Been trying to fix the bog at wide-open-throttle “stomp”, and I’ve got a combination that seems to be pretty darned good. Figured I’d share it with you all, feel free to add to, correct, or comment.
The carb is a basic Edelbrock 1406, so a 600 with an electric choke. The testing was done at roughly 1,000 feet elevation, and about 85 degrees Fahrenheit.
The car: 1967 300 convertible, blocked heat risers, stock 440, Lunati 60300 cam (close to stock duration, higher than stock lift, but pretty close to the stock 350 horse cam overall), stock exhaust manifolds, stock intake manifold, stock fuel pump, stock torque converter, 2.76 gears, 29” tall tires.
Basically a stock “standard” 440 with a careful rebuild and blueprint. The example here should apply to any 66-71 350 HP 440 with a 2.76 or 2.94 axle, such as Imperial, New Yorker, Town & Country, etc.
The example here does NOT apply to a 440 TNT/Magnum – the TNT had an 11” torque converter (higher stall), a 3.23 axle, and a cam with longer duration. An entirely different situation as far as tuning is concerned.
The example here uses blocked heat risers and the heat riser valve (in the right exhaust manifold) is removed. The example also has a fresh-air intake, similar in style to other posts on the dry dock. So the jetting is probably richer, and the pump shot is probably larger, than what would be needed on a manifold with open heat risers, a functioning heat riser valve, and a stock single snorkel air cleaner.
On the other hand, the testing was done with ethanol-free premium, and gas with ethanol leans the mixture about 4%, so take that into consideration as well.
It is really hard to get the bog out of a heavy car, with a low-stall converter, and a low numeric gear. The example does not have an MSD or a Rev-N-Nator on the car (yet), but those types of high-power ignitions often will light the mixture so well they cover a lean or rich bog. Which adds to the challenge in this case, I suppose.
Modifications OTHER THAN to Carburetor: Blocked heat risers, cold-air intake tube, and modified the distributor – to equate to the same curve as the Mopar Performance distributor, P3690432 if bought separately, P3690428 if bought in a kit. Vacuum advance comes in at about 9.5”, appears all in at about 15”, car idles at 19” to 20” of vacuum. (Note – mild cam) Timing is 12 degrees initial, 38 total, vacuum advance disconnected. Exactly what Mopar Performance tells you to do for timing on a 440.
Modifications to Edelbrock 1406 Carburetor: Pump arm in top hole (closest to carb body), #43 squirters (the largest), orange step-up spring, .098 main jets (didn’t change main jets), .073 X .037 Metering Rod, .098 secondary jets.
The stock set-up is pump arm in the middle hole, #28 squirters, yellow step-up spring, .098 main jets, .075 x .047 metering rods, and .095 secondary jets.
Long story short – richened the “power” side up to be like a 1405, (but leaner on cruise than a 1405, so as not to kill the mileage), gave it the biggest accelerator pump shot possible, and gave it a mild performance distributor curve.
It will kick down to 1st and light the tires at a 15 mph roll. !banana
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
Good writeup, Cyclone! !thumb
Something I've noticed to pass on to everyone, Cyclone kinda touched on it:
Eddy tends to calibrate their elec-choke carbs for economy, and the manual choke versions are set for performance. So, if you know you need a richer setup, you can buy a manny carb adn add the elec choke to it. Cost works out pretty close and it might save buying/changing jets/rods/springs..
Joined: Wed Sep 03 2008, 12:35AM
Location: St. Catharines, ON
Posts: 39
So, I should have gotten a 1406 instead of the 1411?
I was going to get a 1406 too, but I read up and the edelbrock site lead me to the 1411. It was kind of a toss up, really. In the moment of decision, I went bigger.
It sounds like I should have gotten the jetting kit, too.
I used the 1406 because I had one laying around from an old parts car, not because it was my 1st choice for my 440. If I was buying new I'd have probably chosen a 750 or 800 Edelbrock or a Holley 770.
Enough people were compaining about a bog that I thought I'd see if it could be fixed. It can.
I'd bet if you have the performance distributor (key #1) and put a #43 squirter with the pump in the top hole (key #2) it won't bog.
I don't know your altitude. If you are in Denver, you won't richen it up. If you are closer to sea level, you can change metering rods that richen only slightly at cruise, but richen more at heavier throttle.
For best performance, imitate the jetting and rods in a 1412. You can pretty much either buy a 1411 and set it up like a 1412, or buy a 1412 and add an electric choke, but either way you wind up in the same place. Just don't forget the #43 squirters and the top hole.
My guess is Edelbrock 1406 and 1411 are set up for cars to pass emission rules. Which means they are somewhat lean, but it also means they are ideally suited for cars with really small cams, factory air cleaner, a restrictive single exhaust with catalytic converter, and an EGR. Put them on any free-breathing engine, like a 60's B or RB with dual exhaust, and they go from "somewhat lean" to "way too lean."
The rod & jet kit for a 1411 carb is an Edelbrock 1489, the accelerator nozzle kit is an Edelbrock 1475.
Joined: Thu Oct 20 2011, 07:41PM
Location: Melbourne, Australia
Posts: 101
Thanks for the information. I hope this is not a hijack, but what would be the difference be with a 383? I have a 1406, performer intake and the rest is stock which I am setting up, but haven't driven yet. Could I apply some of the tips to my setup?