on a stock 5.2-5.9 motor? just wondering wut hp gain u see.nobody has a dyno of a before/after with them so it is y i ask. i recently bought hs 1.7 rr's some waiting to be installed. heard it gives .030-.050 more lift

 

i want to know this also

 

At .500 lift at the valve, (which the stock cam does not do.... just an example.) swapping to the 1.7 rockers would yield .531~ lift. But, it isn't all just about gross lift..... the higher ratio will also tend to open the valves faster, giving you more duration at >.050 valve lift. (more "area under the curve")

Not much info available in the way of just how much you get out of 'em. Best guess appears to be 15 to 20 horseys, and slightly higher numbers on torque.

 

John Mercedes at Southeastperformance (one of the engineers of the HS rocker for magnum engines) used to advertise 22hp. I recall that he had told me on the phone once that he thought the numbers might actually be slightly higher on a 5.2 (can't remember why, I think it was due to the lighter faster reving of the smaller block), but they had only dynoed the 1.7's on stock 5.9 and 5.9 R/T's. I'm sure you can get those dyno sheets from him if you asked him, or they might even still be up on their website.

You are correct about the lift, but keep in mind too that the stock rockers are stamped steel and flat tip. The HS rockers have roller fulcrum and roller tips, and are made of aluminum. This adds speed and efficiency and reduced drag of the arms itself. That equals extra ponies too, so as HeyYou said, there is more to it then just the lift #'s.

 

Actual dyno gains I seem to remember being 10-15RWHP.


I did the calculations a while ago, the 5.2 has a little more lift than the 5.9, actual lift increase was around .027" for the 5.2 and .023" for the 5.9.

How much smoother it runs from 4500+rpms was worth it alone.

 

What are the specs for the stock cam? (lift and duration, etc.)

 

https://dodgeforum.com/forum/2nd-gen...num-360-a.html

 

How about 5.2L cam? I keep hearing that it is actually hotter then the 5.9L cam and it makes me wonder if I should have put the 5.2L cam in my 5.9L when they were both out of my truck.

 

http://www.pavementsucks.com/board/t...tock-cam-specs

 

Ya, the 22hp number probably not rwhp. I agree on the smoothness, but I felt like it was much lower then 4500. I felt it from about 2000 on up. Just feels like it pulls harder through most of the RPM range. One of my favorite mods.