Unfortunately, tuning an engine by hand is a lost art, and I have no idea where I can go to have someone help me learn. Westech handles everything from routine old-school tune-ups to sorting out complex late-model electronics. Plug Wires As received by Westech, the C was misfiring and stumbling. It was also surging under cruise. Initial inspection revealed several spark-plug wires lying on the headers. In dim light, arcing was actually visible on No. Mena custom fabbed a complete new wire set from MSD bulk 8. This equates to about flywheel horsepower. At this point, the carb was internally box-stock; still, even after properly adjusting the idle mixture, the carb was lean at part-throttle tip-in, lean at cruise, and fat on top, with an
Vacuum ports on a Quadrajet
Feared by many, and ignored by many more, the vacuum advance can is an important component of your ignition platform that offers both performance and economy. Leaving it unplugged is akin to throwing free engine efficiency straight down the drain. To fully understand why the vacuum advance can is a necessity in any street-going car, we need to dive into spark timing as a whole and cover some ignition basics. Why do I need ignition advance at all? In a theoretical world, air and fuel in a combustion chamber burn instantaneously as the spark plug ignites them, sending the piston downward in the bore and producing horsepower.
What actually happens is that the air and fuel mixture take time to burn.
This distributor provides mechanic advance along with the vacuum advance for a smooth and reliable service. The advantage of this type of set up over a standard Bosch distributor is – NO MORE FLAT SPOT when you take-off from a stop sign.
By Mark Gearhart August 24, When you are working with a vehicle that makes around 65 horsepower to the rear wheels, you need that power to work as efficiently as possible — loosing up hill drag races to semi trucks can be embarrassing. If you have ever owned a classic car with a stock inline 6 cylinder, you know exactly what I am talking about. We are going to be yanking the dying engine for a HP ci in a few months, but I wanted to get all I could out of the engine before it is yanked.
Even though it ran, it ran rough. I started with all the simple updates — new air filter, PCV, spark plugs, and a oil change. None of that helped.
Spark It Up: How to Convert a Ford or Mopar Distributor to GM HEI
Ann Arbor, MI Bikefixr said: Someone at Summit told you that most people unplug their vac advances? Wow, you found a true idiot. Most people run vac advance.
Most vacuum advance will advance timing 20 degrees give or take a few. Add that to initial timing. When the butterflies start to open in off idle condition the vacuum signal to distributor decreases.
Tuning Y Block Distributors at Home You may want to review why advance is needed by reviewing this page. I find that the advance curves that came on almost everything made during the “points” era to be lazy and not at all optimized for the kind of performance I expect. During my younger days, my family obligations and financial situation made buying expensive bolt on equipment out of the question, and therefore I turned to carburetion and ignition modifications to satisfy my hot rodding urge.
I found that this area of hot rodding is generally overlooked by most folks, and that there is a satisfying degree of performance both in power and economy that can be gained by the average joe who is willing to spend a little elbow grease to solve the problem. The more load that your Y block must pull around, e.
On the other hand, many Ys have relatively low compression, which helps quite a bit in how aggressive you can be in speeding up the advance curve.
Everything You Wanted to Know About Vacuum Advance and Ignition Timing
Be sure to save the illustrations separately. The opinions expressed here are my experiences, and your experiences may vary. I don’t put myself forward as the world’s leading expert on Holleys, but I do have some helpful ideas. In some cases, I may not be able to answer specific questions, but I’ll do my best. I know very little about other brands of carburetors and have no information about them, only general operating principles. I have NO experience with any type of supercharger or turbocharger, so please don’t ask me anything about your blower or turbo applications.
Everything You Wanted to Know About Vacuum Advance and Ignition Timing All carbureted cars were set up with direct vacuum to the distributor before more stringent emissions requirements reared.
I have some spare time, so decided to do a write up of how I do it. I will come back at a later date and add some photos to help. I also ask readers to give me feed back on any area that doesn’t make sense so I can elaborate or revise my wording. Let me know of an easier or alternate method, and I will include it.
Turn the crankshaft to Top Dead Center, so that the timing mark on the crank pulley is at the TDC or 0 mark on the timing reference. Since the crankshaft turns at twice the speed of the camshaft, not only do you need to line up the timing marks, but you have to make sure the 1 piston is at the top of its compression stroke.
Six-Cylinder Tuning & Performance
Get smoother operation, reliability, and power from your Mustang Six Jim Smart November 1, When Ford introduced the Mustang in April of , the base powerplant was the Falcon’s ci six with horsepower and lb-ft of torque. Later that year, in August, Ford updated the Mustang’s engine line-up with the seven main bearing ci six as standard equipment.
Both the and ci sixes are well known and respected for rugged dependability. But engineering shortcomings have plagued them since the beginning. The greatest shortcoming is a lackluster induction system, which is positioned directly over a hot exhaust manifold.
Make sure the vacuum advance connection is removed, and now rev the engine up to around 2, to 2, rpm. Ideally, the timing now should be somewhere around 34 to 36 degrees to total advance. With 34 degrees of total mechanical advance and 14 degrees initial timing, you have 20 degrees of mechanical advance—14 + 20 =
A simple vacuum canister can be the key to better driveability Jeff Smith Jul 14, Share View Full Gallery Some very valuable tuning tools are greatly misunderstood. Take the lowly vacuum advance canister. Many enthusiasts dismiss this device as superfluous—or worse—only for emission-controlled engines. There is no excuse for not making use of vacuum advance for a street-driven performance engine.
Sure, there are those who will claim their engine runs fine without that cheesy little can hanging off the side of their distributor. But the reality is that they are sacrificing throttle response, part-throttle power, and fuel mileage.
Ford 351 Cleveland 2V Tuneup
I would like to state that my truck is not computer controlled. If your truck has an ECM, I would not advise doing this because you will need to change everything. This is the only thing that is controlled electronically on mine. I decided to change this over to just a regular HEI without the ESC module and knock sensor since I had already done just about everything else. Below is a brief description of the ESC system. This will not affect emissions.
Jul 17, · If so, hook the distributor up to a manifold (vacuum at all times) port, whether on the intake or at the carb, and see how it likes it. You will get all sorts of varying opinions, however, ported vacuum is an emissions control device.
Ask Away with Jeff Smith: Is this a better way to go with a street engine? What kind of timing should I be running and should I disconnect the vacuum advance? First, on a street-driven engine there is no good reason to lock out your ignition timing. If we had to use a generic maximum advance that seems to work for most pump gas engines, somewhere around 34 to 36 degrees before top dead center BTDC is a good number. But with this much initial timing in the engine it will be difficult for the starter motor to crank the engine.
You can get around this with an ignition cut-out so that the engine cranks and then you hit the ignition circuit, but this is unnecessarily complex for a street car. The better plan is to start with a decent initial timing of roughly 10 to 14 degrees. This can be checked with the engine running at idle with a timing light. Make sure the vacuum advance connection is removed, and now rev the engine up to around 2, to 2, rpm.
Ideally, the timing now should be somewhere around 34 to 36 degrees to total advance. Now connect the vacuum advance from the carburetor to the distributor and read the timing on the harmonic balancer while revving the engine to 2, rpm.
How to hook up vacuum advance linr.?
Distributor advance It doesn’t matter what kind of ignition you have, if the advance curve is not set properly it won’t make any power. The ignition is advanced so you reach peak cylinder pressure right after TDC top dead center. If the spark comes too soon the burning fuel will try to push the piston back down the cylinder before it reaches TDC, resulting in a loss of power and possible engine damage. If the spark is too late you will not reach full power and get poor gas mileage.
Feb 27, · If the vacuum level drops off, you either have a bad advance canister of a leaking vacuum hose; find the culprit and repair or replace it. If the canister holds vacuum, remove the distributor cap and rotor.
Jun 20, Any of the cars without ported vacuum will need the later ported carburetor body or have the port precisely drilled. All the later Zenith carbs with the EGR ported vacuum we have checked have been exactly in the correct location for the proper ported vacuum needed for vacuum advance. Vacuum advance does not operate under load. If the timing is set at 10 to 12 BTDC and the distributor is in good operating condition with 11 to 13 mechanical advance you’ll be in the range of good safe performance.
Mechanical advance controls timing under load and through out the RPMs. If your over advancing under load your distributor is not operating properly. Assuming your distributor is operating as it should vacuum advance enhances overall performance. It should be part of a normal tune up to check the distributor mechanical advance on all cars with or without adding the vacuum advance.
Remember that all we are offering is the vacuum unit that did not exist before to convert the later distributor to operate as the early hard to find distributor. When installed and set up properly gives early TR and TR6 performance. This is quit a difference in overall performance compared to the later TR6 with the retard system. It’s up to the person installing the parts to fully understand how it operates.
Distributor vacuum., run it or plug it??
Feeding the coil with 14 volts instead of 7 automatically improves spark intensity, improving throttle response, fuel mileage, and maybe even adding a bit more power, too. The average person thinks anything from the factory is automatically the best it can be, but real car people know new technology usually means improvement. Honest Ford guys will admit that the Duraspark system has not lived up to its name, and replacement boxes are even less reliable.
While original factory Mopar ignition boxes are good, the design for both the Ford and Mopar boxes suffers from an often overlooked, yet crucial design consideration. A magnetic pickup creates a signal when the rotating pole piece on the distributor shaft crosses the fixed magnet. This generates a tiny signal that triggers the coil — essentially an electronic version of a set of mechanical points, except no voltage passes through the pickup like it does with ignition points.
Apr 03, · There is another small vacuum port at a 45 degree angle that I hooked up the vacuum advance on the distributor to. The pcv valve went to the lower one on the front. Lastly I have one that is hooked up to my th trans that I put somewhere, can’t remember off the top of my head.
There are more vacuum ports on the Quadrajet then on the Edelbrock and I’m wondering if anyone knows where I should hook everything up. I put the brake booster on the back in the same place it was on the Quadrajet. There is another small vacuum port at a 45 degree angle that I hooked up the vacuum advance on the distributor to. The pcv valve went to the lower one on the front. Lastly I have one that is hooked up to my th trans that I put somewhere, can’t remember off the top of my head.
I guess I’m wondering if I installed the vacuum advance and tranny line in the correct locations. Sorry for no pictures and a bad description. I looked in my book and couldn’t find anything that looked like my quadrajet. Thanks in advance Click to expand Vac advance is the bottom port on the drivers side front of the carburetor, PCV is the large port on the rear. Do you have emissions equipment on the truck, or is it stripped bare?
If its bare, you can plug off the un needed ports. If you have an electric chock, ther is usually a vacuum port on the choke tha runs through hard lines to the exhaust crossover in an OEM manifold, but otherwise, you can run a line directly the the port on the top rear pass side port on the carb air horn.
Advancing Opportunity – Effects of Vacuum Advance on Pontiac Engines
A good basic tool that gets the job done. The idle air flow is balanced first. The Uni-Syn is adjusted so that the ball rises about half way up the tube. By adjusting the idle speed screws the idle speed is maintained about RPM and the flow is adjusted so that the ball raises the same on both carbs. Once the idle air flow is balanced the service screw is used to raise the engine speed to RPM. The Uni-Syn is adjusted so that the ball rises about half way up the tube at this higher speed.
The primary vacuum is from the base there on the lefthand side shown. The secondary vacuum is at the side of the carb. The primary vacuum goes to the dist. advance port at the front of the dist. if you don’t have a dual diaphram dist. you don’t need the secondary and shoul leave it plugged.
The 9 cap is available at your local GM dealer. Ask for AC Delco type RC32 part and a 10 cap is available at most autoparts store under a Stant part number , if they don’t have it, have them order it for you. The lower pressure rated caps are not carried by the store much but they are available. Wright One item that makes the radiator leak is using the wrong Pressure Cap.
Should be 9 pounds no greater than 10 pounds. Therefore I use a 7 pound cap for many years. Also your coach is running much Many fan clutches do not work properly Duane Temperature Sender This may be old news for most but doesn’t hurt to be told. This has caused a lot of engine damage when engine starts to overheat. Since the standard pressure cap raises antifreeze solution boiling point to degrees this will be more accurate readings.
I don’t know why they did this but it is a serious problem.