66 TI question

[Tim L.]

My project 66 L79 has the transistorized ignition option. I have the original distributor and have found the TI module in a box. The distributor looks to be in good condition, but the module has a broken mounting ear. Doing research on TI it seems like it works great or it has troubles.

I'm doing a correct restoration on the car, but do not plan on Flight Judging. I do plan on driving the car. My question is: Should I go forward with the TI, or go back to conventional points? Can the TI distributor be used for points?

If I continue with TI, I know the circuit board needs to be upgraded. What's the best approach to rebuild/check distributor? I am unfamiliar with TI.

Any insight is greatly appreciated.
Tim

[Mark F.]

Re: 66 TI question

Tim,

Dave Fiedler of TI specialties can rebuild your box with newer and improved circuitry.
he can also do your distributor (if you like).
He redid both of mine in 1999ish(?) and I have never had a problem since

http://www.tispecialty.com/index.htm

[Carl N.]

Re: 66 TI question

Tim, Mark has provided contact for R&R of module and distributor. These units are very sensitive. If you stay with it, IMO rebuild the
he distributor and buy a new wiring harness from the module to distributor. I redid all of mine on '65 L78 in 1988, drive it weekly and it has worked great. For the money it cost today to R&R back to TI you may wish to consider one of the pointless systems like Pertonix. Very few mechanics are left that have any idea of what the early TI systems consist of, dealership will not have a clue. Keep it all dry if you pressure wash the engine bay ! And remember all the wiring in the original TI harness may be corroded and brittle. IF you switch back to TI make sure plugs are new, plug wires are good, timing is correct, valve lash correct before you switch over. Also be sure vacuum advance is correct and you may have to play with springs on mechanical advance if they have been changed in the past. Good luck !

[Ray K.]

Re: 66 TI question

Tim,
I would suggest that you try to retain the TI system. Purchase a new harness as Carl suggested and maybe a new circuit board for the amplifier, just so that you have one in case it is needed. Even with a broken ear on the amp box I would put it all together and see if the engine would fire. If is does - great. If not, than replace the amp circuit board and try again. Also as Carl stated, new plugs, good wires and correct timing.

Ray

[Duke W.]

Re: 66 TI question

If it was me and I planned to not have the car judged and use it as a typical vintage car that accumulates a few hundred to a few thousand miles per year I would go to points. Both the TI and single point system used the exact same finish machined housing. To make the conversion you'll need a breaker plate to replace the stationary pole piece, a cam assembly to replace the rotating pole piece, a ballast resistor, a ...202 or equivalent ignition coil, and probably some wiring changes. You can even buy a band with the part number of the single point distributor to replace the band with the TI distributor part number. Study the AIM and CSM wiring diagrams, and don't make any changes you can't easily undo. There's a dimple in the dash that was drilled for the ballast, but I was not drilled for TI, and you can probably figure out a way to mount the ballast without drilling the dimple.

Since it's an original TI car keep the amp harness and parts you swapped out of the distributor for future owners if they want to convert it back to TI.

I had a TI system (from the '67 12-mile L-88) on my SWC from '68 to '75. The original owner didn't want it. I tried to convince him that it was better than the Joe Hunt magneto he wanted that was a modified version of a Vertex magneto that actually had breaker points, but he wouldn't listen. I was always having a problem with the ignition in my 327/340 breaking up at as little 4500 revs, so I offered him the option price on the window sticker and he said "deal".

It worked perfectly, but one day in 1970 the engine cranked but wouldn't fire. Testing showed no spark, so I removed the amp, removed the rear cover and found that a wire from the main power transistor that's mounted to the die cast heat sink housing had broken away from the circuit board. So I pushed the wire back into the via, added a drop of solder, put the cover on and the amp back on the car and it fired right up.

It worked perfectly for the next couple of years (I had to store it from '71 to '75) and then a few months after retrieving it from storage I had another no-start condition. At that point I had learned how to make the OE single point distributor give a reliable spark to 7000 revs, so I pulled out the TI and put the single point back in.

Later I set up the TI on the bench with a 12V motorcycle battery and an electric drill to rotate the distributor and quickly found the problem was some corrosion on a terminal in the amp connector, which I quickly cleaned up, and the system tested good. Before I started the repair it was my intention to never reinstall the TI system back on my SWC, but I knew it was "special" because it came off one the 20 1967 L-88s. I reconfigured it with all the original parts, brown cap, VAC with the clipped off nipple, centrifugal weights and springs, and put it in a box.

In 1988 I became acquainted with a '67 L-88 owner who lived not to far from me and told him the story. He knew David Burroughs who at the time owned the L-88 that the TI system had come from and asked me if he could give Burroughs my contact info. I said sure because I wanted to see the system go back on the car it came from. At that time fake L-88s were beginning to show up and I didn't want this system to fall into the wrong hands.

Burroughs called and I said I was willing to sell, but didn't know what the system was worth. So he rattled off values for the distributor, amp, and harness, which I added up to be ten times what I paid and agreed to sell it.

The nice thing about these vintage Corvettes is that they are SIMPLE... simple electromechanical analog systems that are easy to troubleshoot and inexpensive to repair. A set of points should last at least 15K and up to 30K miles. Yeah, it's a good idea to check dwell and timing every few thousand miles to keep the car it top tune, and a lot of guys have a small bag of spare parts and tools including a set of points, condenser, and maybe a coil, so if the single point system ever quits you can probably fix it by the side of the road. You can't do that in a modern car, and in my experience, unlike electronic systems that can fail suddenly without warning, the single point system usually gives you plenty of warning that it is sick and needs attention.

Duke

[Tim L.]

Re: 66 TI question

Mark, Carl & Ray - Thanks for the input. I've never seen the car run, it's been off the road since '77. I'm starting from scratch and would be replacing all wiring. More concerned about the reliability and ease of maintenance. Have some thinking to do.
Tim

[Tim L.]

Re: 66 TI question

If it was me and I planned to not have the car judged and use it as a typical vintage car that accumulates a few hundred to a few thousand miles per year I would go to points. Both the TI and single point system used the exact same finish machined housing. To make the conversion you'll need a breaker plate to replace the stationary pole piece, a cam assembly to replace the rotating pole piece, a ballast resistor, a ...202 or equivalent ignition coil, and probably some wiring changes. You can even buy a band with the part number of the single point distributor to replace the band with the TI distributor part number. Study the AIM and CSM wiring diagrams, and don't make any changes you can't easily undo. There's a dimple in the dash that was drilled for the ballast, but I was not drilled for TI, and you can probably figure out a way to mount the ballast without drilling the dimple.

Since it's an original TI car keep the amp harness and parts you swapped out of the distributor for future owners if they want to convert it back to TI.

I had a TI system (from the '67 12-mile L-88) on my SWC from '68 to '75. The original owner didn't want it. I tried to convince him that it was better than the Joe Hunt magneto he wanted that was a modified version of a Vertex magneto that actually had breaker points, but he wouldn't listen. I was always having a problem with the ignition in my 327/340 breaking up at as little 4500 revs, so I offered him the option price on the window sticker and he said "deal".

It worked perfectly, but one day in 1970 the engine cranked but wouldn't fire. Testing showed no spark, so I removed the amp, removed the rear cover and found that a wire from the main power transistor that's mounted to the die cast heat sink housing had broken away from the circuit board. So I pushed the wire back into the via, added a drop of solder, put the cover on and the amp back on the car and it fired right up.

It worked perfectly for the next couple of years (I had to store it from '71 to '75) and then a few months after retrieving it from storage I had another no-start condition. At that point I had learned how to make the OE single point distributor give a reliable spark to 7000 revs, so I pulled out the TI and put the single point back in.

Later I set up the TI on the bench with a 12V motorcycle battery and an electric drill to rotate the distributor and quickly found the problem was some corrosion on a terminal in the amp connector, which I quickly cleaned up, and the system tested good. Before I started the repair it was my intention to never reinstall the TI system back on my SWC, but I knew it was "special" because it came off one the 20 1967 L-88s. I reconfigured it with all the original parts, brown cap, VAC with the clipped off nipple, centrifugal weights and springs, and put it in a box.

In 1988 I became acquainted with a '67 L-88 owner who lived not to far from me and told him the story. He knew David Burroughs who at the time owned the L-88 that the TI system had come from and asked me if he could give Burroughs my contact info. I said sure because I wanted to see the system go back on the car it came from. At that time fake L-88s were beginning to show up and I didn't want this system to fall into the wrong hands.

Burroughs called and I said I was willing to sell, but didn't know what the system was worth. So he rattled off values for the distributor, amp, and harness, which I added up to be ten times what I paid and agreed to sell it.

The nice thing about these vintage Corvettes is that they are SIMPLE... simple electromechanical analog systems that are easy to troubleshoot and inexpensive to repair. A set of points should last at least 15K and up to 30K miles. Yeah, it's a good idea to check dwell and timing every few thousand miles to keep the car it top tune, and a lot of guys have a small bag of spare parts and tools including a set of points, condenser, and maybe a coil, so if the single point system ever quits you can probably fix it by the side of the road. You can't do that in a modern car, and in my experience, unlike electronic systems that can fail suddenly without warning, the single point system usually gives you plenty of warning that it is sick and needs attention.

Duke

Thank you Duke for the opinion. Good to know my distributor will work with changes you stated. Your last paragraph is probably why I posted the question. I'm starting to lean towards converting it to single point system and of course keeping all the TI components for the next caretaker.

Great story on the L-88 TI.

Tim

[Jimmy G.]

Re: 66 TI question

I will add my opinion. I guess I am old school. I have had several cars with TI. They work well when they work. Problem is that they can die in an instant so if you rum a TI make sure you have a back up amp - preferably solid state. I prefer old fashion points. If they die in the middle of nowhere any mechanic can install a new set (kept in the car at all times). I am not at max performance anymore so points work well for me. I went coast to coast in a 60 (7000+ miles) with points and no issues. I had a TI car fail me in the driveway. TI is good --- just have spare parts.

[John D.]

Re: 66 TI question

Tim, Contact Don Baker if you would like you TI distributor restored. You will be pleased. Quite affordable also. Reach him at 815-498-9522.
John D.

[John D.]

Re: 66 TI question

Now for an old story for your amusement. I had a new 66 BB convertible with side exhaust and the works.
The TI was so unreliable. I went thru two TI boxes and then my Dad complained to the dealer that my poc Corvette cost more that his new Cadillac. He was the dealers friend.
Dad did this on his own. One day I came home from work and on the kitchen table was a new TI box. Dad got it from the dealer as a loner to keep in my car if mine broke down again. True story. JD