Switched from comp pro magnums to crower because I was told that there have been cars gain 10-30 at the wheels switching to crowers is this true? What are your guys thoughts on this?

 

10-30 hp gain from the same ratio rocker? I don't see that happening.

 

How if they both achieve 1.6?

 

Sounds like someone just wanted to make $$ of you.

 

I've heard before that the crower's were better then comps! But nothing along the lines of picking up 10-30hp from swaping them.

 

hold a comp beside a crower
crower are alot higher quality.......not sure about any power gains

maybe you meant pushrods

 

HP gains from stock, maybe, but not compared to another 1.6 ratio rocker.

 

No, I meant rockers. A well known shop told me this. Their a sponser on ls1tech. I didn't really understand either maybe their alittle lighter and stable which free's up a few. Just wanted to see if someone could vouch for this. Thanks

 

they are full of crap

 

"Survey says...ERRR!"

Sorry man, they were just trying to make a buck off of you. Those are right about the expected power gains going from the stock ration to a 1.6 rocker. If you didn't install them yet, I'd return 'em.

 

if you want nicer RR, the Comp stainless are a nice piece too...won't gain you anywhere close to 30hp over the Procomp's of the same ratio though.

 

Those are what I run...and they seem to last as I'm ready to start my 13th year with them...

--Alan

 

Well... that's the question isn't it? The ratio of lobe to valve lift isn't constant accross the lift range due to the geometry involved, as well as set up (travel accross the valve stem during lift). The stated ratios for rockers are good average numbers, but not exact at all valve lifts. I believe Crane comments on this in their advertising/articles.

It's possible the rockers are say 1.62:1 and advertised as 1.6:1 (several 1.5:1 rockers are like this)... but I really doubt any of this amounts to 30hp extra.

 

Crower's are nice but I'd NEVER pull ProMags (a proven, reliable rocker) and replace them with the same ratio crowers... waste of time and $$$.

Exception? if going to a huge solid roller cam with aggressive lobe profiles and strong springs, or say 7000+ rpm runs (aftermarket PCM). If that was the case I'd expect to be in shaft rocker territory anyway... no point to high price rockers using studs (ProMags on ARP 7/16" studs are plenty sturdy otherwise).

real hp gains? doubtful... unless the baseline run was done with extra tight lifter setups or poor geometry (pushrod length).

 

What sponsor?