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#1
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Roller Cams with low lift and long ramps
In the pursuit of a 70 MPH Highway application, 455 Pontiac getting good MPG in Overdrive, and may be towing. Is there a Pontiac Roller Cam with;
low lobe lift and long lobe ramps for sustained highway use, no lifter brace needed and Valve springs typical to a High-lift Flat HYD cam (110 Lb closed, 2xx open)? I have a darn-good Roller cam core with 0.442" lobes; would be ashamed to get it reground to meet the above goal, if the small roller is off-the-shelf.
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12.24/111.6MPH/1.76 60'/28"/3.54:1/SP-TH400/469 R96A/236-244-112LC/1050&TorkerI//3850Lbs//15MPG/89oct Sold 2003: 12.00/112MPH/1.61 60'/26"x3.31:1/10"/469 #48/245-255-110LSA/Q-Jet-Torker/3650Lbs//18MPG 94oct Sold 1994: 11.00/123MPH/1.50 60'/29.5"x4.10:1/10"/469 #48/245-255-110LSA/Dual600s-Wenzler/3250Lbs//94oct |
#2
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Butler now sells Hyd roller versions of the popular Pontiac HFT cams, 067, 067, 744, and 041. Might check their website. Made by comp...
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1977 Black Trans Am 180 HP Auto, essentially base model T/A. I'm the original owner, purchased May 7, 1977. Shut it off Shut it off Buddy, I just shut your Prius down... |
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#3
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I think the old comp lobe families like high energy and magnum might be close to what you are looking for.
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#4
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Why don’t you first try to sell your .440” lobe lift roller to partialy fund a custom ground solid roller.
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#5
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A fwiw, About a year ago I had a solid roller cam reground at Bullet Racing Cams with less lobe lift it was $157.50 + freight.
Obvious the lobe separation cannot be changed but instead of solid roller lobes it could of been reground using profiles for a hyd roller. .
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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 |
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#6
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Also you might find a cam can only be ground so far based on potential surface hardness issues.
Related article: Camshaft Heat Treatment Explained https://www.cpgnation.com/camshaft-h...ent-explained/ .
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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 |
#7
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3162/3163 - 230/240 @ 110 .428/.428 HR - ???
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#8
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Those lobes in conjunction with 110 LSA would have 77 degrees overlap based on the advertised duration.
Not a good fit if one were to adhere to this.... These are the valve timing overlap ranges that are most likely to work correctly (thanks to David Vizard for providing this): trucks/good mileage towing 10-35 degs overlap daily driven low rpm performance 30-55degs overlap hot street performance 50-75 degs overlap bracket/oval track racing 70-95degs overlap dragster/comp eliminator engines 90-115 degs overlap ( Information provided in this post does not represent any endorsement of those overlap numbers and is offered for general interest only. I might suggest David Vizard had a small block chevy in mind ) .
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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.; 04-02-2021 at 06:40 PM. |
#9
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Quote:
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#10
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Clay Smith has gentle, non aggressive roller profiles with lots of seat duration
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#11
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Again, not as any sort of recommendation but only to serve as an example of a cam with the specific description as follows:
"Smooth idle, good mileage for 455, strong towing cam". That is for the Comp High Energy 260H cam. It's a hyd flat tappet cam but note it only has 212 duration at .050" ! The lift is .440". And for interest that single-pattern cam has 40 degrees overlap. If you had it ground with 6 degrees additional exhaust duration and with 114 LSA it would have 35 degrees overlap. .
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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.; 04-02-2021 at 07:19 PM. |
#12
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I have been REALLY happy with the Stump Puller!Have it in my 434 RA V.70 MPH at 1900.Tom
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#13
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Bottom line Half-Inch Stud needs to come back with a bit more specifics. At least some thoughts on his idea of "low lobe lift and long lobe ramps". And at least a general idea of the .050" duration.
And the 110 lbs seat pressure for a roller cam might be a somewhat of a controversial topic .
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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 |
#14
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Quote:
As for Intake, the lift ought be 0.5" for traditional inhale need for HP. I just don't see the need for high seat pressures for rpms kept below 5000 rpm, for a long ramp profile. 230* duration at .050" should be capable with slow ramps. Asymetric ramp? i dunno. im definitely not looking for fast ramps; Seems stoopid for street, high mileage goals. No lifter brace in this deal. Sealed power ht-2148 lifters seem similar in weight to the Flat HYD lifter. So the spring pressures i've been using appear viable.
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12.24/111.6MPH/1.76 60'/28"/3.54:1/SP-TH400/469 R96A/236-244-112LC/1050&TorkerI//3850Lbs//15MPG/89oct Sold 2003: 12.00/112MPH/1.61 60'/26"x3.31:1/10"/469 #48/245-255-110LSA/Q-Jet-Torker/3650Lbs//18MPG 94oct Sold 1994: 11.00/123MPH/1.50 60'/29.5"x4.10:1/10"/469 #48/245-255-110LSA/Dual600s-Wenzler/3250Lbs//94oct |
#15
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Again offered for general interest only and to serve as an example to something close to the ideas in post 15........
Intake: Lobe number HR296/345 .006"- 296 .050"- 230 .517" lift Exhaust: Lobe number HR291/300 .006" - 291 .050" -236 .450" lift I used 6 additional degrees exhaust duration only because it's common. However that could be adjusted to suit the exhaust-to-intake flow ratio of the cylinder heads in use, that and the exhaust system in use. The cam could be ground with what ever lobe separation desired. https://www.bulletcams.com/Masters/HRlobes.htm .
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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.; 04-02-2021 at 10:45 PM. |
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#16
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Quote:
I also run a Stump puller in a low compression 455+ w/ low enough compression to run 87octane - and yes. A great cam. Aluminum heads, etc. |
#17
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I'm not why the OP is afraid of lift..this isn't the old days..modern engines have lift. If aluminum heads were in the budget..combined with a cam similiar to the stump puller with an overdrive it would be 20mpg plus at 70mph.
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466 Mike Voycey shortblock, 310cfm SD KRE heads, SD "OF 2.0 cam", torker 2 373 gears 3200 Continental Convertor best et 10.679/127.5/1.533 60ft 308 gears best et 10.76/125.64/1.5471 |
#18
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Quote:
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 |
#19
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FYI,George at Clay Smith runs 150 seat on his hyd roller street cams.Tom
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#20
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With Bullet cams you can at least ask them what the specs are on the opening and closing rates. It will give you and idea what the true seat timing are. At least I do. I call up, ask the specs for the cam at the tappet lifts I am interest in and they tell me.
From compcams one of the marine HR lobes would likely be one of the their gentler profiles with more seat timing and easier on components. I think Bullet can easily beat that though. FWIW...I have been surprised how much overlap can run and not effect economy. I think early EVO cam events seems like they can kill economy as bad as anything. Seems like it has adversely effected economy on most the engines I have done. I would look at single pattern cams for economy. IMO, Best economy will have lazier ramps, good compression, and be a single pattern or reverse split installed strait up. It takes a little more seat pressure to hold the roller to the profile versus a flat tappet. Force vectors for the roller go from the the roller contact through the axle. Flat tappet vector is at the edge and more straight up. Gentle roller profile you can run less spring rate though. Last edited by Jay S; 04-02-2021 at 10:57 PM. Reason: Edit |
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