Fuel & Lubrication Systems

In recent years various fuel manufacturers have added any number of new unpublished additives to their blends rendering some of them incompatible with synthetic rubber lined hose. Earl's Speed-Flex Teflon® lined stainless braided hose is impervious to any automotive fuel blend known to us and may be the best choice for use with modern racing gasolines. All Speed-Flex hoses are compatible with gasoline, hydrocarbon fuels, alcohols, nitro-methane, mineral and synthetic lubricants, and high density fuel additives. Size 6 is carbon lined to dissipate static electricity.

Some caution is necessary in the selection of armored Teflon® hose. The Teflon® liner is manufactured in two wall thicknesses, commercial (.030") and aircraft specification (.040"), Earl's uses the thicker and stronger wall. There are also hoses in the marketplace manufactured in such a manner that the stainless braid is loose on the Teflon® liner. These hoses offer good pressure capacity but limited expansion resistance.

Earl's Speed-Flex hose is the standard of the industry. Beware of imitations. Designed to be used with Speed-Seal hose ends only.

Hydraulic Systems

Standard automotive flexible brake hoses are manufactured from synthetic rubber and reinforced with multiple layers of fabric braid. They were designed and developed for use with drum brake systems. When disc brakes were developed for racing cars, line pressure requirements increased considerably. With the larger and heavier cars, like Ford's GT-40s, enough of the available brake pedal travel was used up in expanding the flexible brake hoses so that there was insufficient pedal travel left for safe braking.

In the mid-1960s, Earl's pioneered the use of armored flex hose of extruded teflon to solve this problem. The stiffness of the teflon liner combined with the tightly woven high tensile stainless steel outer braid solved the pedal travel problem. By eliminating the line swell it also dramatically increased the firmness and feel of the brake pedal which allowed the drivers to modulate the brakes more efficiently. Improved abrasion resistance and increased temperature capacity are secondary advantages.

Since brake actuation produces high pressure with very little fluid displacement, we recommend -2 & -3 Speed-Flex for brake systems. Clutch actuation, on the other hand, requires moderate pressure but considerable displacement of fluid. For hydraulic clutch systems we recommend the use of -4 Speed-Flex.