L88

[Howard K.]

Can anyone tell me if any L88s were equipped with smog pumps--THANKS

[Patrick H.]

Re: L88

Yes.

All.

[Steve B.]

Re: L88

No 67 L88 Corvettes had A.I.R. equipment. All 1968 and 69 L88s were equipped with A.I.R.

[Billy Olson]

Re: L88

I was once told that smog pumps were actually added as a performance enhancer. The logic being that the cold air injected would cause the hot exhaust gasses to contract and reduce backpressure. Its an interesting notion and may have some merit, but I'll bet the power loss to drive the pump is actually greater than any backpressure reduction benefit.

[Joe L.]

Re: L88

Billy------

The pumps were never added as a means of increasing performance as far as I know. However, the AIR system provides exhaust emissions control with less power loss than any other scheme for exhaust emissions control. That's the reason that AIR was utilized in 70-71 for LT-1 and LS-6 engines, while all others used the CCS (or, CEC) systems. It's also why it was used on all 1968-69 Corvettes, while virtually all other Chevrolet cars with automatic transmissions received the CCS system. The AIR system allows the engine to be, mostly, unchanged from pre-emissions control days and the exhaust subsequently "cleaned up" to the degree necessary for the day. That's also why it was the exclusive exhaust emissions control technology in the "transitional period" of 1966-67 when it was, basically, just added on to existing engines. The AIR system gets far more negative comment than it deserves. It really isn't a bad system, at all, from a performance perspective.

The one "problem" with AIR is cost. That's why GM (and, other auto manufacturers) came up with "alternate systems" to achieve the required exhaust emissions control. The "alternate systems" resulted in somewhat greater power and driveability loss, but they were a lot less expensive to install.

Increasing emissions control regulations in the 60s brought the AIR systems back into the picture in addition to, effectively, the "alternate systems" + additional control measures. AIR, a tried-and-true, albeit costly, emissions control system, is still used on some cars to this very day.

[Duke W.]

Re: L88

'67 L-88s didn't even have a closed crankcase ventilation system as required by federal law, so they were illegal for normal street and highway use.

The '68-'69 versions did have PCV systems and the AIR system to meet tailpipe emission standards.

Duke

[Patrick H.]

Re: L88

Darn. See what happens again when a C-3 guy talks about C-2s.
Maybe next time...

Patrick

[Mark #28455]

Re: L88

The AIR pump and system used for the 1969 L88 is actually the 1968 style pump with the pressure relief valve in the casting and the 1968 style diverter valve. Incidentally, I believe there were 3 or 4 different styles of muffler attachment to the diverter valve in 68-69 so if you're paying, make sure you get the correrct style for your car.

Good luck,
Mark

[Tom R.]

Re: L88 & A.I.R. Cost

The cost was estimated to be at about $861.00 (in 1960 dollars) for equipping the GM fleet (each vehicle) with an A.I.R system...so as JL indicates use was sparse and limited to only special high-performance vehicles. CCS was the "economy" emission system, quite restrictive and therefore used on most GM non-performance vehicles.

You'll recall your Black Book lists K19 in 1967 at $2,573 while in 1970, NA9 listed at $1758.00. In contrast in 1970, LT1 option could be picked up for $1,287.00. So the $861 is an average per vehicle figure.

There is a great book out on 60'70's emission control technology published by SAE. I conversed with its author who was and is an emission control engineer. His role with Corvette was as a consultant to the powerteam group.

[Duke W.]

Re: L88 & A.I.R. Cost

You've mixed up the production quantities with price. The "sticker price" of K-19 in 1967 was $44.75, and NA9 in 1970 was $36.90.

A cost of $861 per vehicle for AIR doesn't jibe. Back in the early sixties you could buy a 327/340 long block for about $500 at a dealer. The actual "cost of goods sold" for GM (material and direct labor) was probably on the order of half this amount. The other items to complete the engine obviously add cost, but consider that in the sixties the sticker price of a well equipped Chevrolet passenger car with a 327 was about $3500. Say if the dealer margin was 20 percent, the invoice price works out to about $2800. Assuming GM's gross margin was 40 percent, the actual direct cost of building the complete car was only about $1700.

Of course, all this was before inflation begin to dramatically increase in the late sixties and the cost of providing benefits to employees and retirees did not exceed net after tax profit in a good year!
Duke

[Tom R.]

Re: L88 & Cost to meet 75 Clean Air Stds

Ok...should have reviewed the context before posting but this was a auto industry study to look at costs for implementing the 75 emission standards (including NOx)which included a device described as a catalytic converter, single bed, dual-bed and/or three-way we are now quite familiar with. I believe this was an early 70's study the discussion included development of EGR, thermal reactors, the cats and the catalysts. Of course, as this group knows, NOx was the greatest emission challenge and to meet the 50,000 miles durability requirement "a cost estimate of $860 per vehile was calculated for a system using a dual catalytic converter, a low-grade rich thermal reactor, and EGR...assuming non-leaded gasoline would be available."

The source is "Cleaner Cars: The History & Technology of Emission Control Since the 1960's."

[Duke W.]

Re: L88 & Cost to meet 75 Clean Air Stds

Circa 1970 everybody was running around in circles predicting that the sky was going to fall, because NOBODY knew how to meet the proposed 1975 emission standards. I know, because I was doing research in the field at the time.

The standards WERE met, but it WAS expensive, and car performance and mileage suffered greatly, but new technology and cost savings with volume production came to the rescue.

Three way catalyst and oxygen sensor technology saved the day, and by the late eighties this emission control architecture was pretty much industry standard.

Now car engines have higher specific output, broader torque bandwidth, lower fuel consumption, and much lower emissions that we ever could have imagined in 1970.

HC and CO emissions of new cars are down 99+ percent from uncontrolled cars and gasoline engine NOx has been reduced about 90 percent.

Duke

[Tom R.]

Re: L88 & Cost to meet 75 Clean Air Stds

Yep!