Question about vacuum lines…

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.

Six-Cylinder Tuning & Performance

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.

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.

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.

The typical response on many forums to questions about these factory ignitions is the simplistic: Before we get into the details of how easy it is to adapt an HEI module to a Ford or Mopar magnetic distributor, we have to put this whole brand loyalty thing on the table. But for the rest of the performance world who is open-minded enough to learn something new and to whom performance efficiency is more important than blind brand loyalty, please follow along.

If we look closely at a wiring schematic of either system, both include either a resistor wire Ford or a ballast resistor Mopar that limits the voltage to the positive side of the coil.

Distributor vacuum., run it or plug it??

He probably has a fair bit of initial timing and the advance mechanism curve would also be set to come in at a fairly low rpm. Also, an engine like Jason’s won’t pull much vacuum at an idle so it’s hard to get the vacuum advance to work right. You usually have to go to an adjustable vacuum pot or one with a weaker spring to get it to work on an engine with a big cam. Also, on a high performance engine you often have to limit the travel of the vacuum advance.

Jul 28,  · Remember, anytime you set the timing with a vacuum advance distributor, the vacuum canister should be disconnected when setting the initial timing and the hose plugged up using a golf tee or the sharpened end of a pencil.

If you set the timing at 24 BTDC with the vacuum hose disconnected and plugged, when you hook the vacuum hose back up your timing will be around 34 BTDC. At wide open throttle WOT you will still have proper timing, but your idle quality may be poor. You may also experience some off-idle stumble and hesitation when the timing drops 10 degrees or so as you let out the clutch and start to move off the line.

At idle your timing will be at 24 BTDC, but as soon as you let out the clutch and start off the line your timing will drop to approximately 14 degrees. Moving a stock Corvair turbo off the line is not the time when you want to retard your ignition timing from the factory setting of 24 BTDC. The low compression ratio coupled with the comparatively poor throttle response of this engine begs for all the ignition lead it can get at that time.

The electronic control circuit monitors engine RPM and sends a signal to the vacuum solenoid. Vacuum solenoids are very common on any late model vehicle. These are easily obtainable at salvage yards. Any vacuum solenoid will work for this application. You only need one inlet and one outlet port, but if the vacuum solenoid which you find has other ports, these can be easily blocked off.

SBF Distributor

Cool, I am on the right track for that. The original cap is in the trunk has a non nipple chrome cap on the oil filler tube now. Distributor Vacuum Advance should be attached to a Ported Vacuum source, meaning no vacuum at idle, but vacuum just off of idle. Unaware if the Carbon Canister should also be attached to Ported Vacuum. Yep- a ported vacuum source off the carb does go to the vacuum advance, via a T fitting that also goes to the cannister.

Very nice kit in every aspect but the vacuum advance unit was to short to fit the GM style HEI distributor that I️ am running on my 75’ jeep wagoneer with AMC v8.

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. If the spark plug were fired at true top dead center 0 degrees in crank revolution , the piston could be well on its way to bottom dead center — maybe even past it and onto the exhaust stroke — before combustion of the air and fuel was completed.

That would make for an engine that was horribly inefficient and made terrible power.

Distributor Vacuum Advance Hose

Although most “shade tree mechanics” know the function of a distributor, many forget that its operation must be perfectly phased with that of the camshaft. A person might go to great lengths to mark the position of the distributor on the engine block and then completely overlook the position of the rotor shaft, or vice-versa. This mistake is so easy to do that even “seasoned” professionals constantly make it, ending up with an engine that won’t start or is so far advanced or retarded in timing that it barely runs.

The following is presented to show you how to avoid mistakes and gain a little confidence in the process, whether you are replacing the distributor in an old engine or reassembling a new one. Remember at all times that both valves on the “master” cylinder usually 1 cylinder must be closed, meaning the piston is at Top Dead Center. Step 1 – Crank The Engine Before doing anything with the distributor, crank the engine to Top Dead Center, so that the timing mark on the crank pulley is at the TDC or 0 mark on the timing reference.

Jun 19,  · There is a vacuum port of my carb that goes to a T fitting, and runs to the vacuum advance on the distributor, and to a black can on the inside driver’s side fender.

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.

How to Replace A Distributor Without Going Crazy

I had my vacuum advance hooked up to the ported vacuum port after reading this article I hooked it up to full manifold vacuum adjusted the idle rpm. The car has so much more power now. As many of you are aware, timing and vacuum advance is one of my favorite subjects, as I was involved in the development of some of those systems in my GM days and I understand it.

Many people don’t, as there has been very little written about it anywhere that makes sense, and as a result, a lot of folks are under the misunderstanding that vacuum advance somehow compromises performance.

Apr 29,  · I know that hooking up the vacuum advance to manifold vacuum will produce advance whenever there is a vacuum in the manifold, such as at idle, cruise, and .

They frequently suffer acerbic reviews by those who don’t quite understand them, and they are often removed and replaced by “progressive” centermount carburetors that lack the engineering of the originals that provide dependable service and excellent driveability once you set them up correctly. Here is what is going on with that weird left carburetor, and this will make it all crystal clear to you. Since the beginning, VW controlled idle speed by a screw that positioned the throttle plate opening.

Not much air is required to idle a VW, and they had to dump a lot of gas into the mixture to make sure a combustible mix made it all the way to the cylinders. It worked well, but it was pretty smoggy. These were the Pict 2 days where the idle speed screw was staring right at you at the top of the throttle lever. In , VW discovered that they could make an engine idle with a lean fuel mixture to meet emissions standards, yet still have decent driveability if you increased the air speed.

Instead of a lazy trickle of air around a huge throttle plate, they crammed the air through a high velocity passage and mixed the fuel into that airflow.

How to hook up vacuum advance linr.?

Although most “shade tree mechanics” know the function of a distributor, many forget that its operation must be perfectly phased with that of the camshaft. A person might go to great lengths to mark the position of the distributor on the engine block and then completely overlook the position of the rotor shaft, or vice-versa. This mistake is so easy to do that even “seasoned” professionals constantly make it, ending up with an engine that won’t start or is so far advanced or retarded in timing that it barely runs.

The following is presented to show you how to avoid mistakes and gain a little confidence in the process, whether you are replacing the distributor in an old engine or reassembling a new one. Remember at all times that both valves on the “master” cylinder usually 1 cylinder must be closed, meaning the piston is at Top Dead Center.

Technical Drawings and Schematics – Section I Electrical and Wiring: (Distributor Vacuum Advance Control) – 8 Cylinder E/D, F with M/T and w/o A/C. x , K: Back-Up Lamp Switch and Wiring – Typical 4-Speed Manual Transmission.

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.

hooking up a vacuum advance

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.

Oct 29,  · Where does the line to the distributor vacuum advance hook up to on a blown engine? Does it go before the blower at the carb bases, or after the blower at .

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 Tune-Up On Edelbrock Performer carbs, step-up metering rods regulate primary-side fuel metering. Because each rod rises out of the primary jet orifice as the throttle blades open further and engine vacuum decreases, thinner smaller od rod tips richen the fuel curve.

1964 GMC “Crustine”- Vacuum advance fixed.