I picked up a complete 8 stack webber system to bolt to my small block ford. I got the car running pretty damn good with a nice idle and great power but im a bit curious on my ignition timing. Since i am funneling much more air and fuel into my engine should I run more initial timing? currently im set at 15 initial and 33 total. Talked to a few guys who said I can bump my initial to 18-22 safely as long as i don't max it out above 34 degrees total. can anyone here who is familiar with these webber multi carb systems comment. this is the first time i have ever used one on any of my cars. I got each carb synced up 99% so far and like is said it runs great but i think too rich still and maybe i need more timing to ignite all the extra fuel im burning.
You can try adding some timing, but it helps to have a vacuum gauge hooked up to watch MANIFOLD vacuum. As you advance the timing, watch the vacuum reading. It should remain constant, or increase slightly. If the vacuum falls off, you have gone to far with the timing.
Where do you think its running rich? Idle, or main circuit? Jim Inglese says roughly 18*. Then look at plugs. There is a hole rainbow of jets for them. Idle circuit runs to aprox 3k, then the mains pickup. Once you know when and where its rich, you can target the idle or main jets. Are you running a mech distributor?
What kind of Webers are you running? IDA's, IDF'S, DCNF's, 48's, 44's, 42's? The idle jet should be accessible from the side. Usually has either 50, 55 or 60's in it. Most all the time a 55 works fine. There is a guy on the Dogfight forum that is running DCNF's on a small block ford in his Capri. He might give you some jetting tips. Mk1 Capri is the thread. We used to run hotter spark plugs to cure the rich idle in our VW's. We ran them rich to cool the combustion chamber and keep from pinging. You are using the same amount of air as you would with a conventional set up eg. 4 barrel. The advantage is you are able to fine tune the fuel mixture much more precise. They are made for racing so you can tune the car for the track quickly and easily. You can compensate for altitude and RPM's you want to run. The engine draws the same amount of air unless you supercharge or turbo charge it. You could possibly use less fuel. Webers are so tunable, it is said you could make it run on a lawn mower.
I think these are ida styled. I think its rich by the smell at low rpm like putting around under 2800rpm after that they crack open and the result is insane. My plugs look very mildy fouled with carbon but very mild. Im running a 060 plug gap with some autolites and a msd pro billet.mplug electrodes look perfect though
guys here is a photo of a sparkplug from cylinder 1, i am running Autolite 3924 these may not be the best plug for this but i don't know. what do you guys think?
I like NGK plugs because it's easy to tell the heat ranges and move up and down the steps. Pull your idle jets and see what you have. Just unscrew them from the side and it will come out with the jet holder. 48 IDA's? Pictures? Check this out: http://www.redlineweber.com/html/Tech/idf_adjustment_controls.htm
Sounds like the idle jets too big, and the mains are good if it screams after 3k. IF they are IDA's, what size chokes are in? 37mm or 40mm?
How much fuel pressure are you running? Has to be less than 4 lbs. of pressure. More than that and you risk the overpowering the needle and seat.
I don't think you can get a good vacuum reading with individual Weber carbs because you don't pull from a common plenum. You will get a pulsing reading. Set your ignition timing with total advance. Don't rely on initial timing. Your total timing is more important. Then check your initial. Ago
I run 2 450 Holleys on my 306 SBF. I run 18 initial and 32 total. Mallory dual point dizzy with a Pertronixs kit. My plugs look like they just came out of the box.
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