1970 bb coupe engine restoration

[Terry M.]

Re: 1970 bb coupe engine restoration

Now THAT should be an interesting one.... ... which is hopefully many, many years away.

I certainly hope so Patrick, but I am looking forward to the service. I just have to tie up some loose ends so my wife has no choice in the matter. She doesn't share my point of view on such things.

[Chuck Z.]

Re: 1970 bb coupe engine restoration

Not trying to steal this thread but my eye was caught by the discussion of the TCS. I am the original owner (ordered it in June 1969 expecting to take delivery in late September but we all know about GM's decision to introduce the "new" Camaro and Firebird mid year and they also tied the Corvette to the mid year roll out...Ugh!) of a 70 Convertible, LS-5, 4 speed and vaguely remember where the TCS was positioned on the engine but the picture refreshed my memory. Somewhere in the life of my car the TCS was removed. Cannot remember if it was me or Art Gallo back in 1975 when the original Q-Jet went bad and replaced it with a Holley Spread Bore. The car is running great and I am just wondering if I need to round up the parts and reinstall the TCS system. Any thoughts or recommendations on the matter would be greatly appreciated.Thanks,Chuck

[Terry M.]

Re: 1970 bb coupe engine restoration

Not trying to steal this thread but my eye was caught by the discussion of the TCS. I am the original owner (ordered it in June 1969 expecting to take delivery in late September but we all know about GM's decision to introduce the "new" Camaro and Firebird mid year and they also tied the Corvette to the mid year roll out...Ugh!) of a 70 Convertible, LS-5, 4 speed and vaguely remember where the TCS was positioned on the engine but the picture refreshed my memory. Somewhere in the life of my car the TCS was removed. Cannot remember if it was me or Art Gallo back in 1975 when the original Q-Jet went bad and replaced it with a Holley Spread Bore. The car is running great and I am just wondering if I need to round up the parts and reinstall the TCS system. Any thoughts or recommendations on the matter would be greatly appreciated.Thanks,Chuck

Chuck,

You should decide what you want to do with your car. If driving your car is what you want to do, then enjoy it running well as it is.
If having it judged is your desire then consider replacing your carburetor and adding the TCS system as time and money permit.

[Chuck Z.]

Re: 1970 bb coupe engine restoration

Hi Terry,Thank you for your reply. A few years ago I had the Q-jet rebuilt and restored. However I just kept it all wrapped up in a couple of lint free towels with the full intention of replacing the Holley someday. About a week ago, the accelerator pump on the Holley gave up the ghost and started leaking gas all over my intake manifold. So off came the Holley and after a thorough clean up of the engine on went the Quadrajet along with the original air cleaner. It all looks nicer than the smaller, open chamber air cleaner I had to use (hood clearance issue) with the Holley. Never gave much thought to having the car judged (by NCRS) and know I would probably lose points or be disqualified with my Petronix ignition. Other than the Petronix and missing the TCS hardware on top of the engine, the car is pretty much just the way it was when I took delivery of it on March 16, 1970. Did a frame-on restoration three years ago and it really looks great. :-)Best regards,Chuck

[Leif A.]

Re: 1970 bb coupe engine restoration

Chuck,How's that Petronix ignition working for you? I've been thinking of ditching the old points and installing the Petronix system.thanks,Leif

[Terry M.]

Re: 1970 bb coupe engine restoration

Hi Terry,Thank you for your reply. A few years ago I had the Q-jet rebuilt and restored. However I just kept it all wrapped up in a couple of lint free towels with the full intention of replacing the Holley someday. About a week ago, the accelerator pump on the Holley gave up the ghost and started leaking gas all over my intake manifold. So off came the Holley and after a thorough clean up of the engine on went the Quadrajet along with the original air cleaner. It all looks nicer than the smaller, open chamber air cleaner I had to use (hood clearance issue) with the Holley. Never gave much thought to having the car judged (by NCRS) and know I would probably lose points or be disqualified with my Petronix ignition. Other than the Petronix and missing the TCS hardware on top of the engine, the car is pretty much just the way it was when I took delivery of it on March 16, 1970. Did a frame-on restoration three years ago and it really looks great. :-)Best regards,Chuck

Petronics and/or missing CS will not get your car disqualified. There are very few things what can get a car disqualified. Believe me, without going into details, it is far easier for YOU to get disqualified than your car to get disqualified.

Depending on the type of electronic ignition system you have (I understand some have just one wire) and the skill and available time of the judges, you may not even receive a deduction. Even if you do, you may not lose more (guessing here because you can do the real research if you want) 5 of the 4510 available points. The missing TCS will cost a few more points I expect, but not too many more. My point is neither is too big a deal in the grander scheme of things. And if you have no desire for judging at NCRS or Bloomington Gold it doesn't matter anyway, so why care about it.

[Monte M.]

Re: 1970 bb coupe engine restoration

I know you said you did not want to eliminate the vacuum advance all together. It sounded like you originally want to make the system look correct but have the vacuum advance open/on all the time.
The easiest way to do this is ground the jumper wire. The jumper wire that goes to the sensor on the head is a normally closed sensor. Which mean it has it grounds the TCS solenoid resulting in the vacuum advance working.
As the engine heats up the sensor in the head opens which open the TCS solenoid circuit, which closes the vacuum off to the distributor.
So, if you splice into the TCS jumper at the plug where the dark blue and green wires meet, typically behind the head, and take the splice to ground, this should ground the TCS solenoid circuit leaving the TCS solenoid open allowing the vacuum open all the time.

I think that should do the trick.
Best of luck,
Monte

[Chuck Z.]

Re: 1970 bb coupe engine restoration

Leif,Replaced the points on my car back in the 80's with Mallory's Uni-lite set-up. Never had a problem with it but there were an awful lot of people that did. Replaced the Mallory system with the Petronix a few years ago and am very happy with it. Recommend that you buy their coil and go with a set of AC Delco platinum plugs, and contact Lectric Limited (they advertise in the NCRS Driveline) and get a new set of original spark plug wires. You will be very happy and so will your car. :-)Chuck

[Randy C.]

Re: 1970 bb coupe engine restoration

Hello Terry, This is belated but thank you very much for the pics. They are helping us tremendously in restoring the '70 BB. I'm not a mechanic but the man I'm working with is, and he is especially particular about Chevrolets and other GM products. We know the owner of this car wants it to be as close as possible in appearance to what it looked like when it was on the showroom floor and your pics were just what we needed to address that part. Thank you again! Best Regards, Randy C.

[Terry M.]

Re: 1970 bb coupe engine restoration

Hello Terry, This is belated but thank you very much for the pics. They are helping us tremendously in restoring the '70 BB. I'm not a mechanic but the man I'm working with is, and he is especially particular about Chevrolets and other GM products. We know the owner of this car wants it to be as close as possible in appearance to what it looked like when it was on the showroom floor and your pics were just what we needed to address that part. Thank you again! Best Regards, Randy C.

I am glad to help.

[Michael F.]

Re: 1970 bb coupe engine restoration

I took the tcs off my 73 auto with 350 I bought from original calif owner and could not even tell the difference.