Help me select a cam

Posted By: DGS

Help me select a cam - 03/26/14 10:40 PM

Need some help for selecting a new cam for my 70 Charger.

Here is what I have:

440 with 915 heads = higher than stock compression
3.23 SG rear end (won't change since I do some long distance trips)
intake: Holley Street Dominator or Edelbrock Performer RPM
carb: Quickfuel 750 vacuum secondary or 850 Thermoquad
cheap headers
current cam: Mopar .509
A-833 4-speed (2.66 first) tranny

Should I go for an off the shelf cam or a custom cam? Any recommendations?

Thanks

Posted By: 340SHORTY

Re: Help me select a cam - 03/26/14 11:59 PM

call a cam company and get their reccomendation. Thats where you will get the best info you will ever get.

Posted By: DaytonaTurbo

Re: Help me select a cam - 03/27/14 12:53 AM

lunati voodoo 60303. I ran it in a smogger 440 and it was a little soft in the bottom end. but with your compression and the stick shift it would be right at home

Posted By: BSB67

Re: Help me select a cam - 03/27/14 01:17 AM

Quote:

440 with 915 heads = higher than stock compression

Can you be specific?

Posted By: gch

Re: Help me select a cam - 03/27/14 02:01 AM

Quote:

Need some help for selecting a new cam for my 70 Charger.

Here is what I have:

440 with 915 heads = higher than stock compression
3.23 SG rear end (won't change since I do some long distance trips)
intake: Holley Street Dominator or Edelbrock Performer RPM
carb: Quickfuel 750 vacuum secondary or 850 Thermoquad
cheap headers
current cam: Mopar .509
A-833 4-speed (2.66 first) tranny

Should I go for an off the shelf cam or a custom cam? Any recommendations?

Thanks

Max performance I would sar rpm intake and quickfuel 750
Max mileage I would say Thermoquad but w/o street dominator.

Street dominator is an excellent intake but I would rather have a dual plane in a heavy car with 3.23 gears.The standard performer would work but would sacrifice some mid range/top end.

Are you going to run the stamped stock rocker arms or aftermarket roller/adjustable??
We do need to know your actual compression and whether any work has been done to the heads for a specific recommendation.

Off the shelf stuff I would say somewhere in the high 220's/low 230's on the intake duration at .050.

Posted By: ahy

Re: Help me select a cam - 03/27/14 02:33 AM

Does it need to be hydraulic? If solid is an option, the MP 528 cam is a good one. It should be more streetable and not give up much if any HP. Otherwise, a fast ramp shelf grind from Hughes or Comp in the 230'ish range (intake duration @.050) should work well. Note I'm assuming since you put some miles on you may want a bit less overlap vs the 509.

On Hydraulic vs solid... the solid has the edge in power and drivability and I think its easier to set up compared to a hi po hydraulic. Either really needs adjustable rockers. The solid will make some "sewing machine" valvetrain noise but so will a fast ramp hydraulic.

Posted By: 451Mopar

Re: Help me select a cam - 03/27/14 08:04 AM

The Performer RPM is fairly tall and may make air filter to hood clearance a problem unless your car has a scoop?
I like the Voodoo cams, they use the 3-bolt timing gear. The Comp XE cams are also good if you need to use the single bolt timing gear.

Are you looking for a cam milder than the Mopar 0.509?

knowing the actual compression ratio would help. Do you know what pistons are used and the cc's of the heads?

Posted By: Mr.Yuck

Re: Help me select a cam - 03/27/14 01:14 PM

Six pack, MP 528 solid w/ 1.5 roller rockers lash tight. It will run great. If you want a hydro cam, call and have a custom grind made or go with the Eddy RPM cam 7177 (488/510)

The six pack will give you better performance and economy than either of those carbs. If you want to stay 4bbl, I'd go with an old fashion 750DP or 750HP. (although for max HP you'll need a bigger carb)

Attached picture 8090222-4406a.jpg

Posted By: DGS

Re: Help me select a cam - 03/29/14 09:11 PM

Thanks guys. Unfortunately I don't know the exact compression ratio - engine was rebuilt in the past but previous owner didn't what was done to the engine.
Not stuck on a hydraulic grind but I would like some more vacuum than with the 509.
I have a set of BB max wedge adjustable rocker arms on the shelf - not a true 1.5 more like 1.45 I've been told. Would these work or should I get a different set of rocker arms?

Posted By: DGS

Re: Help me select a cam - 06/25/14 08:47 AM

I was recommended the Comp Cams XS274S. It has an intake duration of 236 @.050 which should work well.

Before I pull the trigger on this cam is there anything from Hughes which would work?

Posted By: Hughes

Re: Help me select a cam - 06/27/14 11:19 PM

Shoot me an e-mail at kevin@hughesengines.com with the answers to as many of these questions as possible and I will help you pick one out.
Engine size (cubic inch displacement)
Weight of vehicle, with driver (if a driver is used)
What category does your use fit? 1 thu 8 See below.
Altitude where vehicle will be run.
Desired ET or MPH
Present camshaft (duration @ .050", Lobe separation angle, lift etc...)
Final gear ratio
Stall speed of torque converter
Tire height and width
Fuel type
Static or Mechanical compression ratio
Iron or aluminum heads
Measured Compression Ratio
Intake manifold
Header type and size
Carburetor size
Rocker arm type and ratio
Will power adders be used? (N.O.S., turbo, supercharger etc...)
Cylinder head air flow numbers

Posted By: ahy

Re: Help me select a cam - 06/27/14 11:55 PM

Quote:

Thanks guys. Unfortunately I don't know the exact compression ratio - engine was rebuilt in the past but previous owner didn't what was done to the engine.
Not stuck on a hydraulic grind but I would like some more vacuum than with the 509.
I have a set of BB max wedge adjustable rocker arms on the shelf - not a true 1.5 more like 1.45 I've been told. Would these work or should I get a different set of rocker arms?

On the rockers, I think those (iron adjustables I assume) would work fine if in good shape. The iron rockers need a shaft with correct hardness. If you are not sure about yours, new shafts recommended by the cam supplier would be good insurance. The shafts Comp supplies with their cast steel rockers would be fine also.

Posted By: Dunnuck Racing

Re: Help me select a cam - 06/28/14 12:36 AM

Do yourself a favor and call a couple cam companies, including Hughes. See who asks all the important information to make a wise choice. As you can see by Kevin's post, Hughes will.
The only company I trust enough to pick something if I didn't spec my own would be Hughes.
Keith

Posted By: therocks

Re: Help me select a cam - 06/28/14 02:27 AM

IIRc a member Dwayne Porter will also grind you a custom cam.I believe Ron 383 Man used his cam.He will make you one that works.Rocky

Posted By: DGS

Re: Help me select a cam - 06/30/14 12:47 PM

Thanks guys, I will shoot an e-mail to Kevin an Dwayne.

Posted By: B3422W5

Re: Help me select a cam - 06/30/14 04:14 PM

I second Dwayne. He has been spot on in cam choices when I have used him

Posted By: ademon

Re: Help me select a cam - 06/30/14 04:22 PM

If the engine runs now take a cranking psi reading ... that will give a good idea to the cam company on which way to go. And what the engine will be happy with.

Posted By: Diplomat360

Re: Help me select a cam - 06/30/14 06:56 PM

What are your goals in the NEW cam as compared to what you have right now?

Sounds like you are looking to stick with something right for the gear ratio you have (if I'm reading the posts correctly). I second the 230@0.050 recommendation...beyond that you may want to play with the LSA and so forth to smooth out the idle and drive for more vacum at lower RPM.

Posted By: DGS

Re: Help me select a cam - 06/30/14 10:07 PM

You're right I want to stick with the 3.23. Goals are nice torque curve with enough vacuum for power brakes.