Installing A Distributor

[Michael Mayben]

It's been suggested by one of our members that we need a stickee regarding the subject of installing a distributor and verifying the spark plug cable locations. So here it is...this process will work with appropriate adjustments for both an sv engine and the 152/196 (I-4). I've extracted and edited the text from a very early thread that was posted to this sub-forum based upon an issue brought up by ihon member travis:

"align the timing Mark on the crank balancer (or hub depending upon the engine series) to tdc on the compression stroke for number eight (8) cylinder. As you come to tdc, stop rotating just before the timing Mark aligns, do not go past the Mark and then come back to it! Important! The most acccurate way of determining top dead center (tdc) is to remove the valve cover on the passenger side head and look at the rocker arm position for #8 cylinder (#1 cylinder on an I-4 engine). On the compression stroke, both rocker arms will be closed and kinda "loose" when ya move 'em.

Make certain that the oilite bronze bushing is in correct position in the block just above the oil pump drive, it must be there otherwise that distributor will not last more than 10 minutes once the engine cranks.

Then align the distributor rotor with #8 plug wire terminal on the cap and rotate the distributor about 1/8th of a turn counter-clockwise and then drop into position while ya wiggle the rotor to allow the gears to mesh, the oil pump drive tang will go into it's slot first and then the drive gear will slide into mesh with the cam gear. The rotor tip should now be pointing at the #8 cap terminal (or #1 if an I-4). It won't be perfect alignment until ya rotate the distributor a tad.

Next just snug the distributor hold-down in place to allow the distributor to be rotated by hand so you can set the timing.

Looking straight down onto the distributor, the distributor "direction of rotation" for these engines as installed in passenger vehicles is clockwise.

Next up, re-wire the distributor cap starting with #1 cap terminal which is the terminal just to the right of #8 sv application, looking down on the top of the cap). The firing order again is...1, 8, 4, 3, 6, 5, 7, 2. Firing order for the I-4 is 1, 3, 4, 2. So follow that pattern around the cap, plugging each wire into it's appropriate cap terminal and then the spark plug for that cylinder.

Once you have the distributor cap wired correctly, verify either dwell if the distributor uses breaker points, or the reluctor air gap if the distributor is either a Holley electronic or the prestolite electronic.

Once the engine is running and dwell is confirmed, then set the base ignition timing using your preferred method."

 

[HeyCharger]

Just remember that some of some of us from downunder (and other parts of the world) your passenger side Is not our passenger side.

 

[wmnan]

I am having quite an issue with my 72 sii, 304. I had the vehicle running, but was having issues with the hot air choke no operating correctly, and it was backfiring. I put a timing light on it and tried to time it from the #8 cylinder. Tc as my manual says, the truck wouldn't start, had to turn the dist all the way to 10deg btc. Truck was running smooth, with the exception of the choke. Choke spring was broke. I converted to an electric choke.... While waiting for the part to come in, I replaced oilpan and valvecover gaskets cuz they were leaking bad. Got all parts on, put the plug wires back on as the book describes. Now I can't get the rig even try and start. Turns over but acts like no spark is getting to the cyls. Checked the coil and its putting out juice. It has points, but I did not touch them. I am at a loss. What step do I take next?

 

[wmnan]

Found the problem, apparently the po installed the disto wrong. The distro cap has a #1 on it, had to put the #8 plug wire on and proceed from there. If I am understanding things correctly, the #1 plug wire should be on it, which means I will eventually have to/ should pull the distro and re-seat it in the correct position. Please let me know if I am tracking correctly. Thanks

 

[Scoutboy74]

Forget about the labeling on the distributor cap. It has no bearing for IH v8 engines, since they are timed off #8. Most other makes of this era are timed off #1, hence the label on the cap which is meaningful to the chryfordrolet crowd. The keys to proper distributor orientation and plug wire routing are well documented in the early posts of this thread. In a nutshell, #8 cylinder must be at top dead center tdc on the compression stroke. That means compressed air will be forced out through the vacant #8 spark plug hole as the piston travels to the top of its stroke. At this point, the timing scribe on the crank hub will be aligned roughly between 0 and 5 degrees below tdc. Now the distributor can be oriented so that the vac advance canister is facing forward, with about equal clearance between the water pump housing on one side, and the valve cover on the other. Whatever tower location on the cap is above the rotor is your #8 plug wire location. The remain plug wires are then oriented from there in a clockwise fashion according to the firing order. The #1 plug wire should be the final wire connected to the cap.

 

[wmnan]

Got it. Thanks for the help.
Having other issues now, have posted under electrical forum. Power problems..

 

[Brandonium]

Not to sound like an idiot but there's something about the original post that's not clicking with me.

"next up, re-wire the distributor cap starting with #1 cap terminal which is the terminal just to the right of #8 sv application, looking down on the top of the cap). The firing order again is...1, 8, 4, 3, 6, 5, 7, 2. Firing order for the I-4 is 1, 3, 4, 2. So follow that pattern around the cap, plugging each wire into it's appropriate cap terminal and then the spark plug for that cylinder."

alright, so your rotor is pointed to #8 terminal and now the re-wire. Following this, number 1 is not directly to the right of #8 if you're looking down on the cap. It's actually directly to the left if I follow the 1,8,4,3,5,7,2? Otherwise the firing order with #1 directly to the right would be 8,1,4,3,5,7,2?

Is this a typo or am I seeing it all wrong?

 

[1975IH200]

not to sound like an idiot but there's something about the original post that's not clicking with me.

"next up, re-wire the distributor cap starting with #1 cap terminal which is the terminal just to the right of #8 sv application, looking down on the top of the cap). The firing order again is...1, 8, 4, 3, 6, 5, 7, 2. Firing order for the I-4 is 1, 3, 4, 2. So follow that pattern around the cap, plugging each wire into it's appropriate cap terminal and then the spark plug for that cylinder."

alright, so your rotor is pointed to #8 terminal and now the re-wire. Following this, number 1 is not directly to the right of #8 if you're looking down on the cap. It's actually directly to the left if I follow the 1,8,4,3,5,7,2? Otherwise the firing order with #1 directly to the right would be 8,1,4,3,5,7,2?

Is this a typo or am I seeing it all wrong?

Not a typo, but I think the terminology used should be "clockwise" or "counter-clockwise" as viewed from above. Which is the typical view you have when working on an engine ignition system.

Possibly you are over thinking this. The engine timing is set with the #8 cylinder and the distributor installation is most easily understood when the engine at tdc on #8 cylinder on the ihc sv-8 engines. (ie. The timing Mark lined up on the harmonic balancer and the #8 cylinder at tdc of the compression stroke) therefore, when you start placing the high tension spark plug leads onto the distributor cap, start with #8 (where the rotor is pointing to) then continue around the distributor in a clockwise manner in the firing order. Or....in other words, the #1 high tension lead is one spot counterclockwise of #8, with the remaining high tension leads (4-3-6-5-7-2) are located clockwise from #8, in order.

Or,...you know where #8 goes or now actually is located, so the rest is simply following the firing order in a clockwise manner. The firing order is 1-8-4-3-6-5-7-2 and does not change because the timing is set with #8. The crankshaft rotates twice per full sequence of cylinders firing, while the distributor rotor rotates once per engine cylinders firing sequence. Once you understand this, then eventually you will come to the understanding that the engine can just as easily be timed from #5 as #8.

 

[Brandonium]

Ok, it makes sense now.. And it really doesn't matter which terminal I use for #8 just as long as 1). I am at tdc for #8 and 2). I connect whichever terminal I designate as #8 to the corresponding plug.. Follow that up with just following the firing order sequence.

For some reason it confused me, but I do tend to overthink things. I've never stabbed a dist so I want to ensure I do it right.