Roller Rockers on Stocker Engine ?

Aubrey N Bruneau · 06-05-2009, 08:00 PM

After having more fun in Mission than I can really believe, I seem to have been bitten pretty bad !
I am preparing the car to go to Edmonton for the IHRA Rocky Mountain Nationals, and for that, I am going to install a set of Comp stainless roller rockers ( the engine can be tough on the intake rockers ).

My question is, should I expect huge gains in HP, like is suggested in the advertising ?
I'm skeptcal. What do members here feel that I will notice with the roller rockers, over the factory type stamped steel parts ?

just trying to plan

Alan Roehrich · 06-06-2009, 06:01 AM

I seriously doubt you'll see huge gains. A couple of HP, maybe. A well executed valvetrain on a Stock engine doesn't leave a whole lot of room. If you have the Holroyd stuff or something similar, and a good set of 7/16" 0.125" wall pushrods, you likely won't see any measurable gains with roller rockers. In fact, in going back to 7/16" studs from the Holroyd 9/16" stud, I'd be very concerned about breaking rocker studs. Read an old Chevy Power Manual and they warn you that roller rockers are notorious for breaking rocker studs. That's why stud girdles were invented.

Aubrey N Bruneau · 06-06-2009, 06:28 AM

Thanks Alan,
As I'm sure is for most of us, we always want to go faster !

Can't fit 7/16" pushrods in my engine... intake runners leave no room.
I have Manton .125" wall 3/8" pushrods. Lift at valve is between .500" - .510"
I have only 7/16" studs. However, I was very careful to not mill anyore from the top of the stud boss than necessary. In fact, these new rockers are very VERY close to the base.

Changing to the roller rockers is more to eleviate my intake "fatigue" problem, than anything else ( using Crane "Nitro-Carb" BBC 1.7 ratio rockers, which are somewhat tough to find now ).

Jim Cassels · 06-06-2009, 06:53 AM

Aubrey,
Not familiar with IHRA but do they allow roller rockers on a stock motor?

Bob Pagano · 06-06-2009, 07:20 AM

Roller rockers are legal in IHRA

Jim Cassels · 06-06-2009, 07:43 AM

Thanks Bob I was not aware.

Jim Cassels · 06-06-2009, 07:07 PM

Quote:

Originally Posted by smracer2002

Its good to see a W headed motor out there.

Thread jack,Jim C how you doing?.

Unjack.

Chris email me. jimmyca@windstream.net

Aubrey N Bruneau · 06-06-2009, 09:44 PM

Thanks SM

Yes, I think I finally got her working too !

Aubrey N Bruneau · 06-07-2009, 11:02 PM

Thanks Al... good point
Rockers are on now. All's good. Geometry is dead on.

I actually had a bit of an issue with the stamped steel rockers when I assembled the engine. These new Manton pushrods have a different tip than normal, and I found all the intake rockers getting "bumped" on the inner/underside, by the pushrod, when near full lift. I had to take my die grinder, and create an ever-so-slight little "pocket", so the pushrod would not touch it.

The other thing too, is that my valve lift is very near my maximum, and changing pushrods... especially if slightly longer, could put my lift over the top.

randy wilson · 06-08-2009, 10:05 AM

pushrod length does not change valve lift or duration. only cam profile, rocker ratio, and valve lash can do that.

06-05-2009, 08:00 PM	#1
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Roller Rockers on Stocker Engine ? After having more fun in Mission than I can really believe, I seem to have been bitten pretty bad ! I am preparing the car to go to Edmonton for the IHRA Rocky Mountain Nationals, and for that, I am going to install a set of Comp stainless roller rockers ( the engine can be tough on the intake rockers ). My question is, should I expect huge gains in HP, like is suggested in the advertising ? I'm skeptcal. What do members here feel that I will notice with the roller rockers, over the factory type stamped steel parts ? just trying to plan __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

06-06-2009, 06:01 AM	#2
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,066 Likes: 1,487 Liked 1,630 Times in 378 Posts	Re: Roller Rockers on Stocker Engine ? I seriously doubt you'll see huge gains. A couple of HP, maybe. A well executed valvetrain on a Stock engine doesn't leave a whole lot of room. If you have the Holroyd stuff or something similar, and a good set of 7/16" 0.125" wall pushrods, you likely won't see any measurable gains with roller rockers. In fact, in going back to 7/16" studs from the Holroyd 9/16" stud, I'd be very concerned about breaking rocker studs. Read an old Chevy Power Manual and they warn you that roller rockers are notorious for breaking rocker studs. That's why stud girdles were invented. __________________ Alan Roehrich 212A G/S

06-06-2009, 06:28 AM	#3
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: Roller Rockers on Stocker Engine ? Thanks Alan, As I'm sure is for most of us, we always want to go faster ! Can't fit 7/16" pushrods in my engine... intake runners leave no room. I have Manton .125" wall 3/8" pushrods. Lift at valve is between .500" - .510" I have only 7/16" studs. However, I was very careful to not mill anyore from the top of the stud boss than necessary. In fact, these new rockers are very VERY close to the base. Changing to the roller rockers is more to eleviate my intake "fatigue" problem, than anything else ( using Crane "Nitro-Carb" BBC 1.7 ratio rockers, which are somewhat tough to find now ). __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

06-06-2009, 06:53 AM	#4
Jim Cassels Junior Member Join Date: Nov 2002 Location: Cairo, Ga. Posts: 90 Likes: 2 Liked 0 Times in 0 Posts	Re: Roller Rockers on Stocker Engine ? Aubrey, Not familiar with IHRA but do they allow roller rockers on a stock motor?

06-06-2009, 07:20 AM	#5
Bob Pagano VIP Member Join Date: Jun 2002 Location: New Holland, PA Mooresville,NC Posts: 1,163 Likes: 232 Liked 16 Times in 11 Posts	Re: Roller Rockers on Stocker Engine ? Roller rockers are legal in IHRA __________________ Bob Pagano A/SA

06-06-2009, 07:43 AM	#6
Jim Cassels Junior Member Join Date: Nov 2002 Location: Cairo, Ga. Posts: 90 Likes: 2 Liked 0 Times in 0 Posts	Re: Roller Rockers on Stocker Engine ? Thanks Bob I was not aware.

06-06-2009, 09:44 PM	#8
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: Roller Rockers on Stocker Engine ? Thanks SM Yes, I think I finally got her working too ! __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

06-07-2009, 11:02 PM	#9
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: Roller Rockers on Stocker Engine ? Thanks Al... good point Rockers are on now. All's good. Geometry is dead on. I actually had a bit of an issue with the stamped steel rockers when I assembled the engine. These new Manton pushrods have a different tip than normal, and I found all the intake rockers getting "bumped" on the inner/underside, by the pushrod, when near full lift. I had to take my die grinder, and create an ever-so-slight little "pocket", so the pushrod would not touch it. The other thing too, is that my valve lift is very near my maximum, and changing pushrods... especially if slightly longer, could put my lift over the top. __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

06-08-2009, 10:05 AM	#10
randy wilson Senior Member Join Date: Jan 2007 Location: N/A Posts: 882 Likes: 0 Liked 22 Times in 22 Posts	Re: Roller Rockers on Stocker Engine ? pushrod length does not change valve lift or duration. only cam profile, rocker ratio, and valve lash can do that. __________________ don,t have one