What Cam?

[stroke]

Im building a 383 Small Block can any one tell me what cam would get the most out of me engine and if i need to change the converter. I do know i want Hydro Roller. Here are some specs of my engine and drive line.

ENGINE SPECS
10:1 compression
Edelbrock Performer RPM Air-Gap Intake Manifold
Hooker Super Competition Headers
CNC DART ALUMINUM SBC PRO 1 23° CYLINDER HEADS•INTAKE PORT VOLUME 225CC VALVE INT 2.08" EXH 1.600" •CHAMBER 72CC HEADS HAVE COMPLETE CNC PORTS AND COMBUSTION CHAMBERS •INTAKE FLOW 320CFM @ .700 •EXHAUST FLOW 234CFM @ .700
Holley750 cfm Ultra Double Pumper or Holley 700 Double Pumper
1” tall Street Sweeper Super Sucker carb spacer

TRANSMISSION
A Monster 700R4 Transmission, Remanufactured, 4x4, Super, Heavy Duty, 4WD From Monster Transmission This Transmission comes with a 3.06 ratio in first gear, and a 30% overdrive
A 1650 RPM Super Duty Torque Converter From Monster Transmission
700R4 External Lock-Up Kit from Monster Transmission

[vetteoz]

What is your intended use?
Are very big heads for a street 383 . Cam to work best with those heads is not going to be very street friendly
Then that sort of cam will need low gears and hi stall (3K or higher )

[stroke]

This engine is for my Pro Street trophy truck (A Truck built for High Performance Street and off road dessert Racing) I don't really know what to call it. I just want to go fast on and off road. No rock climbing. No 6 inch lift Just long travel suspension

My goal is for 500 HP and 500 pounds of torque. I am planning to dyno it. I also wanted a cam that range was at max 2000 rpm to at least 6000 rpm with a very mild to a mild rumpety rump

The reason I'm using big heads is Because I'm using 6 inch H beam Rods with 5cc Flat top pistons with two valve reliefs and two get my 10:1 compression ratio i needed 72cc heads. I'm also planning to CNC the intake manifold if it needs any where just to help it flow better

Why would the cam size be based off the head size and not the compression ratio?

[vetteoz]

Originally Posted by stroke

Why would the cam size be based off the head size and not the compression ratio?

I was refering to the 225c intake port size. Most are running 195cc intakes on 383's with flows in the 260-280 range.
Big ports are designed to move air at revs ; at low revs engine can become unresponsive because port velocity is too slow meaning fuel drops out.
To see the benefit of 320cfm you need a big cam (hi lift / long duration ) to hold the valves open low enough.Big duration cam = crap bottom end , rough idle and low vac for brakes

[vetteoz]

Check out this build
http://www.sallee-chevrolet.com/Chev...8s/383-500.cfm

500Hp 383 using 195 heads and and relatively short duration of 234° / 238°

[67chevelle]

If you haven't bought those heads yet I'd go with some smaller runner sizes. As far as your cam is concerend I'd go with a solid roller instead of a Hyd the weight of the Hyd will make it a little more sluggish at lower rpms. To be honest with you for your intended purpose your combo might not give you the performance your after. ThAt motor is more of a drag setup that will run great from 3500- 7000. With those heads I'd look into a monster cam something north of .680 lift and a pretty tight lobe seperation. If you have the time swing by a book store And grab the sa design book how to build horsepower. It is outdated but it'll give you a good basis for understanding engine dynamics.

Nathan