Fuel pressure regulator placement

[23 T 4sp]

I had this Holley regulator on top of the motor near the thermostat housing. It was opening up right
after shutdown. The gauge near the carb would be
3.5 running then 6-7 when stopped. Edelbrock carb
with 1/2 “ wood spacer. The fuel pump is rated at 7 psi. Thinking about moving it to position in pictures. 3” from the header pipe.
Is this to close ?

There will be a small bracket to the head to hold it in position.
This is the second regulator I tried in the original
position.

 

[Spanky]

Don't mean to be a smart alec, but why do you need a regulator with a mechanical pump? 7 psi should be just fine with your setup.

 

[23 T 4sp]

Yeah I struggled with flooding issues. Went through
all the suggestions then ended up using this.
The temp of the regulator housing was 190 degrees
so decided to move it. The 90 degree in and out
is a pain for locating it .

 

[Rip VW]

I understand that Evilbrock carbs like no more than 5 psi so a regulator would be a good idea. My evilbrock carbs on my T are going to be fed via a bypass adjustable regulator located on the frame rail and my pump is an in the tank pump. Set up like this if I ever want to go EFI I will already have a bypass regulator which helps manage fuel pressure..

 

[23 T 4sp]

Decided to place it behind the carb. Runs cooler now.
The PSI will rise 2 lbs at shutdown no matter what the temp is. Adjusted it to about 2.8 lbs so it’s around 4.5 lbs after shutdown. Also readjusted the floats. They were to high and one was 1/4 inch lower when hanging.

 

[Indycars]

Since that is a dead head pressure regulator, it has no way to relief the pressure when the
key is turned off. The pump continues to run for a second until the motor quits turning.

If you had a return (bypass) style pressure regulator, then it would go to zero when the key is
turned off.

The mounting and routing of lines does look nice and clean !

 

[Indycars]

Are you using a liquid fill gauge to monitor fuel pressure ?

 

[23 T 4sp]

No it’s not. I just ordered some gaskets. Should have added that. It will quiver sometimes while driving.
Thanks for the compliment. Push lock hose has really helped routing the fuel lines.

 

[Indycars]

It's possible that you could run from the second output on the regulator back to the input
coming from the pump and in that line put a very small orifice, When I say small orifice,
I'm thinking in the area of .030" or smaller. Just enough to bleed the pressure off when
you shut the engine off , but not enough to reduce the your pumping capacity while it's
running.

Now I'm not completely sure this would work. But if it doesn't, then it would be easy to
reverse the change. Or you could do nothing if this is not really bothering you.

 

[MMC757]

It's possible that you could run from the second output on the regulator back to the input
coming from the pump and in that line put a very small orifice, When I say small orifice,
I'm thinking in the area of .030" or smaller. Just enough to bleed the pressure off when
you shut the engine off , but not enough to reduce the your pumping capacity while it's
running.

Now I'm not completely sure this would work. But if it doesn't, then it would be easy to
reverse the change. Or you could do nothing if this is not really bothering you.

Indy, is your concern leakage into the carb or leakage from the lines?

 

[Indycars]

Indy, is your concern leakage into the carb or leakage from the lines?

It would be leakage into the carb, the lines should NOT be leaking.

My comments are really based on my understanding of your comment below. The
engine may run OK cruising around town, but adjusting the pressure lower to 2.8 psi
could starve the engine for fuel under Wide Open Throttle (WOT). You are not fixing the
problem, you are compromising by setting the pressure lower when the engine is running.

Adjusted it to about 2.8 lbs so it’s around 4.5 lbs after shutdown.

No it’s not. I just ordered some gaskets. Should have added that. It will quiver sometimes while driving.

Related to your comment above, read the Technical Bulletin #903 from Aeromotive about
the subject.

Well, you really don't want a liquid filled gauge as they are very inaccurate. As the temp of
the gauge goes up, the pressure it reads goes down. But the ACTUAL pressure did not
change. This is why I asked about the liquid filled gauge.

 

[23 T 4sp]

The main problem was gas in the engine after shutting off the engine. The regulator was hot 190+ degrees. Moving it was needed anyway. It did help. Adjusting the pressure was next. Then adjusting the floats. This was a new carb early last year. Waiting for carb gaskets
before trying it out.
The gas tank is a new aluminum spun type. I didn’t
think about adding a return line at the time.
Thanks for the info on the filled gauge.