20 to 30hp from roller rockers????

[kkchevy3]

So in the process of rebuilding my stroker after the cam/distributor gear went south. Had called up one of the companys that is building stroker parts and motors and was chatting with the guy. I had mentioned about getting my throttle body bored out and he sugests that i go with a set of their non adjustable roller rockers that i would see alot more bang for my buck. He told me they are seeing a 20-30 hp improvment with just this? That just dont sound right. What are you guys thinking.

[gonridnu]

Roller cam yes....roller rockers doubtful. Maybe if the cam was way too small for the application and an increase in the rocker ratio corrected it but not from friction reduction of the rockers or the fact they are slightly more accurate in ratio. Politico would rate this "pants on fire".

[Antifreeze2]

I also doubt that the gain would be that high. To my understanding, RR's reduce friction, reduce valvetrain weight, reduce flex in the rocker arm--keeping the ratio truer. In my book, it amounts to the potential to run higher RPMs. I'm trying out RR's in my build because I've never had them before, and I hope Crower SS rockers will last > 100K.

[5-90]

Rollerised rockers will reduce friction in the top end - which reduces parasitic drag. The extruded aluminum bodies also tend to be stiffer, giving more consistent valve action.

I could see a few BHP output improvement, but not 20-30.

Rollerised tappet feed allow the use of a more aggressive camshaft profile (opening/closing is much quicker,) which increases the "area under the curve" and allows for greater airflow - /that/ can be worth a few dozen BHP gain, depending on timing changes coupled with more aggressive lobe ramps.

However, I don't consider installing rollerised rockers to be a performance modification /in/ /se/ - although it usually does complement other valvetrain mods when trying to make power (and I also think that reducing the friction helps to increase reliability.) The best RRs would have bearings at three points - pivot, valve tip, and pushrod seat (sort of a "swinging cup" deal for that, needle bearings in the middle, and a single large roller tip out at the working end.)

[SilverXJ]

I doubt you will see a gain in HP. What you will have is a more controlled valve train with consistent action, your valve guides will last longer from the lack of the rocker trying to pull them back and forth, cooler oil temps from reduced friction, and ease of setting a uniform preload.

[IH 392]

Maybe at 7000 rpm's?

[Cheromaniac]

I doubt you will see a gain in HP. What you will have is a more controlled valve train with consistent action, your valve guides will last longer from the lack of the rocker trying to pull them back and forth, cooler oil temps from reduced friction, and ease of setting a uniform preload.

Mostly agree with the above. At best you'll gain 0-5hp. The biggest benefit of roller rockers (especially shaft-mounted) is a more stable valvetrain at higher rpm. Yes there's reduced friction but not enough to see a measureable fall in oil temp. from my own experience. Adjustable RRs do allow you to set the proper lifter preload without needing to either shim rocker arm bridges or change pushrod length, but you'd need a Hesco valve cover spacer and a Hesco thermostat housing spacer to provide the necessary clearances.

[wjtom]

i have a good guess who you called.dont buy anything from them!i did and am sorry.took 5 months too get my parts and the answer to every problem is its a project.basically meaning its your problem.if you want to email me i will discuss it but i am not going to have a pissing match on here with someone.i know how much i spent and should not have had the issues i did!all i have to say is it wasnt hesco!

[Cheromaniac]

i have a good guess who you called.dont buy anything from them!i did and am sorry.took 5 months too get my parts and the answer to every problem is its a project.basically meaning its your problem.if you want to email me i will discuss it but i am not going to have a pissing match on here with someone.i know how much i spent and should not have had the issues i did!all i have to say is it wasnt hesco!

I'll bet it wasn't Ghostbusters but you kinda let the cat out of the bag when you posted this in another thread:

can only say take everything from 505 with a grain of salt.everything i got from them was reboxed in blank packages.i worked in a speed shop for a bunch of years and have never seen a custom camshaft without some sort of identifing mark so it could be tracked.mine have nothing but the lobe separation on them.where it came from is hard to say plus it took close to 2 months to get.