DIY alky question

[snodgrass]

I bought the famous Shurflo pump to use in my alky setup. While bench testing the system, the pump will cycle rapidly on the internal pressure switch. I made a grainger type pressure regulator just to try on the system, and it allows the pump to run continuosly at 60 psi. It returns the extra alky pressure to the tank while keeping pressure in the system. Is this the common solution to cure the pump from cycling like it does without the regulator? Isn't it rough on the pump to cycle like it does? Thanks for any opinions, Jeff

 

[78trbolesbr]

Where can I purchase the Shurflo pump from? Summit?

 

[Lee Thompson]

pump

I installed a TEE on the discharge side of the pump. Ran a line back to the holding tank with a nitros nozzle in the fitting at the tank. By changing the size of the nozzle I can control how the pump acts. I have a Surflo pump from a supplier that installed a 100 psi spring.

 

[chris]

Originally posted by 78trbolesbr
Where can I purchase the Shurflo pump from? Summit?

Tractor Supply or Northern Equipment.

 

[Razor]

Well see there is no 100 lb spring. Its the same pump, same motor, same diaphram. Only difference is on one the allen head screw is turned down a bit further than the other. So save yer money.

The reason your pump cycles on and off is due to the size of the jet/nozzle being used. Hence why it has a pressure switch on top of the pump. The easy/correct fix is drop the voltage to the pump, so it doesnt bounce off its rev limiter , or increase jet size where flow isnt restricted for it to hit the pressure switch limit. On my systems that is how things are accomplished. Turn the pressure screw down, and control voltage to pump..works super effective.

As far as hurting the pump by it cycling..nope.. its doing what its suppossed to do.

Many DIY kits running a Shurflo at 60 PSI.. with it pulsing on and off for years.. depends what you want to do.

HTH

 

[Lee Thompson]

pump

What is the part # on the pump? I/m curious if it is the same pump I have.
Me of little mind probably don/t know what I/m doing.
Seems every thing I/m doing is wrong or won/t work or not necessary.

 

[Red Regal T]

I'VE BEEN PULSING AT 60 PSI FOR YEARS WITH SUREFLO #2687.

 

[Razor]

Re: pump

Originally posted by Lee Thompson
What is the part # on the pump? I/m curious if it is the same pump I have.
Me of little mind probably don/t know what I/m doing.
Seems every thing I/m doing is wrong or won/t work or not necessary.

8000-543-236

 

[Lee Thompson]

pump

The pump I/m using is Shurflo part # 8000-643-210- NO ADJUSTING SCREW-- originally 60 psi--You have to change the spring to a 100 psi spring--which I have done. This pump does not cycle---it has an internal bypass to keep the pressure @ 100 psi--once the hobbs switch has been satisfied, it runs until boost drops off. Thats my story an I/m sticking with it.

 

[Razor]

Lee I hear ya. Dunno bout your pump..see Shurflo makes like hundreds of different pumps, all out of different materials.. for different applications. Just becuase it says Shurflo doesnt mean its the pump to use.

On the pumps used for the DIY kits, it has an adjusting screw. And whats to say your car wouldnt run faster at 90 PSI or 110 PSI. Just becuase it works, doesnt mean its rite . Hence why adjustability gives the results. You spray too much alky, the MPH comes down on the top end of the track. Spray too little..it will knock in third gear.

Thats my story, and i'm sticking to it

Cheers..I'll dig up the materials used in your pump..and see if compatible.

Julio

 

[Lee Thompson]

pump

According to the Surflo rep. at the PRI show, this is the pump I needed for what I wanted to do (methanol). So far I am very happy with it. Also the place I ordered from recommended this same pump. What do I know? Just because it is not the same pump everyone else is using, doesn/t mean it is wrong either.
I rest my case.

 

[Razor]

Pump

Good. Then I wont look it up. Saves me the trouble.

case closed

 

[snodgrass]

Lee, where did you get your pump, and how much did it cost? It sounds like that internal bypass feature on your pump might be a nice feature for someone that isn't using an electronic speed controller like Razor has. I just can't afford that progressive speed controller right now, so I'm going two stage. I have the more commonly used pump, and I don't like the way it cycles. I know the guys here are having good results with it, but i would rather have a more constant spray from a continously running pump. Thanks, Jeff

 

[Lee Thompson]

pump

SYSTEM ACCESSORIES
P.O. BOX 7782
MARIETTA, GA
770-917-1199
Ask for Art and ask him to install the 100 psi spring.
$112 last year.
I had the one that would cycle off and on. Drove me nuts. Sent it back for this one. This one runs continuously. I have a 2 stage using 2 different boost pressures, soon to be a 3 stage using 3rd gear signal for the 3rd set of nozzles. Good Luck

 

[Razor]

Originally posted by snodgrass
Lee, where did you get your pump, and how much did it cost? It sounds like that internal bypass feature on your pump might be a nice feature for someone that isn't using an electronic speed controller like Razor has. I just can't afford that progressive speed controller right now, so I'm going two stage. I have the more commonly used pump, and I don't like the way it cycles. I know the guys here are having good results with it, but i would rather have a more constant spray from a continously running pump. Thanks, Jeff

Jeff, adding a 100 PSI switch to your pump only increases the pressure. Actually a .35 cent allen wrench turning down the screw on the top will accomplish the same. See that pump is designed to run a much larger hose/nozzle. If you put a restriction on its output, it will try and increase pressure.. once it hits 100 PSI..it can only do one thing..shut off until pressure drops under 100 psi..then it starts back up.. on-off-on -off. Some guys have hit 250+ PSI on that pump by bypassing that pressure regulator switch assy. So look at it like its a 250 PSI pump, that needs to be tamed..only way using the switch on top so it doesnt go over current and kill itself. Some guys use accumulators, others make a return, etc.. My method is dropping voltage to the pump. Whereas at 6 volts it wont spin fast enough to hit the internal limiter. I sell a controller for 139.00 that does just this. By the time you price all your options, Hobbs switches, nozzles, lines, solenoids, relays, wiring, etc.. its really not a bad deal. Its not progressive, but hey it works on a budget.

Solenoids can go bad, they must be alcohol compatible, and place one more point in the system for a leak to occur/issue to arise. I dont recommend them unless absolutely necessary like in the case on a Hot Air car.

Lee.. Arts a good guy.. thumbs up.