The Ford Barn

George Miller · 12-06-2011, 09:43 PM

You are going to need a fuel pump. The pressure is not as much of a problem as the small 1/4 inch line just won't let enough gas get to the carb fast enough for fast driving with out a pump to push it there.

Phred · 12-07-2011, 05:44 PM

Is your Pertronix module a red Pertronix II or the black Pertronix I?
FS ignition has said they switched back to the Pertronix I, citing occasional electromagnetic interference at 1500 and 3000 rpm with the Pertronix II.

I doubt this is your problem, but something to keep in the back of your mind if you have the red module.

Peace

Jason in TX · 12-07-2011, 05:51 PM

Also check the height of the float in the carb. May be too low and the bowl is emptying faster than it can fill on gravity.

I'm not currently running a pump on a dual 81 set up and it runs better with a full tank of gas (more fuel pressure to the carbs) than when the tank is low. So, another reason that I will be adding a pump and regulator.

I had actually had a 4 lb max pump on there with no regulator and was driving one day and noticed that the electric pump was forcing gas out the accelerator pump and all down the engine. I removed the electric pump and went back to gravity. I now have a regulator and need to hook it back up.

Lawrie · 12-07-2011, 09:46 PM

You can get the 97 to run on gravity feed OK,I have one on my A,it too is only about 3in below the bottom of the tank,I made a different setup on the float needle,this actually pulls the needle open as the float drops,so far about 10ks on it, the only thing I miss is playing with the GAV,
Lawrie

12-06-2011, 09:43 PM	#21
George Miller Senior Member Join Date: May 2010 Location: NC Posts: 2,975	Re: Tuning problem with modified A engine You are going to need a fuel pump. The pressure is not as much of a problem as the small 1/4 inch line just won't let enough gas get to the carb fast enough for fast driving with out a pump to push it there.

12-07-2011, 05:44 PM	#22
Phred Senior Member Join Date: May 2010 Location: IL Posts: 303	Re: Tuning problem with modified A engine Is your Pertronix module a red Pertronix II or the black Pertronix I? FS ignition has said they switched back to the Pertronix I, citing occasional electromagnetic interference at 1500 and 3000 rpm with the Pertronix II. I doubt this is your problem, but something to keep in the back of your mind if you have the red module. Peace

12-07-2011, 05:51 PM	#23
Jason in TX Senior Member Join Date: May 2010 Location: ⓉⒺXⒶⓈ Posts: 2,047	Re: Tuning problem with modified A engine Also check the height of the float in the carb. May be too low and the bowl is emptying faster than it can fill on gravity. I'm not currently running a pump on a dual 81 set up and it runs better with a full tank of gas (more fuel pressure to the carbs) than when the tank is low. So, another reason that I will be adding a pump and regulator. I had actually had a 4 lb max pump on there with no regulator and was driving one day and noticed that the electric pump was forcing gas out the accelerator pump and all down the engine. I removed the electric pump and went back to gravity. I now have a regulator and need to hook it back up. __________________ -------------- Drive it like you know how to fix it! DMAFC / OILERS CC-MC

12-07-2011, 09:46 PM	#24
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,215	Re: Tuning problem with modified A engine You can get the 97 to run on gravity feed OK,I have one on my A,it too is only about 3in below the bottom of the tank,I made a different setup on the float needle,this actually pulls the needle open as the float drops,so far about 10ks on it, the only thing I miss is playing with the GAV, Lawrie