63 340HP Distributor Orientation

[John L.]

Re: 63 340HP Distributor Orientation

I think everyone missed Norm's statement " the distributor will only go in one of two ways because of indexing to oil pump drive"
Norm when you pulled the distributor the drive shaft moved and now you need to move it where ever you need to, to get the vacuum can to where you need it.
The motor is "disturbed" now so use the steps in your manual to reinstall it where you want it. You should be able to get the vac away from your coil no matter what type of trigger you have.

edited:
Norm, if you didn't move the motor and you carefully marked the rotor position before you pulled the distributor up, you can use the undisturbed method but you need to move the oil pump drive to where it will engage with the rotor and VAC where you want it. that would be away from the coil brkt but still fit in the cutout in the ign, shield

[Duke W.]

Re: 63 340HP Distributor Orientation

With the cap off, it's quite clear that you have a electronic ignition conversion of some sort. I have not seen that system before and have no idea who makes it. I would think that its orientation and installation placement may be outside the normal points configuration placement and affecting orientation and operation.

Since you do not have a stock setup, IMO...all bets are off for a normal configuration until you get to a baseline configuration, i.e. conversion back to points. If you can get information on the electronic conversion and potential adjustments of the stator and rotating trigger actuator, this may allow you to adjust for proper distributor placement with respect to the VAC clearances.

I agree!!! These "electronic points" conversions can cause no end of hassles in some cases.

It's easy to swap in a set of points.

It's not clear if you verified that the #1 coil wire is on the correct cap terminal, so VERIFY this with an ohmmeter before you proceed. If the wires are not properly indexed on the cap you will never get it set up properly.

Start by setting the notch on the balancer at about 12 BTC on the timing tap, #1 on the compression stroke. At this point the rotor should be pointing about 20 deg. right of engine centerline. In the photo it's not even close!

Start the installation by holding the rotor tip approximately inline with engine centerline. Use a mirror or rotate the bottom of the dist. up to note the orientation of the shaft flange that engages the oil pump drive shaft notch, and use a paint mixing stick or similar tool to align it with a shaft flange so they engage as you drop in the dist. As the teeth engage the rotor will rotate about 20 degrees CW and the dist. will seat on the manifold if the oil pump drive was properly oriented. If not, remove the dist. and tweak the oil pump drive shaft as required. Once fully seated the rotor tip should be pointing about 20 degree right of engine centerline.

Connect an ohmmeter between the coil negative terminal and ground. Rotate the dist. base until the points open, which is indicated by the meter jumping from zero to infinite resistance. This is called "static timing the engine", and it's easy to do with mechanical points, but not necessarily easy with an electronic points conversion.

If the proper tooth is engaged and you rotate the dist., the points should open when the VAC is about midway between interference points and the cap window is approximately normal to engine centerline.

Note that the above is done with the engine not running and the key off, so it doesn't take much time, but it can take a little experience to get the oil pump drive properly aligned so the distributor properly seats on the manifold.

Start the engine and set the timing with a light. If you want to reinstall the electronic switch, go ahead, and check timing again. If it changes significantly then the electronic switch is not designed to be compatible with the specific dist. installation orientation required on Corvettes.

Duke

[John D.]

Re: 63 340HP Distributor Orientation

Nice Pics Duke, The Flint guys really didn't car that they damaged the crap out of the VA's did they. I mean look how deep your dent is. In old days they didn't have the dead blow hammers we have. (Did they?) They must have had one I have had since a kid. Although it's rubber it's solid like steel. I bet they used those. JD

[Timothy B.]

Re: 63 340HP Distributor Orientation

Norm, Now that you have turned the lower gear 180* you have installed the distributor in the engine wrong. Please note the distributor will go in in every position, it's just a matter of walking the oil pump drive around to line it up. If you lift the distributor just high enough to disengage the camshaft/distributor gear and keep turning the rotor clockwise in and out of the engine you will pick up the oil pump drive and walk it around with each in and out to the correct position.

Once you try it you will understand, the oil pump drive will follow the clockwise motion of the distributor shaft. On my 67 with the breakerless SE I had the same problem with the vacuum advance just tight against the coil bracket and had to rotate the gear 180* to center the V/A control.

One more thing IMO, the breakerless SE is a nice conversion for your car much better than points and your engine will run better.

[Duke W.]

Re: 63 340HP Distributor Orientation

Those aren't my photos, but I wanted to comment that they illustrate, very well, proper C1/2 distributor installation.

I don't think Flint had any issues with distributor installation because the distributors arrived with the gear properly indexed.

When I first disassembled my dist. circa '65 I followed the shop manual procedure carefully, but since it said nothing about orientation of the drive gear it ended up on the bad side of the 50/50 random chance, and it took too more removals/inspections for me to notice the dimple and count the 13 teeth, which was a Eureka moment.

So I ended up with the "dent in the VAC", but that OE 201 15 was replaced not long after with a 236 16 when I realized the 15" OE 201 15 did not pass the Two-Inch Rule and was the source of idle instability and stalling on the 340 HP engine.

I'm not aware that a TSB was ever written on this issue, and I find it that surprising as all '63 340 HP engines must have suffered from the same malady. And why didn't GM identify the problem in testing? All I can figure is that replacing the '62 non-VAC dual point distributor with a VAC single point was a fairly late decision. Whoever picked the 201 15 was clueless and there was inadequate testing.

They finally got it right for '64, but '63 owners were on their own to solve the problem.

Duke

[Norm B.]

Re: 63 340HP Distributor Orientation

Thanks Tim, I think I understand what you mean. I was careful to ensure the engine was not disturbed when the distributor was out. I did not know that the oil pump drive could be moved to line it up. I thought it was fixed to whatever drives it. I will give what you suggested a shot tonight or tomorrow and let you know what happens.

As for the Breakerless-SE ignition conversion, yes it was a nice neat and easy installation if I remember correctly. I got it from Lectric Limited back in 2007 ($143) and have not had a lick of trouble with it. I did save the original points, etc. though so I could return it back to original if necessary.

I also finally got in touch with the owner that had the car back in 1966 and had the engine apart. He said he did not change any major components like distributor or cam from the original. I know that I am owner #7 so who knows what happened and when?

[Timothy B.]

Re: 63 340HP Distributor Orientation

Norm,

Don't give up on it, if you walk the oil pump drive around and miss or think you may be on the wrong tooth just go around again. No big deal, you will get the hang of it.

Also, if you have the 069 distributor that's even better for your 340hp car, my thinking is that you should be able to get the vacuum control centered.

[Norm B.]

Re: 63 340HP Distributor Orientation

Mission accomplished. Thanks for all your help guys, I couldn't have done it without you. Thanks for the excellent explanation on the oil pump drive Tim. And Duke, that suggestion of using a paint stick is genius. You can clearly see how the slot is oriented without having to look into the hole with a flashlight. I think I will gather up all my paint sticks in the basement and take them to Carlisle next year. I figure I will put a part number on them, call them "Precision Anti-Magnetic Heavy Duty Oil Pump Drive Alignment Instrument", and sell them for $29.95.

[Duke W.]

Re: 63 340HP Distributor Orientation

Was the dimple in the gear properly oriented?

How about the wire indexing. Was it correct?

If the above two issues were okay then it was just a matter of the distributor being installed improperly, which is a common issue.

Duke

[Norm B.]

Re: 63 340HP Distributor Orientation

Hi Duke. No, the dimple was not oriented properly and I had to drive out the pin and turn the gear 180 deg. I wonder how many people know about that and the fact there is an odd number of teeth on the gear. The wire indexing was ok. Once I found out that the oil pump drive could be moved independently it became just a matter of trial and error to get the distributor to sit down with the rotor in the correct position. Quite a simple task actually once you understand the basics of how it all goes together and have a little patience. Thanks again.

Off topic but one interesting thing that came out of this that was when I called owner #2 a couple of days ago, who had the car in around 1965, I found out that it may have a bit of drag racing history with owner #1 at Cordova in Illinois. Unfortunately he could provide me with no more details than that. Time for me to do some detective work.