Top VIdeos

In a squarebore, the bores are closer to the same size, though, in some squarebore carbs, like cfm Holleys, the primaries may be noticeably smaller than the secondaries. However, even then the bores share the same centerline. Many aftermarket intakes, such as mine, and the Edelbrock Performer and RPM, etc, are “dual pattern” intakes the area where the carb bolts on looks like a butterfly. Either a squarebore OR spreadbore can be physically be mounted on them with no adaptors. Carter Thermoquads, Rochester Quadrajets, and Holley ‘s, ‘s, and ‘s are spreadbores. If the intakes are true squarebore intakes four individual holes or true spreadbore intakes again, four individual holes, though of different size , you cannot really bolt a squarebore carb on a spreadbore intake and vise versa.

Installation Instructions – HEI Distributor

I’m also pretty sure that a V8 with two cylinders blocked won’t be correct, either. You can easily recognize an odd fire distributer just by looking at the cap carefully, the cam if it’s “points” and undoubtedly the reluctor if it’s electronic. There is a wider space between every other two cylinders, due to the design of the crankshaft. You can see this easily on a scope, every other two cylinders firing closer together, with a big space in between.

There was a bunch or at least 3 of different caps and distributers–“they are NOT all the same.

TSP’s HEI Distributor has everything you need, all under one cap. With a high-quality aluminum housing and hardened steel dual bushing construction, it is built to last. It features fully adjustable mechanical and vacuum advances, meaning precision is a breeze. It has a high-output module, high-spark 65, volt coil, solid brass terminals, and an easy one-wire hookup.

Cap held on by clips. The can be converted to pertronix electronic, but it takes a weird kit. Mark A knows which one to use for dissy. I think it is possible to drop in the Toyota electronic ignition by changing out the breaker plate and swapping the point cam for a trigger wheel. Haven’t done it yet, but that’s essentially what Denso did in California spec dizzy has both vacuum advance and retard. The retard is the nipple coming out of the top of the vacuum advance can, the advance is coming out horizontally.

The vac canister has 2 vac fittings. Outer fitting is advance, inner fitting is retard.

DUI HEI Distributor AMC Inline 6 USA Made!

Remove the coil, and coil bracket from the engine. Remove the vacuum hose attached to the vacuum advance canister. Read all instructions before starting installation. Flame-Thrower HEI distributors come with machined steel distributor gears which should not be used in applications with billet camshafts. Consult camshaft manufacturer for distributor gear compatibility.

A very good vacuum advance. I liked the fact that its adjustable. It lists a bunch of distributor part numbers and you adjust it based on your application or to your liking if you like to tweak things on the peformance side.

Remove the distributor cap, right valve cover and the 4 cyl rocker arms and pedestal. Set up a dial gauge on the 4 intake push rod. Rotate the engine to TDC 1 cylinder. If the dial reads thousands, your valve timing is right. If the dial reads thousands, your valve timing is retarded or your chain is streched.

If the dial reads thousands, your valve timing is to far advanced. These s are for stock engines and wouldn’t work for engines with aftermarket cams. By inducing high voltage in the tube, the gas is ionized and thereby lights up. In the case of plug wires glowing, the Corona effect can happen when atmospheric conditions are right.

Mallory Answers Some Questions About Distributor Choices

In the mid-’70s, leaner mixtures demanded greater voltage and more spark energy to kick off combustion. The HEI distributor is still an inductive-discharge ignition, but exchanges points for an electronic device called a module. Since this system produces more voltage and amperage output than a point-type ignition, it requires a larger-diameter cap to prevent voltage crossfire inside the distributor cap.

This distributor also has an adjustable vacuum advance, and this will allow you to control just how much advance it adds to your initial timing when it’s hooked up. The effects of this can also vary depending on what source you hook it up to.

It features a high quality, fully adjustable mechanical advance and an accurate magnetic pickup trigger. The CNC-machined aluminum body and hardened steel shaft, guided by a sealed ball bearing on top and a sintered steel bushing on the bottom, ensure stability up to 10, RPM. The dielectric cap features bolt-down and twist-lock capabilities. It has solid brass terminals and comes with a color-matched wire retainer.

It features a CNC-machined billet aluminum body and hardened steel shaft, with a sealed ball bearing on top and a sintered steel bushing on the bottom. It also comes with a fully adjustable mechanical advance, vacuum advance, magnetic pickup trigger, and a high-output circuit board module with digital tach output. The dielectric cap comes with solid brass terminals and a color-matched wire retainer.

TSP JM6511R AMC/Jeep 232-258 L6 HEI Distributor with Red Cap

All of the above issues can greatly affect the performance of your engine. These are just a few of the things that most old distributors have going on with them. For the low cost of a complete brand new one, it just makes little sense to used the original distributor. When we rebuild any early model engine, we insist the customer purchase a new distributor.

You will notice a performance difference in your engine if you have any of the above issues with your old distributor.

Vacuum advance uses a vacuum diaphragm connected to a link that can move the plate that the points are mounted on. By sending engine vacuum to the vacuum advance diaphragm, timing is advanced. On older cars, the vacuum that is used is port vacuum, which is just above the throttle plate.

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.


Would you like to merge this question into it? MERGE already exists as an alternate of this question. Would you like to make it the primary and merge this question into it? MERGE exists and is an alternate of. The information here applies to various Buick V8 and V6 engines, so make sure you understand the details as they apply to your engine.

Our HEI includes high-output module, centrifugal advance components, and adjustable vacuum advance canister. **THIS DISTRIBUTOR WILL NOT WORK WITH FUEL INJECTION** FREE BONUS Included is the HEI pigtails!!

It’s a little long, but has alot of good info on ignition timing and what is best for your application. I have made every attempt to present factual, technically accurate data wherever possible. If you find factual errors in this information, please let me know so I can correct it. Background The vacuum advance control unit on the distributor is intended to advance the ignition timing above and beyond the limits of the mechanical advance mechanical advance consists of the initial timing plus the centrifugal advance that the distributor adds as rpm comes up under light to medium throttle settings.

When the load on the engine is light or moderate, the timing can be advanced to improve fuel economy and throttle response. A control unit that responds to engine vacuum performs this job remarkably well. Also, a GM V8 engine, under light load and steady-state cruise, will accept a maximum timing advance of about 52 degrees. Some will take up to 54 degrees advance under these conditions.

Anything less than 52 degrees produces less than optimum fuel economy at cruise speed. The following considerations must be made when selecting a vacuum advance spec: How much engine vacuum is produced at cruise? If max vacuum at cruise, on a car with a radical cam, is only 15 inches Hg, a vacuum advance control unit that needs 18 inches to peg out would be a poor selection. If the distributor has very stiff centrifugal advance springs in it that allow maximum timing to only come in near red-line rpm, the vacuum advance control unit can be allowed to pull in more advance without the risk of exceeding the degree maximum limit.

HEI Distributor Installation for V-8s