Carburettor issues

[peter1956]

My '56 (312) has a Holley carburettor. I think, maybe, it is not original? It is not the teapot type. The numbers on it are: ECZ V , L1ST1273.
I don't seem to be able to get the float level right. There is not the adjusting screw on the outside like more modern types, so bending the tang on the float arm seems to be the only way of adjustment. I have done this several times, to the point where the float now sits quite low, but fuel still spills out when I remove the level check plugs. The float valves look fine, could even be new by the look of things.
On a second note; is there a more modern carburettor that fits? Maybe even a 2-barrel. Improving economy would be good. Gas is over $8 a gallon here in NZ!

 

[gbhrps]

peter1956,

I can't help you on the float issue, but one of our parts suppliers here in North America provides not only a rebuilt 57 carb for $339 USD if you send them your old one. Add another $250 to the price if you don't.

As well, they have an aftermarket direct bolt on for the 57 TBird for $484.79 USD, that requires a different fuel line that they sell separately for $25.95. Keep in mind that all these dollar amounts are from their 2011 catalogue, so prices may be higher, or not, today.

Should you decide to check it out, they have an online catalogue that is very complete. "Hill's Thunderbird Center" out of Racine, Ohio, USA. Check online at "www.thunderbirdcenter.com" for the listings and prices. They are good people who are most helpful. They even have access to some used parts.

 

[paul2748]

Is it the 56 style (teapot) or the 57 style? Both were Holley's.

 

[Rusty1]

carb problems

peter1956,
If the float is all the way down or "very low" and fuel still spills out the level ports then the floats are saturated or have a hole and not "floating". Is there fuel inside the floats? The Holley master list shows it as an original '57 carb though it is not "original" to your car. The 56's all had teapot carbs. If the floats are ok then the needles or seats are at fault. They may look good but actually not. How is your fuel pump pressure? If it is too high it may push fuel past the seats. Depending on the mods to make this carb work on your engine, you could replace it with a newer Holley. A two barrel might be a slight improvement in mpg but not a lot. Have you tried going to smaller jets? If you do be careful of going too lean. With todays gas this could cause valve problems.Would be about the same as two V. Back then they really didn't much worry about mpg's, gas was cheap. At $8 a gal. you must not drive it much. I sure wouldn't be. Good luck with it.
Rusty1

 

[peter1956]

Thanks guys. I have naturally checked floats, fuel pressure, etc. Yes, the float valves may be at fault. I think I will go to a new Holley. Should be better all round.

 

[Jimz Bird]

Peter,

Just one other question.

If it doesn't have the "Teapot" Holley 4000 do you still have the stock double diaphragm distributor?

That needs to be changed for the newer Holley carbs to work correctly.

Jim

 

[peter1956]

Yes, it is the '57 style.

 

[peter1956]

The distributor has a single diaphragm vacuum unit, so must be '57 style also.

 

[paul2748]

55's are also a single diaphragm.

The best way to tell them apart is looking on the inside. 55's and 56's had advance springs on top of then points plate. 57's had them under the points plate so you can't see them.

The distributor has a single diaphragm vacuum unit, so must be '57 style also.

 

[peter1956]

Finally fixed my carb. The light springs that sit under the float weren't there. Once they were put in, I think it made a bit of a difference, but still ran too rich. Finally discovered the power valves were the wrong ones. They had a too stronger spring, so couldn't be pulled shut. Runs really good now.