back in the late 1960s and early 1970 most of us were gullible enough to actually believe, most of the magazine engine build results were legit, and when some racer promoted the cam he used many guys figured that was all they needed, to add to their stock 302 z28 to run those track times, after all we had been told it was basically a track car,, it took awhile for the smarter guys to figure out that what you were told was in an engine and what actually was in an engine might be vastly different.
brownfield heads, crane fireball ported heads, etc were all just starting to be used.
I still remember seeing a "stock" 1964-1965 GTO (built and run by a local dealership)run 12.2 second times (only to find out a few years later that the "stock" 389 was a 12.5:1 cpr 421, with an acid dipped hood, front fenders ,trunk, and stripped interior)
Standard 302 (30-30) cam, P/N 3849346
Casting #3849347
254 duration @ .050" (intake & exhaust)
.485" lift (with 1.5 rockers)
114 deg. lobe separation
Exhaust Max lift @ 116 deg. BTDC
Intake Max lift @ 112 deg. ATDC
First Design Off-Road cam, P/N 3927140
Casting #3927141
Intake 257 duration @ .050" (333 advertised)
Exh. 269 duration @ .050" (346 advertised)
Lift: .493" intake, .512" exhaust
Intake Max lift @ 108 deg. ATDC
Exhaust Max lift @ 116 deg. BTDC
2nd Design Off-Road cam, P/N 3965754
Casting #3965751
Intake 248 duration (324 advertised)
Exh. 267 duration (334 advertised)
Lift: .512" intake, .535" exhaust
(CRANE CAMS USED TO SUPPLY MANY G.M.PERFORMANCE CAMS,
Chevrolet Performance LT4 Hot Cam Hydraulic Roller Camshafts 24502586
this is no longer true and QUALITY has dropped off noticeably by who ever is currently supplying the cams)
back around 1969,we used to buy those cams for $47 each at the Chevy parts counters, matched lifter sets we $38 they sounded great,but they were designed for road racing not drag racing,and we found that there were better designs for drag racing cams
but we soon found the faster cars were running a CRANE 110921 in heavy cars with 3.90:1-4.11:1 rear gears and for lighter cars with a 4.56-4.88:1 rear gear the 110981(back then they were called something else, before crane changed their part numbers)
if your convinced you need a hydraulic lifter cam this crane 110711 gives reasonably good performance in a 10.5:1-to-11:1 compression 383 built to similar specs
both cams really require a 350-383 displacement with about 10.5-11.5:1 cpr, headers and a decent intake to run effectively
you might want to read thru these
viewtopic.php?f=55&t=3431&p=9088&hilit=crossram#p9088
viewtopic.php?f=87&t=1938
viewtopic.php?f=55&t=444&p=10794&hilit=+dual+quads#p10794
viewtopic.php?f=32&t=511&p=636&hilit=corvette+crossram#p636
http://www.cranecams.com/userfiles/PP0811A_SinglePages.pdf
BTW if you do decide to build a 302 displacement engine, getting the engine compression up in the 11.5:1 range and using some mildly ported vortec heads, with bigger valve springs, better clearance, and 1.6:1 roller rockers, with a matching vortec single plane intake and a crane 110921 flat tappet solid lifter cam,and a manual transmission, with a 3.9:1-4.56:1 rear gear ratio, and a good 7-8 quart baffled oil pan has repeatedly proven to make a decent combo in a fairly light car
brownfield heads, crane fireball ported heads, etc were all just starting to be used.
I still remember seeing a "stock" 1964-1965 GTO (built and run by a local dealership)run 12.2 second times (only to find out a few years later that the "stock" 389 was a 12.5:1 cpr 421, with an acid dipped hood, front fenders ,trunk, and stripped interior)
Standard 302 (30-30) cam, P/N 3849346
Casting #3849347
254 duration @ .050" (intake & exhaust)
.485" lift (with 1.5 rockers)
114 deg. lobe separation
Exhaust Max lift @ 116 deg. BTDC
Intake Max lift @ 112 deg. ATDC
First Design Off-Road cam, P/N 3927140
Casting #3927141
Intake 257 duration @ .050" (333 advertised)
Exh. 269 duration @ .050" (346 advertised)
Lift: .493" intake, .512" exhaust
Intake Max lift @ 108 deg. ATDC
Exhaust Max lift @ 116 deg. BTDC
2nd Design Off-Road cam, P/N 3965754
Casting #3965751
Intake 248 duration (324 advertised)
Exh. 267 duration (334 advertised)
Lift: .512" intake, .535" exhaust
(CRANE CAMS USED TO SUPPLY MANY G.M.PERFORMANCE CAMS,
Chevrolet Performance LT4 Hot Cam Hydraulic Roller Camshafts 24502586
this is no longer true and QUALITY has dropped off noticeably by who ever is currently supplying the cams)
back around 1969,we used to buy those cams for $47 each at the Chevy parts counters, matched lifter sets we $38 they sounded great,but they were designed for road racing not drag racing,and we found that there were better designs for drag racing cams
but we soon found the faster cars were running a CRANE 110921 in heavy cars with 3.90:1-4.11:1 rear gears and for lighter cars with a 4.56-4.88:1 rear gear the 110981(back then they were called something else, before crane changed their part numbers)
if your convinced you need a hydraulic lifter cam this crane 110711 gives reasonably good performance in a 10.5:1-to-11:1 compression 383 built to similar specs
both cams really require a 350-383 displacement with about 10.5-11.5:1 cpr, headers and a decent intake to run effectively
you might want to read thru these
viewtopic.php?f=55&t=3431&p=9088&hilit=crossram#p9088
viewtopic.php?f=87&t=1938
viewtopic.php?f=55&t=444&p=10794&hilit=+dual+quads#p10794
viewtopic.php?f=32&t=511&p=636&hilit=corvette+crossram#p636
http://www.cranecams.com/userfiles/PP0811A_SinglePages.pdf
BTW if you do decide to build a 302 displacement engine, getting the engine compression up in the 11.5:1 range and using some mildly ported vortec heads, with bigger valve springs, better clearance, and 1.6:1 roller rockers, with a matching vortec single plane intake and a crane 110921 flat tappet solid lifter cam,and a manual transmission, with a 3.9:1-4.56:1 rear gear ratio, and a good 7-8 quart baffled oil pan has repeatedly proven to make a decent combo in a fairly light car
Last edited by a moderator: