67 Transistor Ignition amplifier

[Hector G.]

Working on the 67 today and made the following discovery regarding my 67'sTransistor Ignition pulse amplifier (TI). First some background:


For the last year or so, I've been busy documenting and preparing my 67 for NCRS future meets. IMHO, it is a remarkable low mileage, 15 k, L71. Tank sticker still on the car. The original, born with parts and components are impressive. The car was sold at BOB SALTER'S Chevrolet in Pensacola, FL. It is now Sandy Chevrolet.

As a side note, if anyone knows about the dealership and it's history, I would appreciate the information. My understanding is that it was a dealership that sold quite a few cars to naval pilots earning their wings.

Back to the story. In cleaning and documenting the car, I noticed that the configuration of my TI was inconsistent with the 67, 5th Edition, Corvette TIM & Judging Guide (Guide). The Guide describes the TI's rear access plate as being "...gold cadium with the outside edges rolled rather than flat like later models and current replacements." I was disappointed but not surprised since how likely was it that the original TI would still be on the car and working. So I proceeded to remove the TI and to my surprise I saw the following information stamped on the back of the plate. 7D13 or 7D17. Which I interpret as April 13 or 17 of 67. Not absolutely sure about the very last digit.DSC08884.JPG

My Car's production date is April 27, 1967. That got me thinking. Better do some more research. Called Dave Fiedler and he told me that some plates did in fact have a date stamped on them and that my guess regarding stamped info was correct. By the way, Dave is a wonderful person. He took the time to explain this information to me despite being busy. He also told me that the back of the internal circuit board would have date stamped diodes (I forget what Dave called them. I'm calling them diodes) Sure enough they have GM part #s and dates.DSC08899.JPGDSC08898.JPG DSC08902.JPG6L25, interesting enough, would be, in my opinion, December 25, 1966! And 6J23, would be October 23, 1966. One of the resistors on the front board has a date as well. I believe 6G2.

Dave explained to me that the rear access plate changed from the rolled edges to the flat plate in January 1967 which is consistent with my findings.

My humble conclusion is that the Guide is partially correct as to the configuration of the rear access plate for the 67 Corvette. A flat plate is also correct depending on the car's year of production.

CAVEAT: I have not been able to obtain the latest version of the 67 Guide. Does anyone know if the Guide has changed as to the configuration of the rear access plate?

Thanks once again Dave. Hope you don't mind me mentioning your help. You're a gentleman, extremely knowledgeable in your craft and a wonderful source of information. I will definately being using you services in the future


Hector

[Richard M.]

Re: 67 Transistor Ignition amplifier

Hector, In January I was told that the JG will be updated to clarify the backplate information. I'm not sure if it will be in the latest JG though.

For reference, here is a post from last fall when I was working on a 1967 TI system showing the transistors and dates.

https://www.forums.ncrs.org/showthread.php?108979-1967-Body-Lift-for-Chassis-amp-Frame-Restoration&p=754842&highlight=transistor#post754842

One thing.....I'm thinking both you and I got the transistor date codes wrong. I think a "L" date code is actually November. Delco's Indiana transistor manufacturing facility probably eliminated the letter "I". I think your 6L25 is actually November 25, 1966. I think December would have been "M".

Rich

[Duke W.]

Re: 67 Transistor Ignition amplifier

...don't know if you're aware Hector, but I had the TI system from the "12-mile L-88" on my SWC for several years. It failed twice, so I had to remove the cover from the amp to repair, which turned out to be easy. The second failure was likely moisture related, which opened up one of the terminals on the amp connector, which was another easy fix - just cleaned all the terminals. At that point I removed the system from my car, and it sat in a box for over ten years until I sold it in 1988 to David Burroughs who owned the "12-mile L-88" at the time. I was happy to see it reinstalled on the original L-88 that it had come from.

That L-88 was delivered to my U. of Washington ME classmate in May '67, so the build date is likely very close to yours.

Type II cad (gold) fades over time to a dull brown or even a dull silver. From the photo I can see what appears to be some faded gold "splotches" and one area that appears to be rusted, which means the plating is completely gone in that area.

I've also got some comments/questions on the configuration of the circuit board and components, so I'll call you this evening to discuss.

Duke

[Joe R.]

Re: 67 Transistor Ignition amplifier

Duke,

Is that one called the Lincoln L-88?

JR

[Hector G.]

Re: 67 Transistor Ignition amplifier

Yes Duke, there is a faded area on the back of the plate. The inside is remarkably clean and shows no signs of fading. The gasket is also in very good shape. Looking forward to your call Duke. Just learning about the TI.

Thanks Rich. Just finished looking at some of you previous posts. Very interesting.

[Wayne M.]

Re: 67 Transistor Ignition amplifier

This TSB mentions Nov '67 for the new gasket design and silicone grease for the plug cavity (flat back plate on the unit on the right ) -- don't know what the new '67 TIM&JG says. Without searching, I believe there's an earlier Service News mention of the new back plate.

[Duke W.]

Re: 67 Transistor Ignition amplifier

I specifically recall that the 12-mile L-88 had the early narrow gasket even though is was probably built in April. That's not unusual because the TI was a low volume option, so the amp may have been several months old before it got installed.

I remember when I was in the Van Nuys plant for the Firebird pilot line in August '68 I ran across a whole bin of them that must have contained several hundred - probably months worth of production.

The second failure I had circa 1976 was due to moisture getting into the external connector, which caused exfoliation corrosion on the terminals leading to one open circuit.

I suppose the 12-mile L-88 could be referred to as the "Lincoln Corvette". The original owner ended up selling it to Lincoln Auto Parts in Seattle who specialized in Corvette salvage after his project to turn it into the "ultimate drag racer" failed. His wife divorced him, he lost his job at Boeing and was broke. I lost touch with most of my old buddies in Seattle by the early seventies. I was 1500 miles away and too many things going on in my life. I found out what happened to the car from an article in Corvette News in the mid seventies.

As I read it and realized the connection I practically broke into a cold sweet... one of those OH SH...T! moments. I knew what the car and the objetive meant to the original owner. It was his life's ambition. The car was still in a partially disassembled state as I remembered it from the late sixties. - engine, drivetrain and rear suspension removed. One photo showed it being moved with a fork lift. I almost had a heart attack!

It was quickly sold to someone in Minnesota, then Burroughs bought it a few years later. I think he sold it to Roger's Corvettes in Florida about 15-20 years ago via the Bloomington auction for about about $600K. I understand a year or too ago it was sold privately to a collector in Chicago for well over $3 million.

Some have asked me why I didn't buy it. For one thing by the time I found out it was gone, but even if I knew about it before the original owner sold it to Lincon I probably would have passed. I knew it was totally unsuitable for road driving, and I couldn't afford to race a Corvette much less the cost of prepping it for SCCA A- production.

That was within a few years of me moving to California. I bought a house and a new Cosworth Vega a couple of years later. I was racing a TR-3 in SCCA E-production, working full time (USAF), attending the UCLA graduate business school, and thinking about restoring my SWC. I also had a GF who understood that I was only available from early Saturday evening to early Monday morning, most, but not all weekends. I was tapped out financially and timewise.

I didn't even own a TV back then - no time to watch. When I did have time to kick back I listened to classic rock on my killler stereo/quad system and drank beer, which I still do. The Pioneer QX-949 quad receiver/amp and open reel Akai tape and turntable have been replaced with a modern receiver/amp and CD player, but the four Pioneer CS-901 speakers are still in their respective corners the the great room in the Disco Palace. Recently I found a dead super tweeter in one of them, and, amazingly, found two exact replacements on ebay for thirty bucks.

Nothing's changed other than having more free time in retirement.

Duke

[Joe R.]

Re: 67 Transistor Ignition amplifier

Duke,

I would also bet that you were not ready to step up to the plate when you discovered that the original engine was long gone!!!!! Somewhere in a boat by that time!!!

JR

I specifically recall that the 12-mile L-88 had the early narrow gasket even though is was probably built in April. That's not unusual because the TI was a low volume option, so the amp may have been several months old before it got installed.

I remember when I was in the Van Nuys plant for the Firebird pilot line in August '68 I ran across a whole bin of them that must have contained several hundred - probably months worth of production.

The second failure I had circa 1976 was due to moisture getting into the external connector, which caused exfoliation corrosion on the terminals leading to one open circuit.

I suppose the 12-mile L-88 could be referred to as the "Lincoln Corvette". The original owner ended up selling it to Lincoln Auto Parts in Seattle who specialized in Corvette salvage after his project to turn it into the "ultimate drag racer" failed. His wife divorced him, he lost his job at Boeing and was broke. I lost touch with most of my old buddies in Seattle by the early seventies. I was 1500 miles away and too many things going on in my life. I found out what happened to the car from an article in Corvette News in the mid seventies.

As I read it and realized the connection I practically broke into a cold sweet... one of those OH SH...T! moments. I knew what the car and the objetive meant to the original owner. It was his life's ambition. The car was still in a partially disassembled state as I remembered it from the late sixties. - engine, drivetrain and rear suspension removed. One photo showed it being moved with a fork lift. I almost had a heart attack!

It was quickly sold to someone in Minnesota, then Burroughs bought it a few years later. I think he sold it to Roger's Corvettes in Florida about 15-20 years ago via the Bloomington auction for about about $600K. I understand a year or too ago it was sold privately to a collector in Chicago for well over $3 million.

Some have asked me why I didn't buy it. For one thing by the time I found out it was gone, but even if I knew about it before the original owner sold it to Lincon I probably would have passed. I knew it was totally unsuitable for road driving, and I couldn't afford to race a Corvette much less the cost of prepping it for SCCA A- production.

That was within a few years of me moving to California. I bought a house and a new Cosworth Vega a couple of years later. I was racing a TR-3 in SCCA E-production, working full time (USAF), attending the UCLA graduate business school, and thinking about restoring my SWC. I also had a GF who understood that I was only available from early Saturday evening to early Monday morning, most, but not all weekends. I was tapped out financially and timewise.

I didn't even own a TV back then - no time to watch. When I did have time to kick back I listened to classic rock on my killler stereo/quad system and drank beer, which I still do. The Pioneer QX-949 quad receiver/amp and open reel Akai tape and turntable have been replaced with a modern receiver/amp and CD player, but the four Pioneer CS-901 speakers are still in their respective corners the the great room in the Disco Palace. Recently I found a dead super tweeter in one of them, and, amazingly, found two exact replacements on ebay for thirty bucks.

Nothing's changed other than having more free time in retirement.

Duke

[Duke W.]

Re: 67 Transistor Ignition amplifier

I've never sorted out from the various stories what happened to the original block, but I think it disappeared when the car was in Minnesota.

Duke