makes GZ Pumps Different?
While most vacuum pumps may appear to work the same, the
fact is that there are major differences on the inside, where it counts. The recently redesigned Pro Racing Vacuum Pump is a purpose built pump specifically
designed for the hot, wet and oily environment found in race car crankcase
An all new diecasting, only available from GZ Motorsports,
forms the core of the new pump with much closer tolerances than previous models, enhancing its air flow potential. Closer tolerances in the new diecasting
allow the Pro Pump to generate 26% more air flow than similar sized competitors' pumps! Updates also include improved and beefed up port locations, totally
rebuildable bearing sections and long life wipers.
As with all GZ Vacuum Pumps, Rulon Wipers are still used
exclusively, as Rulon is the best material we'v found to use for tough, hot and oily
applications. In fact, this pump can suck in and spit out anything
but metal without sticking! In fact, recent durability testing we've conducted
with our new extended life wipers proved that this pump can run 500 hours at
3500 RPM with a light oil mist and still maintain full vacuum! Compare that
service life with any other brand pump and you'll find nothing else comes close
to lasting that long.
With GZ Motorsports Vacuum Pumps, there is no need to spray
brake cleaner into the pump between rounds to keep the internal vanes from
sticking, a necessity with all other brands of pumps because they aren't
designed to run in an oily atmosphere. Unlike the others, GZ pumps use a proven
vane design that doesn't stick!
Quieter Operation...Want to run a vacuum pump on a street
car? You don't want an annoying click-click-click to give away what you have
under the hood. GZ Motorsports vacuum pumps are much quieter than the
competition. Their pumps make a loud clicking sound as they rotate, when they
work correctly. GZ operates quietly, and stealthily under your hood without
pumps are manufactured in our shop in Glencoe, CA. After assembly, each pump is tested on our
pump dyno at 3500 rpm. During testing, Red Line racing oil is run thru them, so when you get your
pump you will see "blackened" oil at the inlet and outlet ports. This
is normal and due to the break-in process. GZMS vacuum pumps all show the test
vacuum and date tested on the part sticker on the pump.
Skip White Performance Testimonial
The photo above is one of our engines on a dyno run. We use a vacuum pump kit for dyno testing. The vacuum pump kit shown above has been used to test over 1,000 engines over three years and is still going strong.
GZMS vacuum pumps are designed to have oil pass through them,
and require oil for lubrication of the wipers at the vanes. Experience has
shown that synthetic oil yields a longer pump life. A dry pump will wear out
prematurely due to friction between the Rulon wipers and the carbon fiber
GZMS vacuum pumps are warranted for one year with proper
use. If a pump is returned that has been run dry, any warranty is void.
GZMS products are installed and used by others, no warranty
is made as to use of products as regards performance or safety. Motorsports are
inherently dangerous. The user of GZMS products assumes all potential or risk in
using those products.
Pulley ratio is typically 64% of crankshaft speed. This is
generated by using a 3.5" Crankshaft Pulley and a 5.5" Pump Pulley
unless noted otherwise with a maximum pump rpm of 6000. GZMS Sportsman vacuum
pumps are successfully run at higher RPMs, however, this is not recommended.
GZ Motorsports pumps may pull in excess of 20 in. hg. of
vacuum, therefore a vacuum relief valve is likely necessary.
Please consult your engine builder for the proper vacuum
level for your engine. If you're not sure how much to run, it is generally
considered safe to limit total vacuum to 10 - 12 in. hg., but there are varying
opinions on running more than that, depending on engine setup, possible oil
pressure drop, etc. Many competition engine builders will run up to or over
20" when the engine is designed for those levels.
For high output power adder engines, we highly recommend the
use of a data logger to monitor vacuum levels downtrack. In general, vacuum
should increase the longer the engine runs, and as the engine RPM climbs. If
piston rings start to have problems, such as if engine timing is excessive, a
loss of vacuum tends to occur due to the increased blowby when ring seal is
compromised. You may find a benefit to not running a vacuum relief valve at low
levels in this situation if you want to observe this occurring, as a relief
valve may mask this early warning signal that may be caught by a data logger of
ring seal issues.
In all-out competition, where engines are ran on the edge,
closely setting pump RPM to limit vacuum to the level desired may be preferable
to limiting vacuum with a relief valve in order to help observe ring seal
problems. This is something that should be discussed with your engine builder
and or tuner.
The vacuum your engine will make is dependent on the amount
of blow by it generates and any air leaks it may have. No two engines are
Ring Packages such as low tension rings typically generate
an increase in ring blowby requiring a larger, or faster spinning pump.
Power Adders such as Nitrous Oxide, Superchargers,
Turbochargers all increase cylinder pressure generating increased ring blowby
requiring a larger or faster spinning pump. The amount of Nitrous you are
spraying, or the amount of boost you are generating increases the needs for a
larger or faster spinning pump. Large Displacement engines typically generate
proportionately larger amounts of blowby.
The use of alcohol, especially in a "rich"
condition, generally reduces net vacuum and could require a slightly larger pump
than a gasoline engine.
Vacuum leaks in the crankcase, valve covers, distributor
base, timing chain cover, oil dipstick, etc. reduce the amount of vacuum you
will generate. You can easily check your engine by pressurizing it with air. Be
careful though, you donâ€™t need much to find leaks and you could damage gaskets
If you are going to continue to use a dipstick, consider
removing the dipstick while running the car and covering the dipstick tube
opening with a rubber vacuum plug to seal the tube off. That way you can
eliminate leakage, but still pull the plug and check your oil level when need
All engines are different depending on how fresh they are,
how much ring end gap is used, cylinder prep and ring design. This is a general
guide based on typical engines GZMS has fitted over the years as well as