flathead fuel problem

M

m.e.pouncy

Member
I have a 40 Ford with a 53 Ford engine twin carbs on an Edmunds intake, Holley Electric fuel pump mounted low with a filter before it in the back 1 foot from the tank. Bob Drake gas tank (New) new gas 5 gallons. 1/4 copper line from tank to pump....then #6 braided line to Holley pressure regulator set at 4 lbs. 2 NEW Holley 94's with economiser valves blocked and# 42 jets. Car starts ,Idles, Revs good...But when I go to drive it..it will hardly run ..acts like it's running out of fuel. Copper line goes into tank about 1" with ferrel and Ford nut. MSD ignition. HELP ME PLEASE everything is brand new,
 
take out the PV block offs and use 3.5 or 4.5 power (ecomonizer) valves and 48 or 49 main jets..
i did the same PV block offs and jetting as you cause flathead jack said it would work fine. it did not.
without the PVs and useing 42 jets it will not have enough fuel to run under load even though it will rev fine with no load.
 
You are dead on Flathead Jack...also in another post I read about Helmet Air cleaners..I have them also. Thanks I'll try to find Power Valves.
 
M.E. Is the electrical fuel pump to prime the motor then run off mechanical ....If so you may need to create a by- pass loop with a check value as the mechanical pump cant pull the fuel thur the electrical pump after 30 mph.....
 
Here's my view, others may and will disagree.

Stock (7.5) power valves.
Stock (51) jets.

Set fuel regulator to 2.5 pounds.

Copper pipe may not be ideal due to long term fatigue, but will not cause the problem you are having.

Mart.
 
m.e.
Power valves or no power valves. I've built a bunch both ways. No power
valves I generally use 50 to 52 jets. With power valves (4.5"hg) I use 46 to 48 jets.
These are average starting points and will get you going in the ball park.
For cruising around town ,not a lot of high speed stuff, no pv's work good.
You will go lean at high speed without pv's if you roll down the interstate at 65 or
70. I grill my customers prior to building multi carb setups so we are on the same
page.
The above for 2x2's.
Charlie ny
cas5845@yahoo.com
 
Thanks I'll take off the carbs and change the jets and reistall the power valves and leave off the air cleaners and set vacuum at 4.5 and turn down the pressure to 2.5 and try it...the worst thing is I have the identical engine etc. in a 34 Ford Pickup I'm putting together..argh Thanks guys
 
To All my friends here on Ford Barn Thank You I did what Charlie from NY said, and I took off the Helmet Air Cleaners from "F lathead Jack" it runs great the new carbs from Dennis Carpenter were nice except the jets won't come out through the access plugs. Thanks again for all the help.
 
The stock tank is 5 1/6 and needs to go into tank about 4 inches.I used compreesion fiitings and went to 3/8 line to fuel block.
I think 1/4 line is to small.I also used steel line.
picture.php
 
Helmet air cleaners,#42 jets and power valve block offs all recommended and sold to me from Flathead Jack..Today I drove it for the first time nice...next I'll redo the fuel pickup from the tank. The helmet air cleaners don't allow enough air. We would set the carbs up rev it up ,idle then install the air cleaners before driving. This time I left them off ...perfect.
 
m.e.pouncy said:
To All my friends here on Ford Barn Thank You I did what Charlie from NY said, and I took off the Helmet Air Cleaners from "F lathead Jack" it runs great the new carbs from Dennis Carpenter were nice except the jets won't come out through the access plugs. Thanks again for all the help.
Click to expand...
They will if you have the tool i have. ken ct.:)
 
Bestdamnjettool is the long discontinued Snap-on, which can be pushed into the jets in a fully assembled carb, unscrew them, and reliably grip them well enough to be pulled out. You only need to remove the access plugs.
There are actually three modern ones with same basic design, but all are a bit shaky on the exact shape of the tip pieces and may not rliably slide into and grip the jets in an assembled carb. I suspect some light massaging with a file might improve them.
I have one of each and have not tried anything since I do have Snap on ones...all came from Speedway:
There is a Speedway manufatured L-shaped one, short side of the L fits the plugs
There is a screwdriver shaped one made my Holley
then there is a replica of the Holley one made by Speedway.
 
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