Cam and Roller Rockers
Thread Starter
Instructor
Joined: Jun 2010
Posts: 120
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From: CT
Cam and Roller Rockers
New request for technical opinion and advice:
I have a new concern that my approach to avoid roller rockers in lieu of roller tip rockers in order to keep the L-82 Valve Covers (due to clearance issues) may put me at risk of additional early wear to my flat tappet cam. I know I need to have appropriately lengthened and hardened push rods and that there is a small HP loss with conventional (roller tip) rockers over genuine roller rockers but I wonder if non-roller rockers present a significant risk of accelerated wear on more aggressive flat tappet cams with dual high pressure valve springs?
I’m not completely sold on having the CAM Nitrided or Nitride Treated. I did some research on this that suggests the possibility of microscopic surface cracking to differing degrees as a result of the Nitride process and the additional possibility of premature wear to the lifter surface due to dissimilar hardness between the cam and the lifter.
I have a new concern that my approach to avoid roller rockers in lieu of roller tip rockers in order to keep the L-82 Valve Covers (due to clearance issues) may put me at risk of additional early wear to my flat tappet cam. I know I need to have appropriately lengthened and hardened push rods and that there is a small HP loss with conventional (roller tip) rockers over genuine roller rockers but I wonder if non-roller rockers present a significant risk of accelerated wear on more aggressive flat tappet cams with dual high pressure valve springs?
I’m not completely sold on having the CAM Nitrided or Nitride Treated. I did some research on this that suggests the possibility of microscopic surface cracking to differing degrees as a result of the Nitride process and the additional possibility of premature wear to the lifter surface due to dissimilar hardness between the cam and the lifter.
Last edited by hadams; Dec 5, 2011 at 07:59 PM.
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
I think all a roller rocker is for is mainly the tip on the valve stem and weight reduction if you get aluminum.
Larger cams require "long slots" for the stud.
A good set of roller tips like Comp Cams make or the equivalent should be sufficient
Larger cams require "long slots" for the stud.
A good set of roller tips like Comp Cams make or the equivalent should be sufficient
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
Howard, have you tried a set of roller rockers on your engine to see if you have clearance? I'm running a set of Crane Energizer full roller rockers (1.5 ratio) on my '73 350 for about 15 years and have had no clearance issues at all. My covers don't have the "drippers", but beyond that everything is stock.
A while back I did replace the valve cover gaskets and went to a set of thick gaskets for some added insurance, but not because they were hitting.
Good luck... GUSTO
A while back I did replace the valve cover gaskets and went to a set of thick gaskets for some added insurance, but not because they were hitting.
Good luck... GUSTO
Last edited by GUSTO14; Dec 5, 2011 at 09:16 PM.
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Crower makes a neat set of lifters called their cool face not cheap but bet they help with wear, check into it.
Never used them but if I ran a healthy flat tappet probably would.
Never used them but if I ran a healthy flat tappet probably would.
Drifting
Joined: Aug 2005
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From: League City TX
Safety Car
Joined: Oct 2000
Posts: 3,593
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From: Southern Indiana
In the spring I am going to buy a new set of rockers like the ones i mentioned, the ones that Comp Cams makes with just the roller tip and they are just going to have to do.
I did buy a set of the "stainless" full rollers and they weighed 19 lbs as a full set, the weight has to play a role in efficiency. I would think that is very heavy. I put them back on Ebay and sent them packin!!!
Here is what i will use or likley a an ebay knock off for less$$$
Last edited by Tim H; Dec 6, 2011 at 01:10 AM.
Team Owner
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
WTF are you talking about? 19 lbs. are you saying each rocker is over a pound each? I have boxes of different ratio steel RR's
The advantage to roller tips over stamped OEM is twice the strength and maybe some less ware
The advantage to roller tips over stamped OEM is twice the strength and maybe some less ware
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
lets revise that 9lbs. at 12:30 in the morning it hard telling what i write!
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Melting Slicks
Joined: Jun 2002
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From: Orrtanna Pa.
If you are running stock valve covers and a near stock cam I wouldn't lose any sleep over the horsepower loss when comparing stamped 1.50 rockers to roller tip, or even full roller rockers. These are routinely installed as must have parts on many street engines, that really have no need for them. Stamped rockers were the norm back in the 60's on 327's pushing 350 horsepower, that ran 100,000 miles...
Now,...If you're talking major lift, high spring pressures, and such,....totally different story. How big of a cam are you thinking about?
Now,...If you're talking major lift, high spring pressures, and such,....totally different story. How big of a cam are you thinking about?
Drifting
Joined: Jul 2004
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From: Kissimmee fl
Finalist 2021 C3 of the Year - Modified
2017 C3 of Year Finalist
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St. Jude Donor '07
You can go with full rollers and keep your L-82 valve covers. You can trim the drippers as rollers direct the oil right to the pivot bearing of the rocker. If you need additional space inside you can use a set of these:
They are 1/4 in thick and when installed, will give you an additional 7/16th in. of clearance inside the valve cover, and will work with AC and stock alt. locations. PM me if you would like more info.
They are 1/4 in thick and when installed, will give you an additional 7/16th in. of clearance inside the valve cover, and will work with AC and stock alt. locations. PM me if you would like more info.
Le Mans Master
Joined: Dec 2006
Posts: 5,557
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From: Oquirrh Mountains
St. Jude Donor '09
The hd stamped steel rockers are better than plain roller tip rockers. All the info to the contrary is marketing hype. The key to making any rocker work is to set up the valvetrain geometry correctly.
Full rollers are nice but can get a bit pricey for a good set. Harland Sharp is a good brand that aren't too expensive if you go that route.
Full rollers are nice but can get a bit pricey for a good set. Harland Sharp is a good brand that aren't too expensive if you go that route.
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
If you are running stock valve covers and a near stock cam I wouldn't lose any sleep over the horsepower loss when comparing stamped 1.50 rockers to roller tip, or even full roller rockers. These are routinely installed as must have parts on many street engines, that really have no need for them. Stamped rockers were the norm back in the 60's on 327's pushing 350 horsepower, that ran 100,000 miles...
Now,...If you're talking major lift, high spring pressures, and such,....totally different story. How big of a cam are you thinking about?
Now,...If you're talking major lift, high spring pressures, and such,....totally different story. How big of a cam are you thinking about?
Stock rockers are supposed to be 1.50s but I have heard they vary as mush as down to a 1.45, so at least get a nice name brand 1.52 like a Comp Cams type.
Burning Brakes
Joined: Mar 2005
Posts: 1,231
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From: Ontario
[ Stamped rockers were the norm back in the 60's on 327's pushing 350 horsepower, that ran 100,000 miles...
The stamped rockers that GM put on performance engines ( LT1s, ect ) were not the same rocker arms used for regular production low HP engines of the day.
Bill
The stamped rockers that GM put on performance engines ( LT1s, ect ) were not the same rocker arms used for regular production low HP engines of the day.
Bill
Thread Starter
Instructor
Joined: Jun 2010
Posts: 120
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From: CT
Well, to address the previous questions, the CAM I have to install this Winter is a Lunati: Hydraulic Flat Tappet 286. PN – 60103LK.
• Advertised Duration (Int/Exh): 268/276
• Duration @ .050 (Int/Exh): 227/233
• Gross Valve Lift (Int/Exh): .489/.504
• LSA/ICL: 110/106
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 1800-6200
It’s not crazy as far as lift but I feel like it’s far enough over OEM specs that I would be best advised to go with a full roller rocker. I’m not at all concerned about any HP gain or loss based on rocker selection. The HP will come with the CAM grind and the heads not the rockers. It’s wear reduction (break-in and longevity) that I’m concerned with. It’s a little more money but I think it’s worth the piece of mind to get a good set of 1.5:1 roller rockers since it seems like they’ll still accommodate the L-82 Valve Covers. I already have 1.6:1 roller tips on my stock heads but the piston to valve clearance will be too close since exhaust valve lift will be .538. Max is .512 for the heads so it would be .026 HOOS to run them with the Lunati CAM and the Trick Flow Twisted Wedge Heads I have. (Exhaust valve is rotated closer to exhaust port. therefore closer to piston).
• Advertised Duration (Int/Exh): 268/276
• Duration @ .050 (Int/Exh): 227/233
• Gross Valve Lift (Int/Exh): .489/.504
• LSA/ICL: 110/106
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 1800-6200
It’s not crazy as far as lift but I feel like it’s far enough over OEM specs that I would be best advised to go with a full roller rocker. I’m not at all concerned about any HP gain or loss based on rocker selection. The HP will come with the CAM grind and the heads not the rockers. It’s wear reduction (break-in and longevity) that I’m concerned with. It’s a little more money but I think it’s worth the piece of mind to get a good set of 1.5:1 roller rockers since it seems like they’ll still accommodate the L-82 Valve Covers. I already have 1.6:1 roller tips on my stock heads but the piston to valve clearance will be too close since exhaust valve lift will be .538. Max is .512 for the heads so it would be .026 HOOS to run them with the Lunati CAM and the Trick Flow Twisted Wedge Heads I have. (Exhaust valve is rotated closer to exhaust port. therefore closer to piston).
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I know I need to have appropriately lengthened and hardened push rods and that there is a small HP loss with conventional (roller tip) rockers over genuine roller rockers but I wonder if non-roller rockers present a significant risk of accelerated wear on more aggressive flat tappet cams with dual high pressure valve springs?
.
.
Did you actually measure you piston to valve distance? anything less than .600 is really low lift
Rockers of higher ratio induce higher loads on the cam lobe. Comp cams sells a pot metal cam that is prone to failure and I would not buy their standard line.
Last edited by gkull; Dec 8, 2011 at 08:08 AM.
Safety Car
Joined: Oct 2000
Posts: 3,593
Likes: 103
From: Southern Indiana
Well, to address the previous questions, the CAM I have to install this Winter is a Lunati: Hydraulic Flat Tappet 286. PN – 60103LK.
• Advertised Duration (Int/Exh): 268/276
• Duration @ .050 (Int/Exh): 227/233
• Gross Valve Lift (Int/Exh): .489/.504
• LSA/ICL: 110/106
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 1800-6200
It’s not crazy as far as lift but I feel like it’s far enough over OEM specs that I would be best advised to go with a full roller rocker. I’m not at all concerned about any HP gain or loss based on rocker selection. The HP will come with the CAM grind and the heads not the rockers. It’s wear reduction (break-in and longevity) that I’m concerned with. It’s a little more money but I think it’s worth the piece of mind to get a good set of 1.5:1 roller rockers since it seems like they’ll still accommodate the L-82 Valve Covers. I already have 1.6:1 roller tips on my stock heads but the piston to valve clearance will be too close since exhaust valve lift will be .538. Max is .512 for the heads so it would be .026 HOOS to run them with the Lunati CAM and the Trick Flow Twisted Wedge Heads I have. (Exhaust valve is rotated closer to exhaust port. therefore closer to piston).
• Advertised Duration (Int/Exh): 268/276
• Duration @ .050 (Int/Exh): 227/233
• Gross Valve Lift (Int/Exh): .489/.504
• LSA/ICL: 110/106
• Valve Lash (Int/Exh): Hyd/Hyd
• RPM Range: 1800-6200
It’s not crazy as far as lift but I feel like it’s far enough over OEM specs that I would be best advised to go with a full roller rocker. I’m not at all concerned about any HP gain or loss based on rocker selection. The HP will come with the CAM grind and the heads not the rockers. It’s wear reduction (break-in and longevity) that I’m concerned with. It’s a little more money but I think it’s worth the piece of mind to get a good set of 1.5:1 roller rockers since it seems like they’ll still accommodate the L-82 Valve Covers. I already have 1.6:1 roller tips on my stock heads but the piston to valve clearance will be too close since exhaust valve lift will be .538. Max is .512 for the heads so it would be .026 HOOS to run them with the Lunati CAM and the Trick Flow Twisted Wedge Heads I have. (Exhaust valve is rotated closer to exhaust port. therefore closer to piston).
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
The newer LS motors don't use a roller tip on their roller rockers, I seem to remember a video of a roller tipped rocker and the roller on the tip didm't move to much, in fact or two of them didn't even roll across the tip, it just slid across
Last edited by MotorHead; Dec 8, 2011 at 01:15 PM.