test
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Former Vendor
Joined: Aug 2007
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From: Danbury,CT
test
Some time ago there was a large thread here on Rennlist addressing concerns about water pump issues on our cars. After much debate and fact finding I volunteered to try and develop a fix for all the concerns and build in a little piece of mind for the owners of the 928.below is a copy of the results of our efforts.
The Engine Guardian Water Pump Drive System (EGDS)TM
WP-Rev.G-800 cropped.jpeg
Perfex Manufacturing, Inc.
EGDS was developed for the Porsche 928 32 valve engine because of the need to prevent catastrophic engine damage in the event of a water pump failure. The water pump is driven by the timing belt which also drives the camshafts. If the water pump shaft seized or became difficult to turn this would cause the timing belt to fail and in return cause internal damage to the valve train by way of piston to valve contact.
The EGDS incorporates a separate large double row ball bearing to do the job of idler pulley in the valve train system, and couples that energy to spin the water pump shaft via a consumable coupler. The consumable coupler is engineered to shear itself from its drive sprocket at a load point less than the load point that would cause the timing belt to slip or stop.
The EGDS protects the valve train in case of pump failure and increases the life of the water pump shaft bearing immensely as it no longer has to carry the load of the valve train. Also, the separation of linear side to side loads from the timing belt tracking issues from the shaft to the larger bearing eliminate pulley and impeller migration which has also been a ticking time bomb in these engines . The EGDS increases the life of the water pump as a result.
The EGDS includes a removable cover to allow inspection/ replacement of the coupler at anytime. The removable cover also allows the inspection of the water pump shaft and drive bearing play at service intervals. The EGDS impeller is drilled and pinned to the shaft for added measure to assure no migration into the engine block.
Pumps that are received for modification are inspected at time of arrival including shipping box condition and pump condition. Perfex Manufacturing, Inc. assign the pump an ID number and perform a pre mod test and inspection of all parts and pump condition, as well as Impeller clearance, bearing stiffness/noise and a torque test. These items are continuously monitored during the disassembling and assembling of the pump to ensure no damage has been done during the process. During assembly at Perfex Manufacturing, Inc. all operations are paint marked after completion to assure quality .A final inspection and torque test and the pump is packed with a focus on impeller and drive pulley protection, and a copy of the report for the customer’s records.
Perfex Manufacturing, Inc. offers brand new water pumps with EGDS as well as in house rebuilt pumps with EGDS.
bzcrd-400.jpg
The Engine Guardian Water Pump Drive System (EGDS)TM
WP-Rev.G-800 cropped.jpeg
Perfex Manufacturing, Inc.
EGDS was developed for the Porsche 928 32 valve engine because of the need to prevent catastrophic engine damage in the event of a water pump failure. The water pump is driven by the timing belt which also drives the camshafts. If the water pump shaft seized or became difficult to turn this would cause the timing belt to fail and in return cause internal damage to the valve train by way of piston to valve contact.
The EGDS incorporates a separate large double row ball bearing to do the job of idler pulley in the valve train system, and couples that energy to spin the water pump shaft via a consumable coupler. The consumable coupler is engineered to shear itself from its drive sprocket at a load point less than the load point that would cause the timing belt to slip or stop.
The EGDS protects the valve train in case of pump failure and increases the life of the water pump shaft bearing immensely as it no longer has to carry the load of the valve train. Also, the separation of linear side to side loads from the timing belt tracking issues from the shaft to the larger bearing eliminate pulley and impeller migration which has also been a ticking time bomb in these engines . The EGDS increases the life of the water pump as a result.
The EGDS includes a removable cover to allow inspection/ replacement of the coupler at anytime. The removable cover also allows the inspection of the water pump shaft and drive bearing play at service intervals. The EGDS impeller is drilled and pinned to the shaft for added measure to assure no migration into the engine block.
Pumps that are received for modification are inspected at time of arrival including shipping box condition and pump condition. Perfex Manufacturing, Inc. assign the pump an ID number and perform a pre mod test and inspection of all parts and pump condition, as well as Impeller clearance, bearing stiffness/noise and a torque test. These items are continuously monitored during the disassembling and assembling of the pump to ensure no damage has been done during the process. During assembly at Perfex Manufacturing, Inc. all operations are paint marked after completion to assure quality .A final inspection and torque test and the pump is packed with a focus on impeller and drive pulley protection, and a copy of the report for the customer’s records.
Perfex Manufacturing, Inc. offers brand new water pumps with EGDS as well as in house rebuilt pumps with EGDS.
bzcrd-400.jpg
Last edited by OBehave; Oct 7, 2010 at 12:22 PM.
