How To Set The Distributor On A Chevy 350

(Image/Jeff Smith)

Dropping a distributor into the engine is a time-honored process that has been around since the first engines coughed their way to life more than 100 years agone.

With the latest generation of distributor-less engines, this tribal cognition has slipped from its "must-know" status. But if you are working on an older engine with a benefactor, this is essential information.

The process is easy and it will accept longer to read most than to actually perform the chore, so permit's get started.

For this procedure, we will apply a pocket-sized-cake Chevy because that was the closest engine for the photos. Even so, the procedure we'll describe is exactly the same for any four-stroke engine.

Our particular engine is a brand new Chevrolet Goodwrench crate engine on which nosotros've already installed a new intake manifold.

In our case, the spark plugs were all removed, which makes turning the engine over very easy. If the engine is in the car, you lot can use the starter motor to crank the engine.

With the Number One spark plug removed, place your thumb over the hole while turning the engine. Once you feel compression building, look for the zero marker on the harmonic balancer to approach the timing tag. We prefer to set the initial timing for most engines at 10 degrees Before Top Dead Center (BTDC).

With that set, remove the cap from the distributor. We're using a Summit HEI distributor. We employ a black Sharpie to place a marking on the benefactor trunk where we want the Number One spark plug wire to be located. This tin can be placed anywhere you like, just if you are a Chevrolet traditionalist, this ends upwards roughly at nearly the 5 o'clock position on the distributor as yous are looking at it from the front of the engine.

As well identify a mark on the respective Number 1 plug wire position on the benefactor cap. We used a piece of masking record.

With these marks in identify, drib the benefactor with the gasket into the distributor hole with the rotor pointing near the Number One mark.

As the benefactor drive gear engages the teeth on the camshaft, this will motility the rotor slightly clockwise. Position the distributor so that the vacuum accelerate canister is located on the passenger side of the engine pointing roughly frontward. If the rotor is non pointed close to the Number Ane marking, pull the distributor and re-position the rotor until information technology comes shut.

Unless you are very lucky, the benefactor will not drop fully into the intake manifold. In almost all cases, the distributor will sit almost 3/eight inch off of the manifold. This is normal and is caused by the oil pump bulldoze not engaged into the drive tang in the benefactor. You can remove the distributor and try to re-orient the oil pump drive slot with a long straight screwdriver, but this is somewhat difficult.

It's easier to leave the distributor in place and then crash-land the engine with the starter motor while placing very light down pressure level on the distributor body. After a half rotation or so, the distributor will drop in place. Now we will need to crank the engine until once again it is located at 10 degrees BTDC. With this accomplished, cheque to ensure the rotor is pointed virtually the mark on the benefactor torso for Number 1 spark plug wire. If the rotor is non pointing at Number One, y'all could twist the distributor body, simply if it is off by more than one tooth, this volition require turning the distributor body besides far. Instead, you will need to remove the distributor and repeat the previous process as the rotor is not in the correct position.

With the rotor shut to the Number One position, twist the benefactor trunk until the rotor points directly at the Number One spark plug terminal position mark on the distributor. Now install the distributor cap and sure-fire the distributor body downwards to the intake manifold with the concur-down clamp. Tighten this lightly—we may have to move it again when the engine starts.

With the distributor in place, install all of the spark plugs. Now nosotros can connect the spark plug wires to the distributor.

Let'south assume that you've never done this earlier. Before we can place the wires in the benefactor cap, the starting time matter we demand to know is which direction the rotor turns.

For our Chevrolet engine y'all'll annotation that the rotor turns clockwise. Small- and big-block Fords turn counter-clockwise.

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Tech Tip: One quick way to tell on whatever vacuum accelerate style distributor is to lay your hand parallel with the vacuum advance canister so curl your fingers in toward the eye of the distributor body. The management your fingers point is the direction of rotor movement. On a Chevy distributor, yous would utilize your left hand, and on a Ford y'all'll use your right hand. This is a cool little trick you can apply on any distributor to determine its rotation.

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On small- and large-block Chevy engines, the Number 1 cylinder is always the commuter's side front.

Chevrolet also numbers its cylinders with odd numbers on the left (driver) side and even cylinders on the right.

The left side is numbered i-3-5-7, and the right side is two-iv-6-eight.

Ford does it differently. Ford numbers its cylinders with Number Ane on the correct front, numbered on the right side i-2-3-four with the left side v-6-vii-viii. Other manufacturers number their cylinders differently, so you should cheque online if you're non certain.

See OnAllCylinders' firing order cheat sail for installing the plug wires in the correct order.

Our modest-block Chevy firing lodge is 1-8-iv-three-6-5-7-2, so that'southward the order in which nosotros volition install the plug wires.

We started with Number 1 and worked our fashion around the benefactor cap clockwise using a gear up of Summit spark plug wires. The best way to practice this and so you don't go dislocated is to just follow the firing order installing each plug wire through the guild.

Leave a little extra room with the spark plug wires to allow freedom of movement in the distributor. For Chevys, be careful to make sure 5 and 7 are installed correctly. If the wires are accidentally switched, the engine will not be happy.

Before we try to kickoff the engine, exist sure the distributor is connected to switched power. With an HEI benefactor, there is a three-wire inboard connector between the HEI module and the cap.

On the outboard side of this connector, in that location are ii smaller private connectors—i for power from the ignition switch (marked BATT) and the other for a tach. With those connections in place and the distributor, plugs, and wires connected, we're almost gear up to start the engine.

Connect a timing light to the Number One cylinder. Now we're ready to fire the engine. Bold the engine starts, brand sure the engine is idling at proper idle speed and not on the fast-idle cam of the asphyxiate.

It'southward important that the engine be idling at its warm-idle rpm. Information technology'southward likely that our static ignition timing at the crankshaft at idle may not exist the desired 10 degrees BTDC.

If it must be changed, merely loosen the agree-down nut and adjust the distributor until the initial timing on the crankshaft is at the desired timing figure. Of course, yous are gratis at this point to set the initial timing at its proper spec.

Nosotros volition save the word nearly initial, mechanical, and vacuum advance for a subsequent story, but you now accept the distributor fix in place and the plug wires installed correctly and it's entirely possible that the engine volition run much improve now with a properly timed ignition.

These are the parts we'll use for this distributor install, including a new Summit HEI benefactor, 90-caste plug wire ends for the male ends on the distributor and a benefactor concur down clamp. (Epitome/Jeff Smith)

We marked where nosotros wanted the Number One spark plug wire positioned on the benefactor body. The mill placed it in this location on almost Chevy distributors. We marked the body and placed a piece of tape on the cap. (Image/Jeff Smith)

Next, we used the commodities on the crankshaft clockwise to plow the engine until nosotros felt compression in the Number Ane spark plug hole and placed the balancer at ten degrees earlier top expressionless centre (BTDC). (Prototype/Jeff Smith)

(Image/Jeff Smith)

Notation inside the distributor bulldoze gear is a male person tang that will engage the oil pump drive slot to spin the oil pump as the distributor rotates. This tang becomes important when we drib the distributor in identify equally the tang will likely not appoint the oil pump drive. (Image/Jeff Smith)

Identify a break-in lube or engine oil on the distributor gear and with the gasket on the distributor, drib the distributor in the hole in the manifold. Line the rotor slightly counterclockwise of the marker on the body and engage the gear teeth. The gear teeth are curved which volition swing the rotor slightly. You may accept to play with this a couple of times to identify the rotor in the right position. (Image/Jeff Smith)

Y'all have almost a 20-percent chance of dropping the distributor all the way down to sit flush on the intake because of the oil pump drive tang. It'southward almost guaranteed that the distributor will sit off the intake manifold and look like this. Do not strength the distributor down. (Prototype/Jeff Smith)

To appoint the oil pump bulldoze, put very light pressure on the elevation of the distributor housing and rotate the engine clockwise until the distributor drops into identify on the manifold. Once the distributor drops in, install the benefactor hold-down clamp and tighten it slightly. (Image/Jeff Smith)

Now rotate the engine clockwise with your finger over the Number One spark plug pigsty until the rotor once more achieves 10 degrees BTDC while noting pressure on your finger over the spark plug hole. Also make sure the rotor is withal pointing at the mark indicating Number 1 position on the distributor. Install the distributor cap, making certain the tape marker is lined up with the Sharpie mark on the distributor body. (Image/Jeff Smith)

To decide distributor rotation, align your manus with the vacuum accelerate canister. The direction your fingers curl will reveal the distributor's direction of rotation. In this case with a Chevy distributor, the rotor spins clockwise. (Image/Jeff Smith)

We like to place each wire on the spark plug and route them to the distributor kickoff. Then we measure each plug wire separately assuasive room to twist the distributor to set concluding timing and then crimp the HEI male terminal on the wire. We place a pocket-size corporeality of the supplied lube in the boot to make it easier to push onto the wire. (Image/Jeff Smith)

With the distributor in place and the wires installed, the only thing left to exercise is set the initial timing. (Image/Jeff Smith)

We started the engine and checked our initial timing and found it was slightly advanced at xvi degrees then nosotros pulled information technology dorsum to 10 degrees which also slowed the idle speed to around 850 rpm. (Image/Jeff Smith)

Writer: Jeff Smith Jeff Smith has had a passion for cars since he began working at his grandfather'southward gas station at the age x. After graduating from Iowa State University with a journalism caste in 1978, he combined his 2 passions: cars and writing. Smith began writing for Motorcar Arts and crafts magazine in 1979 and became editor in 1984. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Since 2003, Jeff has held various positions at Automobile Arts and crafts (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Now he serves as a regular contributor to OnAllCylinders.

Source: https://www.onallcylinders.com/2020/04/16/how-to-install-a-distributor-and-set-initial-timing/

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