How To Select The Right Performance Hose
The decision to switch over to a performance grade hose assembly can be a tough
one. Some people do it for the racy look it gives while others use it for the added strength and
durability it provides. In any case making sure you get the right hose requires a bit of insight
before placing an order.
Performance hose can be broken down into three categories: Stainless steel outer
braid covering Buna-N hose, Stainless Steel covered Teflon hose and high pressure smooth or cloth
covered hose. Each category has its pluses and minuses.
Standard ss Buna-n hose provides both burst and abrasive protection. It requires a cut off saw or
fine tooth hacksaw to cut and needs to be replaced after a few years if it is used with gasoline.
The ss covered PTFE (Teflon®) hose also offers high pressure ratings and the abrasive protection
that the ss buna-n hose has but it also is slightly smaller in outside diameter and can last virtually forever
if properly maintained. The downfalls are: fitting cost, assembly time and cutting the actual hose
to length. High pressure hose is available with either a smooth finish or a textile outer braiding.
The smooth style makes the hose less conspicuous than the SS hose while the textile braiding gives
a European look. These hoses have a lower pressure rating than the SS hose and need to be checked
frequently for dry rot. It can be used with standard barb fittings and also the Push Lite hose ends.
Once you have chosen your hose you then need to figure out which hose ends and
adapters you will need. Hose ends are made specific to the type of hose and should never be mixed.
Hose ends are sized by the AN system. AN stands for Army Navy and is basically refers to the inside
diameter of the hose or end in 16ths. For example a #8 AN is 8/16ths or 1/2". Adapters are exactly
what the name implies, they adapt AN size threads to pipe,straight or metric threads. These are great
when plumbing a line from a intake manifold or water pump that has female threads. Sometimes you can
get aftermarket race parts that already have the required AN fittings on them. This is simply a matter
of attaching the mating female AN hose end to complete the connection.
Hose ends are made in several angles and also different attachment styles. The cutter style, like our
Fragola Series 3000 Hose ends, is where the socket draws the hose over the nipple and into the cutter. The seal is formed by the cutter
imbedding itself into the end of the hose. These ends are reusable but the end of the hose must be
re trimmed. The next style is the "single nipple" system, as used in the Fragola series 2000 Hose Ends, whereby the socket draws the hose over the
nipple and seals it by crushing the hose between the socket and the nipple. Since there is no cut
hose to remove, the hose ends are easy to reinstall on a new piece of hose. Then there is the hose
ends for PTFE (Teflon®)hose. These are typically made from steel and feature a sleeve and
compression nut. These reusable hose ends feature a miniature “olive” that retains the hose inside
of the fitting. An example of these would be the Fragola PTFE Hose Ends. By replacing this “olive” the hose end may
be reused over and over. Some sizes are now available in aluminum. Lastly we have the socketless hose. These hose ends are used with the
pushlite and pushlok hoses. You simply push the hose over the barb and secure with a crimp clamp or
Each hose type has its own method of assembly. You will find that there are certain
necessary tools needed for a successful and reliable assembly. These are: A bench vise for holding the
hose while cutting and also for clamping the hose end for assembly, soft vise jaws to hold the fitting
securely without damaging it, Duct tape to wrap the hose at the cutoff point to prevent fraying of
the braid, Assembly Lube to prevent galling of the hose end threads, AN wrenches to tighten the hose
end assembly without damaging the finish, A Koul Tool kit to make inserting the braided hose into
the socket easier and finally a pressure test kit to make sure the finished assembly is leak free.
By following these guidelines and taking your time during assembly you should end
up with a leak free line that can handle the rigors of a racing enviorment.