Holley 500 problem

[275 GTB-4]

Anyone had experience with new valves not sealing and causing fooding(drowning)?

Do I need a pressure regulator?

I have a 500 Holley on a Holden 308 HJ. It does a fair job, but that is not the subject. Everything had been going fairly well after a dyno. Towed a caravan interstate etc. On a trip out west the valve remained closed. No fuel!

Was able to get old valve and get home. Replaced the valve with new one and set it up. Bought another to give to guy in Young. A couple of weeks later the car would not run/start. Float bowl over full, so adjusted level. On a trip to Sydney had numerous stops with flooding. Even changed to another new valve. Same problem. I changed to the old valve and came home. Haven't done any stop start driving so maybe this valve will fail?

What is the problem? only thing changed was the valve. So are new valves of poorer quality than old ones?

The broken valve had been in use in the carbie for 20 years and carb was secondhand then. Probably the orig valve.
Thoughts, ideas, experiences?

[Morris 1100]

Maybe the float (if it don't float is it a sink?)

[Mattracer]

How about EFI?

[noise boy 2]

If this is a new trick, I would suspect that the primary side float (I am assuming it is a four barrel) is not floating. Easy to check and fix. Otherwise, assuming you haven't changed the fuel pump, I would put a pressure gauge inline between the pump and carb, and check the line pressure at all rpms, it shouldn't exceed 5.5 to 6 psi or it will blow the needle valve off the seat. Good luck. Robert

[BlueBlood]

If it is a dual fuel application,I Have seen the brass floats get holes in them from rubbing on the carb chamber when there is no fuel in the bowl, which makes them sink and therefore causes flooding..
Sometimes you cant see the hole, but when you take the float out and shake it , you can hear the fuel in it.

[275 GTB-4]

Thanks everyone - this is going to be good when it is sorted!!

[coln72]

I was going to suggest throw it away and by a Rochestor (original carby)

Seriously, the first thing my old man did with cars fitted with Holley's was to fit something else eg. Carter, Stromberg. normally would run just as well and wouldn't be a prick to tune.

[275 GTB-4]

Originally posted by coln72
I was going to suggest throw it away and by a Rochestor (original carby)

Seriously, the first thing my old man did with cars fitted with Holley's was to fit something else eg. Carter, Stromberg. normally would run just as well and wouldn't be a prick to tune.

Weeellll....Coln7, thats what ended up happening!! Running well now!! Cheers

[Bigguy]

Does anybody else find the close proximity of "Holley 500" and "275 GTB-4" strangely disturbing?

[275 GTB-4]

Originally posted by Bigguy
Does anybody else find the close proximity of "Holley 500" and "275 GTB-4" strangely disturbing?

I'd rather tune a Holley 500 than 6 downdraft Webers any day of the week!