Robert, Check your Ercoupe manuals and you will see that the .060 restriction goes on the output side of the fuel pump, not the input. This will restore the correct input to the header tank. Tom A&P/IA Good flying to you................
--- On Thu, 9/17/09, Robert Blanchard <[email protected]> wrote: From: Robert Blanchard <[email protected]> Subject: [ercoupe-tech] Fuel Replenishment Rate To: [email protected] Date: Thursday, September 17, 2009, 3:51 PM Group: We have just finished a major rebuild of 415-CD #4787, N94676 airframe. Restoration work was accomplished by a highly experienced team composed of an AP and an AP/IA. The C-85-F engine was majored just prior to my purchase and fitted with the 0-200 modification. Currently, TTSM is 28.6 hrs. As part of the rebuild, the fuel plumbing system was replaced due to use of unauthorized components an unworkable plumbing configuration. The new system follows the configuration shown in Figure 34 of the Ercoupe Service Manual. All tanks are vented with serviceable gaskets. The orifice input fitting at the fuel pump was measured at .062". During post rebuild flight tests, it was discovered that, although fuel was being pumped from both wing tanks, the flow rate was insufficient to fully replenish the fuel drawn from the header tank. This was particularly true with the fuel burn rate experienced during touch and go landings. We did not receive any engine performance data on the C-85-0200 engine with the airplane. Fuel consumption data for the C-90 is appreciably higher than for the C-85. Assuming the C-85-0200 is reasonably approximated by the C-90 fuel consumption at various power levels, it occurred that the header tank fuel replenishment rate for the C-85-0200 may be higher than that allowed by the current orifice in the fuel pump of .062”. So far, we haven’t been able to find data on the required orifice for the C-90 or 0200 Continental engines. First, can anyone provide fuel consumption data for the C-85-0200 engine? Is the C-90 a reasonable approximation? Is the restriction orifice of .062” adequate for this engine modification, or should it be relieved? If so, by how much? The fuel system IS transferring fuel from the wing tanks to the header tank, but the fuel transfer rate seems to be insufficient. I am concerned that a fuel burn rate resulting from a long climb at full power would deplete the fuel from the header tank to an extent it would take an inordinately long time at cruise to replenish. We would greatly appreciate any insights, experiences, or recommendations that might be offered. Thanks to all. Bob Blanchard, Owner/Pilot N94676
