1971 LS5 engine: AIR-required, or not?

[Daniel K.]

I am one of the lucky guys who got a 5th edition of the TIM at Carlisle. A huge thank you to everyone who worked on it -- it is terrific.
With respect to AIR Systems, the 4th edition (p. 76) says, "Those cars equipped with AIR systems included all LT1s, 1971 LS6 engines, all 1972 454 engines, 1972 base engines (200 hp), and all delivered for California."
The 5th edition (p. 139) reads quite differently: "Those cars equipped with AIR systems included all LT1s, 1971 LS6 engines, all 454s, and all delivered for sale in California."
I read this to mean that my 1971 LS5 is supposed to have the AIR system (it also seems to mean that 1970 454's should have it, and that 1972 base engines should not have it).
Am I reading this correctly? If so, can someone describe some of the input received to determine that all 70 and 71 454's should be AIR equipped?
I took a look at the 1971 AIM, which I admit I'm still getting familiar with, but I do note that the pages describing the assembly of the AIR system (L326, L363, L364) are all marked "LS6" -- which is more in accord with the 4th edition of the TIM which indicated that AIR appeared on 1971 LS6 but did not appear on 1971 LS5.
Obviously there's an answer I'm hoping for, but really just looking for information. Thanks!

[Patrick H.]

Re: 1971 LS5 engine: AIR-required, or not?

I think you found our first error...

[Terry M.]

Re: 1971 LS5 engine: AIR-required, or not?

Neither of those communicated the correct idea because one can interprete each of those descriptions several different ways.
Try this for 1970-72:
All solid lifter engines were equipped with AIR. Additionally 1972 base engine equipped Corvettes destined for sale in California reveived AIR, as did all 1972 454 engines.

[Daniel K.]

Re: 1971 LS5 engine: AIR-required, or not?

Thanks gentlemen. Big sigh of relief here.

[Mark E.]

Re: 1971 LS5 engine: AIR-required, or not?

Neither of those communicated the correct idea because one can interprete each of those descriptions several different ways.
Try this for 1970-72:
All solid lifter engines were equipped with AIR. Additionally 1972 base engine equipped Corvettes destined for sale in California reveived AIR, as did all 1972 454 engines.

I learned something: In addition to all '72 engines, I also thought all '71 engines have AIR. So we're saying the '71 base and LS-5 don't have AIR?

[Joe L.]

Re: 1971 LS5 engine: AIR-required, or not?

I learned something: In addition to all '72 engines, I also thought all '71 engines have AIR. So we're saying the '71 base and LS-5 don't have AIR?

Mark------


As far as 1971 LS-5 is concerned, none have AIR. As far as LS-6 goes, all were equipped with AIR.

As far as base engines are concerned, I believe those with "CJK" code (i.e base engine with M-40) were equipped with AIR whether they were California-delivered, or not. Other base engine cars were not equipped with CCS.

[Randy C.]

Re: 1971 LS5 engine: AIR-required, or not?

I have a '71 CJK base engine THM coupe that was delivered to Angels Camp, CA and, as far as I can tell (Bought the car in '78 in Alameda, CA, and I've since been through all the mechanicals on the car), it has never had AIR.

Randy C.

[Joe L.]

Re: 1971 LS5 engine: AIR-required, or not?

I have a '71 CJK base engine THM coupe that was delivered to Angels Camp, CA and, as far as I can tell (Bought the car in '78 in Alameda, CA, and I've since been through all the mechanicals on the car), it has never had AIR.

Randy C.

Randy------


Well, that's interesting and the kind of empirical information I like. The information I have must be incorrect. Interesting, it also discounts the allegation that California-delivered base engine 1971's had AIR. At least, it discounts it for THM-equipped base engine cars. Does anyone out there have a 1971 with "CJL" or "CGT" coded engine?

[Patrick H.]

Re: 1971 LS5 engine: AIR-required, or not?

Randy------


Well, that's interesting and the kind of empirical information I like. The information I have must be incorrect. Interesting, it also discounts the allegation that California-delivered base engine 1971's had AIR. At least, it discounts it for THM-equipped base engine cars. Does anyone out there have a 1971 with "CJL" or "CGT" coded engine?

My 71 is a CJL (base 4 spd) and I've likely worked on a CGT (base auto). No AIR.
The only AIR base motor cars are those in 1972 which specifically call for it.

[Joe L.]

Re: 1971 LS5 engine: AIR-required, or not?

My 71 is a CJL (base 4 spd) and I've likely worked on a CGT (base auto). No AIR.
The only AIR base motor cars are those in 1972 which specifically call for it.

Patrick------


Actually, until I recently found this apparently incorrect information that "CJK" coded engines were equipped with AIR, I always thought that the only 1971 Corvettes that were equipped with AIR were LT-1 and LS-6. So, now I'm back to that belief.

1972 was different. All 1972 Corvettes were equipped with AIR except federal emission (i.e. non-California) base engine, both manual and auto trans.

[Gary B.]

Re: 1971 LS5 engine: AIR-required, or not?

Terry and I was together yesterday. Meadowdale International Raceway in Dundee, IL.

We laughed, giggled over this, as his initial post was incorrect. He went back and corrected it. But, we came to decision that a "table" of what does and does not have AIR. Seems no matter how it is worded, it is tough to describe and understand. So, on my list of things to do, update manual with a table.

69 350hp engines with 4-speed, have AIR. Did they continue that in 1970? 350 with Automatic trans?

Gary Bosselman

[Duke W.]

Re: 1971 LS5 engine: AIR-required, or not?

Mark------


As far as 1971 LS-5 is concerned, none have AIR. As far as LS-6 goes, all were equipped with AIR.

As far as base engines are concerned, I believe those with "CJK" code (i.e base engine with M-40) were equipped with AIR whether they were California-delivered, or not. Other base engine cars were not equipped with CCS.

Early emission controlled engines with manual transmissions were more difficult to certify than the same engine with an automatic. That's because when you lift off the throttle to shift, manifold vacuum goes to at least 22" Hg momentarily, which causes more fuel/air emulsion to be drawn in from the carburetor idle circuit and that creates a HC spike in the exhaust. So it's common to see a base engine with a manual have AIR, but no AIR if coupled to an automatic.

The above is also the reason why there were a few years in the late-seventies/early-eighties that one could not order a Corvette for California delivery with a manual transmission.

I don't think the '70 L-46 was available with an automatic.

Duke

[Mark E.]

Re: 1971 LS5 engine: AIR-required, or not?

...a "table" of what does and does not have AIR. Seems no matter how it is worded, it is tough to describe and understand. So, on my list of things to do, update manual with a table.
Gary Bosselman

A table is a good idea. Are "running" updates/corrections possible? Or does all of this wait for the next edition?

[Joe L.]

Re: 1971 LS5 engine: AIR-required, or not?

Terry and I was together yesterday. Meadowdale International Raceway in Dundee, IL.

We laughed, giggled over this, as his initial post was incorrect. He went back and corrected it. But, we came to decision that a "table" of what does and does not have AIR. Seems no matter how it is worded, it is tough to describe and understand. So, on my list of things to do, update manual with a table.

69 350hp engines with 4-speed, have AIR. Did they continue that in 1970? 350 with Automatic trans?

Gary Bosselman

Gary------


ALL 1969 Corvettes, base engine to ZL-1, standard transmission or THM, were equipped with AIR. NO exceptions (no matter what some people may think).

For 1970, only the LT-1 was equipped with AIR. The L-46 was not available with THM-400.

[Terry M.]

Re: 1971 LS5 engine: AIR-required, or not?

A table is a good idea. Are "running" updates/corrections possible? Or does all of this wait for the next edition?

In the past corrections/clarifications have waited for the next edition of the manuals. There is a place on this board for corrections/clarifications to the TIM&JGs, but it is largely unknown and unused. Posting corrections/clarifications there would IMO be useless as we would continually have to direct the unknowing and helpless to that location.