cam lift on 440??

[crash]

what lift can you go with stock springs on a 77 model 440??  i'm getting 9.9 hyperutectic pistons,  going to get a purple shaft cam, was wondering what is max lift for stock springs, it's dual wound springs on the one side if that matters.

[Rolling_Thunder]

wild guess..    around .500" ?

[firefighter3931]

Valve springs should allways be replaced when instaling a new cam. 

The stock heads will support .510 lift before you have to midify the valve guides for additional clearance. 



Ron

[crash]

motor is very low miles pulled it apart everything is new, almost hate to be buying pistons and rings, bearings, considering everything there is practically new because the motor is very low miles, clean enough to eat off of inside the engine,  can still see the hone marks in the cylinders, all the gaskets are oe gaskets with the pentastar on em.   

so i can go up to .510 if i wanted to with the stock springs? 

[crash]

oh yeah forgot to mention i've got a set of N.O.S. valvesprings that an old mopar guy gave me a while back when he was cleaning some stuff out his shed so was wondering about using those and what max lift was for the stock type spring.

[firefighter3931]

Different cams have different valvespring requirements. The critical specs are seat pressure and open pressure....if the springs are too soft for the application you will go into valvefloat and create a huge mess ! 

Too much pressure can wipe out the cam or lead to lifter collapse (hyd cam)

The springs need to be measured for pressure at their installed height (seat pressure) and at the cam's max lift (open pressure) Also the coilbind spec is very important....you want .050 over max lift to ensure no coilbind....very important !

Failure to properly set up the springs can lead to catastrophic damage....bent pushrods, dropped valves, broken pistons, possible cracked block.....you get the idea. 



Ron

[crash]

Different cams have different valvespring requirements. The critical specs are seat pressure and open pressure....if the springs are too soft for the application you will go into valvefloat and create a huge mess ! 

Too much pressure can wipe out the cam or lead to lifter collapse (hyd cam)

The springs need to be measured for pressure at their installed height (seat pressure) and at the cam's max lift (open pressure) Also the coilbind spec is very important....you want .050 over max lift to ensure no coilbind....very important !

Failure to properly set up the springs can lead to catastrophic damage....bent pushrods, dropped valves, broken pistons, possible cracked block.....you get the idea. 



Ron

yeah i got ya,  was looking at a set of eddybrock rpm springs, a friend can get me a pretty good deal on them.... it's a comp .470 lift with 224 duration at .50  i'm going to get aftermarket springs most definately, would hate to be outrunning that chevy, and my motor goes    then i'ma be  and the chevy boys will be