OPR Callies SBF Camshaft Challenge Cam 727HP Pump Gas
This is the OPR-Callies Solid Roller Camshaft from The Weingartner Racing SBF Camshaft Shootout. Out of 17 Entries this camshaft placed 2nd Overall. This was the smallest camshaft, based on Intake Duration in the Competition.
This Contest was performed on a Ford Windsor Based 427 CID engine with 11.2:1 Compression. Weingartner Ported TFS High Port 20° Cylinder Heads, BMP Ported Intake and a Dominator Carburetor.
We were the 3rd Camshaft to run and maintained the Overall lead all week long until the last 2 camshafts made slightly more peak horsepower exchanging our overall position with our Callies Teammate Chris Allmond from Allmond Competition.
Chris Allmond designed the lobes for both of the Callies Cam Entries. We provided Chris the event timing, duration and lift ranges we felt would work well for this engine package and he worked his magic to develop the lobes that allowed us to own the top two spots out of 17 Competitors.
We maintained the 1st Place Position for highest Average HP and highest Average Torque. We were scored 2nd for Peak Torque. These were the 3 metrics we focussed on for this Dyno Competition. The Cams were only scored from 5000-7500 RPM.
We designed this camshaft with a 3 lobe design. We compensated for the Intake Manifold runner length differences to optimize wave tuning by using a different Intake lobe on the end cylinders vs. the center cylinders. This change allows all the cylinders to maintain a more equal Air Fuel Ratio over the entire operating range.
With single carbureted intake manifolds, the outboard cylinders typically run very lean at the beginning of the rpm sweep, the center cylinders start out rich. At the end of the rpm sweep, they swap positions. This is due to the intake runner lengths coming 'into tune' at different rpm's. This causes more air to feed the cylinders that are working best. The fuel does not always follow, so some cylinders starve for fuel while others receive too much fuel.
With our 3 lobe design we compensate for this with additional duration on the end cylinders and equalize the A/F ratio. This is what provides a wider powerband and additional torque throughout the rpm range.
Our 3 lobe design is only possible due to Callies 100% in-house manufacturing capabilities. Callies is the exclusive manufacturer of our camshaft, they build the custom cores for us from raw materials and produce the finished camshafts.
So what were the results?
We had 4 total runs and the 4th run was scored.
701.6 HP @6900 RPM 578.3 lb/ft @5000
Average HP 5000-7500 650.3 HP Average Torque 5000-7500 549.4 lb/ft
You can watch the raw live feed of our runs on YouTube HERE
On August 7th, 2025 We conducted additional testing on our Camshaft. These tests were conducted under real world conditions: The Dyno Cell Inlet air was 102F, the Engine was tested on 91 Octane Pump Gas.
We tested the as ground 106° Intake Centerline vs. 108° and found this engine package to pick up power everywhere above 4400 RPM. This will vary depending on your particular cylinder head and induction package.
Under these conditions this Camshaft Produced the Following:
726.6 HP @7300
569.2 lb/ft @5500
Along with a flat torque curve producing in excess of 500 lb/ft from 4600 RPM all the way past Peak HP, This cam carries in excess of 700 HP from 6700 RPM past 7600 RPM.
Due to the design of this cam, the useable RPM is in excess of 2000 RPM while still maintaining idle vacuum and throttle response. With a capable valvetrain, shift points at or above 8000 RPM will not affect performance.
Camshaft Specifications: (For Cam Degree Purposes)
Cam Grind Number OPR SBF-25X-272-111+5
Lifter Wheel 0.750
Lobe Separation 111°
Intake Centerline 106° (Install at 108° for Peak HP)
Exhaust Centerline 116°
Intake Rocker Ratio 1.6
Exhaust Rocker Ratio 1.6
Intake Lash 0.015
Exhaust Lash 0.015
Lift Data: Lobe / Net @Valve
Intake Lift 0.479 / 0.751 Exhaust Lift 0.494 / 0.775
@ .050" Lobe Data
Intake Duration 256.6° Exhaust Duration 272.3°
Intake Open 22.9° BTDC Exhaust Open 71.9° BBDC
Intake Close 53.7° ABDC Exhaust Close 20.4° ATDC
[email protected] 43.3°
@ .020" Lobe Data
Intake Duration 285.5° Exhaust Duration 302°
Intake Open 38.2° BTDC Exhaust Open 87.5° BBDC
Intake Close 67.2° ABDC Exhaust Close 34.5° ATDC
Overlap 72.7°
This Camshaft is intended for Racing Applications in a highly developed engine package. While this cam idles and makes manifold vacuum to possibly operate power brakes, it is suited for Drag Racing and Road Racing. Limited Street Use.
Callies fully finished camshafts are machined and heat treated entirely in house. This continuity of manufacturing allows Callies to deliver high quality camshafts on schedule. Our finished cams are ground with the latest Landis CNC technology. They are ADCOLE and Jenoptik inspected for accuracy, making them the most consistent cams on the market today. If required, your cams can be finished with inverted flank lobe profiles and complex VVT oil channels and drillings.
Callies Cam Research Lab – Valvetrain durability is a key ingredient to the success of every engine. The Callies Cam Research Lab has been established to guarantee that our cams are capable of extended life cycles in abusive applications. When combined with our metallurgical capabilities, the Callies Cam Research Lab allows evaluation of lobe profiles, valvetrain systems and processing methods like no other cam company. Spintron testing enables our engineering staff to evaluate valvetrain stability in minute detail up to 11,000 RPM. Programmable test cycles allow complete event simulation. Sixteen channel data acquisition can provide monitoring of temperatures, pressures, flows, loads and strain. Let Callies help you design your next step forward.
