Performance Gain Stock Rockers to 1.5RR?

[Dan Fahey]

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

[SSDiv6]

Originally Posted by Dan Fahey

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

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.

[Dan Fahey]

Originally Posted by SSDiv6

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 preferred(corrected sp) vendors are Jesel, TD or Harlan Sharp.

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.



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

[Dave Gantz]

Originally Posted by Dan Fahey

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.



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

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.

[Billy Nees]

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

[Rsmith38]

Originally Posted by Dan Fahey

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.



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

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

[Mark Yacavone]

Originally Posted by Billy Nees

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

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

[Glenn Briglio]

Originally Posted by Rsmith38

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

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

[L.Fite]

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

[SSDiv6]

Originally Posted by Mark Yacavone

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

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.