by Gomer Pound » Sat Nov 12, 2016 6:03 pm
Hi Timothy, Please clarify for me. They way I have read your posts is you are having your Weldon pumps overhauled for $400/pump to Weldon specs. You are also talking about the overhaul station getting approval for a a new electric motor to drive the Weldon fuel pumps which will replace the short, fat Weldon electric motors currently attached to your Weldon pumps.
Are you having your electric fuel pump motors overhauled as part of the $400/pump, or are your electric motors OK? Are you replacing your Weldon electric motors with the new motors the company has developed, or are you keeping your current electric motors?
Do you have any info on the specs of the new motors being approved, such as GPH and size?
Charlie, of CJ Aviation, who also also overhauls the Weldon fuel pumps,told me he planned to develop a new electric motor/pump combination to replace the original short, fat motor Weldons. . He does not care for the newer, slim, Weldon electric motors available via an installation STC when they are mated with the Weldon pumps because the electric motors are not as durable as the original short, fat, pumps
He said his new motor would be slimmer so it would fit easier, but would also have a lower GPH pump since he feels one of the main problems with the Weldon pumps wearing out is the way the pumps keep recirculating excess fuel flow inside the pump since, unlike a Cessna 310 or Bonanza, for example, there is no "return fuel" line that goes back to a tank for the excess fuel flow which would reduce heat build up.
Charlie said the constant recirculation causes the pumps to run hot which damages the brass inside the pumps. He said the fuel flow does not need to be 35 GPH for an IO320 , that the pump was just chosen off the Piper rack of available pumps. The reason to make a slimmer electric pump is purely for ease of installation and removal. With slimmer pumps the fuel selector does not need to be removed to change an electric fuel pump from what I understand. This seems very plausible to me.
Clear Skies,
Gomer