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Using a TBI pump with a carb

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John, thanks for the info.
Are you using the Mallory regulator?
If not, which brand and model?

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A TBI pump only develops a max of 15 psi. I am sure of this. Other FI pumps "can" pump alot more pressure, not a TBI in this case.

Summit has the regulator you need.
Summit Regulator

John
 
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How can a regulator increase pressure?

How does restriction INCREASE pressure?

Last I checked, fluid was a lot like electricity. Same pressure (voltage) but more restriction (resistance) = LESS flow (current) last time I checked, unless I am missing something here.

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The parallel to electricity still holds. Current is flow volume. Voltage is pressure. Restriction is resistance. The pump is delivering flow, so it is like a current source. If you deliver a fixed volume of fluid, the pressure increases proportionally to the restriction. Theoretically, this could increase indefinately, but in reality, the pressure begins to slow down the pump down and eventually it's own seals could not handle the pressure. Still, the principle is accurate within a range of operating conditions.

The pressure regulator basically just opens whenever the specified pressure is exceeded. So if the pump is flowing more, the regulator just allows more fuel back to the tank. The difficulty of the electrical parallel to this circuit is that it is very unusual to see a voltage regulator fed by a current source.
 
John, again- thanks for useful info.
The description of the Summit (SUM-G3135) regulator states
that it has one inlet and two outlets.
So you just plumbed one of the outlets as a return to the tank and restricted the flow??
Did you have a pressure gauge tied in to check pressures as you were setting the restriction?
Interesting.
 
[ QUOTE ]
[ QUOTE ]

How can a regulator increase pressure?

How does restriction INCREASE pressure?

Last I checked, fluid was a lot like electricity. Same pressure (voltage) but more restriction (resistance) = LESS flow (current) last time I checked, unless I am missing something here.

[/ QUOTE ]
The parallel to electricity still holds. Current is flow volume. Voltage is pressure. Restriction is resistance. The pump is delivering flow, so it is like a current source. If you deliver a fixed volume of fluid, the pressure increases proportionally to the restriction. Theoretically, this could increase indefinately, but in reality, the pressure begins to slow down the pump down and eventually it's own seals could not handle the pressure. Still, the principle is accurate within a range of operating conditions.

The pressure regulator basically just opens whenever the specified pressure is exceeded. So if the pump is flowing more, the regulator just allows more fuel back to the tank. The difficulty of the electrical parallel to this circuit is that it is very unusual to see a voltage regulator fed by a current source.

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It seems that in what I've learned in the last 24 hours that unlike electricity, "pressure" (voltage) is not a constant. Flow (current) IS, with the other factors changing to meet this.
 
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IIRC the pressure is maintained in the line all the way from the pump to the reg and any excess is bled out the return with the injector being between pump and reg


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Thanks.
 
I appologize if this is a repeat, but the post is too long to read through the whole thing...

I snatched my tired ol TBI injected motor out of the '88 I used to have and stuck in a Goodwrench 350, a 600cfm Edelbrock carb and a Holley fuel pressure regulator. I capped off the return line to the tank and ran the pressure line through the regulator (no other lines to or from the gas tank or regulator) to the carb and she ran like a champ! Had it like that for a year before I sold it, no problems at all.
 
[ QUOTE ]
So you just plumbed one of the outlets as a return to the tank and restricted the flow??
Did you have a pressure gauge tied in to check pressures as you were setting the restriction?
Interesting.


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Yes, I used a pressure guage on the carb inlet line to set the pressure as I restricted the flow. You can also use the regulator to help bring the pressure down some too.

John
 
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if the reg is doings its job what would create this constant 15psi you refer to?
pumps just pump, restriction makes pressure

[/ QUOTE ]

How can a regulator increase pressure?

How does restriction INCREASE pressure?

Last I checked, fluid was a lot like electricity. Same pressure (voltage) but more restriction (resistance) = LESS flow (current) last time I checked, unless I am missing something here.

[/ QUOTE ]a Regulator increases pressure at the pump outlet. On large Industrial pumps we control flow by a valve in the outlet of the pump.If you throttle the outlet down it will decrease flow and the motor current will drop. you could do the same thing with the fuel pump. put a needle valve in the line and set it to the pressure you want.....
 
Enough beating the regulator thing to death - now the $Dollar.298 question is....

























What the **** are you up to? /forums/images/graemlins/peace.gif
 
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