![]() ![]() Find the timing mark on the vibration damper (the big round wheel about 1 inch thick behind the belt pulleys at the very bottom front of the engine). Step One Determine the base line of the settings that affect timing and write them down. Timing that is set outside the parameters of the capability of the engine may cause severe damage to the engine. Total timing is determined by measuring Initial timing (distributor setting) + Vacuum Advance (the setting of the small diaphragm can attached to the distributor) + Mechanical Timing, the advance caused by the weights attached to the distributor plate and controlled by the strength of the springs.Ĭorrect adjustment of timing affects the quickness of the engine starting, gas mileage, amount of horsepower, rod bearing life, valve ping, and idle quality. Centrifugal force created by the speed of the turning distributor shaft is transferred to the weights attached to it. Mechanical Advance- consists of weights attached to the distributor shaft, controlled by coil springs attached to the distributor plate. The source of the vacuum is a ported opening in the carburetor. It is controlled by the amount of vacuum the engine produces. Vacuum Advance – a device that increases or decreases the timing by moving the distributor plate. You'll pick up a little free horsepower & torque.Distributor – the primary device, which is adjusted to establish minimum timing. Hint: If you find yourself launching down in the 2000-3500 range (low stall or a stick car on street tires), have your chip burnt to change the table so that full advance is realized much sooner, say at 2000rpm instead of 3000rpm. Ignore that last line in your reference table PKRWUD, the curve that jimberg has is what the computer is using. Most timing retard modules will offer a 'Start Retard' function that actually reduces timing advance during startup so that the high compression race engine doesn't suffer 'kick back'. Alot of heat is absorbed since the combustion was started, and well developed, before the piston ever reached TDC. It built good vacuum, but it also made the engine idle hotter since I was starting the combustion process so much earlier in the cycle. After 1300rpm, the timing table dropped back to pretty much stock. When I was running the ole pukey E303 cam and we had to make 16 inches of vacuum to pass tech, I had a chip burnt that pumped the timing up to 55 degrees (total), but only up to 1300rpm. You're asking for serious performance and engine problems if you run this for any length of time on the street, especially under high heat or load conditions. If they set it at 35 degrees, then at full advance you'd be running about 53 degrees of total timing. End result? 7hp more with the SPOUT in and the computer handling the timing advance.ĭon't set your base with the SPOUT in. I total timed the car at 34 degrees and dyno'd it, then set the base to 16 degrees and dyno'd it. I've run my car both ways, and dyno tested both ways. An important note to this is if you have a 1986 5.0, and you convert it to MAF, you CANNOT exceed 14 degrees of initial advance (base timing) due to a unique head change that year. With 14 degrees of base timing, the total advance is around 38 degrees. Most people set their base timing to 14 degrees to start, and test and adjust it from there. If you leave the spout out, the timing will not advance when the rpm's do, and you will lose power. After the timing has been set, you MUST reinstall the spout connector, so that the ECM can control the advance for you. When the spout connector is removed, the timing you see at idle with a timing light is the real timing, not computer controlled timing. This is done by removing the spout connector. So, in order to trick the ECM by advancing the base timing, the signal from the distributor to the ECM must be disabled. If you try and change the base timing, the ECM will try and correct it, and you'll end up with a lousy running engine. The factory recommends it be set at 10 degrees BTDC, so the ECM is programmed to respond like the timing at idle is set to 10 degrees advanced. Your Mustang is electronically fuel injected, which means the ECM (the "computer") takes over the job of advancing the timing for you, so you no longer have a vacuum or a mechanical advance. For a stock engine, the average total advance is about 34 degrees. You will usually find the engine has reached it's total timing by 3000 rpm. You could improve things.Īn engines total timing is the combined total of it's base timing (where you set it at idle), it's maximum vacuum advance (if equipped), and it's maximum mechanical advance (if equipped). That means your base timing is about 11 degrees advanced, which is just about stock. ![]()
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