Performance Gain Stock Rockers to 1.5RR?
 

Is there any Dyno Time article or video documenting a power gain from the Stock Stamped Rockers to Roller or Roller Tip Rockers ?

Re: Performance Gain Stock Rockers to 1.5RR?
 

There is a lot of documented data by many. engine builders.
It provides stability to the valve train and if you select the right vendor, you will get the correct ratio. Stamped rocker arms are all over the place as regards to ratios. Moreover, you prevent a pushrod going through the stamped rocker arm and allows adjustment. My prefered vendors are Jesel, TD or Harlan Sharp.

Re: Performance Gain Stock Rockers to 1.5RR?
 

I have been looking everywhere, including old Dyno Books.
Found a video testing Stamped Rocker vs RR Dyno Test on a Jeep engine. They did a lot of interesting upgrades and used Harland Rockers 1.7 Rockers.

After running a series of head and header tests. They ran a test with the Stock Rockers. RR's showed a measurable improvement. The Video did not say what the Stamped Rocker Ratio was. This needs to be answered. If roughly the same the RR's was a nice improvement.

https://www.youtube.com/watch?v=KWtfo4uT61E&t=338s

Our LT1 Stock Engines in our Impalas and Camaros it popular to add a 1.6 RT or RR's replacing stock rockers measured at 1.47.

Dyno testing with Bryan Herter showed measured 15hp rear wheel improvement. Got another 5-7 with an upgraded tune for total of 22hp.


Dan

Re: Performance Gain Stock Rockers to 1.5RR?
 

Stock Eliminator, in theory, is the antithesis of the internet. People have worked for 30, 40 or more years to find out what they know about what makes their combo get to the end of the track before you. Now, you want them to tell you what they learned?
The internet can seem to be about "tell me what you have worked hard to learn. Oh, and, thanks." But responses can be cryptic. And I would expect them to be. Just like in the "prehistoric" days. You have to take what you're told and make the best of it.

Re: Performance Gain Stock Rockers to 1.5RR?
 

Dan, on my 307 (definitely not an LT-1!) going from the stamped rockers to roller rockers was worth absolutely nothing.

Re: Performance Gain Stock Rockers to 1.5RR?
 

Havent seen the video but the stock ratio rockers are speced as 1.6 and actually measure 1.54 - so yes the RR made more power but are not legal in stock eliminator because of the ratio increase

Re: Performance Gain Stock Rockers to 1.5RR?
 

I have seen this right on the dyno too. Another "it depends".

Re: Performance Gain Stock Rockers to 1.5RR?
 

If the spec for stock rocker arm is 1.6 you can surly use an aftermarket roller rocker of 1.6.

Re: Performance Gain Stock Rockers to 1.5RR?
 

Probably minimal performance gain, but better longevity/reliability...
(Read: less breakage)

Re: Performance Gain Stock Rockers to 1.5RR?
 

Mark is correct. It depends on the engine, especially on the type of engine, horsepower output and RPM. A higher horsepower/high RPM engine will benefit from aftermarket rocker arms due to reduced rocker arm deflection and stabilization of the valvetrain. Since the liberalization of camshaft specifications with more radical lobes and high pressure valve springs, a stamped rocker arm will have a very limited life.