63 (64-65 also?) Fuelie Distributor Orientation

[Troy P.]

When I bought my car it had a dent in the vacuum advance canister so the distributor could be turned more counter clockwise toward the fuel injection plenum to set the timing correctly. Didn't look right to me. So during restoration I put on a new vacuum advance. But in order to get the timing for good idle I had to set the distributor one tooth off clockwise to prevent the canister from hitting the plenum. As a result I cannot read the timing using the tab on the timing chain cover.

Recently I was searching past posts on this Discussion Board and came upon discussion of this problem. But the solution was not clear to me. Can someone clarify how to deal with this correctly?

I have verified that the distributor gear is installed correctly and the igniton wires are in the proper location on the distributor cap. The engine was rebuilt and the cam changed before I bought it. Cam is unknown.

I read one post in which it stated that the poster had spoken with a worker at the engine assembly plant that said they used to whack the distributor advance control with a rubber mallet and dent it against the plenum...just like I found mine! Is this the correct procedure?

[Michael G.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Troy,

Most likely you have a reproduction cam. For some reason, some of the cams on the market require that you install the distributor 1/2 tooth off. I know that sounds absurd, but it worked on my car.

The way to do that is take the distributor out, remove the pin holding the gear to the bottom of the distributor, slide the gear off, turn the gear 180 degrees, slide it back on, reinsert the pin, and put it all back together with the rotor pointing between #1 and #8.

I hope that is clear.

[Troy P.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Will that get you back to the timing tab correctly?

Seems to me when I put the new, undented vacuum control in and found that it hit the plenum I pulled the distributor and found the gear was on backwards already. So I put it on correctly as part of my expected solution. So maybe the prevous owner was on the right track but didn't index the distributor correctly when it was reinstalled?

[Duke W.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Installing the distributor gear "correctly" means that the dimple is in line with the rotor tip with a camshaft that has a properly indexed distributor drive gear.

If you are absolutely certain that this is the case and the wires are indexed IAW the 1963 Corvette Shop Manual, then cam gear indexing is suspect, and rotating the gear so that the dimple is facing 180 degrees from the rotor tip should result in proper distributor orientation.

With initial timing in the 8-16 degree range, the VAC should be approximately halfway between the manifold/plenum and wire support interference points and the cap window should be approximately normal to engine centerline.

I've never heard of production workers denting the VAC to get the initial timing correct.

Duke

P.S. I just dawned on me that you are the same member who started the other thread about misfires, so I assume it's the same engine. It's never been clear to me if these electronic switches alter distributor indexing with the same timing, so that may be something else to consider.

[Troy P.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Its been 20 years since I last pulled the distributor and reversed the gear. I know I reversed the gear to get the vac can away from the plenum but I'm not sure whether I set it in the factory direction or turned it 180 degrees. I'll have to pull it and sort it all out. Since then I've been timing it by ear rather than using the timing marks.


Good question about the electronic switch possibly messing up the timing. I don't think it does because I searched the Discussion Board for all threads about Pertronix and no one mentioned that problem.

[Troy P.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

You point it between 1 & 8 rather than at No. 1. Interesting. I assume you do this using the engine disturbed procedure - No. 1 on the compression stroke TDC? Correct?

[Michael G.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Yup, with #1 on TDC compression. The reversed gear will allow you to insert the distributor with the rotor several degrees counter-clockwise from its normal position at TDC compression. You will then be able to rotate the distributor farther to set timing, without hitting the plenum.

[Duke W.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Set the engine at the initial timing point on the #1 compression stroke, NOT TDC!!!

The rotor should be pointed at no. 1. cap terminal. When you withdraw the dist. the rotor will rotate CCW and be about parallel to engine centerline when the gears clear.

Upon installation start with rotor tip pointing approximately parallel to engine centerline. As the gears mesh the rotor should move CW and end up about 20-22 degrees right of engine centerline. If it won't seat properly, the oil pump drive needs to be tweaked. Look at the bottom of the dist. with the rotor pointing along engine centerline and the VAC properly oriented and tweak the pump drive slot to align it with the pin.

Now, with points, you either visually or using an ohmmeter rotate the dist. until the points just begin to open (visually) or until the meter connected between the coil neg. terminal and ground shows open circuit. This is called static timing. With a little experience the timing should be within a degree or two of your target, which is where you set the balancer notch on the timing tab.

I dont' know if it's statically possible to determine when an electronic switch opens, so in this case set the dist. housing such that the VAC is about halfway between the interference points or a bit further CCW. This should get the initial in a range that will allow the engine to start.

You should now be able to start the engine. A timing light activated during cranking should allow to you see initial timing and you can tweak the dist. if it's not somewhere between about TDC an 18.

Once the engine has started, set the initial timing at a speed BELOW where the centrifugal starts with the VAC disconnected or set it at about 38 at a speed ABOVE where the centrifugal is all in. The beginning and ending
revs of centrifugal advance are in the AMA specs and service manuals, but they should be VERIFIED with a dial back timing light as it was common to change them back in the day and to this day.

Timing "by ear" can be very inaccurate except for those very experinced at the task. There is really no substitute for a timing light, and nowadays a decent dial back timing light can be had for about 50 bucks if you don't have a buddy you can borrow one from.

Duke

[Troy P.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

I've got a dial back light but haven't been able to use it on this car since it doesn't flash anywhere near the timing tab.

Previously it was suggested that I need to set the distributor 1/2 tooth off by turning the distributor gear and then set the rotor to point between 1 & 8. Now you are saying to go to 1, which is the normal approach.

[Duke W.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Then the timing must be no where near correct or you can't make out the notch on the balancer, which is a common issue. The last one I checked I rubbed a yellow tire crayon crosswise along the length of the notch that made a nice easy to see yellow line.

Duke

[Jerry G.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

It is possible to statically align the distributor with this electronic setup. You can "see" a closing of the circuit with a Volt ohm meter. It's how I do the race car to get a starting point. Jerry

Set the engine at the initial timing point on the #1 compression stroke, NOT TDC!!!

The rotor should be pointed at no. 1. cap terminal. When you withdraw the dist. the rotor will rotate CCW and be about parallel to engine centerline when the gears clear.

Upon installation start with rotor tip pointing approximately parallel to engine centerline. As the gears mesh the rotor should move CW and end up about 20-22 degrees right of engine centerline. If it won't seat properly, the oil pump drive needs to be tweaked. Look at the bottom of the dist. with the rotor pointing along engine centerline and the VAC properly oriented and tweak the pump drive slot to align it with the pin.

Now, with points, you either visually or using an ohmmeter rotate the dist. until the points just begin to open (visually) or until the meter connected between the coil neg. terminal and ground shows open circuit. This is called static timing. With a little experience the timing should be within a degree or two of your target, which is where you set the balancer notch on the timing tab.

I dont' know if it's statically possible to determine when an electronic switch opens, so in this case set the dist. housing such that the VAC is about halfway between the interference points or a bit further CCW. This should get the initial in a range that will allow the engine to start.

You should now be able to start the engine. A timing light activated during cranking should allow to you see initial timing and you can tweak the dist. if it's not somewhere between about TDC an 18.

Once the engine has started, set the initial timing at a speed BELOW where the centrifugal starts with the VAC disconnected or set it at about 38 at a speed ABOVE where the centrifugal is all in. The beginning and ending
revs of centrifugal advance are in the AMA specs and service manuals, but they should be VERIFIED with a dial back timing light as it was common to change them back in the day and to this day.

Timing "by ear" can be very inaccurate except for those very experinced at the task. There is really no substitute for a timing light, and nowadays a decent dial back timing light can be had for about 50 bucks if you don't have a buddy you can borrow one from.

Duke

[Troy P.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

I put a white line on mine 23 years ago. Still there.

[William C.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Or the incorrect timing cover has been installed. If the engine runs, the timing mark should hit the tab somewhere if you accurately have identified the #1 plug wire...

[Joe M.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

A first step is to use a piston stop to find TDC in an effort to make sure your timing mark lines up with the line on the timing tab.

I had a heck of a time checking the timing on my 63 FI with the idler pulley and air cleaner in the way.

[Troy P.]

Re: 63 (64-65 also?) Fuelie Distributor Orientation

Funny you should mention that, Bill. Years ago when I tried to sort out this problem that was one of my thoughts as well. Still I don't know the answer because I don't know what a 63 fuelie timing cover should look like.