72 base motor--A.I.R.?

[Mike E.]

The 70-72 juding manual indicates that base motor cars were equipped with AIR. Yet the spec book indicates way too few K-19 equipped cars compared to base-motor production numbers. Two questions:
1) Were all 72 base motor cars equipped with AIR, and
2) What does the much lower number of K-19-equipped cars in the spec book and black book indicate?
Thanks!

[Michael W.]

Re: 72 base motor--A.I.R.?

I'll take a WAG and say that the K19 was fitted to engines other than L48 when sold in California.

[Jack H.]

Re: 72 base motor--A.I.R.?

I'll also wager an educated guess...

If A.I.R. was an integral part of the base engine, then it wouldn't show up in the K19 option count since it was a standard feature and not a bona fide 'option'...

Going further, that would suggest the K19 production count only applies to those versions of the engine whose normal factory configuration lacked the A.I.R. feature/function...

[Edward J.]

Re: 72 base motor--A.I.R.?

Mike, my base motor 72 does not have AIR, But am sure that calif. cars were with the base motor and believe that the LT1 cars were all with AIR.

[Mike E.]

Re: 72 base motor--A.I.R.?

I'll also wager an educated guess...

If A.I.R. was an integral part of the base engine, then it wouldn't show up in the K19 option count since it was a standard feature and not a bona fide 'option'...

Going further, that would suggest the K19 production count only applies to those versions of the engine whose normal factory configuration lacked the A.I.R. feature/function...

Jack--
I wondered that, too. That would in essence imply that there were 3000+ base motors equipped with AIR for California usage, because the LS5 and the LT-1 were already AIR equipped. That flies in the face of the JM indicating that all the base-motor cars were AIR equipped.
I'm asking because I came across a reasonably low-mile and quite original base motor 72 that has no indication it was ever AIR equipped.
Mike

[Terry M.]

Re: 72 base motor--A.I.R.?

Mike,

I think you are misreading the JM, but I can see where that is easy to do (4th Edition, Page 76).

In 1972 only those base motors destined for delivery in California had AIR (CDH & CDJ). The other 200hp engines (CKW & CKX) had no AIR. That is the meaning of Exhaust Emission Controls (EEC) [EEC=AIR in 1972] on page 55 of the 4th Edition). Those are Chevrolet's codes, not ours.

[Mike E.]

Re: 72 base motor--A.I.R.?

Mike,

I think you are misreading the JM, but I can see where that is easy to do (4th Edition, Page 76).

In 1972 only those base motors destined for delivery in California had AIR (CDH & CDJ). The other 200hp engines (CKW & CKX) had no AIR. That is the meaning of Exhaust Emission Controls (EEC) [EEC=AIR in 1972] on page 55 of the 4th Edition). Those are Chevrolet's codes, not ours.

Terry--
Thanks!!!!
There I go letting 9 years of college get in the way of my reading skills again!
Mike

[Wayne M.]

Re: 72 base motor--A.I.R.?

I'll also wager an educated guess...

If A.I.R. was an integral part of the base engine, then it wouldn't show up in the K19 option count since it was a standard feature and not a bona fide 'option'...

Going further, that would suggest the K19 production count only applies to those versions of the engine whose normal factory configuration lacked the A.I.R. feature/function...

Jack -- you're hot on the trail; I have in front of me a list of 19 Canadian-delivered 1972 Corvettes (the detailed microfiche from GM Vintage Canada).

All the LS5's have K19AJ5 code, among their other options. None of the base engines nor the LT1's have it. I owned (new) a base engine 4-sp. car that's on this list and I'll guarantee with photographic proof that it did not have A.I.R.

[Mike E.]

Re: 72 base motor--A.I.R.?

Terry--
As you probably have already read on p. 76 of the JM, it says this:
"AIR REQUIRED VEHICLES
Those cars equipped with AIR systems included all LT-1's, 1971 LS6 engines, all 1972 454 engines, 1972 base engines (200hp) and all delivered for sale in California."

I'm struggling to figure out how that doesn't imply that base 72 engines should have AIR.

The paragraph prior to that list what the AIR system consists of, and mentions pump, bracket, diverter valve, hoses, check valves, and ex. man. tubes.

[Terry M.]

Re: 72 base motor--A.I.R.?

Terry--
Thanks!!!!
There I go letting 9 years of college get in the way of my reading skills again!
Mike

We need to reword that paragraph on Page 76. I can see how one could come to the conclusion you did. 30+ years of looking at C3s is all that saved me from that fate. I would do better if I had the number of years you have been looking at C1s.

If they start teaching Corvettes in college I might go back, but as far as I can tell all the fun classes are done with. Of course I don't suppose ALL your 9 years was fun.

[Terry M.]

Re: 72 base motor--A.I.R.?

Terry--
As you probably have already read on p. 76 of the JM, it says this:
"AIR REQUIRED VEHICLES
Those cars equipped with AIR systems included all LT-1's, 1971 LS6 engines, all 1972 454 engines, 1972 base engines (200hp) and all delivered for sale in California."

I'm struggling to figure out how that doesn't imply that base 72 engines should have AIR.

The paragraph prior to that list what the AIR system consists of, and mentions pump, bracket, diverter valve, hoses, check valves, and ex. man. tubes.

And I wish I knew how that wording got there. I could offer excuses, but the bottom line is it is wrong.

[Michael W.]

Re: 72 base motor--A.I.R.?

Would this be more correctlier?

"AIR REQUIRED VEHICLES
Those cars equipped with AIR systems included all LT-1's, 1971 LS6 engines, all 1972 454 engines and all 1972 base engines (200hp) delivered for sale in California."

[Terry M.]

Re: 72 base motor--A.I.R.?

Mike, That certainly would be more correct than what is there, but it is possible that some AIR equipped base motor 1972 Corvettes were sold outside California. I think we are safer for the 1972 base engines specifying which suffix codes had AIR and which did not. That way we can leave out the California thing.

When the revision team gets to the mechanical section I will recommend a change. We will see what comes out of committee -- now there is a scary thought.

[Monte M.]

Re: 72 base motor--A.I.R.?

I hate to jump in the middle of you discussion, but I was reading the old 53-72 spec guide( mine is at least 25 years old). I think the explaination under the codes does a pretty good job of explaining it for 1972. Page 47 in my book. I may be wrong, but it appears that the K-19 had the different camshaft as well as the AIR system. Does that sound right to you, or is the cam just part of the system on all AIR cars?
Monte

[Joe L.]

Re: 72 base motor--A.I.R.?

I hate to jump in the middle of you discussion, but I was reading the old 53-72 spec guide( mine is at least 25 years old). I think the explaination under the codes does a pretty good job of explaining it for 1972. Page 47 in my book. I may be wrong, but it appears that the K-19 had the different camshaft as well as the AIR system. Does that sound right to you, or is the cam just part of the system on all AIR cars?
Monte

Monte------


1972 base engine cars with AIR did not use a different camshaft than non-AIR-equipped engines. The GM #3896929 camshaft was used for both. The same camshaft was used for all 1967-80 base engine Corvettes, with or without AIR.