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#21
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When talking about area under the curve. Should we be talking about using the lifter raise curve or the valve lift curve? Because the valve lift area sure looks different with 1.5:1 ratio rocker arms than with higher ratios.
Stan
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Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#22
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Sure, your graph illustrates increased lift and the increased duration at .200. Changing cams without changing cams.
However big rocker ratios stress other components and require more frequent checks, maintenance and even can require heavier duty parts. Going from 1.5 to 1.6 isn't a big deal if you have the room, but going 1.7 and up can be. Last edited by Tiger Paw; 01-04-2017 at 06:37 PM. |
#23
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Stated- "Should we be talking about using the lifter raise curve or the valve lift curve?"
They will be different. As the engine runs the cam will loose area under the curve. Example for Comp XE hydraulic roller lobe 3315 First two, as measured on a 'cam Dr' : Duration 'on the tappet' ( 0.0006" ) 282 degrees duration Duration measured 'at the valve' itself with a true 1.5 rocker ratio 288 degrees duration Third, duration as measured on a Spintron machine under running conditions: About 278 degrees (it will vary, example with lifter pre load, push rod flex and the lifter 'gives' just a little as you load it under running conditions, thus the 10 degrees less duration measured at the valve) Lobe is rated 230 degrees at .050" tappet lift Max lift at the tappet 0.3400" (lobe lift) Max lift at the valve w/1.5 ratio 0.5100" Max lift under running conditions about 0.5040" Area thru the entire lift curve from the tappet (.0006) thru max lift is 55.22 At the valve it's 82.8 (w/1.5 ratio) At the valve under running conditions 80.9 (w/1.5 ratio) Similar situation happens on a solid cam when you factor in valve lash. .
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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 Last edited by Steve C.; 01-05-2017 at 12:09 AM. |
#24
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From Steve C quoting UD Harold that all of his designs have a hydraulic Intensity of 53.88 degrees at 0.004 tappet lift would this mean that the Voodo advertised duration of the 702 cam for instance would be 219+53.88=272.88 at 0.004" compared to the actual advertised duration of 262 presumably at 0.006"?
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#25
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Quote:
http://forums.maxperformanceinc.com/...4&postcount=58 Here is a quote about the advertised rating. Might explain why some newer cam cards differ from the adv catalogue values. Quote:
Last edited by pastry_chef; 10-13-2020 at 07:00 PM. |
#26
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pastry_chef
It all seems to make sense. I am just trying to make a comparison between cams at 0.004 tappet lift for calculating dynamic compression. Thanks, |
#27
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A tid bit here for interest only.....
"The Lunati Voodoo cams are not old Ultradyne cams, although as designer of both there are certain similarities. Both are unsymmetrical, with aggressive opening sides and gentle seating ramps (to control seating noise). The specs on the Voodoo's are set by Lunati's former sales manager as far as lift and duration. The shape of the curve is the way I design, the names Ultradyne and Voodoo aren't interchangeable." Harold Brookshire Also another fwiw tid bit, Lunati does not have any of Harold's original UltraDyne lobe masters. Some of the cams Lunati sells with the 'same' specs as the old UltraDyne cams are not ground with actual UltraDyne masters. Lunati pirated the UltraDyne masters and made copies before Harold was fired by Lunati. All the original UltraDyne masters were sold to Bullet Racing Cams who also have the rights to the UltraDyne name. .
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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 Last edited by Steve C.; 10-16-2020 at 10:42 AM. |
#28
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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 |
#29
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Quote:
From the horse's mouth Quote:
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#30
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Vizard is one of the few experts who value DCR. A great article here.
https://www.hotrod.com/articles/0311em-power-squeeze/ I personally looked at it and played with the math back in the 90s.. but stopped shortly after. Harold Brookshire Quote:
Mike Jones Quote:
Chris Straub Quote:
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#31
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Correct, Lunati made copies of all the UltraDyne masters. The original masters went to Bullet racing.
Semantics .
__________________
'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 |
#32
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Depends if you are suggesting Harold's lobe blueprint would be degraded by using a master 'copy'. Even ordering the same lobes from the same company can result in more end variation (depending on the machine).
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#33
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Another question would be how much use did a master have and how close was the last cam ground with that master to the first cam ground cam ground with that master?
Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#34
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Quote:
Agree.. and the relevance to Harold's Quote:
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#35
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Mike,
I have no idea about these masters and how much use they had. But whoever has Harold's original work can use that to create a band new master if needed. Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#36
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It would be interesting to know about UD blueprint remains, outside of masters.
Mike O'Neal created those masters when he worked at Ultradyne, he was the first hire Sept, 1981. After Ultradyne closed Mike, Steve and eventually Harold went to work for Lunati. Mike was still there in 2009. Not sure why they would copy a finish master if you have the raw blueprint. Before Bullet purchased UD remains. |
#37
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I’ve never ground a cam or worked in a shop that so I’m confused by some of the terms thrown around. “Master” seems to refer to an actual hard copy camshaft most of the time but then also as a CAD master drawing.
Once you have the CAD to write a CNC machining and CMM inspection programs what would need a physical “master” for? Just trying to learn the process here.
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68 GTO,3860# Stock Original 400/M-20 Muncie,3.55’s 13.86 @ 100 Old combo: 462 10.75 CR,,SD 330CFM Round Port E's,Old Faithful cam,Jim Hand Continental,3.42's. 1968 Pontiac GTO : 11.114 @ 120.130 MPH New combo: 517 MR-1,10.8 CR,SD 350CFM E's,QFT 950/Northwind,246/252 HR,9.5” 4000 stall,3.42's 636HP/654TQ 1.452 10.603 @ 125.09 http://www.dragtimes.com/Pontiac-GTO...lip-31594.html |
#38
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Quote:
From what I understand it is quicker to copy a master than to create a new one. which means less $$$$$ spent. Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#39
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Quote:
Stan
__________________
Stan Weiss/World Wide Enterprises Offering Performance Software Since 1987 http://www.magneticlynx.com/carfor/carfor.htm David Vizard & Stan Weiss' IOP / Flow / Induction Optimization - Cam Selection Software http://www.magneticlynx.com/DV Download FREE 14 Trial IOP / Flow Software http://www.magneticlynx.com/DV/Flow_..._Day_Trial.php Pontiac Pump Gas List http://www.magneticlynx.com/carfor/pont_gas.htm Using PMD Block and Heads List http://www.magneticlynx.com/carfor/pont_pmd.htm |
#40
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"Depends if you are suggesting Harold's lobe blueprint would be degraded by using a master 'copy'."
Not my intention. There are some interesting material out there related: http://www.superchevy.com/how-to/eng...ing-technology https://www.youtube.com/watch?v=g5T2eerPtkg .
__________________
'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 |
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