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#21
08-09-2021, 11:32 AM
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@CLIFF, is the Summit SUM-2821 (which i picked for the SPARE 455 Build) is a decent match to your snappy Crower 60213?
@STEVE25, you turbulence explanation seems fine. I see the turbulence being primarily caused in same way, but prefer a differing word-choice; that the floor-flow detatches at the short-turn and crashes into the roof-flow. Your solution addresses that problem clearly. I figure the pushrod bulge played a role in causing early turb-choke, and when ground-down partially will mitigate the choke-flow. tiny string in port will wiggly badly behind the stock pushrod buldge (right?) during turbulent-choke. But the velocity at the Bowl, and turn still needed addressed. You make that good point clear. Any effort that promotes a uniform velocity across the runner will be quiet, non-turbulent and flow well Last edited by Half-Inch Stud; 08-09-2021 at 11:42 AM. |
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#22
08-09-2021, 11:45 AM
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Mark,
Crower spec for 60213. 308/314 Adv 248/256 @ 0.050" .518" .537" 108 LC Brutal mid to top end torque and horsepower. RPM Power Range: 3500 - 6500 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 |
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#23
08-09-2021, 09:23 PM
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The 60213 cam was an early cam we tested when I first started using Crower cams.
It's not a cam for the faint of heart or for a low compression street engine. It makes BRUTAL mid-range power and requires high compression. Even with our small chamber heads on a zero decked flat top Ross piston 455 it had very "rough" idle quality and needed a LOT of initial timing and idle fuel to be happy. It's not pulling to 6500rpm's in a 455 build, at least not one with iron heads on it because I had it in another 455 with very well prepared #48's and it was DONE by 5500rpms. In both engines it was "raspy", stinky, super quick throttle response and hit so hard in the mid-range it felt like it was going to rip the car in half! Even so and as I've mentioned many times on here evaluating power and vehicle performance by the "seat of your pants" is very misleading and unreliable. It was removed from the first engine and replaced with a Road Paver from Dave at SD and a set of his #62 iron heads. The vehicle picked up everyplace and ran quite a bit quicker at the track even though it really didn't "feel" all that much stronger with the engines new smooth/broad/flat power curve........FWIW.......Cliff
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If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
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#24
08-10-2021, 07:54 AM
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Stan, Cliff, geez that is a big cam. Reasonable (not too quick) lobes. My bad; big difference in 050 values. I had UD make a cam like that on 104 LC; idled like a Chinook in hover.
The SUM-2821 is 304/316 for 231/241 for slow reliable lobes. Smaller than my Crower show in 12.2 below. Thinking the 48s with an 080 Cometic Gasket on the Spare 462 will play on 93 Octane @STEVE25 I assume you port to eliminate the turbulent-choke.
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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 |
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