What 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 vapors.
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 annoying clicks.
GZMS 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.
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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 vanes.
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 identical.
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 and seals.
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 be.
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 customer reports.