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What are these ports?

Started by Corey Bowcutt, February 25, 2021, 08:28:19 AM

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Corey Bowcutt

Can anyone tell me what these ports are?

Corey

Special Ed

Heat routing to the carb for warmup going into bottom intake under carb area needed in the cold weather.

shelbydoug

Those are for the exhaust crossovers that provide heat for the choke.

Unless you are driving the car everyday in the winter, you probably don't need them.


The Mr.Gasket intake kit used to have a sheet metal stamping included with it for blocking them that you install while you are doing the gaskets.

If you have an automatic transmission you might find the heated choke more desirable in that it will eventually kick down all the way to minimum idle. With a manual transmission it isn't as important but the engine might not idle down under 1100. 1050. 1000 rpm or so in the cold weather with them blocked.

In my case I switch to AFR heads which don't even have them at all and I am using a Holley electric choke which at the moment works ok.

On the carb that you are usuing, the choke thermostats are not universal. There is a specific choke thermostat for that car. It is much slower then the Holley "universal" replacement choke which on my car opens way too fast before the car gets hot enough to idle correctly. So keep the thought of having the correct choke thermostat on the carb in mind if you start screwing with the choke heat passages.

It is not rocket science but the learning curve is steep and instantaneously demanding.


I keep a five pound "lumping hammer" handy to handle the frustrations but I use that mostly these days on my computer and "stupid" phone. I hear there are "smart" phones out there, but I didn't get one of those?
68 GT350 Lives Matter!

KR500

As this is posted in the 68 section it is as Ed says. It is an exhaust passage crossover that heats the intake to improve cold driveablity. On a 68 it does not heat up the choke bimetallic spring from the intake manifold. The exhaust manifold is the heat source for the choke on a 68. Later years yes, the heat source can be the intake manifold crossover.
Rodney
Rodney Harrold,Ohio SAAC Rep,SAAC 68 Shelby Concourse Judge,68 GT500KR 02267

shelbydoug

Quote from: KR500 on February 25, 2021, 09:33:04 AM
As this is posted in the 68 section it is as Ed says. It is an exhaust passage crossover that heats the intake to improve cold driveablity. On a 68 it does not heat up the choke bimetallic spring from the intake manifold. The exhaust manifold is the heat source for the choke on a 68. Later years yes, the heat source can be the intake manifold crossover.
Rodney

Correct. It is not the direct heat source. it is the indirect heat source.
68 GT350 Lives Matter!

Special Ed

Yes FEs got carb choke heat from exhaust manifolds but some engines got carb choke heat from heater hose routing along the side of automatic choke black cap and some later 429 cj etc the carb choke heat came from intake under automatic choke setup that had a lever coming from intake to the choke setup. Boss 302 429 289 hi-po and 1970 428 cjs had manual chokes. Boss 429 and 426 hemi used rear heat tubes routeing heat from a rh exhaust manifold flapper to the rear intake under carb since hemi heads dont have heat crossover ports in center of heads because of the hemi design unlike the wedge design. The hemi rear heat tubes setup had to be on the cars in order to sell them to the public if u lived in alaska or hawaii.

KDunne

Can't really tell from the picture but looks like there is quite a bit of corrosion around the water jackets on the front of the engine.  I wonder if that's where the seepage is coming from?