1968 L36, M20 with A/C

[Charles F.]

Hi all:

Three different questions all rolled into one post:

(1) Emission sticker: the judging guide (p56-57) indicates that this is "a white label about 1 1/2 by 6 inches located on the top driver's side of the radiator in early 1968 production. It shifted to the firewall above the brake master cylinder in later 1968 and all of 1969".

My car was built on (or about) April 21, 1968. Which location should the sticker appear (per JG, P/N 3927744, code either "F" or "W") ?

(2) I bought a date coded GM fire extinguisher (I know, they don't get any more credit than a new one) that works with my build date. I read the archives on the subject and essentially learned that these were after- market at the GM dealer and not a factory option. Therefore, they should not be mounted on a bracket.

So, how do I attach it to the car (rolling all over the place doesn't sound like a good solution) ? If I bought a new halon extinguisher, wouldn't that be bracket mounted ?

(3) Engine question: my engine had a problem overheating at idle. I posted on the subject about a year ago but, unfortunately, none of the solutions seemed to fit the problem. The engine has now been rebuilt fully and the problem was uncovered: the original intake manifold has porosity at one of the hose junctions to the radiator and was "bleeding" air, although it was water tight. You could feel the air flow through the casting (definately not the hose or clamp tightness). I understand that this de-pressurized the system and allowed the engine to overheat at ideal.

Does this make sense ? Is it possible that the aluminum casting of the intake manifold was like this from the factory (it is original) or is this something that develops over time ?

Fortunately, the porous area was reachable and has been internally sealed with two layers of epoxy. Hopefully, this will hold. It had solved the overheating problem for the moment.

Thanks.

Chuck Faillace

[Terry M.]

Re: 1968 L36, M20 with A/C

I'll comment only on your #2 question, and leave the other questions for those more astute than I.
Leave the fire extinguisher in the packaging it came in. That will keep it from rolling around. There are few ways to mount it to the car (and maybe no ways) that will not receive a deduction -- remember no fire extinguisher was mounted in the car at St. Louis.

[Joe L.]

Re: 1968 L36, M20 with A/C

Hi all:

Three different questions all rolled into one post:

(1) Emission sticker: the judging guide (p56-57) indicates that this is "a white label about 1 1/2 by 6 inches located on the top driver's side of the radiator in early 1968 production. It shifted to the firewall above the brake master cylinder in later 1968 and all of 1969".

My car was built on (or about) April 21, 1968. Which location should the sticker appear (per JG, P/N 3927744, code either "F" or "W") ?

(2) I bought a date coded GM fire extinguisher (I know, they don't get any more credit than a new one) that works with my build date. I read the archives on the subject and essentially learned that these were after- market at the GM dealer and not a factory option. Therefore, they should not be mounted on a bracket.

So, how do I attach it to the car (rolling all over the place doesn't sound like a good solution) ? If I bought a new halon extinguisher, wouldn't that be bracket mounted ?

(3) Engine question: my engine had a problem overheating at idle. I posted on the subject about a year ago but, unfortunately, none of the solutions seemed to fit the problem. The engine has now been rebuilt fully and the problem was uncovered: the original intake manifold has porosity at one of the hose junctions to the radiator and was "bleeding" air, although it was water tight. You could feel the air flow through the casting (definately not the hose or clamp tightness). I understand that this de-pressurized the system and allowed the engine to overheat at ideal.

Does this make sense ? Is it possible that the aluminum casting of the intake manifold was like this from the factory (it is original) or is this something that develops over time ?

Fortunately, the porous area was reachable and has been internally sealed with two layers of epoxy. Hopefully, this will hold. It had solved the overheating problem for the moment.

Thanks.

Chuck Faillace

Chuck------


I would say that your engine tune-up (emissions) label should be mounted above the master cylinder for a car built in late April, 1968.

As far as the manifold goes, it's very possible that your manifold suffers from casting porosity. If so, it's something that the manifold was "born" with and not something that developed over time. However, it is possible that some sort of sealant was originally used and that sealant degraded over time. I think the epoxy is an effective way to repair the porosity problem. However, if it were me, I'd prefer to use the epoxy on the INSIDE surface of the manifold rather than the exterior surface. Doing BOTH surfaces would be even better.