Integral choke coil

[jocko463]

I have just gotten the Q-jet "core" I plan to use for my Pontiac project. The carb looks to be in great condition; it appears to have been restored as opposed to simply being rebuilt; the body and air horn castings all have a chromate green coating, the choke pull-off is new and the filter/fuel line threading is perfect. It is a 17057202 1887 AOL built on the 188th day of 1977. The seller told me it is OEM for a '77 Corvette. I plan to use it on my '67 326-powered Tempest coupe. The plan is to use Cliff's book as a guide in rebuilding this carb and making the tweaks needed to properly feed the "little" Poncho 326.

The carb has what appears to be a hot air choke assembly except there aren't any provisions for tubing manifold heated air through it.

How does this choke coil work?

Does it sense the ambient air temperature near the exhaust crossover in the intake manifold?

Functionally, would it be better to swap in an electric coil or keep the original set up? I like the compact dimensions on the carb and not having to add wiring would keep things simpler.

Thanks,

Mike 

[Cliff Ruggles]

Mike, nice carb.  They are a tad lean for what you are trying to do, I would recomend getting some tuning parts from us, and upgrading the accl pump and needle/seat asssembly. 

If the 326 is pretty mild, no mods to the idle system will be needed.

For the choke, it will need to be converted to an electric unit, we sell them here, complete with a pig-tail for the wiring harness.

Our chokes are high quality, and "clock" correctly on the q-jet, not the cheap 2bbl chokes that don't work right and clock upside down when installed.

The vacuum supply to the housing is blocked off during the install, otherwise it is just bolt on and go......Cliff

[jocko463]

Thanks Cliff for the initial appraisal. The guy I bought the carb from (on eBay) lives near you and has been in your shop ....told me a bit about the Pontiac you race. Anyway he had this carb (the one I bought) but got a date correct model for his 77 'Vette ...one that you worked up for him.

When you or your shop rebuilds a Q-jet, do you put some type of stamp on it? Reason I ask is that the carb I bought has what looks like the letter"C" stamped into the manifold gasket area of the base plate.

I plan to leave the 326 pretty stock; it's not a heavy breather like the 400 so I'd like to maximize it's flat torque curve. Stock CR is right at 9.0:1 which is perfect for pump gas. I plan to use a stock grind or very mild cam ....Summit Racing has a 204/214 cam that is very close to the stock unit. The Q-jet will sit atop a factory (1968) iron manifold. Other mods would be swapping in some RARE repro Ram Air factory iron exhaust manifolds and dual exhaust and a upgrade in the ignition department. Overall nothing too radical. 

[jocko463]

For the choke, it will need to be converted to an electric unit, we sell them here, complete with a pig-tail for the wiring harness.

The vacuum supply to the housing is blocked off during the install, otherwise it is just bolt on and go......Cliff

I'm thinking the hot air choke coil was swapped in at some point by the previous owner. The carb must've originally had an electric coil because there are no hot air connections either on the coil housing or on the carb.

mike

[Cliff Ruggles]

The choke housing may have been swapped out at some point, most of those carbs from that era were hot-air, no electric. 

In most cases, you can verify this by the vacuum passage in the main casting that leads to the housing.  If it was open at some point, the carb was a hot-air choke model.....Cliff