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Kinsler Tough Pump Series 2

Posted By: Evan J. Smith
Kinsler Tough Pump Series 2
Written by the FSC staff
Photography courtesy of Kinsler Fuel Injection
Priding itself on performance and reliability, Kinsler Fuel Injection says that not one of its fuel pumps has failed in the past 17 years. Its original Tough Pump mechanical fuel pump supplied the fuel for the engines that powered winners of the heralded and grueling Knoxville Nationals for dirt sprint car race. In last year’s all seven championship events were won by Tough Pump customers.
“In 2007, Kinsler had a customer who just had to finish the last race of the season to win his dirt sprint car Championship,” Brad Cauzillo, Manager of Sales at Kinsler Fuel Injection, recalled. “His pump failed about halfway through the race. He begged Jim (Kinsler) to make him a pump.”
Rather than building an electric fuel pump, the company set out to create a mechanical pump that would deliver the flow, pressure, and reliability needed in high-performance environments that will work not only with Constant Flow Fuel Injection but also support EFI applications, without relying on a vehicle’s electrical system to supply huge amperage that taxes the electrical system. Moreover, the company wanted a design that would cure the ills suffered by other pump designs. 
The company recently expanded upon its Tough Pump line with the Series 2 pumps that deliver as much as 23 gallons per minute to feed the most demanding applications. The pumps share the same design hallmarks, but feature larger housings and the biggest model makes use of the largest optional outlet fittings to support fuel-hungry engines at the highest levels.
“All the pump designs at the time were less than ideal. None of them used premium
metal or coatings and they all had excessive internal clearances that caused about 15 percent of the fuel to leak back past the gears from the outlet side back to the inlet side,” Jim Kinsler, Director of Kinsler Fuel Injection, explained. “This was very bad because when the fuel blows down from a high pressure to a low pressure, it causes bubbles to be formed. These bubbles do not get compressed back to liquid fuel as they go back past the gears… they travel out to the nozzles.”
Rather than using gears mounted to a separate shaft, all the Kinsler Tough Pumps make use of one-piece gear shafts made from a rugged steel alloy that is heat-treated and coated for enhanced durability. To eliminate that internal leakage, Kinsler developed a sleeved design that separates outlet pressure from the internal seal to avoid leakage.
“The housing was designed to be stiffer than other pumps so it would have minimum deflection from pressure. The inlet port comes straight into the gears rather than making a 90-degree turn like most pumps, allowing 7,000 pump rpm (14,000 engine rpm) without cavitation,” Kinsler explained. “The housing is very precisely machined from high alloy aluminum, then hard-coated .002-inch thick, right down into the corners. The gears are precisely machined to the internal diameter of the housing. The pump is run in at 150 psi. This pressure pushes the gears apart slightly due to the clearance in the roller bearings, allowing them to grind into the hard coat about .0003-inch. This gives an almost perfect seal of the gear teeth to the housing to reduce the internal leakage.”
The cover of that housing is retained by 12 fasteners and it can contain pressure as high as 400 psi. Since pump housings expand as they heat up, leakage can increase with other pumps. The Kinsler design’s movable side plate ensures that the seal remains tight even as wear occurs, though these pumps are said to wear minimally all while delivering huge fuel volume. 
The Tough Pump Series 2 models support flow ranges including 8.9-, 10.8-, 12.9-, 15.8-, and 23-gpm, which is new. These units support rpm as high as 5,000 pump rpm and 10,000 engine rpm without cavitating. 

While Kinsler Fuel Injection’s original Tough Pump mechanical fuel pumps proved rugged and up to the task for many applications, the Series 2 units use the same construction and design, but their larger housings help support even more horsepower for demanding applications like drag racing, off-shore boat racing, pulling tractors, sprint cars, and more.

Those bolt-on inlet and outlet fittings are available in -8AN, -10AN, -12AN, and -16AN for all the pumps and the largest 23-gpm model accepts a massive -20AN fitting. By using these bolt-on fittings, it isn’t necessary to tap and thread the housing, which could weaken the pump.

Eschewing the more common design with gears running against plates, the Kinsler pumps utilize a fixed side plate and a second plate sealed to the housing via an O-ring that uses pump pressure to force it against the gears. This design minimizes internal leakage. The plates are hewn from alloy steel with a 6-micron finish and a coating that is harder than carbide, which is lapped to an even glossier 2-micron finish.

Kinsler’s Tough Pump Series 2 makes use of a case-hardened, precision-ground, one-piece gear shaft enhanced by a proprietary coating that further improves its durability. This one-piece design not only prevents radial movement and prevents contact with the housing. It can also withstand contamination without failure.

Before selling its first fuel pumps, Kinsler dedicated more than a year of development and engineering for durability on a six-station flow bench. These days, the company flow-tests each pump, runs them for two hours, and retests them before they are shipped. If the pump doesn’t, meet the company’s lofty internal standards, they aren’t sent to customers.
Kinsler Fuel Injection
(248) 362-1145

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