cam, but i think keeping it in the 292* or higher range will be comparable in sound, but i dont think i need 525 lift with my intended usage.

the 3310 stays just for the fact its brand new. its a 1982 model, but i bought it new in the box....all metal parts!

i havent settled on a distributor yet either.

as soon as this car is put back together its for sale anyway.

[rumblefish360]

IMO, when it comes to cams, the best advice is from the PRO's. This is what they and I say all the time;

Choose the cam based on the cruise RPM range of your car. Though this does leave room to play in, so to speak, it gets you in the ball park right, and right quick.
If in doubt, choose the smaller cam. It will deliver more torque and thats a very nice thing in a street ride.
Also, try and cram in as much lift as you can. More the merry. But not more than your head are capable of flowing in or out.
(In example, your ported heads flow great to .500, it is really kind of pointless to get a lift of .600)
Split duration cams help the engine breath better. If your heads are ported well, then it will not matter as much, but it is still a help in most cases.

On intakes, theres only 2 IMO to choose from. The MoPar single M-1 or the Edel. RPM. The RPM has a little more torque for the street without a lose at the upper RPM for HP. The M-1 single rocks! Best for serious street strip duty or factory head port location racing. Raised port are another ball of wax.