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#1
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Rockers for "big" springs / race engines
I currently have a set of Harland Sharp 1.65's, and I'm sure they are the "Originals". I learned recently that HS also make a "Heavy Duty" version for higher spring pressures.
Got me wondering how many are running or have run the Harland Sharp "HD" rockers? I understand shaft-mounted rockers are the superior rocker system - they're also way more expensive. I'm interested in stud-mounted systems for roller cams with higher spring pressures (over 200lb seat, over 500lb open). What's the scoop? Who's are reliable? Any reason not to use the HS HD (part number SH6001-65)?
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Matt 70 GTO 400 4-speed "Turbos make no noise and leave the line like Baby Diarrhea!" - GTOGeorge |
#2
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Would not a quick email to the rocker maker give you the low down right from the sourse!?
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#3
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Here's the difference in size!
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Darby 74 Grandville 2Dr 455 c.i 4550# 2011 1.60 60 ft,7.33@94.55-11.502@117.74 2017, 74 firebird -3600 lbs (all bests) 1.33 60 ft, 6.314@108.39 9.950@134.32 M/T 275/60 ET SS Drag Radial 2023,(Pontiac 505) 1.27 60 ft, 5.97@112.86, 9.48@139.31.... 275/60 Radial Pro's |
#4
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Illinois Outlaw Gassers 6.27@107 9.97@131 |
#5
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We usually use Crower SS rockers with stiff roller springs and have never had a failure.
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#6
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Quote:
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Darby 74 Grandville 2Dr 455 c.i 4550# 2011 1.60 60 ft,7.33@94.55-11.502@117.74 2017, 74 firebird -3600 lbs (all bests) 1.33 60 ft, 6.314@108.39 9.950@134.32 M/T 275/60 ET SS Drag Radial 2023,(Pontiac 505) 1.27 60 ft, 5.97@112.86, 9.48@139.31.... 275/60 Radial Pro's |
#7
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I don't think so? I would call them and see tho.
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Darby 74 Grandville 2Dr 455 c.i 4550# 2011 1.60 60 ft,7.33@94.55-11.502@117.74 2017, 74 firebird -3600 lbs (all bests) 1.33 60 ft, 6.314@108.39 9.950@134.32 M/T 275/60 ET SS Drag Radial 2023,(Pontiac 505) 1.27 60 ft, 5.97@112.86, 9.48@139.31.... 275/60 Radial Pro's |
#8
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Quote:
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2001 Trans Am,WS6 Sunset Orange Metallic (sold) 1973 Trans Am 455,4speed 1970 GTO |
#9
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Steve, I'm looking for real world experience as opposed to marketing sales pitch. I'm sure they would sell them to me touting they would work perfectly. And I'm ok with that, I'd just like to know what common practice is.
Darby, what ratio are those pictured?
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Matt 70 GTO 400 4-speed "Turbos make no noise and leave the line like Baby Diarrhea!" - GTOGeorge |
#10
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Quote:
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Darby 74 Grandville 2Dr 455 c.i 4550# 2011 1.60 60 ft,7.33@94.55-11.502@117.74 2017, 74 firebird -3600 lbs (all bests) 1.33 60 ft, 6.314@108.39 9.950@134.32 M/T 275/60 ET SS Drag Radial 2023,(Pontiac 505) 1.27 60 ft, 5.97@112.86, 9.48@139.31.... 275/60 Radial Pro's |
#11
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You would atleast have a base line for what they say both models are rated at psi wise !
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#12
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Might be of interest. This article lits max open pressure for various companies....
http://www.hotrod.com/articles/hrdp-...r-arm-comparo/ .
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'70 TA / 505 cid / same engine but revised ( previous best 10.63 at 127.05 ) Old information here: http://www.hotrod.com/articles/0712p...tiac-trans-am/ Sponsor of the world's fastest Pontiac powered Ford Fairmont (engine) 5.14 at 140 mph (1/8 mile) , true 10.5 tire, stock type suspension https://www.youtube.com/watch?v=qDoJnIP3HgE |
#13
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Scorpion RACE rockers(aluminum) are rated to 850 lbs and lifetime warranty. I used them on a 528 Ford I built about 8 yrs ago. Manley Nextec springs Net lift at valve(after lash) was .767" . Advertised ratio was 1.73 but at valve it it was 1.77??. Motor was drag raced one season before he gave that up and put motor in his boat. Its still alive and well.
I also like Crower stainless rockers. Never had an issue with them. IMO the best stud mount rocker...just cost more than aluminum. Was NOT impressed with a set of Comp pro magnums that were in a friends 351w. Mild hydraulic roller and wheels on rockers were very sloppy after 5000 miles. He replaced them with Crane energizers. |
#14
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I run Norris SS roller rockers. Very nice, stiff rockers with a large bearing. I run them on iron HOs, solid roller with a stud girdle. Lash just does not change really. I check it now and then but do not have too adjust. Wish they still made them for Pontiacs.
Bet the Crowers are similar. |
#15
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Quote:
Conflicting data... http://www.harlandsharp.com/STYLES.html "Designed for high spring pressure and High lift geometry, Harland Sharp’s Heavy Duty Series can withstand over 1000lbs of spring pressure. " Whereas the hotrod article claims 750 lbs. max rated open spring pressure. I've also spoke with several using "Origianl" Harland Sharps with high pressure (over 600lbs) springs. Just food for thought...
__________________
Matt 70 GTO 400 4-speed "Turbos make no noise and leave the line like Baby Diarrhea!" - GTOGeorge |
#16
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Harland Sharp "Original" vs. HD rockers
Both these are HS 1.65 ratio rockers.
Left is "Original" Right is "HD/Heavy Duty" Pictures kinda don't really do justice to how much beefier the HD's are. I'll try to weigh them and see weight difference. Edit* not sure why first pic rotated but on that one, top is HD rocker.
__________________
Matt 70 GTO 400 4-speed "Turbos make no noise and leave the line like Baby Diarrhea!" - GTOGeorge |
#17
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I have run the original HS rockers at around 750lbs spring pressure and have not had an issue.
Last year I went to the Crower Stainless, best move I ever made. Valves stay adjusted and lift is dead on as advertised.
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66 GTO Nostalgia Super Stock/Street Legal Car 421 CID, stock block, Wenzler Intake, 2- Carter 750 AFB's, 3.90 Gears, Full Factory Interior, Full Exhaust, Stock Suspension 3750LBS 9.77@136.99 Multiple NSCA/NMCA World Champion 66 GTO 389 3x2, 4 speed, 4.33 gear, Montero Red 33K original Miles 67 GTO 2dr Post, 428, Tri Power, 3.55 Gears 80 Trans Am Black SE Y84 W72 WS6 |
#18
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You might have a look at Yella Terra shaft rockers. They're pretty dang nice and the Yella Terra guys are Pontiac guys as well.
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#19
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The HS heavy duty looks just like Crane Gold rockers
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#20
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Quote:
Brian
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Boobs & bacon |
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