1957 270hp Carb Adjustments

[Edward L.]

I would appreciate any input as to how to adjust the carbs on my '57 270hp.
(2626, 2627)
The car is running so rich that the birds fall dead from trees when I pass by.

The carburetors have gone through a rebuild by a reputable rebuilder. I have followed the procedures outlined in the ST-12 and other manuals (vacuum guage, etc.)to no avail.

Other than a .060 over-bore, the engine has all stock componets.

I would appreciate any and all suggestions short of going to a 1x4 set-up.

Thanks

[Jack H.]

Re: 1957 270hp Carb Adjustments

The 2x4 carb setup has a reputation for running rich, but an overly lean adjustment can also stimulate complaint(s)...eyes burning from exhaust fumes, Etc. Is it possible you've gone past optimum on your setup?

How do the plugs look--looking at the ceramic insulators around the electrodes tell a LOT? Also, if there's a local shop with an exhaust gas analyzer, you can nail down the WHOLE story of what's up...

Last, running plugs that are hotter tipped than factory stock is reported to help. We often fail to remember exactly what the idle profile of these cars actually was back in the 'good old days' holding them in comparison to modern cars with on-board computer controlled dynamic spark/fuel systems. Gas was $0.25-30/gal and there were no emissions standards, so designers didn't really strive to achieve/maintain optimum burn.

[Edward L.]

Re: 1957 270hp Carb Adjustments

Jack:

Thanks for the response.

I'm running AC-46 plugs, exhaust is black carbon,plugs are also black with carbon deposits.

[Robert Willis]

Re: 1957 270hp Carb Adjustments

Floats set a little high ?

Bob




57

[Jack H.]

Re: 1957 270hp Carb Adjustments

Sure could be a sunken set of floats OR float adjustment set too high. Another question would be what happens if you jury rig to run on only the primary carb (the secondary carb shouldn't be active at idle)? That would rule out an incorrect setup of the progressive linkage. Plus, if the carbs were sent to a reputable restorer, he should be willing to help/consult....

[Joseph T.]

Re: 1957 270hp Carb Adjustments

In additon..make sure your exhaust flow is clear and that the heat riser is open. Unless you are starting the car in a cold climate..you might consider replacing the heat riser with a spacer..like used on the fuelie cars..to keep the exhaust flow open.

Joe

[Clem Z.]

2626 and 2627 should be the 245 HP carbs

maybe they were jetted to 270 specs which are much richer than the 245 HP carbs. the 245 carb specs works well on a 270 on the street. with the covers off see if the power piston is down at idle as you may have too heavy a spring and you are on rich stop at idle

[Edward L.]

Re: 2626 and 2627 should be the 245 HP carbs

Gentlemen:

Thank you.

[Joe C.]

Re: 2626 and 2627 should be the 245 HP carbs

Hi Ed,

270 HP 283 should run 2613/2614 carbs. Which engine do you have, the 270 with 097 cam, or hydraulic 245?

[Rod K.]

Re: 2626 and 2627 should be the 245 HP carbs

According to the Judging Guide and other sources, including Gary Hodges, 2626/2627 carbs are correct for Nov '56 and later 270HP cars. 2613/2614 usage is not documented prior to Jan '58.

[Clem Z.]

anyone who wants the jetting for WCFB carbs

e mail me. these spec are from the AMA.

[Mike B.]

Re: 2626 and 2627 should be the 245 HP carbs

I stuggled with richness on my 2x4 245 for a while. Ultimately as suggested above I found a good compromise by adjusting the floats to be more restrictive (less fuel in the bowls) than as advised in the manuals. The improvement was especially pronounced when I adjusted the front carb floats. I don't know if this is true for your car but my engine is not dead level front to back. Thus the prescribed bench-top float adjustment of setting the distance from the carb flange was not a guarantee of a correct set up. Once dialed in my plugs all now burn a nice tan color although to the nose at idle there is still a hint of richness. But as pointed out by others, that was a perfectly acceptable tuning status back in the day.

If all else fails pop the top off of the carbs (do the front one first) and bend the float tangs a bit so that the needle valves seat earlier; you can always bend them back. Make sure that you carefully note the position of each screw as you take them out as they are different lengths. A piece of cardboard or styrofoam works well to provide a holder in which to poke each screw in its respective position. While you are at it remove and shake each float to ensure that there is no fuel inside any which will definitely cause the richness symptoms you are experiencing.

Good luck!

[Clem Z.]

if your carbs are boiling the gas block the

heat riser cross over in the intake to remove the excess heat which causes problems with this newer gasoline

[Clem Z.]

i have sent out several scan to different people

but your computer mail box will not accept them. it was sent as a JPEG and if you are using a company computer a lot will not accept JPEGS