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My buddy with the 454 Camaro is currently running roller rocker arms. I was doing some reading and it says that roller rockers are good for 15-30 HP. That's a pretty considerable gain if you ask me.
Are those numbers correct? For 15-30HP I'd consider getting myself a set of Comp Cams Magnum 1.72 roller tip rocker arms :yesnod:
What do you guys think?
BTW: My next purchase is a 3.70 rear end....should help me wind the gears up a bit quicker :)
The roller rocker arms that I'm looking at getting are the Comp Cams Magnum Roller Tip Rocker Arms for the big block chevy (1.72 Ratio ; 7/16th Stud). Jeg's has them for $145.99. For 15-30 horsepower I think it's worth it.
I'm using comp cams pro magnum 1.6's on my small block. I do believe you get a bit of a boost from them. I'd go full roller, not just the tip, I think to get the full benefit you need a roller folcrum as well.
From: WANTED: '68 rear valance with b/u light assemblies IM, e-mail, or PM me here. Thanks!
Re: Roller Rocker Questions? (bence13_33)
Cam selection becomes critical when changing rocker ratios, not to mention possible valve/piston clearance issues. Some cams don’t work well with 1.72:1 rockers because of a very steep lobe profile… causes valvetrain issues at high rpm. Consult the cam manufacturer before making the purchase and the rocker manufacturer about pushrod length.
Bence I recently changed mine over, It did pick up a little bit but not tons, I actually think it picked up more by recurving the distributor from where it was stock, I may have picked up about 10 horse with them, but I don't think my engine is capable of taking full advantage of them yet since I'm not spinning it over 5500 rpm at any time and high rpm is where they make the most difference. As far as life expectancy, I got the same kind as they put on the LT-4's, if GM will warranty them for 36k miles they must be pretty stout, at least that was my line of thinking.
Believe HP increase claims due to roller rocker useage are sometimes overstated, unless you are really turning some high (6,000 plus) RPMs. Primary advantage is less friction which results in less heat, lower oil temps. and yes, some power increase. Roller tips have advantage of less valve stem and valve guide wear, especially when used on high lift cam applications.\
Believe for most street applications, good roller tip rockers, like Comp. Cam's, are all that is needed. Also note that in many application, full roller rockers will require installation of taller, than stock, valve covers to assure necessary rocker to valve cover clearance.
I believe they say "Up To 20 hp", so a zero hpp improvement is still legal :rolleyes:
Some say you have to chrome plate & add stingray for the most gain. :cheers:
Full roller rockers add 0 over same ratio roller tip. Any gain is due to increase of ratio as stock measure less than specs. Roller tip is all you need unless over 350 lbs. spring pressure &/or turning over about 6500 rpms, then you need full rollers to prevent galling of the ball pivot.
I bought my roller rockers just to save on valve stem wear. I also run lash caps to prevent wear on the valve. Any horsepower increase is just a bonus.
Norval
They are probably a one off set thus the increased cost. Roller tipped rockers are standared equipment on the newer 3.8 gm motors. They also use floating bronze bushed wrist pins, a windage tray, roller cam , slipper pistons and thin rings.
I understand that roller tip rockers will prevent a rocking motion being induced to the valve, thus prolonging valve & guide life (so it would make sense to fit them along with new valves & guides). But a 15 - 30 HP gain? Er, how? So there will be less friction with the roller tips & fulcrums, but enough to release at least 15hp? Could somebody please explain how (I figure that if there is that much friction due to the rockers then surely the cams & followers would suffer heavy wear)? Or is that the reciprocating mass of the roller rockers is a lot less than standard, allowing better valve seat sealing at high rpm?
Are these power increase figures based on replacing worn valves, guides & rockers with new & roller rockers?
I've fitted mushroom head tappet adjusters in an engine famed for having bad rocker geometry. These also prevent valve rock and prolong valve/guide life (by a margin of several hundred % judging from the condition when I last looked). But, I didn't notice any sudden increase in power (pity!) :(
I'm not being negative here, it's just that I find it hard to believe that I can just bolt on 15 - 30 hp to my L81 so easily.
:cheers:
Paul