Ok, so my Edlebrock 1411 has been running rich ever since I installed it, the plugs are sooted up all the time and when I blip the throttle a puff of black smoke comes out the exhaust. Its also pretty sooty exhaust emissions when on choke, but I guess thats normal. I've also never been able to get the idle mixture screws to work very well. If I slow down the idle speed screw to close the transfer slots so that that mixture screws are opperating then the engine just tries to stall at such a slow speed. I am going to take another look at the timing, and advance it if needed, think its at around 8 degrees initial at the mo. One thing I discovered last weekend was that the carb to manifold gasket is wrong. Its a single plane gasket, on a dual plane intake, so thats probably not helping. The other thing is I have a calibration kit and have now finally worked out how to correctly read the calibration chart, which calls for the 110 primary jets to be swapped for 107's along with the associated rods ( cant remember the numbers) my question is, do I also change the secondary jets too? Acording to the chart they have 104's installed at the factory, and to go a stage leaner means a set of 101's. Which are not included in the 1411 calibration kit.
OK. So what's your car and engine combination? Is the choke staying fully open after the engine warms up for a few minutes? Is the engine stock, slightly warmed up, or have any major modifications? What' the fuel pressure and what kind of pump(s) are you using? What's the manifold vacuum reading at idle and cruising speeds? Are the primary metering rods moving freely in their bores? Are the metering rod tips bent? Have you tried to install the air horn without first removing the metering rods? Get yourself a vacuum gauge if you don't already have one. It can be a big help for carburetor and tune up diagnosis.
Not that I know much about carburetors, but my Holly was about the same until my friend lowered the float on it. He said it was bleeding over into the primaries. Apples to Oranges, but it’s a quick check.
58 Buick, 364 Nailhead, re bored to 0.40 The electric choke opperates fine, Runing an electric pump with a holley regulator, its set to and showing a steady 5psi Vaccuum gauge is in the green at around 17 - 18, but when I slow the engine speed down with the idle screw, to try and get the idle mixture screws to opperate, it then falls into the red "Late Ignition timing" section. Meetering rods are moving fine,
Oh, it has an HEI distributor too..the stock one had an issue and the car wouldnt drive at all. It now drives fine and has no flat spots etc, just running rich and idle screws do nothing. It also has functioning Lake Pipes. I Played with the timing a while back and seemed to remember setting it at around 8 degrees intital, which i think was giving around 24 total at 2,700 rpm. It still has the factory fitted silver springs, having looked online seems most people use one sliver and one black. Lastly the heat crossover passeges in the intake have been blocked off
Pretty sure on the Edelbrock I went through, I used a 7/16th drill bit as a gauge. But it’s been a few years, so verify.
24 degrees of timing sounds a bit on the skinny side, but I've no particular experience of your application, but I'd be expecting North of 30. The tiny clips on the Edelbrock linkages have a mind of their own. Cover the intake, just in case, and have a magnet against them when releasing. I don't think I've ever found one that's got free! Chris
From what I remember from previous threads, and correct me if wrong, the timeline goes like this- the car is not an import model. Engine rebuilt a few years back and ran fine with a 2-barrel carburetor and stock distributor. Issues started when the 4-barrel intake and carburetor was added. HEI distributor installed later. The 1411, @ 750 CFM, even with those jets, should not overwhelm a properly built 364. So let's go back- Compression ratio- when the engine was rebuilt aftermarket pistons were probably used. The compression height of aftermarket pistons is lower than stock. Compound that with composite head gaskets, and unless the engine builder compensated by decking the block, the CR is probably in the low 8s. Nailheads are all about the quench. Poor quench means poor fuel utilization and running rich conditions. Camshaft- when the 364 came out in 57, they had an aggressive camshaft. So much so Buick tamed the cam down in 58 due to customer complaints of rough idle. An aftermarket cam was probably used in the rebuild and must be degreed. I have seen cam lifts all over the map with these cams. I had to advance my cam 3 degrees in my 401 when I put it together to get it in spec. You could have late cam timing, but the vacuum is pretty good. I am running an 800 CFM on my 401 with .113/.110 jets and have tan plugs, but also 10 to 1 CR. I would try the .107 jets and 1447 metering rods and see if you can clear it up some. What intake are you using?
Wow, well remembered. Top marks. When the engine was rebuilt I put the Holley 2bbl on which is what it had run on since we bought the car in 93, but it had an ill fitting adapter plate, that was very losely fitted to the intake..it ran ok with this for a short while, but then I started having issues with flat spots at part throttle. I then switched to a suposedly rebuilt Carter 2bbl, again this worked ok for a short while but then I started having issues. A few 2bbls later and I got hold of an original 364 4bbl intake. First off trying a Carter , this had mixed results. Then the edlebrock. It wasnt until I recently changed the stock distributor for the HEI that it seemed to resolve the issues. Once I had re set the timing and worked out to out the vaccuum advance on the passenger side port..i have read so much conflicting info regarding this. Edelbrock says to hook it to driver side for non emission controlled engines, which is what mine is, but then it would have full vacuum at idle and none at higher revs. Seems the opposite of what I'd need. It now has no stumble or flat spots, its just running rich. If I could just get the idle circuit to opperate and set the mixture screws then I'd be laughing, but I have to set the throttle blades open too wide in order to get it to tick over once warmed up. I have a 1" phenolic spacer to fit, plus the correct gaskets now, so maybe that will help improve the running. And yep, going to change jets and rods. The 1411 calibration chart calls for 107 primaries and 73 x 37 (1454 )rods Do I also need to change the secondaries? Chart says 107's are installed and to swap for 104's to go one stage leaner. https://youtube.com/shorts/lJY5mR7o--M?si=4SYlyL8uYzbGHNz5 Heres a fairly recent video of it how its now currently running. As you can see, it takes off ok, thats going up hill too, i had to ease off the throttle before reaching the gates at the end of the track, it felt faster than it probably looks.
Are you sure you're connecting your vacuum gauge to a source of full manifold vacuum? If you're connecting it to the carb there's a chance you may have it hooked up to a ported vacuum source. Ported vacuum won't register until the throttle plates open slightly past the idle setting.
Watch your metering rods when idling - if they move at all, the spring is (still) too strong. My blown flathead has an Edelbrock 600 carb and due to low vac signal the rods started to lift way too soon - thus richening the mixture. Even the weakest spring was too strong so I made 10 gr heavier vac pistons to compensate this. Fine idle, no soot on plugs anymore and a lot lower fuel consumption.
I'm connecting it to the drivers side vacuum port ( manifold vacuum) on the carb, seems to be where most people connect it from all the youtube videos I've watched.
I've had it running with the retainer caps to the rods opened to see that they are fully seated when idling, but I will double check these.
I suggest having the distributor hooked to manifold vacuum. That will advance ignition timing at idle, which will also increase idle rpm. Then lower idle rpm to desired level, closing the throttle blades more than current. Then the idle mixture screws will become more sensitive to adjustment. Vacuum at all throttle positions above idle will continue to be the same as with the current, ported vacuum.
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