I am happy to report to Ferrari 355F1 owners' community and mechanics who repair these beautiful cars that I developed a cost-effective and practical solution to 355 F1 gear pump head replacement, which has been "unobtanium" from the start, because it has never been sold by Ferrari or Ferrari parts dealers/distributors as a separate part. The original (stock) pump heads have been manufactured by Marzocchi Pompe S.p.A. (Italy), for Hydraulic Ring GmbH (Germay) company, which has been sold and resold a couple of times since the late 1990s - early 2000s. These hydraulic pump heads have not been manufectured by Marzocchi since the original limited production run and this pump model has never been listed in Marzhocchi catalogues.
Although in general these types of gear pump heads are virtually indestructable, they still have a limited life-time, because the inside bearings are made of bronze, which wears out and, as the result, these pumps can not generate sufficient pressure. Consequently, electric motor works overtime and wears out to the point that it fails. During the past 2-3 years the umber of 355F1 units that I have been refurbishing for various mechanics and parts companies increased drammatically, because these cars are now 20 years old and now not only the motors, but also the pump heads are failing progressively, but these pump heads could not be purchased anywhere ! As the result, many 355F1 owners had to use Hill Engineering kit to modify their F1 hydraulic power units by connecting to electrohydraulic pumps from 360F1 cars. However, this solution is cumbersome, is not concourse-compatible, and costly in terms of cost of labor. This actually was the reason to why I became motivated to develop new aftermarket "reproductions" of electric motor and the gear pump head for 355F1.
So, here it is - a "reproduction" and performance upgrade of the original hydraulic gear pump head for 355F1 (Marzocchi part # ZKD169/388A), which I have developed, finally. It is located inside the hydraulic fluid receiving reservoir of hydraulic power unit (Ferrari part # 177686) as indicated by a yellow arrow in the attached picture. For comparison, I also provide pictures of stock pump head (from Marzocchi). The new upgraded pump head has much higher output (0.27 ml/rev) than the stock pump head (0.16 ml/rev), so that the pump cycle is almost twice shorter using this pump head. You can notice the difference in thickness of the middle section of my new pump, which is almost twice wider than that in the old stock pump from Marzocchi. This part is the housing for gears that pump hydraulic fluid while rotating. The wider the gears, the more fluid can be trapped between the gears and pumped out into the high pressure port (a small opening on the shaft side of this pump). When instaled together with the new motor I developed, the pump cycle duration is shortened to only few seconds. These pump heads should last another 25-30 years, because these are made from much better and newer type of materials than stock pump heads.
Thus, a HUGE problem of "unobtanium" parts for 355F1 system, both the electric motor and gear pump head, has finally been solved !!!
Both parts are now offered on eBay:
# New pump with higher output: http://www.ebay.com/itm/252979780864
# New electric motor with higher RPM and torque: http://www.ebay.com/itm/252963873225