Actually the summit carb was modeled after the Holley 4010.

lowercasesteve wrote:

Don't know about your truck, but the top loader was a direct replacement for the original 3-speed in my Mustang.  The only major change was to the speedo cable.  The top loader has it on the right side while the 3 speed has it on the left side.
 

Well thanks for that. The 3 speed doesn't get any love but I know they're tough and I like the gear spread for a street driven pick up.

MS wrote:

If I recall, I am at about 12 BTDC

Reason I ask is because I noticed when I installed an A/F gauge I tended to focus on fuel circuits at first, and your #'s are looking so good across the board I thought it may be worth playing with base timing just to watch the gauge and  observe its effect at idle.

I run up to 17* base even on stock motors and limit mechanical advance to 20*. It's tougher on the starter but always seems happier at idle for me.

It seems feasible to me anyhow that advancing the base timing, being such a simple check, might do the trick.

And I ofcourse agree with TKO and am not suggesting that is the fix, if it did clean up at idle you'd then have to do it right by adjusting the timing curve so as not to have too much total timing.

Same story here Rudi, 289 with tri y's and a pony carbs spreadbore 4100 with a home made choke stove. I used copper line with a braided heat insulation sleeve. I wish I had a pic to share. So similar that really gave me a tickle ;).

I ran the yellow sensing wire to the starter solenoid. I agree there won't be any appreciable voltage drop, but my thinking was I want the alternator to maintain voltage at the main power hub.

I use a 150 amp mega, 175 seemed like if I got to the point of blowing that I'd have bigger issues by then.

I have yet to install it, but I acquired a volt guage from rocket man-
https://www.rccinnovations.com/index.php?show=menu-volt-all

M1Mustang69 wrote:

Jon, thank you Kindly for the responses....I appreciate your concern also.....I think youre right and I have concluded that as a last resort I will have to recheck the Throttle Plates.  I rebuilt the carb entirely; which means EVERYTHING was off.  I am very careful and particular but anything is possible!.....

I'm the same way, yet what I've found is as simple as these 4100's are, they can be a little fidgety and finicky about adjustments and changes. If the plates are all the way closed they will stick closed as they will try to wedge themselves in the bores- read, a tight tolerance.  

M1Mustang69 wrote:

to question the "Idle Orphancies being above the Throttle Plates"  if theyre not, how would that occur?  what would be a fix?

Do to their age and unknown history with multiple rebuilds with mix matched parts and shade tree tuning mods one never knows. It's doubtful it's the case with yours but I'm just suggesting to look out for any weirdness like that over the last guy that may have monkeyed with it. If a fix is needed I could help the best I could by measuring my carbs and feed you the size and placement info.

M1Mustang69 wrote:

I did mention the engine and trans, this is bolted to 100% stock and original 289 2bbl Mustang Engine!  C4 Auto...…..this EDC model is a pretty rare (im guessing on CFM) 1.06-1.08 model. the primaries are significantly smaller than the secondaries.

These do have smaller primary venturis but the bores and plates are the larger 1 9/16" rather than the 1 7/16" on the 1.08 4100's equipped on the 289. Since the EDC was engineered for an entirely different application this may be what you get without changing orifice sizes in the idle, transition, and main circuits. Those smaller venturis will deliver a stronger vacuum signal to the boosters, but the boosters and orifices were metered to work in conjunction with them to meet the demands of the heavier Edsel with the larger 361. The 2

You seam quite sure about the plates, but this is awfully strange so I'd re-check and make sure the orifices for the idle circuits are above the plates and there's no grooving or score marks or some other screwyness at that intersection.

If all checks out all I got left is raw fuel leaking somewhere instead of being drawn through the idle circuit alone.

Maybe a vacuum leak at the timed port for advance? I'm really hoping you get this sorted.

Sorry for the double post.

Something like a carburetor heat shield- sorry, no link.

TKOPerformance wrote:

A lot of those shaft bushing deals have to be reamed to fit, or are universal, so I'm always suspect.  I never understood why they didn't use seals there.  Some carbs I've seen over the years do, but not very many. 

I completely agree. Daze is going to start including throttle shaft seals with each set of venturi sleeves though, right? 😁

Autolites are notorious for not sealing with most aftermarket manifolds.

Looking forward to you seeing this thru, I have a few EDC 4100's but haven't had a chance to run one so I'm curious as to how she'll run after the final tune is sorted out.

MS, I replaced the PCV valve, check out the original '69  Autolite that was still in service-

I made a few observations yesterday while taking another crack at it. TimC asked if it pops through the carb, it does not. I have dual exhaust with no crossover pipe, boths pipes pop. I did another cylinder cut out test, the popping never stopped.

I can't isolate an offending cylinder and I'm thinking the culprit is somewhere in the ignition system. Seems plausible that the vacuum needle dropping back could be unburned fuel igniting in the exhaust manifold, pushing back on the engine on the exhaust stroke.

The rotor button isn't fitting snug on the distributor and there was evidence of arcing so I'll start by replacing the cap and rotor. I have a new Pertronix I and flamethrower coil and run a ballast resistor, so coupled with my old wires and tired charging system I might have to little voltage feeding the coil at idle. I'll try jumping 12v to the coil and bypass tje resistor to see if it clears up.