News:

It appears that the upgrade forces a login and many, many of you have forgotten your passwords and didn't set up any reminders. Contact me directly through helpmelogin@dodgecharger.com and I'll help sort it out.

Main Menu

Correct cam choice for a 440-6 pack motor?

Started by Hoser2455, July 06, 2012, 12:49:29 PM

Previous topic - Next topic

Hoser2455

I am restoring a car.  I am not after speed at all.  I am more after reliability if anything.  The engine is a 1970 440 six pack motor.  It has been rebuilt 25 years ago balanced and blueprinted.  It has about 6,000 miles on it. Cylinder walls and pistons look good yet. It has 10 1/2  to one pistons in it.  It is 30 over.  I will be using a original four barrel Carter factory carb and a four barrel intake on it because the car is a four barrel carb car.  The cam is a purple shaft hemi ground cam I think.  The cam looks OK. There are no numbers on it but the part # I have from an old receipt looks like part # P3690214. Should I still use this cam and will the car idle real nice yet, or would I be better off buying a new cam?  If I was to buy a new cam, which cam should I buy to get back closest to the original and reliable.  Thanks, not as up as much on the innards of motors.  What would you do.  Thanks, Your advice greatly appreciated.

b5blue

Cam P4452783 w P3690933 springs would be your "basic" HP setup.  :scratchchin: Very "livable" cam.

Hoser2455

I think the springs in there now are heavy duty springs.  Would that still be OK with the cam you are recomending?  Also is this the orginal cam you are recomending or is it an aftermarket?

b5blue

  That is a Mopar "Restoration" cam, it's the cam that would have been in a 70 HP 440 4BBL. The # you listed is not in my Mopar B/RB engine book. Springs MUST match the lift a cam gives, called compressed height. Basically the spring must be able to go down 1.5 times the cam's total lift with a % extra to prevent the coils binding. (The spring would be solid at that point hence bind.) They can be removed and checked for total compressed height. The "1.5" is the ROCKER ratio for a stock engine, the stamped factory rockers. If you have any other type rocker you need to find out if they are 1.5 or 1.6 ratio.
  Confused yet? 

Hoser2455

No, I understand that.  I was just thinking though that this motor has not run for about 20 years now so it would probably be better to replace the springs anyway.  Since some of them would have been compressed all them years they might not all be correct anyway.  Do you agree with this?  Sounds like the cam and springs you mentioned is something that I am definitely looking for.  Sounds like this set up would be a lot more reliable in traffic when it idles at a stop light or in a traffic jam.  Would this cam be a little milder which would not make it run as hot also or would the heat stay the same?  I guess my only other question is where is the best place to get this set up, the Mopar dealer or Mancini or who?  Thanks again for your input.

b5blue

  By today's modified cam ramp profiles that change how much and just when the valve opens I'm sure it's considered archaic by many as it was first used in 1967! It is what I have in my 70 440 Automatic and I'm running a 69 1/2 vintage 6 pack with .060 overbore Speed Pro 9.5 to 1 "Hyper" pistons. I'm like you in that I was looking for reliability and the ease of tuning that comes with a factory parameter build. (Given my old 6 pack.)
  I built (Am building I should say.) my car as a daily driver and have about 3 years on my cam I can tell you I do like it. The 4 concerns I'd have you look into are
1: The lifters, even though the cam will come with lifters I strongly urge you get new ones made in USA, I have some lifter noise that is quite noticeable for much longer than I consider normal, it eventually quiets down but I will be changing them soon. (Johnson lifters, if I remember are what's been highly recommended by others here, I'll have to check to be sure.)
2: If your valve train is NOT adjustable use "cut to fit" pushrods or Smith Bros adjustable pushrods. As engines are rebuilt tolerances start to stack up in the valvetrain, Heads milled or surfaced and blocks decked lower the rocker shafts and valves seated in the heads raise the valve stem, all small amounts yet enough sometimes throw factory new parameters out of ideal or even acceptable. Lower the rocker shaft and you increase the preload in the lifter with a standard pushrod, raise the valve stem and you push the lifter down even more. Get me?
3: Timing, with 10.5 to 1 compression on today's crappy fuel, unless you are spot on having ideal "quench" @ top dead center ping or detonation could be an issue when your back on the road. Getting ignition set up for your exact build with the distributor's advance and curve optimized for 93 octane ethanol rich fuel could be a pain in the butt. (I farmed this task out to Don at FBO with very good results.)
4: Oil, If your not aware engine oil has changed, the zinc phosphate has been extremely lowered. You must check the sticky here on the forum and get up to speed on the dangers of lack of zinc on flat tappet cams! (I'm using Valvoline ZR-1 Racing oil and so far so good.) 
  Check your timing gear set, the cam I listed is a "one bolt" cam. There is a 6 pack cam that is "3 bolt" (P4529270) that requires a matching 3 bolt timing gear set. The lift and duration are exactly the same but the "angle" of the grind is lessened for greater (racing) durability and it requires lifters ground on the bottoms to match that lessor angle.  (The angle is what makes the lifter spin in it's hole. lifter> -/ < angle, looking down the cam's length.) I'm only pointing this out because I WAS going to use this P4529270 cam but had already bought a "one bolt" timing set earlier so I was kinda stuck using what I'd bought.
  You can get any Mopar cam from any vender, Mancini was out of stock, so was Summit so I got mine from Jeg's. Check for availability of everything before ordering anything. This is all I've experienced just trying to stay in the "middle of the road" on my engine build, under a tight budget. The overwhelming choices on any build can leave you drooling in the corner with do this and that but then do that and this options and opinions. I gave up and just went factory with my Mopar Performance Big Block "B-RB" Engines book as my guide. (We haven't even covered what transmission or axle you have.)