Duntov's 1968 L-88 test cars

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Steve

Thanks again. Can you make out if the shifter is the original muncie or a hurst? Would you (or anyone else) know of any additional sources of information about this and the other 68 L-88 test cars. The car I'm most interested in is an international blue convertible.

[Wayne M.]

Re: Duntov's 1968 L-88 test cars

S. ..... Can you make out if the shifter is the original muncie or a hurst? ....

Thomas -- here's four pics from the article. I can see the "T" handle on the shifter (on my magazine copy, with a magnifying glass), so I assume stock shifter and console boot.

You can see the those two console gauges we talked about earlier.

These are just digital pics directly off the magazine -- my scanner wouldn't do much better as the screening dots really show up on such small size originals, and the pages are wrinkled due to (past) wet storage.

[Steven B.]

Re: Duntov's 1968 L-88 test cars

Thomas -- here's four pics from the article. I can see the "T" handle on the shifter (on my magazine copy, with a magnifying glass), so I assume stock shifter and console boot.

You can see the those two console gauges we talked about earlier.

These are just digital pics directly off the magazine -- my scanner wouldn't do much better as the screening dots really show up on such small size originals, and the pages are wrinkled due to (past) wet storage.

Wayne, great job on the pics. When you click on them they are displayed larger than in the magazine and easier to see. You are correct as the original pics. in the mag aren't that good. Your's actually look much better.

Thanks,

Steve

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Wayne & Steve

Thanks for the pictures and information. Gauges look similar to mine except I have a kill switch between the two. New question: Have you or anyone else on the forum ever examined a head from a pre-opened chambered L-88? Are they supposed to be similar to the cast iron square port head? Were they port matched,cc'd and bench flowed from the factory?

[Wayne M.]

Re: Duntov's 1968 L-88 test cars

Wayne & Steve

Thanks for the pictures and information. Gauges look similar to mine except I have a kill switch between the two. New question: Have you or anyone else on the forum ever examined a head from a pre-opened chambered L-88? Are they supposed to be similar to the cast iron square port head? Were they port matched,cc'd and bench flowed from the factory?

By pre-open chamber L88 [aluminum] heads ( #3946074), I assume you're referring to the # 3919842, used on L88 / 89 used for 1968 and early 1969 for L88's and all the '69 L89's. I have a set of these with mid '67 casting, probably OTC or installed in an early '68 Corvette or Camaro. I seem to recall hearing that the '842' was not an exact copy of the cast iron '840', but that the runners had different angles or shape, but can't remember the source.

[John H.]

Re: Duntov's 1968 L-88 test cars

Were they port matched,cc'd and bench flowed from the factory?

Tom -

I doubt if ANY heads were ever port-matched, cc'd and bench-flowed from the factory (not counting those that were prepped in the Motor Room at CEC for Press cars).

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Wayne & John

Thanks again for the help.The heads are 842's. In 1970, a valve spring lock failed on start up. Fortunately, the owner shut the car down immediately.The car was towed to a friend's speed shop who removed the cylinder head to check for internal damage. He found no damage but did find the head had been port matched as well as the combustion chambers altered.There were a series of numbers that were still partially visible by the combustion chambers that he felt may have had to do with chamber volume and flow. But what he felt was peculiar was that the head gasket was the original factory gasket not an aftermarket replacement,and the head appeared to have never been removed before. Is the presence of these numbers something common to these 842 cylinder heads? Were these engines assembled with stock GM head gaskets?

[Joe L.]

Re: Duntov's 1968 L-88 test cars

Wayne & John

Thanks again for the help.The heads are 842's. In 1970, a valve spring lock failed on start up. Fortunately, the owner shut the car down immediately.The car was towed to a friend's speed shop who removed the cylinder head to check for internal damage. He found no damage but did find the head had been port matched as well as the combustion chambers altered.There were a series of numbers that were still partially visible by the combustion chambers that he felt may have had to do with chamber volume and flow. But what he felt was peculiar was that the head gasket was the original factory gasket not an aftermarket replacement,and the head appeared to have never been removed before. Is the presence of these numbers something common to these 842 cylinder heads? Were these engines assembled with stock GM head gaskets?

Thomas------


All GM PRODUCTION engines were built with stock GM gaskets. However, the gaskets for all big blocks were not the same. Cast iron head engines used steel shim-type gaskets. Those with aluminum heads (L-88, L-89) used a composition-type gasket.

If you're talking about a "special build" type engine, I still think it's likely that GM gaskets would have been used.

[Peter G.]

Re: Duntov's 1968 L-88 test cars

I have several more photos of this car that I did not use in my book. However, I was told by a reliable source that "The Mule" was NOT an assembly line L-88 and that it was destroyed at some point in history.

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Pete

Thanks for the reply. I too have heard that test cars were supposed to be retired(scrapped). Also,I had heard that the "mule", while built off the line, was built as an L-88 with the same components as a production L-88. However ,the car that I'm trying to find out about did start out as a production L-88 and then ,when word leaked about the coming December 1967 Car and Driver article, became the focus of a intense (secret?) developement program. There may have been another car(L-88) involved in this program as well, and some sources thought it may have been the "mule" but others felt it was different car.

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Joe

Thanks again for the information. It helps to clear up another question I've had about whether this motor was built "in house" or sent out. Over the years, I've heard various tales about it's developement,but have always felt that if built by someone other than GM (Traco?) that head gasket would not have been stock.

I have some new questions. Certain 1968 corvettes that were designated for export were smog exempt.(true?) First,does anyone know if any L-88's were smog exempt? Did these exempt cars have pcv systems or just the cover mounted breathers like 1967 cars? Do all 68 427 corvette engines get the chrome valve covers? Do smog exempt cars get the orange covers? If there are exempt 68 L-88 cars , do they have road draft tube breathers like the 67 cars?

[Joe L.]

Re: Duntov's 1968 L-88 test cars

Joe

Thanks again for the information. It helps to clear up another question I've had about whether this motor was built "in house" or sent out. Over the years, I've heard various tales about it's developement,but have always felt that if built by someone other than GM (Traco?) that head gasket would not have been stock.

I have some new questions. Certain 1968 corvettes that were designated for export were smog exempt.(true?) First,does anyone know if any L-88's were smog exempt? Did these exempt cars have pcv systems or just the cover mounted breathers like 1967 cars? Do all 68 427 corvette engines get the chrome valve covers? Do smog exempt cars get the orange covers? If there are exempt 68 L-88 cars , do they have road draft tube breathers like the 67 cars?

Thomas-----

With my reference to "special build" engines, I was referring to in-house, Chevrolet special-build engines which originated at the engine plants or the Warren Tech Center. As far as externally assembled special engines, I suppose any parts could have been used.

As far as "smog exempt" 1968 Corvettes are concerned, I have no information and I've never seen any credible information that any "smog exempt" 1968 or 1969 Corvettes, L-88 or otherwise, were ever built for sale to the public, either for the USA or ANY foreign delivery, including Canada. I know of absolutely NONE that have been documented as-such. Personally, I strongly doubt that any such cars were ever manufactured for retail sale. As far as "in-house" prototype or "experimental" vehicles, anything is possible.

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Joe

Thanks again Joe. I have never heard of nor seen any smog exempt cars either.However I have read about their supposed exsistence in a couple of publicatons over the years. If I can find those articles I'll forward them to you. What I'm trying to figure out is why a picture of the engine of this 68 L-88 taken at Milford( or Chandler?) while testing shows no smog, painted covers, and a road draft breather? Is there any way to determine if a motor originally had smog even if it was removed?

[Joe L.]

Re: Duntov's 1968 L-88 test cars

Joe

Thanks again Joe. I have never heard of nor seen any smog exempt cars either.However I have read about their supposed exsistence in a couple of publicatons over the years. If I can find those articles I'll forward them to you. What I'm trying to figure out is why a picture of the engine of this 68 L-88 taken at Milford( or Chandler?) while testing shows no smog, painted covers, and a road draft breather? Is there any way to determine if a motor originally had smog even if it was removed?

Thomas-------



As far as PRODUCTION 68-69 engines go, if the engine has a suffix code of any of the known and published variety, it was built to be equipped with PCV and AIR. However, most of the elements of the emission control systems were installed at the assembly plants. THEORETICALLY, these could have been "left off" for a "smog exempt" application while the "vestiges" of the system installed at the engine plants (e.g. AIR pump bracket, exhaust manifolds with AIR fittings, etc.) would remain. Personally, I don't think that any of this was done for a car sold to the public in the USA or otherwise.

In my opinion and with respect to cars sold to the public, if a 68-69 is found without AIR or other elements of the emission control system, that condition was created post-factory by an owner. I've never seen any documentation that any such car was originally built that way and, of course, system removal was VERY common for many years.

As far as a car such as the one shown in the Car Life article, that sort of car was undoubtedly a special build car from the get-go. With this sort of car, anything is possible. Basically, what this is is a car built to non-PRODUCTION standards by Chevrolet Engineering. It's the same sort of thing that could be done by a private owner to a purchased car except it's done by GM. These type of cars are rarely, if ever, sold to the public.

[Thomas P.]

Re: Duntov's 1968 L-88 test cars

Joe, Thanks again for the reply.As this car has no evidence of smog or pcv systems, I was hoping there might be some tapping or bracket that could indicate that it originally had these systems.I do know they have been off the engine since before March 1970 (when 2nd owner aquired the car with less than 2000 miles) Do you or does anyone else know if the 69 (68?) test car in the car life article had the smog systems intact? I can't tell from the pictures in the article if it's present.Wouldn't removing the pvc and smog systems have voided the warrranty?