Aluminum Rockers For Street-Only Use?

[RevTheory]

Do you guys have a problem running aluminum rockers for long-term street use? I don't really like the idea of some finite life span with no warning. All I can find in 1.65/1.5 combos on 7/16 studs for a SBC are aluminum offerings from Howard's and Scorpion.

Application is another street/tow small block with a fairly aggressive hydraulic/flat cam so spring pressures won't be much.

Any WAG on how many miles one could expect to get out of them before entering the yellow light zone?

[bigjoe1]

I have run Isky aluminium rockers on my own cars , and put 50.000 miles or more on them-- NO Problems-- On engine I build for street drivers, I usually run a Comp Cams steel rocker arms because they always have a much bigger bearing in the trunion area.



JOE SHERMAN RACING

[Newold1]

I think Joe has it right. For the money and larger trunnion I'd use the Comp Pro Magnum stainless rockers. Set the valve lash properly on a good camshaft, use good oil with proper oiling upstairs and those rockers will outlast your engine.

[RevTheory]

I see where I screwed up; I looked at the Ultra Pro Magnum and apparently not the Ultra Pro Magnum XD. They're expensive little buggers but I like the piece of mind and I surely hate clearancing the inside of fancy valve covers to clear bulky, aluminum rockers.

https://www.summitracing.com/parts/cca-1806-8

https://www.summitracing.com/parts/cca-1804-8

I appreciate the help, fellas.

[DaveMcLain]

Ford used the Crane/Cam Dynamics die cast aluminum rockers on the Cobra 5.0 engines from the factory without trouble.

[Mpcoluv]

I never hear of people having much trouble with any of the name brand rockers on a mild street motor.
Plenty of other things to worry about IMHO...

[rfoll]

How much is that additional .05 ratio worth on a street driven engine?

[RevTheory]

How much is that additional .05 ratio worth on a street driven engine?

Probably not enough to justify anything but it keeps my mind busy

[rfoll]

It's pretty easy to get hung up on numbers. Some people don't like mathematics. Hardly a day goes by when I don't make some sort of calculation, including the one where I decide if it is worth the cost and nuisance. Lately, more about the nuisance.

[dualquad]

I think that the quality of the roller bearing/trunion is likely more important than the material of the body of the rocker on a hyd. cammed engine. IMO
I installed a set of crane golds on my dads 67 chevelle 396 approx. 25 years ago. It has a mild hydraulic flat tappet, so relatively low spring pressure, the engine has accrued about 25,000 miles (1,000 mi. per year) with zero problems from the rockers. Also, I believe that the limited production LT4 was equipped with crane golds from the factory.

[user-612937456]

The actual ratio may be more important than the durability factor as there is little failure concern on a street grind and springs. As far as the true rocker ratio geometry goes there is a wide variance look at the 1.6 pro comp it is actually 1.687-1 and the isky 1.6 is more like 1.538-1. I may be wrong on the isky's brand could be another brand if my memory faild me but the is a wide variance in the advertised #'s and the actual true ratio if you use an 1.65 ratio and actually have a 1.56 ratio it could mean as much as 20 or more HP loss from optimal lift and duration at the valve.

It may be superstition but I always prefer a 7/16 stud when available. rarely have valve cover clearance problems

Edit: I found my ratio Data in DV's TorqueMaster program, not available to the public yet but soon to be released. I got my exposure in the seminars. I am not sure if the data is out there somewhere but if you contact the manufacture or maybe even google it you may find what you need, although I haven't explored that avenue.

[RevTheory]

David didn't have his new e-toys when I attended his seminar years ago. I need to reach out and e-slap him and then hand him an e-sangria

[BOOT]

The actual ratio may be more important than the durability factor as there is little failure concern on a street grind and springs. As far as the true rocker ratio geometry goes there is a wide variance look at the 1.6 pro comp it is actually 1.687-1 and the isky 1.6 is more like 1.538-1. I may be wrong on the isky's brand could be another brand if my memory faild me but the is a wide variance in the advertised #'s and the actual true ratio if you use an 1.65 ratio and actually have a 1.56 ratio it could mean as much as 20 or more HP loss from optimal lift and duration at the valve.

Almost mentioned that, in this mag test they measure the actual ratios of several diff brands http://www.hotrod.com/articles/hrdp-130 ... m-comparo/
Have to hi-light n copy/paste to see it tho. it copies complete with boxes n all to something like ms word.

[BOOT]

There got it all

Brand Part No. Price Weight in grams Material Max Rated Open Spring Pressure in pounds A B C D Warranty Lift at the retainer in Inches Ratio Pushrod Length vs. Stock Rebuildable?
Scorpion Race 10001472 SPC1002 $214.95 192 7000 Series Aluminum 850 0.750 0.560 0.600 0.360 Lifetime 0.722 1.656:1 +0.160 No
Scorpion Endurance 10001424 SPC3002 $257.95 163 7000 Series Aluminum 800 0.750 0.560 0.480 0.360 Lifetime 0.720 1.650:1 +0.050 No
Scorpion Platinum 10001442 SPC 2002 $268.95 178 7000 Series Aluminum 800 0.750 0.560 0.600 0.360 Lifetime 0.725 1.663:1 +0.160 No
Crower Stainless Steel 73640-1 73715R-1 $472.95 200 17-4 Stainless Steel 1,200 0.880 0.685 0.550 0.315 Lifetime (body only) 0.714 1.638:1 0.000 Yes
Crower Aluminum 72840-1 72915R $393.95 169 7000 Series Aluminum 900 0.750 0.560 0.550 0.350 1 year (body only) 0.716 1.639:1 +0.015 No
Summit Racing Aluminum SUMG6920B-1 $199.95 190 7000 Series Aluminum 950 0.735 0.560 0.600 0.360 1 year 0.720 1.650:1 +0.050 No
Crane Gold Race 11759 $395.95 162 7000 Series Aluminum 700 0.750 0.560 0.475 0.370 1 year 0.708 1.624:1 0.000 No
Crane Energizer 11746 $239.95 167 380 Series die-cast aluminum 450 0.750 0.560 0.475 0.370 1 year 0.708 1.624:1 -0.100 No
Howard’s Purple Race 90071 $239.95 189 7000 Series Aluminum 900 0.750 0.560 0.600 0.360 Lifetime 0.724 1.660:1 +0.150 No
Lunati Voodoo 15310 $264.95 177 7000 Series Aluminum 550 0.750 0.560 0.540 0.360 90 days 0.710 1.628:1 -0.015 No
Harland Sharp Original 10001-1 $239.95 144 2024 T3511 Series Aluminum 650 0.750 0.475 0.550 0.375 Lifetime 0.724 1.660:1 0.000 Yes
Harland Sharp Heavy-Duty H1002 $229.95 159 2024 T3511 Series Aluminum 750 0.750 0.475 0.550 0.375 Lifetime 0.717 1.645:1 -0.100 Yes
Harland Sharp Diamond D1002 $351.99 140 2024 T3511 Series Aluminum 600 0.750 0.475 0.550 0.375 Lifetime 0.720 1.650:1 -0.050 Yes
Proform HS original 66908 $159.95 139 306 Series Aluminum 500 0.750 0.468 0.560 0.375 1 year 0.710 1.628:1 +0.260 No
Proform HS HD 66929 $185.95 159 306 Series Aluminum 700 0.750 0.560 0.475 0.363 1 year 0.697 1.600:1 0.000 No
Comp Cams Hi Energy 17002 $165.95 176 A380 Series Die-cast Aluminum 350 0.750 0.560 0.543 0.360 1 year 0.711 1.631:1 0.000 No
Com Cams Hi-Tech 1102 $403.00 219 15-5PH Stainless Steel 800 0.875 0.685 0.542 0.375 Lifetime 0.713 1.635:1 +0.050 Yes
Comp Cams Ultra Pro Magnum XD 1602 $323.95 154 8650 Chrome-moly Steel 750 0.875 0.685 0.542 0.375 Lifetime 0.727 1.668:1 0.000 Yes
Comp Cams Aluminum (red) 1002 $312.95 154 7000 Series Aluminum 400 0.750 0.478 0.500 0.463 1 Year 0.727 1.668:1 +0.100 No
Comp Cams Ultra Gold 19002 $279.00 168 7000 Series Aluminum 400 0.750 0.560 0.475 0.360 Lifetime 0.720 1.650:1 0.000 No

[RevTheory]

If I remember from Vizard's 2nd BBC book, the steel Comps measure a hair over what's stamped. It's not a bunch but definitely not under so I wasn't too concerned about that but thanks for bringing it up.