Need Help with DSR Zero Pump

ericg25 · 6/18/24, 10:56 AM

Hey all, wondering if there's anyone out there who can help me figure out what i need to do to get my fuel system working properly. I'll list some info below, if anyone has any pump curves for a DSR "0" pump that would be great, it's been really tough to get any good info on this since Darryl passed away.

Pump part number: DSR p/n 0-30069 (card says CCR rotation, 1.66 GPM @ 1800 RPM @ 50 PSI)
Engine: Iron block & Head SBC w/ Willy's 4412 carb. I have dyno sheets that show fuel usage in #/hr vs. rpms

Problem: Engine stumbles a lot on lower rpms, especially starts and restarts. It behaves like a rich stumble. I think the pump provides too much fuel to the carb for it to work properly so i'm looking for help on sizing a bypass system that will take the excess flow away from the carb to help it work more effectively. Waterman won't offer any technical help, only rebuild parts, as they don't have any performance data on the DSR pumps.

Any help or suggestions on who to talk to on getting this sized and sorted out would be greatly appreciated. Thanks!

Frank Reiner · 6/18/24, 11:49 AM

What is the fuel pressure at the carb inlet under full load?

6/18/24, 10:56 AM	#1 Need Help with DSR Zero Pump
ericg25 Member Join Date: Sep 2022 Posts: 9	Hey all, wondering if there's anyone out there who can help me figure out what i need to do to get my fuel system working properly. I'll list some info below, if anyone has any pump curves for a DSR "0" pump that would be great, it's been really tough to get any good info on this since Darryl passed away. Pump part number: DSR p/n 0-30069 (card says CCR rotation, 1.66 GPM @ 1800 RPM @ 50 PSI) Engine: Iron block & Head SBC w/ Willy's 4412 carb. I have dyno sheets that show fuel usage in #/hr vs. rpms Problem: Engine stumbles a lot on lower rpms, especially starts and restarts. It behaves like a rich stumble. I think the pump provides too much fuel to the carb for it to work properly so i'm looking for help on sizing a bypass system that will take the excess flow away from the carb to help it work more effectively. Waterman won't offer any technical help, only rebuild parts, as they don't have any performance data on the DSR pumps. Any help or suggestions on who to talk to on getting this sized and sorted out would be greatly appreciated. Thanks!

6/18/24, 11:49 AM	#2 Re: Need Help with DSR Zero Pump
Frank Reiner Member Join Date: Oct 2013 Posts: 77	What is the fuel pressure at the carb inlet under full load?