Relays
Race Director
Joined: Oct 2008
Posts: 19,185
Likes: 1,669
From: Long Island
TCS relays.
Pollution control, controls the solenoid's for vacuum advance and transmission shifting to "simplify the system" explanation.
Controls the spark advance and idle stop solenoids. Also dependent on transmission - low and high gear + engine temp...
Pollution control, controls the solenoid's for vacuum advance and transmission shifting to "simplify the system" explanation.
Controls the spark advance and idle stop solenoids. Also dependent on transmission - low and high gear + engine temp...
Last edited by BLUE1972; Jan 12, 2016 at 01:52 PM.
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
They are the CEC relays. They are not made anymore and if yours work you could sell them. One is a time delay relay and the other is a reversing relay. It is a 71 only part.
Team Owner
Joined: Sep 2006
Posts: 31,226
Likes: 4,313
From: Westminster Maryland
Hi,
The one mounted forward is the Reversing Relay, and the one to the rear is the Delay Relay.
They're one year only parts and are critical to people interested in getting the CEC system operating.
The additional parts of the system are:
1. A vacuum/electrical solenoid mounted on a small bracket on the left front of the carburetor.
2. A temperature sensor mounted between the #6-#8 spark plugs in the right side head.
3. A sensor in the in transmission that is active when the transmission is in 3rd and 4th gears.
Regards,
Alan
Carb Solenoid:
Temperature Sensor in right side head:
Transmission sensor:
The one mounted forward is the Reversing Relay, and the one to the rear is the Delay Relay.
They're one year only parts and are critical to people interested in getting the CEC system operating.
The additional parts of the system are:
1. A vacuum/electrical solenoid mounted on a small bracket on the left front of the carburetor.
2. A temperature sensor mounted between the #6-#8 spark plugs in the right side head.
3. A sensor in the in transmission that is active when the transmission is in 3rd and 4th gears.
Regards,
Alan
Carb Solenoid:
Temperature Sensor in right side head:
Transmission sensor:
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
DUB
Race Director
Joined: Oct 2008
Posts: 19,185
Likes: 1,669
From: Long Island
The trans switch was activated in high gear, both auto and 4 speed and in reverse.
This is for all small V8's.
Last edited by BLUE1972; Jan 12, 2016 at 08:33 PM.
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Team Owner
Joined: Sep 2006
Posts: 31,226
Likes: 4,313
From: Westminster Maryland
Hi,
There ARE two different systems….'TCS' for 70 and 72 and 'CEC' for 71.
There is somewhat different hardware used for the 3 years.
For example the 70 TCS system doesn't use a solenoid on the carb, the 71 carb solenoid has both mechanical and vacuum functions, while the 72 carb solenoid has just a mechanical function.
So many of these systems were disabled, and hardware removed early in
car's lives that assembling the particular parts needed for each year's system can be a challenge.
Regards,
Alan
There ARE two different systems….'TCS' for 70 and 72 and 'CEC' for 71.
There is somewhat different hardware used for the 3 years.
For example the 70 TCS system doesn't use a solenoid on the carb, the 71 carb solenoid has both mechanical and vacuum functions, while the 72 carb solenoid has just a mechanical function.
So many of these systems were disabled, and hardware removed early in
car's lives that assembling the particular parts needed for each year's system can be a challenge.
Regards,
Alan
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
This is a good read if you are curious about the CEC system. It starts on page 4.
http://ncrsrmc.org/Downloads/Mar-2006-Newsletter.pdf
http://ncrsrmc.org/Downloads/Mar-2006-Newsletter.pdf
Last edited by Sigforty; Jan 13, 2016 at 10:44 AM.
Team Owner
Joined: Sep 2006
Posts: 31,226
Likes: 4,313
From: Westminster Maryland
Hi Sf,
I agree that that article by Jack Humphrey has really helped 71 owners over the years.
Here's a publication that contains even more information and was issued by Chevrolet in 71.
I see them on the bay on occasion for not much $.
Regards,
Alan
There are 11 pages on just the CEC system.
I agree that that article by Jack Humphrey has really helped 71 owners over the years.
Here's a publication that contains even more information and was issued by Chevrolet in 71.
I see them on the bay on occasion for not much $.
Regards,
Alan
There are 11 pages on just the CEC system.
Team Owner
Joined: Sep 2006
Posts: 31,226
Likes: 4,313
From: Westminster Maryland
Hi Sf,
Good for you!
I bought something for my 'glove box' items and the fellow tossed the pamphlet I have in as a freebie.
It's one of those things that is of no interest to anyone except someone trying to get a 71 system operating properly.
Regards,
Alan
Good for you!
I bought something for my 'glove box' items and the fellow tossed the pamphlet I have in as a freebie.
It's one of those things that is of no interest to anyone except someone trying to get a 71 system operating properly.
Regards,
Alan
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
And it is odd that GM took these systems out entirely in future years....which is why I really do not care if they are installed or not when a Corvette comes in the shop.....unless the customer wants all the parts on the car because they are going for purity. Like it has been mentioned...in most cases the system has been dismembered in some fashion.
DUB
DUB