61 Alum 6 Start Up, Carb and Oil Light

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   So a pair of in-line check valves, placed near the carb, on on the tank side one on the engine side, wouldn't work? I'd think the pump pulses would still work with a single inline check right outside the line to the tank, but maybe not. 

Thinking "out loud" here....  The volume moved with each stroke isn't really much. Cam turns at half crank rotation, so if you're running 1500 rpm the pump is making 750 strokes a minute... doesn't need to move a lot of fuel with each stroke. That will probably mean it won't "back up" enough to an external check valve either. But then it's simple hydraulics -- once fuel is in the line a little distance won't matter -- fluids don't compress (with some exceptions, like silicone brake fluid, which traps some air and THAT compresses). 

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farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19689	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Nov/04/2021 at 5:42am
	So a pair of in-line check valves, placed near the carb, on on the tank side one on the engine side, wouldn't work? I'd think the pump pulses would still work with a single inline check right outside the line to the tank, but maybe not. Thinking "out loud" here.... The volume moved with each stroke isn't really much. Cam turns at half crank rotation, so if you're running 1500 rpm the pump is making 750 strokes a minute... doesn't need to move a lot of fuel with each stroke. That will probably mean it won't "back up" enough to an external check valve either. But then it's simple hydraulics -- once fuel is in the line a little distance won't matter -- fluids don't compress (with some exceptions, like silicone brake fluid, which traps some air and THAT compresses).
	Frank Swygert

tomj Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7555	Post Options Post Reply Quote tomj Report Post Thanks(0) Quote Reply Posted: Nov/04/2021 at 8:20pm
	Oh, right. Probably it woudl work, if they were easy to overcome with the mild suction the pump diaphragm produces. THe spring in the diaphragm determines the output pressure. The check valves would have to seal really well and operate at very low pressures. But it will be a lot of fussy work to cobble up two suitable check valves. ANd if it's bad because the pump is old, the diaphragm is probably soon to fail also. The TSM has a good basic pump test. I wouldn't trust a car/pump that didn't pass that test. Edited by tomj - Nov/04/2021 at 8:22pm
	1960 Rambler Super two-door wagon, OHV auto 1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com

farna Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19689	Post Options Post Reply Quote farna Report Post Thanks(0) Quote Reply Posted: Nov/05/2021 at 1:08pm
	Well, the check valves are cheap, and work under low pressure, but as you said... the pump may be on it's way out anyway. I have seen a few that would drain back due to a faulty check valve but the fuel pump was fine, but a rare occurrence. Maybe got trash stuck in it?
	Frank Swygert

vinny Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jan/05/2012 Location: Calgary Status: Offline Points: 2837	Post Options Post Reply Quote vinny Report Post Thanks(0) Quote Reply Posted: Nov/12/2021 at 10:48am
	If it is a Carter RBS carb probably you could get a kit for it and they are quite easy to rebuild. Just look up Carter RBS Rebuild on youtube.

vinny Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jan/05/2012 Location: Calgary Status: Offline Points: 2837	Post Options Post Reply Quote vinny Report Post Thanks(0) Quote Reply Posted: Nov/12/2021 at 10:56am
	It will be difficult to swap engines because of the torque tube driveshaft. Probably it would be easier to change it over to electric and keep the original transmission and differential.