I need camshaft help!! Please
Last edited by jweyhrauch; Dec 19, 2014 at 07:15 PM.
I would work the heads before deciding on the cam because if you increase flow 25cfm that is like 50HP and then you can do some fuel curve changes and that could really be killer.
Remember the engine is an air pump and that is what gets it done bigger cams only access the same head flow for a little longer and usually kill bottom end if they are not designed to the cylinder head flow.
25 years on the Chassis DYno gives me a different perspective than most.
Mark@AlienChassisDYno.com
Much different application but I made the mistake of cam before stall and while the car drove fine it gained no performance at the track. 2700lbs and 3.73s might change make it matter less but I still think it is important.
On the heads first, while I wholly agree heads are the single biggest source of HP on an engine I have also seen cases where tiny little stock cams can not use any more than stock flow.
Take for instance the 5.3l engines from 06-08 they gained what 15hp with the new intake with bigger TB, and an upgrade to 243 heads. I don't know all the cam specs and compression so I won't claim this is a complete picture, but a GM power train engineer told me the intake/TB were worth 6hp by themselves.
Point being I think with a stock truck cam heads won't shine, give it even a mild aftermarket cam and good ported heads and the gains can be huge and make such a lite vehicle feel like a rocket.
Edit:
Went and googled 5.3 cam specs and came up with this.
http://www.hotrod.com/how-to/engine/...st-comparison/
Huge difference in the 5.3 cam vs the LS1 car cam so while a car might make substantial gains with heads alone I don't think a truck will, .030" less lift and 11degrees less intake duration are a big deal.
Last edited by 96capricemgr; Dec 21, 2014 at 06:51 AM.
I would work the heads before deciding on the cam because if you increase flow 25cfm that is like 50HP and then you can do some fuel curve changes and that could really be killer.
Remember the engine is an air pump and that is what gets it done bigger cams only access the same head flow for a little longer and usually kill bottom end if they are not designed to the cylinder head flow.
25 years on the Chassis DYno gives me a different perspective than most.
Mark@AlienChassisDYno.com
Also 96capricemgr, I didn't think that 2700 lb number sounded right either so I googled it and it's stock curb weight is only 2560 lbs so 2700 seems pretty believable.
Last edited by Fry_; Dec 21, 2014 at 11:26 AM.

