Timing is everything with Cams. Timing determines what RPM and range an engine makes power. The single most important event during a camshaft cycle is when the intake valve closes. Fluid inertia and compressibility dictates optimal intake valve closing to maximize cylinder filling in a particular rev range.
The next most important timing event is intake cam duration. Intake cam duration should be optimized based upon what manifold pressure (vacuum or positive pressure) and the primary operating range the engine is operating in. Intake duration determines the maximum amount of air an engine can consume and ultimately the power that can be made. Exhaust valve duration and lobe separation angle are the next most important timing events that dictate overlap, fluid momentum and pressure bleed. Intake valve closing and duration determine how a set of cams can perform and Exhaust timing events adjust the range and peak of the torque curves.
Another key focus of URGE Bumpsitx is reducing cam Jerk or the rate of change of acceleration. The more Jerk a cam profile has, the more wear it creates on the valve train Reducing Reliability. Cam Jerk is typically overlooked and while many customers says my cams are fine, there tends to be many others that have valve train failure.
We also use tool steel alloy which is harder and stiffer than 8620 billet steel. Stiffer material reduces the axial twist along the cam during higher RPM use reducing cam deflection between cylinder 1 and 4. This will improve torque consistency between cylinders providing a better balanced and tuned motor freeing up a few HP.
Ultralight & Endurance Single Valve Spring kit
Throughout our engine testing we felt most aftermarket spring pressures were too light causing valve float with aggressive cams or at higher RPM. We decided to have our own set of Valve Springs wound to our spring pressure specifications. The higher spring rates will improve valve control at high RPM which will reduce horsepower loss. Our Ultralight & Endurance Valve springs will maintain valve control up to 11,000 RPM providing some protection in the event of a miss shift or over rev. We use Single Valve Springs to reduce critical weight reducing high stress momentum in this critical area. Our Ultralight & Endurance Single Valve Spring kit includes Titanium retainers ($200), Steel bases ($90) and valve locks ($90), providing a ready to mount kit
Bumpstix $1280 (Finishing Development)
- RR; Stock Bottom Engines w/ Bolt-ons, 270-300+ HP @ 8000-8500 RPM
- Under Pressure; Supercharged or Turbocharged Engines, 400+ HP, 7-14 PSI, Focus on Mid Range Torque
- Stroker; 99mm+ Stroked Motors, 330-375+ HP @ 8000-9000 RPM
- Will need to Notch Exhaust Rockers for Clearance
- Will Need URGE Ultralight Single Spring Valve Kit
- Ultralight & Endurance Single Valve Spring Kit $790
- w/ Titanium Retainers ($200), Steel seats ($90) & valve locks ($90)
- Tested to 11,000 RPM Capable
- High Fatigue Life, Tested with zero Pressure Drop after 1 season of racing
- MUST have for Stroker Cams
- Supertech H1021D Dual Valve Springs & Retainers $Customer Sourced
- Cost effective option for Type R or Under Pressure Bumpstix
- Type R for Stock Bottom Engines w/ Bolt-ons, 270-300+ HP @ 8000-8500 RPM
- Stroker for Stroked and Built Motors, 330-375+ HP @ 8500-9500 RPM
- Pressure for Supercharged or Turbocharged Engines, 400+ HP, 7-14 PSI, Focus on Mid Range Torque
- Control Dual Valve Spring Kit w/ Ti Retainers, Steel seats & locks $650
- Supertech H1021D Dual Valve Springs & Retainers $Customer Source