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307 walbro fuel pumps?

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Whitettype86

Young William
Joined
Jan 8, 2002
Messages
465
I have two 307 Walbro Fuel pumps on my Atr double pumper setup. I heard this pumps are bad fuel pumps? That they quit working. If there bad should I install to 340 pumps?
If there good are these pumps good to the 10s? Need to know before dropping them in the tank.
 
Walbro 307's are only good to ~60 PSI fuel pressure. They have plenty of flow capacity but the pressure capability is not as high as a 340. If you plan to run higher pressure (ie static FP ~42 PSI +23/25 PSI boost), you'll need 340's.

Check out the info on the Racetronix website. Says the same thing.
 
Really...that's very interesting cause I have Walbro 307 in my GN using a Thrasher chip...FP set at 45(line off)...I consistently run 22-23 PSI boost with no problems...45+22=67 PSI...
 
Got a FP guage on there?

I Just put one on. FP stops like hitting a brick wall @ ~62PSI when the load is on. (42 static +24 PSI boost should be 66 PSI FP) Result was falling O2 volts top of 3rd and into 4th, which shouldn't happen with an extender/translator. New fuel filter made no improvement. Will see if the 340 eliminates the issue.
 
Yep...have tested with a FP guage taped to the windshield...FP was up around 67 PSI at WOT...
 
I used to run one 307 when i first got my car in the tens. Now i run two 307.'s and have seen 80 psi at wot with msd 50's.Althogh everybody says it is not possible. If you have enough injector you won't have a problem.
 
The Walbro 307 IS NOT the same as the 340.
The armature in the 340 is more efficient and will draw less current at a given flow/pressure than the 307.
The internal pressure bypass on the 307 is lower as well making it better suited for naturally aspirated motors.
When running two 307s in parallel you must consider the restriction placed on the outlet of the pumps. If the head pressure of the two pumps combined into one thin line exceeds the bypass pressure of the pumps then a good percentage of their flow will be diverted. This is why Racetronix only uses 340s in its double pump kits.


Jack :cool:
Racetronix
 
So should I get rid of them? I bought the Atr duel pump from somebody else and it had 307. I couldn't wait one the Racetronix
duel pumps and I have not seen one yet. So as u can see I have 83lbs injectors and LT-72 turbo with a 4.1. Are this pumps going to work?:confused:
 
Why would you combine two pumps, actually any two pumps, into one thin line? :confused:

Can't see that being a good double pumper setup.... :(
 
Jack are u calling a stock fuel line tiny?:confused: I don't understand then why would I go to a 340? I know it has greater
psi than the 307 but wouldn't two 307 be the same as one and half of a 340? I know 340 pumps are good to 10s than what are 307 good for?
 
Originally posted by Whitettype86
Jack are u calling a stock fuel line tiny?:confused: I don't understand then why would I go to a 340? I know it has greater
psi than the 307 but wouldn't two 307 be the same as one and half of a 340? I know 340 pumps are good to 10s than what are 307 good for?

Without getting too far off topic perhaps it would be best for you to try what you have? Chances are it will be able to handle your fuel requirements without a problem. The vintage of 307 pump and / or what ATR might have done to them we do not know.

Answers to much of the theory and application of this double pump setup I and others have addressed in a few different threads on TB over the past few months. You can do a search to find them.

Jack :cool:
Racetronix
 
.......a double pumper 340 will work on stock fuel lines but a pair of 307's won't? (too much backpressure on the 307?) Come on.......do you have any tests to prove this? we just want the facts, ya see.....

BTW, when will the Racetronix double pumper be available?

and that double pumper mount?
 
Originally posted by azgn
.......a double pumper 340 will work on stock fuel lines but a pair of 307's won't? (too much backpressure on the 307?) Come on.......do you have any tests to prove this? we just want the facts, ya see.....

BTW, when will the Racetronix double pumper be available?

and that double pumper mount?

If and when we do release this product we will post all the 'facts' and specs you could ever want. Until then the specifics of our tests and design will remain under wraps. I do not see the competition spilling the beans on their R&D. As much as I like to answer your challenge of "Come on.......do you have any tests to prove this?" I will just sit back and let the experts on this board figure it out :D or even better yet you can run some tests yourself to answer your own question. :rolleyes:

BTW I don't see where I posted a 307 will not work. I posted “When running two 307s in parallel you must consider the restriction placed on the outlet of the pumps. If the head pressure of the two pumps combined into one thin line exceeds the bypass pressure of the pumps then a good percentage of their flow will be diverted.

The ATR and RA double pump kits work just fine for most people.

The Racetronix double pump for the Buick is on hold until we get other projects of higher priority out of the way. I am still not convinced that this kit could be made in such a fashion that most people could assemble it themselves with basic hand tools. Being able to meet a price point based on the small TR potential market is another major concern. Building a DIY product sometimes costs more to produce and support than a fully completed PnP product.
When there are any updates they will be posted in the original thread here:
http://www.turbobuick.com/forums/showthread.php?s=&threadid=28532

Jack :cool:
Racetronix
 
Jack:
All I have to say is; "you are the man...!" I have purchased your 340 pump/kit, and am highly impressed with the quality and workmanship of the entire setup. Detail all the way down to the right number of zip ties. Kudos to you and your outfit for making innovative and quality pieces for our aging hot rods! I am also on your back-order list for the Delphi 50's. Do you have any updates about these yet, or their replacement options?
Anyway, my main reason to reply here is to say thanks for providing useful and proven data to back your claims and theories. Real data goes a far bit further than mere opinions!
Keep up the good work!
 
So can I get away with the 307 pumps? I guess I could try and If I have problems mybe I can wire up a kill switch to the motor if one fails. I'll figure something out or mybe call Red Armstrong or Atr and find out about the 307 pumps.:(
 
Originally posted by JToups386
Jack:
All I have to say is; "you are the man...!" I have purchased your 340 pump/kit, and am highly impressed with the quality and workmanship of the entire setup. Detail all the way down to the right number of zip ties...


I always wondered if there were enough ties in the kit...;)
I guess that answers my question:D

Info on the 50lb injectors will be posted in the appropriate thread here:
http://www.turbobuick.com/forums/showthread.php?s=&threadid=46934

Jack :cool:
Racetronix
 
Originally posted by Whitettype86
So can I get away with the 307 pumps? I guess I could try and If I have problems mybe I can wire up a kill switch to the motor if one fails. I'll figure something out or mybe call Red Armstrong or Atr and find out about the 307 pumps.:(
I think you will be just fine!
 
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