holley 390 question

[hootF1]

what is the required fuel pressure for the 390 on a flathead?

[Walt Dupont--Me.]

I would say 3# would be alright if you not running the salt flats. Walt

[51 MERC-CT]

Originally Posted by hootF1

what is the required fuel pressure for the 390 on a flathead?

If you mean what are the fuel pressure limitations of the carb. (doesn't make any difference what engine it's on )
This is Holley specs.

"Recommended fuel pressure should be set at 7-1/2 psi maximum, 5 psi minimum. Fuel pressures above 7-1/2 psi can create severe fuel control problems and are not recommended."

It will be fine with flathead fuel pump.

[scooder]

Can a regular flathead pump deliver the required minimum 5 psi?
The late Merc pump for use with the Holley 885 and tea pot should be good to go, as these carbs used a higher pressure. But the early ones?
Martin.

[51 MERC-CT]

Originally Posted by scooder

Can a regular flathead pump deliver the required minimum 5 psi?
The late Merc pump for use with the Holley 885 and tea pot should be good to go, as these carbs used a higher pressure. But the early ones?
Martin.

It does not need 5 psi. to operate well on any flathead single or double pumper fuel pump in normal driving conditions.

[RandyZ]

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I've been running mine for years on the original fuel pump. No problems.

[WestCoast]

the 390 was originally designed for the bigger bore v/8's,those required more fuel thus more fuel pressure, the stock ford 239 v/8 will not use enough fuel to make it necessay to run more than the 2# to 3# fuel pressure

[JWL]

I am with RandyZ--I ran one for several years with my stock Flathead pump. No problems.

[scooder]

Thanks for the info chaps, it was the "minimum" pressure bit that made me question the suitability of the stock pre Merc pumps. If you guys say it works good, that's ok by me. I'll put there "minimum pressure" filed under baloney, and pay it no mind.
Again, thanks.
Martin.

[41LjH]

8BA modified engine.
my 390 ran 3-5 lbs with a Mr. Gasket electric pump. No regulator installed and the original fuel pump removed..