The Dodge Challenger Message Board

Ok dave after tons of looking i have lost my cam card, i have the specs

hughes,0.538/0.549 lift

duration @.50 223/230

now that is with 5:1 rockers and i switched way back when, (when i lived in another house where the cam card is)
to 6:1 rockers and i dont do math, never could ,so can you figure out what the new lift,duration etc?

If you think rockers are 5:1 and 6:1 instead of 1.5:1 and 1.6:1 then it is no wonder you are getting confused!

I don't see a cam listed at Hughes with either that exact lift or duration. Hydraulic flat tappet cam isn't it? or have you got a roller in there?

They list the valve lift for each cam with 1.5 and 1.6 ratio rockers.

Duration is not effected by the increase in rocker arm ratio because the cam is specified at tappet lift not valve lift.

But assuming you are correct on the lift given then divide that lift by 1.5 to get the tappet (lobe) lift.

0.538/0.549 / 1.5 = 0.358/0.366 lobe lift.

Now multipy by the 1.6:1 rocker ratio;

0.358/0.366 x 1.6 = 0.572/0.585

dave-r wrote:If you think rockers are 5:1 and 6:1 instead of 1.5:1 and 1.6:1 then it is no wonder you are getting confused!

I don't see a cam listed at Hughes with either that exact lift or duration. Hydraulic flat tappet cam isn't it? or have you got a roller in there?

They list the valve lift for each cam with 1.5 and 1.6 ratio rockers.

Duration is not effected by the increase in rocker arm ratio because the cam is specified at tappet lift not valve lift.

But assuming you are correct on the lift given then divide that lift by 1.5 to get the tappet (lobe) lift.

0.538/0.549 / 1.5 = 0.358/0.366 lobe lift.

Now multipy by the 1.6:1 rocker ratio;

0.358/0.366 x 1.6 = 0.572/0.585

Im dizzy after reading that.

ok yes i get number confused quite easily , Im more of an artist than a tech.

yes I looked on Hughes site,and couldent find that cam i bought it in 1999.

They probably quit making it,but i had some issues with geometry and used there adjustable push rod to get the length correct,and went with the 1.6:1 rockers and never figured out the new specs,its a hydraulic cam and lifters,

and since then i havent had any problems,

but i just wanted to know ,and I knew you would know , you love numbers and i dont, thanks a bunch Dave

and yea Wayne this stuff makes me dizzy

Nice Hi-Po cam Drew