Performance Gain Stock Rockers to 1.5RR? - Page 2

Billy Nees · 10-30-2021, 05:13 PM

Quote:

Originally Posted by SSDiv6

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.

And since we're on the subject, the"aftermarket rocker arms" that "reduced rocker arm deflection" and allowed the "stabilization of the valvetrain" ALSO made it a necessity to port your heads and intake if you wanted to stay competitive. In other words, in the good old days, you could either run well and keep your stuff together for a 7 round race or go fast and gamble on when you were gonna break a rocker.

GUMP · 10-30-2021, 05:56 PM

I ran treated and coated stock rockers that we machined to work with a 7/16 stud on my LT1's. I saw no performance gain going to a roller rocker. Limited travel lifters was a different story.....

Larry Hill · 10-30-2021, 06:27 PM

The truck engine liked the 7/16 studs they had less deflection than the 3/8.

Dan Fahey · 10-30-2021, 06:51 PM

Building the Pure Stock engine replaced the 3/8 with a 7/16th stud figuring it was a good bit stronger. Cannot remember the racers name he sent me his modified LT1 SA Stock Rockers. Bought new 7/16th ball, installed them and runs smooth.

Like Billy said, he saw no gain going to Rollers.

Many of our Impala Club members stayed with the Stock LT1 SA rockers installing the popular HotCam with no problems. Figuring the 3/8th Stud was not much of an issue to begin with.

Wondering if someone makes a 1.5 SA Roller Tip?
Use the 7/16th ball and trim the sides up to fit.
Would stop all side loading on the valve and guide.

I have set of original GM SA 1.6 Roller Rockers.
Then again they use 3/8 stud.
Saving them for a project.

Kenny Wigington · 10-30-2021, 08:13 PM

I’ve deleted the pics of some of the pushrod/rocker arm combo’s I had”generated”, before I switched. It wasn’t any faster on track, but I didn’t have one cost me a semi at a Division race again either.

Greg Hill · 10-30-2021, 08:41 PM

Why don’t you try them and see for yourself.

SSDiv6 · 10-31-2021, 04:24 PM

Many years ago, due to the pushrod tip going through the stamped rocker arm pushrod seat, I took a set of Oldsmobile rocker arms, laser welded a piece of 4130 Chrome Moly steel that had been cut and shaped to the contour of the rocker arm pushrod seat, and then had them solution heat treated. It was a matter of longevity than performance; the modified rocker arms were heavier than the OEM replacements by a lot.

The owner of the car approached Danny Gracia at a race, showed him the damaged rocker arms and what he was planning to use in lieu of the OEM replacement rocker arms. Of course, Danny immediately said they would be illegal and he could not use them. Then, some time later, Clark Holroyd comes up with the same concept and design for Chevy and Pontiac engines and were deemed legal to use by Danny.

It appears to be the case of who you are and who you know.

Frank Castros · 10-31-2021, 07:46 PM

Any cam duration, any valve spring, adjustable push rods, adjustable rockers , roller rockers and now solid lifters. The evolution of what we have today.

GTX JOHN · 10-31-2021, 09:18 PM

I had noticed that a couple times about Danny = More often years ago

I "think" he actually likes me now after 30 years.

I would have never got away with modifying the cast rockers.

We broke plenty of them on Mopars and a few on my Big Block Chev.

SSDiv6 · 11-01-2021, 08:58 AM

Quote:

Originally Posted by GTX JOHN

I had noticed that a couple times about Danny = More often years ago

I "think" he actually likes me now after 30 years.

I would have never got away with modifying the cast rockers.

We broke plenty of them on Mopars and a few on my Big Block Chev.

John,

I modified the rocker arms only to address a weakness on the OEM stamped rocker arms after the allowance of higher pressure springs and lifting the duration and overlap specs on the camshafts. They were not installed.

We asked permission to use them and were rejected.
My issue with Danny was the fact that later on, he approved the same exact modification from Clark Holroyd for BBC and Pontiacs.
No matter how it is addressed, Danny was always controversial in many of his decisions throughout the years.

10-30-2021, 05:56 PM	#12
GUMP VIP Member Join Date: May 2002 Location: Shelby, NC Posts: 1,809 Likes: 2,128 Liked 2,302 Times in 539 Posts	Re: Performance Gain Stock Rockers to 1.5RR? I ran treated and coated stock rockers that we machined to work with a 7/16 stud on my LT1's. I saw no performance gain going to a roller rocker. Limited travel lifters was a different story.....

10-30-2021, 06:27 PM	#13
Larry Hill Live Reporter Join Date: Oct 2004 Location: Hickory, Ky Posts: 10,613 Likes: 1,896 Liked 10,650 Times in 2,209 Posts	Re: Performance Gain Stock Rockers to 1.5RR? The truck engine liked the 7/16 studs they had less deflection than the 3/8. __________________ IHM Used Parts https://ihmusedparts.com 888-821-1817

10-30-2021, 06:51 PM	#14
Dan Fahey VIP Member Join Date: Oct 2008 Posts: 2,127 Likes: 1,084 Liked 184 Times in 113 Posts	Re: Performance Gain Stock Rockers to 1.5RR? Building the Pure Stock engine replaced the 3/8 with a 7/16th stud figuring it was a good bit stronger. Cannot remember the racers name he sent me his modified LT1 SA Stock Rockers. Bought new 7/16th ball, installed them and runs smooth. Like Billy said, he saw no gain going to Rollers. Many of our Impala Club members stayed with the Stock LT1 SA rockers installing the popular HotCam with no problems. Figuring the 3/8th Stud was not much of an issue to begin with. Wondering if someone makes a 1.5 SA Roller Tip? Use the 7/16th ball and trim the sides up to fit. Would stop all side loading on the valve and guide. I have set of original GM SA 1.6 Roller Rockers. Then again they use 3/8 stud. Saving them for a project.

10-30-2021, 08:13 PM	#15
Kenny Wigington Senior Member Join Date: Sep 2004 Location: Cumming,Ga. USA Posts: 967 Likes: 36 Liked 60 Times in 12 Posts	Re: Performance Gain Stock Rockers to 1.5RR? I’ve deleted the pics of some of the pushrod/rocker arm combo’s I had”generated”, before I switched. It wasn’t any faster on track, but I didn’t have one cost me a semi at a Division race again either. __________________ 2894 STK

10-30-2021, 08:41 PM	#16
Greg Hill VIP Member Join Date: May 2006 Location: Louisville , KY Posts: 1,995 Likes: 68 Liked 279 Times in 68 Posts	Re: Performance Gain Stock Rockers to 1.5RR? Why don’t you try them and see for yourself. __________________ Greg Hill 4171 STK

10-31-2021, 04:24 PM	#17
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 3,036 Likes: 710 Liked 1,538 Times in 575 Posts	Re: Performance Gain Stock Rockers to 1.5RR? Many years ago, due to the pushrod tip going through the stamped rocker arm pushrod seat, I took a set of Oldsmobile rocker arms, laser welded a piece of 4130 Chrome Moly steel that had been cut and shaped to the contour of the rocker arm pushrod seat, and then had them solution heat treated. It was a matter of longevity than performance; the modified rocker arms were heavier than the OEM replacements by a lot. The owner of the car approached Danny Gracia at a race, showed him the damaged rocker arms and what he was planning to use in lieu of the OEM replacement rocker arms. Of course, Danny immediately said they would be illegal and he could not use them. Then, some time later, Clark Holroyd comes up with the same concept and design for Chevy and Pontiac engines and were deemed legal to use by Danny. It appears to be the case of who you are and who you know.

10-31-2021, 07:46 PM	#18
Frank Castros VIP Member Join Date: Nov 2001 Location: The Lowcountry. Posts: 2,954 Likes: 2,536 Liked 2,610 Times in 948 Posts	Re: Performance Gain Stock Rockers to 1.5RR? Any cam duration, any valve spring, adjustable push rods, adjustable rockers , roller rockers and now solid lifters. The evolution of what we have today.

10-31-2021, 09:18 PM	#19
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,719 Likes: 2,765 Liked 2,425 Times in 687 Posts	Re: Performance Gain Stock Rockers to 1.5RR? I had noticed that a couple times about Danny = More often years ago I "think" he actually likes me now after 30 years. I would have never got away with modifying the cast rockers. We broke plenty of them on Mopars and a few on my Big Block Chev. __________________ John Irving 741 Stock 741 Super Stock Last edited by GTX JOHN; 10-31-2021 at 09:23 PM.