Fuel pump questions for weber set-ups...

sen2two · 09-04-2010, 04:28 PM

I have 3 weber set-ups right now.

45 sidedraft
48 sidedraft
51 IDA (yes, the real deal Racing Beat 51 IDA

)

What type of fuel pressure will each be looking for? What size fuel pump? I have used the blue Holley fuel pump before, but i think it was to much pressure?

51 IDA will be on a full PP 13b. The other two will be on moderate to stock motors. Nothing wild for those.

Any tips would be great. Thanks.

730RWHP12A · 09-04-2010, 06:00 PM

3.5 psi is recommended for weber carbs mallory, carter or holley will work fine when ran with a fuel pressure regulator set at 3.5 psi..
however depending on the needle valve in the 51 ida we ran ours up to 6 psi with a internally regulated Mallory 140 fuel pump. we had issues with fuel starvation with other pumps on the p-port....

sen2two · 09-04-2010, 09:04 PM

So this one carter pump should be suitable to run all three pumps just fine then. Reason being, I plan on running my basically stock motor at first with my 45 webers because its ready to go. Then later dropping in my 6 port full bridge motor that has the 48's on it. And when i finish my PP motor with the 51's on it, drop that in. I don't want to get a new pump with each motor change.

http://www.jegs.com/i/Carter/180/P40...oductId=748050

730RWHP12A · 09-04-2010, 09:12 PM

you will need a better pump for the p-port. the carter will not flow enough volume too keep up with the p-port. if you want to buy one pump then get the mallory 140 and your done.

jtbshaw · 09-08-2010, 02:43 PM

Aww snap, I'm glad Robert posted in here about this. I just got my setup fired up on Monday night....TII with tha Shack's 45DCOE blow through. You are suggesting only 3.5lbs Robert? I'm runnning an Aeromotive A1000 pump and regulatin' with a Mallory 4309 FPR. I had it set to 6psi...too much???? The 4309 is a progressive FPR.

Todd B.
(had any of that crazy sauce lately?)

Buggy · 09-08-2010, 05:02 PM

I know at anything over 3psi on my 48 IDF i had problems with fuel being pushed past the needle and seat and also external fuel leaks from the carb. Keep the pressure low, but go with a larger needle and seat along with a high flow pump. I'm running a 3mm needle and seat on my halfbridge in my Rx-4.

jtbshaw · 09-08-2010, 06:14 PM

That would explain why the car seems to be flooding without ever touching the pedal. I have the pressure set at 6psi. I'll turn it down tonight and see what happens. I still have to dial the timing in as it is a tooth or so off. One thing for sure is that I am not having a lack of fuel.

Thanks for starting this thread Sen2 and thanks for the input fellas.

Buggy · 09-08-2010, 08:37 PM

Quote:

Originally Posted by jtbshaw

That would explain why the car seems to be flooding without ever touching the pedal. I have the pressure set at 6psi. I'll turn it down tonight and see what happens. I still have to dial the timing in as it is a tooth or so off. One thing for sure is that I am not having a lack of fuel.

Thanks for starting this thread Sen2 and thanks for the input fellas.

You could actually watch the fuel drip from the tubes in the barrels of the carb after the car was shut down. That's how I figured out what was going on.

sen2two · 09-09-2010, 09:42 PM

I found a great deal on a basically new Holley Blue fuel pump.

Preset to approximately 14 psi
Flows 70 gph maintaining 9 psi line pressure
Free-flow capacity of 110 gph

If all you need is it to maintain 6psi for a full PP. This should be a nice pump also...

09-04-2010, 04:28 PM	#1
sen2two KTEC Join Date: Jan 2009 Posts: 642 Rep Power: 0	Fuel pump questions for weber set-ups... I have 3 weber set-ups right now. 45 sidedraft 48 sidedraft 51 IDA (yes, the real deal Racing Beat 51 IDA ) What type of fuel pressure will each be looking for? What size fuel pump? I have used the blue Holley fuel pump before, but i think it was to much pressure? 51 IDA will be on a full PP 13b. The other two will be on moderate to stock motors. Nothing wild for those. Any tips would be great. Thanks. __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

09-04-2010, 06:00 PM	#2
730RWHP12A Rotary Fanatic Join Date: Mar 2008 Location: chatsworth, california Posts: 349 Rep Power: 18	3.5 psi is recommended for weber carbs mallory, carter or holley will work fine when ran with a fuel pressure regulator set at 3.5 psi.. however depending on the needle valve in the 51 ida we ran ours up to 6 psi with a internally regulated Mallory 140 fuel pump. we had issues with fuel starvation with other pumps on the p-port.... __________________ rotaryshack.com

09-04-2010, 09:04 PM	#3
sen2two KTEC Join Date: Jan 2009 Posts: 642 Rep Power: 0	So this one carter pump should be suitable to run all three pumps just fine then. Reason being, I plan on running my basically stock motor at first with my 45 webers because its ready to go. Then later dropping in my 6 port full bridge motor that has the 48's on it. And when i finish my PP motor with the 51's on it, drop that in. I don't want to get a new pump with each motor change. http://www.jegs.com/i/Carter/180/P40...oductId=748050 __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

09-04-2010, 09:12 PM	#4
730RWHP12A Rotary Fanatic Join Date: Mar 2008 Location: chatsworth, california Posts: 349 Rep Power: 18	you will need a better pump for the p-port. the carter will not flow enough volume too keep up with the p-port. if you want to buy one pump then get the mallory 140 and your done. __________________ rotaryshack.com

09-08-2010, 05:02 PM	#6
Buggy I've been Wankeled! Join Date: Apr 2010 Location: Mildmay, Ontario, Canada Posts: 260 Rep Power: 16	I know at anything over 3psi on my 48 IDF i had problems with fuel being pushed past the needle and seat and also external fuel leaks from the carb. Keep the pressure low, but go with a larger needle and seat along with a high flow pump. I'm running a 3mm needle and seat on my halfbridge in my Rx-4. __________________ 1976 Rx-4 hardtop. Half bridge 3B 13B, S5 NA rotors, Renesis e-shaft, stat gears, and bearings, balanced rotating assembly, RE dual weber 36 DCD's 203rwhp 137ft-lbs torque DGRR 2011 3rd place 1974 Rx-4 all original 27,000 miles 1988 Rx-7 TII 320rwhp. DGRR 2012 3rd place

09-08-2010, 02:43 PM	#5
jtbshaw ORD - Old Rotary Dude Join Date: Feb 2008 Location: Pelham, AL Posts: 319 Rep Power: 18	Aww snap, I'm glad Robert posted in here about this. I just got my setup fired up on Monday night....TII with tha Shack's 45DCOE blow through. You are suggesting only 3.5lbs Robert? I'm runnning an Aeromotive A1000 pump and regulatin' with a Mallory 4309 FPR. I had it set to 6psi...too much???? The 4309 is a progressive FPR. Todd B. (had any of that crazy sauce lately?)

09-08-2010, 06:14 PM	#7
jtbshaw ORD - Old Rotary Dude Join Date: Feb 2008 Location: Pelham, AL Posts: 319 Rep Power: 18	That would explain why the car seems to be flooding without ever touching the pedal. I have the pressure set at 6psi. I'll turn it down tonight and see what happens. I still have to dial the timing in as it is a tooth or so off. One thing for sure is that I am not having a lack of fuel. Thanks for starting this thread Sen2 and thanks for the input fellas.

09-09-2010, 09:42 PM	#9
sen2two KTEC Join Date: Jan 2009 Posts: 642 Rep Power: 0	I found a great deal on a basically new Holley Blue fuel pump. Preset to approximately 14 psi Flows 70 gph maintaining 9 psi line pressure Free-flow capacity of 110 gph If all you need is it to maintain 6psi for a full PP. This should be a nice pump also... __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2