motorcraft 4300 carb info

[gmonde]

i want to thank all who have gave there advise and comments,all of the info has nailed down alot of unanswered questions that i had,time to tinker gmonde

[SSDiv6]

Originally Posted by gmonde

i want to thank all who have gave there advise and comments,all of the info has nailed down alot of unanswered questions that i had,time to tinker gmonde

Talk to Dean Oliver: http://www.deanoscarbs.com/

[Jeff Lee]

Good advice from Tom here. Tom & I have spoken of these issues in the past and it would appear there are more than one advantage to running a stick car! I have attempted in the past to have the "known" carb builders tae on the challenge of building an Autolite for me and none wanted the work, including Oliver (but maybe he has changed his mind?). One that I received from an un-named "expert" was never tried previous to shipping, as promised, about melted the headers off my new engine. I tried to work with it later on and eventually chucked the $500 POS in the trash! The carb I have used exclusively was built by Mr. Lloyd Bray whom many old timers may recognize from the early days of the 428CJ Mustang. He is also partner to DG Gulliam with their 428CJ GT/A Mustang. I just had two built and have yet to try them; waiting on getting the car back on the track.
Opposite of Tom's comments on fuel pressure, I have always run 6-6.5PSI without any problems, even driving in the pits. Pushing it to 7#'s causes driving in the pits problems and you have to switch the pump on / off. I'm promised the new carbs will not have that problem and should be able to run more pressure if necessary. But then again, I suspect my fuel system is vastly different than what Tom runs so maybe that's why we're seeing different results.

[Duane Eiskant II]

i dont know about those flow numbers but sounds like the holley 950 which actually is only 830. The 4300D ive run for the last 10 years only flows 580. Now thats real word numbers on the WET flow bench. Im sure it could be more if i dry flowed it but it does have to mix with fuel so thats not actually. No power valve, plug 73 and 86 jetting never change it just leave it alone the flap stuck once last year at kinston at the points race so now i just keep some 3 in 1 oil and check it ALL THE TIME.

[vic guilmino]

did the 4300 come on the 460 fords

[Tom Goldman]

Jeff, the problem with 7# and up of fuel pressure only is an issue when running the oem style secondary needle and seat. ....Not an issue when running only a larger primary needle and seat. .....Tom

[SSDiv6]

Originally Posted by Tom Goldman

Jeff, the problem with 7# and up of fuel pressure only is an issue when running the oem style secondary needle and seat. ....Not an issue when running only a larger primary needle and seat. .....Tom

In the past, I have used the Grose-Jet needle and seat assembly which allows you to run higher fuel pressures without flooding the engine.

They are similar to this picture:



I cannot remember if Jeff Lee tried them ion his carburetor in the past. I have succesfully used them in many foreign car applications, Quadrajets and Webers, allowing me to run higher fuel pressure without overriding the float.

[Rory McNeil]

Originally Posted by vic guilmino

did the 4300 come on the 460 fords

Vic, yes the 4300D came on many 460`s, but it seems that all the 460`s in the SS/GT classes run the 74 version, which had a Carter ThermoQuad available as well as the 4300D.

[Duane Eiskant II]

i use both needle and seat assemblies in the carb. Primary and aux, and run 9 # of fuel pressure. No flooding issues. Also since the float bowl area is so small i run a number 10 line from the regulator to the carb inlet which helps act as a log and hold reserve fuel.