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ejm
09-10-2009, 06:42 PM
quick question does the duration of o cam decide torque and horse power??? lets say if you have a cam (solid roller) with a lift of .714/.710 with a duration of 299-310 does it have less torque but more hp than lets say a cam of the same liift but a duration of 315-327? thanks for the clearing up you guys are great help for us rookies!

OneBadGMC
09-10-2009, 07:52 PM
There's far too many variables to take into consideration.

Advertised duration numbers aren't used much. The duration numbers at .020 and .050 are more precise.

That's why it's always best to pick a cam company you like and work with them to develop a custom cam for your application.

Sometimes it'll be a common combination and they'll have a shelf cam that will work. Sometimes it won't, and they can custom grind a cam for you.

russ67chevelle
09-10-2009, 10:08 PM
lets just say your talking a bbc cam.if you do nothing but keep the valves open longer you will move your power curve higher in rpm.but the down side is sometimes by doing that you give up torque.

are you trying to figure out a cam for a particular combo?

oldandtired
09-11-2009, 07:32 AM
Don't forget overlap. Controls the temperment of the cam.
dave

ejm
09-11-2009, 05:45 PM
that all makes alittle more sense now to get really what you need u need to take everything your motor is and then build your cam and russ that was what i was tring to figure outthank you guys

signsbyesa
09-11-2009, 10:12 PM
there are alot of cam companies to buy from and most of them can tell
you what you need when he knows what you want it for, when i orded
my first cam i did not know what i wanted but told him what i had
and what i was going to use it for and i got a real good cam that
had a good response and a lumpy sound and that was the late
chet herbert, he would actualy answer the phone and tell you
the numbers on the phone, he was a good guy, RIP :wink:
i was 16 at the time now im 47 i like the idea of roller
cams, less friction :wink:

Tod74
09-11-2009, 10:53 PM
I think the biggest advantage of a roller is they can have a much more aggressive profile...they can snap the valves open much quicker than you can with a flat tappet.I'm no cam guy I let the experts pick mine for me...the main thing is be completely honest with them in the description of the car/engine and your application.Give them as much ACCURATE information as you can. Especially the compression ratio...don't guess, KNOW what it is, or will be. JUST MY OPINION

ejm
09-12-2009, 08:52 AM
so if the cam i have is not working quite well for me(came in motor i bought) is it better or cheaper to have it ground for my application or to get a new one made

Tod74
09-12-2009, 09:10 AM
Is it a solid roller? Those Can be reground sometimes but I have never heard of a flat tappet being reground....they are cheap anyway.

ejm
09-13-2009, 04:53 AM
yeah its a herbert solid roller