bigsticksupra

iTrader: (3)

I have a stock LS1 with Texas Speed stage 2.5 heads (with the larger valves), GM MLS, Comp Cams XE-R 228/232 .588 .598 on a 112LSA camshaft, Comp Cams dual valve springs/ti retainers, Comp Cams 7.4 push rods, and LS7 lifters. I want a simple way to get a little more power out of it and was wondering if it would be a good idea to put in some Comp Cams Pro Magnum 1.85 ratio rockers? Do you think there would be any PTV issues? how much power can i expect from the rocker swap? Thanks.

bigsticksupra

iTrader: (3)

anybody?

usaf_hess

iTrader: (8)

i would think that it would net you at least a 15 or so hp increase maybe more from swaping up in ratio but dont quote me cause i could be devistatingly wrong but you have to take into sonsideration that your increasing the lift of the cam when you do this, as for piston to valve issues i doubt you would have a problem with the lift your cam is giving which these rockers would bump to around 600 even and you have double springs. id wait and get a few more opinions and talk with a few shops. but seriously anybody who knows more about this than me please chime in.

JPH

iTrader: (2)

XE-R lobe stuff with 1.8s or more probably isn't the best setup. If you want more valve lift, you should have gone with a duration @50 with more lobe lift. With your setup now, I don't see you having any problems making the hp&trq that you so call desire. The expense of the 1.8s on top of your current profile, I believe won't give you the bang for the buck that your looking for. Put a 92/92 on it.

snake charmer

iTrader: (118)

man a 1.85 rocker it would make a lot more lift . especially with .588 and .598 valve lift .
so stock is 1.7 and a 1.85 has that lift you would be looking at a 10% more valve lift on that cam . just going off that your valve lift would look around .646 .657 at least if not more .

SOMbitch

iTrader: (8)

Simply put NO.You can't reliably use those rockers with XE-R lobes because the ramp rate is too steep.

bigsticksupra

iTrader: (3)

Thanks for the input guys. What about the Comp Pro Magnum 1.75 ratio? I can get these rockers for a smokin price so that's why im asking about them.

teke184

iTrader: (5)

if you want more power, swap on the FAST 92/92

or an electric wp

bigsticksupra

iTrader: (3)

already on order but still want a little more power N/A without doing a cam swap so i thought about the rockers..

1989GTA

You have to be carefull about going to higher rockers ratios like you are looking at. You may actually loose horsepower do to valve float. As was suggested in the above posts the acceleration rate of your cam may not be able to use a higher rocker ratio.