Like others have said...Get a custom grind for your 1.7s, but that will mean new springs and custom length push rods.

Push rod length will have to be dead nuts on since the HS rockers you have are non adj.

Stock springs can barely handle a stock cam, especially with some miles on them...And more spring pressure raises the chances of the stock two piece valves snapping the heads off the stems.

 

If I understood the guy I talked to at Hughes about the whiplash cam in the magnum motor I put in my Mazda pickup the centerline of the cam has to due with the relation of the lobes to the the center of the cam. The factory cam is a 114 degree LSA. Dropping the lsa and more lift and duration gives that nice aggressive idle. Now I may not be 100% right, this is just how I interpreted what he told me.

 

You're right, lope at idle comes from tight lobe seperation & large duration, like the 548/547 236/242 @ 108º installed at 104º in my Dakota.

 

Is that .050 duration or advertised?

 

.050 duration

 

So the lsa of this cam is 112 right but what does the intake centerline mean it says it is 108
http://www.compcams.com/Company/CC/c...?csid=659&sb=2

 

Hows about a little reading material.

 

I have read that I just like to hear it from someone so I know I do everthing right.

 

That's a thumper right there.

 

That's a thumper right there.