Ignition failure warning to all owners

[Duke W.]

I guess most are more interested in mice and fake tankers than optimizing distributors, but I want to direct your attention to the following thread and what happened with the breaker plate ground wire. On it's own it only got 141 views, but everyone should be aware of this issue as it can leave you stranded.

https://www.forums.ncrs.org/showthre...print-overhaul

Duke

[Michael J.]

Re: Ignition failure warning to all owners

That is good advice Duke, especially for people who have not done anything inside their distributors for many years. I try to routinely inspect all those hidden parts and wires regularly, just like belts and hoses, things don't last forever. But the mice stuff was fun to chatter about anyway.....

[Edward J.]

Re: Ignition failure warning to all owners

Duke Just to add to your post, being in the automotive repair business, I have also seen this many times even with the HEI distributors. These to can be problems with hardened coating on the wires of the pole piece, as with the point type dist. The vacuum advance rotating the breaker plate will break the harnesses and strand you.I am sure even the T.I. distributors are the same.

[Stuart F.]

Re: Ignition failure warning to all owners

I have seen hardened grounds and leads cause the VAC to hang/stick the plate, not so much with OEM, but aftermarket and conversions. I have replaced both with silicon jacketed wires. I am sensitive to this and tipping plates as they were the very first problems I dealt with back in 1956 on my 55 V8 installation in my 50 coupe. I also use Dyneflite ball bearing plates because of this.

Stu Fox

[Clem Z.]

Re: Ignition failure warning to all owners

since this is a ground wire just use some bare braided cable that is very flexible

[William C.]

Re: Ignition failure warning to all owners

BTW, that plate is the same on all chevy V-8 V8 distributors from 1958 up until they switched to HEI. Not to hard to find and have one in stock..

[Gene M.]

Re: Ignition failure warning to all owners

Duke,
I see your point. This site is not as fully technical as I would prefer. But in fairness to other that do not get as technical and have dirty hands and scratched up knuckles they have interests too. Not all, in-fact a minority are getting down and dirty doing everything on their cars. Talk to members at meets and you will find most Corvettes are "prepared" by paid professional shops. Not my cup of tea but it is what it is...........

[Duke W.]

Re: Ignition failure warning to all owners

BTW, that plate is the same on all chevy V-8 V8 distributors from 1958 up until they switched to HEI. Not to hard to find and have one in stock..

I'm not aware that the single point breaker plate is available from GM or the aftermarket. The number I have from a '77 vintage Corvette P&A catalog is 1962141, but I believe it's discontinued.

Do you have any brand/part number data?

Duke

[Ray G.]

Re: Ignition failure warning to all owners

Duke;
Always read your posts and agree with you this is a critical potential failure area. One of the first items to be looked at when tuning an engine.
Over the years when describing distributor wire failures to fellow Chevrolet owners, I often get a "eyes glazed over" response, unless they have actually worked on distributors.
Have gotten to the point (no pun intended) of having friends bring their cars to me for point & condenser replacement. It is easier than trying to talk them through the procedure.
Ray

[George J.]

Re: Ignition failure warning to all owners

Duke,
Please make this a restorer article. An expanded version with pictures of how to adjust and/or check endplay would also be welcomed. Some of us didn't grow up doing these things, and it is hard to find someone to physically show us. I had my distributor rebuilt by one of the best, but that doesn't help me with long term maintenance, or verification of being in-spec.

George

[Duke W.]

Re: Ignition failure warning to all owners

We didn't take any photos. Overhauling the distributor is relatively simple. The '63 Corvette Shop Manual has the step by step assembly/disassembly procedure and an exploded view diagram.

Set the dwell angle to 30 degrees and mark the balancer slot to be sure you can see it against the timing tab.

Set the engine at the correct initial timing point with the rotor pointing to #1 on the cap. It's best to mark the wire numbers because you need to remove at least four to get the cap out of the way.

Loosen the hold down bolt enough to pull the hold down bracket all the way back, clear of the housing. As you remove the dist. the rotor will rotate and be nearly in line with engine centerline when the gears clear.

Check side play. It should be nearly imperceptible. Measure end play with a stack of feeler gages. This one was .043", so .040" additional shims is what was required to get it into the 2-7 thou range.

Use a thick bladed putty knife or similar tool to remove the tach gear housing.

Tap out the roll pin with a 1/8" punch and remove the gear and shaft. Then remove the rotor, springs, weights, and slide the cam assembly off the bottom of the shaft'

Remove the front VAC screw that secures the breaker plate ground wire, then use a dental currette or similar tool to remove the wavy spring clip that secures the breaker plate to the housing and remove the breaker plate.

Remove the rear VAC screw and the VAC. Then remove the felt washer and use the dental currette to carefully remove the plastic grease well seal. Now the dist. is "field stripped" for cleaning and inspection. Of course, with an FI distributor you have to deal with the pump drive. I've never done one, but the shop manual is your friend.

If you don't have any of the 1960954 grease, use a full synthetic NGLI #2 grease for the grease well and tach drive gears. When you get to installing the bottom gear, add the extra shim thickness you calculated, then look into the hole to ensure that the pin will go through and tap it back in. Be sure the gear dimple is in line with the rotor tip!!!

Begin installing the dist with the rotor aligned to engine centerline - where it was when the gears cleared on removal. Use a paint stirring stick to tweak the pump drive slot if necessary to get the dist. to seat.

Once the dist. is seated tighten the hold down clamp just enough so you can still move the dist. with a little resistance, and rotate it CCW to where it interferes with the plug wire bracket. While observing the points, rotate the dist. CW until the points just begin to open then back a hair. You can also use an ohmmeter between the coil negative terminal and ground. Once the circuit opens you are there, and the initial timing should be within a degree or two or where you set the balancer notch on the timing tab.

The engine should now start, so you can set the dwell, timing, take the new spark advance map, etc.

Duke

[George J.]

Re: Ignition failure warning to all owners

Duke,
thanks. Saved and printed.

George

[Duke W.]

Re: Ignition failure warning to all owners

I did a little editing, so be sure you have the final version of the post.

Duke

[Terry M.]

Re: Ignition failure warning to all owners

Duke,
Please make this a restorer article. An expanded version with pictures of how to adjust and/or check endplay would also be welcomed. Some of us didn't grow up doing these things, and it is hard to find someone to physically show us. I had my distributor rebuilt by one of the best, but that doesn't help me with long term maintenance, or verification of being in-spec.

George

George,
The distributor repair situation is worse than "not having grown up with them." The number of folks who have grown up with distributors is dwindling daily. Do you know how long it has been since an engine was factory built with a points type distributor? For Corvette it is 1973, and I doubt any other manufacturer is much after that. And yes I know the distributor without points went on to 1996 or so. We (my community college Automotive Department) quit teaching rebuilding distributors (carburetors, starters and alternators too) almost two decades ago. If that is typical of automotive education, and I think it is, finding an automotive technician who even recognizes those parts would now present a challenge. Your alternative? Do it yourself. While it does require some skill and knowledge, it is not rocket science. (No offense intended to the rocket scientists in our membership.) Duke has gone a long way toward opening that door for all of us. The Factory Service Manuals (FSM) have extensive information on all of the above.

[William C.]

Re: Ignition failure warning to all owners

One small correction, I think that '74 owners might be very suprised to not find points under the distributor cap. I made beer money doing performance enhancements on the 73-74 distributors.