I recently had a long discussion with a guy who had a rather radical crower 09050 solid lifter flat tappet cam, with .465 lift and 240 duration, installed in what is basically a stock low compression sbc 350 with stock heads thats installed in an older chevelle (1965) with a 3.07:1 rear gear and a 3 speed manual transmission,
his buddies had talked him into installing that crower cam because it runs great in a different car a second friend owns , but that cars at least 700 lbs lighter, has a 4 speed and big aftermarket heads , that flow 250 plus cfm at .500 lift, and has a 3.90 rear gear ratio and its a 350 with 10:1 compression.
while this guys 350 engine has 8.5:1 compression and heads that flow less than 210cfm at max lift.
naturally it runs like crap, its got that low rumble growl idle but its muted in tone due to the low compression and by the time the cam is starting to really come into its designed power band (the crower 09050)(3500rpm-6300rpm) the heads are already reaching their flow limitations in the milder 350 so its all noise and very little power.
theres not a thing wrong with that cam, its a great cam, its just not worth much in its current application as its matched to the wrong components.
I suggested he drop back to a crane 114132 with a 210/216 duration , but hes absolutely sure that cams too mild, even though the current cams a P.I.T.A. to drive and has little power.
I pointed out the differences in the combos and explained as well as I can why the cam that runs so well in his buddy's car is a dog in his application, its not the cam, its just the wrong application for that cam
ITs a RARE hot rodder that has not screwed up an engine combo in his early career by over camming the engine or failing to check all the valve train clearances
but its not a guessing game, theres ways to figure out what duration and lift will work correctly and how to measure port flow rates, theres ways to build an engine with well tested combinations
yes it takes some effort to read the linked info and sub links but its time well spent that in the long term will save you thousands of dollars and months of work
viewtopic.php?f=44&t=38
viewtopic.php?f=52&t=181
viewtopic.php?f=52&t=322
viewtopic.php?f=50&t=4925
viewtopic.php?f=50&t=1249
viewtopic.php?f=52&t=480
viewtopic.php?f=52&t=4906
good flowing heads that flow at least 250cfm at .500 lift, with 200cc-215cc ports, a good low restriction intake, (wieand or edelbrock) 10:1-10.5:1 compression and a cam in the 230-245 duration range, and 3.45:1-4.11:1 rear gears and a manual transmission or 3000rpm stall converter, makes for a responsive combo on a 406 sbc
his buddies had talked him into installing that crower cam because it runs great in a different car a second friend owns , but that cars at least 700 lbs lighter, has a 4 speed and big aftermarket heads , that flow 250 plus cfm at .500 lift, and has a 3.90 rear gear ratio and its a 350 with 10:1 compression.
while this guys 350 engine has 8.5:1 compression and heads that flow less than 210cfm at max lift.
naturally it runs like crap, its got that low rumble growl idle but its muted in tone due to the low compression and by the time the cam is starting to really come into its designed power band (the crower 09050)(3500rpm-6300rpm) the heads are already reaching their flow limitations in the milder 350 so its all noise and very little power.
theres not a thing wrong with that cam, its a great cam, its just not worth much in its current application as its matched to the wrong components.
I suggested he drop back to a crane 114132 with a 210/216 duration , but hes absolutely sure that cams too mild, even though the current cams a P.I.T.A. to drive and has little power.
I pointed out the differences in the combos and explained as well as I can why the cam that runs so well in his buddy's car is a dog in his application, its not the cam, its just the wrong application for that cam
ITs a RARE hot rodder that has not screwed up an engine combo in his early career by over camming the engine or failing to check all the valve train clearances
but its not a guessing game, theres ways to figure out what duration and lift will work correctly and how to measure port flow rates, theres ways to build an engine with well tested combinations
yes it takes some effort to read the linked info and sub links but its time well spent that in the long term will save you thousands of dollars and months of work
viewtopic.php?f=44&t=38
viewtopic.php?f=52&t=181
viewtopic.php?f=52&t=322
viewtopic.php?f=50&t=4925
viewtopic.php?f=50&t=1249
viewtopic.php?f=52&t=480
viewtopic.php?f=52&t=4906
good flowing heads that flow at least 250cfm at .500 lift, with 200cc-215cc ports, a good low restriction intake, (wieand or edelbrock) 10:1-10.5:1 compression and a cam in the 230-245 duration range, and 3.45:1-4.11:1 rear gears and a manual transmission or 3000rpm stall converter, makes for a responsive combo on a 406 sbc
