Kinsler Handbook #32 May 2025

Kinsler Fuel Injection, Inc, 1834 THUNDERBIRD TROY, MICHIGAN 48084 U.S.A. www.Kinsler.com Phone (248) 362-1145 Fax (248) 362-1032 106 © 2024 Safety: To prevent pressure from reaching the shaft seal, a static brass sleeve around the drive shaft is sealed to the housing and to the moveable plate by o-rings. This reduces the possibility of a seal leak and reduces friction on the drive shaft, because pressure is not forcing the seal lip to grip down onto the shaft… gives longer seal life and a reduction in required drive torque. The seal cavity is vented back to the inlet side of the pump to further insure that there is no pressure on the seal. A snap ring positively locates the seal. Smoother Output: Tough Pumps have more teeth on the gears which gives the same average flow output but with smaller peaks and valleys of the wave cycle. This reduces the instantaneous rise and fall of the pressure. This does not show on a conventional flow bench due to the type of instrumentation being used. If an oscilloscope or very quick data acquisition system is used, you can see the pulses from the gears. Why a Tough Pump? This smoother wave cycle allows the by-pass valves to operate more consistently because the valves aren’t being hammered as much by the pressure pulses. Drive Alignment: The drive unit on the engine for the mechanical pump, is often not concentric . The female drive hex and mounting pilot are not concentric to each other. Mounting a pump to a misaligned drive and forcing them together puts a large side load on the pump’s bearings and drive shaft that can cause the bearings to fail. Why a Universal Drive (optional) It eliminates the side loading by allowing the male hex to swivel and absorb minor misalignment; eliminating side loading of the pump’s drive shaft and bearings. The chance of fuel leaking out of the drive end is minimized. 2.290 2.300 2.310 2.320 2.330 2.340 2.350 2.360 2.370 2.380 0.025 0.05 0.075 0.1 0.125 0.15 0.175 0.2 0.225 0.25 0.275 0.3 0.325 0.35 0.375 0.4 0.425 0.45 0.475 0.5 G P M Revolutions of Pump Shaft More Gear Teeth Less Gear Teeth Average Flow More gear teeth = smoother flow 500 Size Pump @ 2000 Pump RPM Mirror Smooth Finish