| Author | Message | ||
     Brian Vogel Grand Master Username: guyslp Post Number: 1851 Registered: 6-2009 |
Before anyone gets exercised I am not planning to do this, at least not in the foreseeable future, but it is a question driven by curiosity. It would seem that the flow rate is more than adequate using a dual SU, but it's also true that dual SUs get frequent, if brief, resting periods when the floats close off fuel input to the carbs. I'm wondering if they are actually designed for any application where continuous pumping is expected? It would seem that there must have been a system design driven reason for using a rotary vane pump in the cars that have them, but I have no definitive information on that, just what my gut and my head both tell me. Is it possible, or desirable, to ever replace a dead Pierburg with a dual SU or is it better to go with another rotary vane pump with a flow rate very similar to the original Pierburg? Brian | ||
| Christian S. Hansen Prolific User Username: enquiring_mind Post Number: 153 Registered: 4-2015 |
The peanut gallery wonders if it might have to do not with flow rate, but ability to maintain a constant pressure for fuel injected systems? | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1852 Registered: 6-2009 |
Christian, To my knowledge, the Pierburg was never used on any of the fuel injected (FI) cars. I think all of those had the Bosch pumps. I'm not sure a rotary vane pump [in the size range that can be fitted to cars] could maintain the kinds of pressures used in FI. I'm sure someone will correct me if either one of those things is incorrect. Brian | ||
| Christian S. Hansen Prolific User Username: enquiring_mind Post Number: 154 Registered: 4-2015 |
Brian... I had no knowledge whatsoever of the Peirburg and confused it with, yes, the Bosch on fuel injected systems. I should have known that you were way ahead of that idea. Accordingly, I will retire back to the Gallery and have a (another?) beer as consolation. Lost count. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1470 Registered: 6-2006 |
Brian, yes and no. No because the SU will wear out too quickly without those resting periods. Yes if you block off the fuel return hose. They switched to a recirculating fuel system to reduce the problem of fuel vaporisation. So if you only use the car in cold weather and block the return you should be fine with an SU. Whether an electronic SU pump and a vastly reduced orifice in the return line would work I'm not sure. One mod on the very first Spirits was to widen the return restrictor very slightly. |
