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SRT17
11-06-2010, 11:10 PM
What is the best cam choice for an b hobby class?
med. banked 3/8 mile track
Motor specs on what I have.

Stock bottom end
Hyper pistons .030 over
stock heads 441 or 882
edelbrock performer intake 7101
Holley 600 single line vac. sec.
1.5 stamped rockers
1.94 & 1.50 valves
Cam rule is .425 lift at the valve..

What would work the best with what I have?
Any advice would be helpful.. Thanks

hpontap
11-07-2010, 07:07 AM
Several grinders make cams for the lift rule you have.
The stock bottem end is your limiting factor here.
For a cheap, off-the-shelf grind, the Howards 110071 or the 112701-06 would get a little more topend.
Good luck.

usafracer
11-07-2010, 07:53 AM
Hyd. or solid lifter?

SRT17
11-07-2010, 09:26 AM
Sorry...Hyd... Would a special grind be a better choice over off the shelf ? With the valve lift rule.

SRT17
11-07-2010, 06:08 PM
I looked at the Howards cams at summit. My next question is which is better more duration or valve lift? Thanks..

hpontap
11-07-2010, 08:12 PM
Theoretically, you cannot get enough valve lift in a SBC head because flow increases with lift which is influenced by the ability of the camshaft lobe/lifters/springs etc., to open/close as quickly/much as possible/optimal timing on openings and closings/ still be dependable and the valve springs able to control the "bounce", vacuum demands /carb booster signal etc. etc. etc. Hence solid roller cams were born.
The bigger duration holds the valve is open longer. Higher duration/more overlap( both intake and exhaust valves open at the same time.)
More duration usually means that the engine will make power higher in the RPM range.
Camshafts are the trickiest thing in an engine to try to understand IMO.
Sorry I cant explain it better.