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selecting a camshaft for a street 383 chevy??

12K views 2 replies 3 participants last post by  vinniekq2 
#1 ·
I was wondering what is the best RPM range for a hydraulic roller camshaft for a street 383 chevy with 9.5 compression, edelbrock rpm heads 185 intake runners, its going into a 1978 chevy truck which i believe is right around 4000 lbs and i am getting 3.42 posi traction unit by the end of the month...

1000 - 5000

1200 - 5400

1600 - 5600

or if you have any suggestions?

ITS A STREET ENGINE ONLY... street light racing, high way cruising or getting down on it from time to time...
 
#2 ·
Is this a Gen I motor, using a retro-fit cam or is it a Gen I L31 roller block or what?

A 1000-5000 cam would be my choice for a daily driver. It's right on the edge of being too short for the 9.5:1 static compression ratio and should make some excellent cylinder pressure. What I like about this cam is its compatibility with the 3.42 gear and a stock torque converter. Pay attention to the squish and bring it in at around 0.040" to help prevent detonation on pump gas. Make certain that the pistons you choose have a generous flat deck on the crown to mate up with the underside of the cylinder head. Installing the cam 2 degrees retarded will help pull some of the cylinder pressure out of the motor at low rpm's.

Here's a retro-fit Crane roller in the general area where I might be looking.....Again, it's the shortest cam I would use in this combination, but it will be the strongest street driver. Should feel real good stoplight to stoplight.

Part number 119811.
Requires cam button spacer, aluminum-bronze distributor drive gear not required. For engines
equipped with mechanical fuel pumps, fuel pump pushrod Crane part number 11985-1 is highly recommended to prevent fuel pump lobe wear.
Brute low end torque and HP, smooth idle, daily usage, towing, economy, also mild turbocharged.
2200-3000 cruise RPM.
8.0:1 to 9.5:1 static compression ratio advised
Grind number HR-260-2-12 IG
Operating RPM Range 1000-5200
Hydraulic roller tappets part number 11532-16. Vertical locking bar design, no machining necessary.
Advertised duration 260/270
Duration at 0.050" tappet lift 204/214
Lobe separation angle 112 degrees
Intake opens (-5) BTDC
Intake closes (29) ABDC
Exhaust opens (44) BBDC
Exhaust closes (-10) ATDC
Intake valve lift 0.429"
Exhaust valve lift 0.452"

Please be advised the the very best way to choose a camshaft is to talk with one of the tech guys at your favorite grinder. I've given you my choice, but it might not be their choice and they know their products way better than I do.
 
#3 ·
I choose cams for the RPM range I want my engine to perform best,and best match the heads flow numbers.The carb/intake and exhaust need to be matched to the cam/heads/CR.
If you have an application that is not ideal to the engines potential then you can compromise the cam to better fit the spot the engine lives in,IE: a very heavy car with poorly matched driveline components,expected to drive under adverse conditions.example Im hinting is a truck used for towing a trailer is not a great place to install a 383 with a lumpy cam that makes top end or peaky power. what other parts are going with this "cam" selection? I
 
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