All Small Six Modified head, 2100 carb, can’t get the idle below 2000 rpm

[eds1965coupe]

We’ve done the 2 barrel modification on our head, new valves, springs, porting, etc. We are running a 1.02 autolite 2 barrel, manual choke. We cannot get the idle down. It runs great, but idling at 2k rpm isn’t going to work. I’d love your thoughts.

 

[bubba22349]

Check the throdle shaft! Good luck

 

[chad]

"...We’ve done the 2 barrel modification on our head..."
Whats that mean? What were the changes specifically? Not the springs, valves etc.
Was any machining done? Gota "done" but "not reassembled" pic?

 

[B RON CO]

Hi, that RPM is good for cam break in, but now I would guess the throttle is being held open, maybe by the high idle cam, and check for vacuum leaks and open vacuum ports. What did you set the ignition timing to? Good luck

 

[chad]

B RON - the mani choke over rides the lil fingers there no? but yeah, all 3 of us think (easy, 1st) ck vac leaks...
Use the spray fora diagnosis?

 

[eds1965coupe]

"...We’ve done the 2 barrel modification on our head..."
Whats that mean? What were the changes specifically? Not the springs, valves etc.
Was any machining done? Gota "done" but "not reassembled" pic?

Everything was done. New valves, new springs, ported intake and exhaust, modified log to accept 2 barrel. If it is in the Falcon Six handbook, we did it. I’m not with the car, so pics will come later.

 

[chad]

"...the 2 barrel modification..."
"What is that?"
"Not the springs, valves etc.
Was any machining done?"

Skip da pic, just use ur words...

 

[B RON CO]

Yes Chad, you are right that the manual choke has a smooth ramp for the high idle, not the stepped ramp on an automatic choke.
It is still possible that the choke cable is not adjusted properly and the high idle screw is contacting the ramp.
X2 on double checking the simple and obvious things. Good luck

 

[Econoline]

What's the story on the carb? Did you rebuild it?

 

[drag-200stang]

On my old draw thru turbo, with a Holley 830 CFM carb three feet away from the cylinders, It would idle a 1200 with out trying to do better...Something is clearly not right.

 

[cr_bobcat]

I would echo the advice to check for vac leaks first. Do you have an automatic? The vac line to the modulator could have been inadvertently disconnected. Happened to me before. Also check that the ported vac tube on the carb isn't open.

From there move to the distributor. Mine doesn't even like to start without a good bit of advance. Try giving it a little more advance and try backing down the idle.

 

[chad]

w/o any "knowns" I can't offer much. Like throwin $ at a problem (or parts). Must geta base 1st.
"...modified log to accept 2 barrel.." goin in circles for me.
Good ign tune 1st, onto a carb tune.