Yenko Camaros (1969) - Two! - Lemont, Il. 1969

[olredalert]

------Orlando,,,I wouldnt put too much stock in what JD told you. It wouldnt be the first time his memory was off a bit. I lived in Hinsdale (although not in 66) worked at Classic Motors in the old JD Chevrolet building and knew just about every last gearhead in the area. I never once heard a breath of a hint that would back up this 427 Chevelle order stuff. If you notice, the add doesnt say 427. It only says 425 which would make me think the add was somewhat creative!!!........Bill S

[66 L78 ragtop]

I agree that its not a good idea to bank on anyones recollections.
JD ad was for 425hp rated 396 motors not 427. He basically sold 66 L78 Chevelles that were rated 425hp at 6400rpm vs 375hp @ 5600rpm. Same engine. Some people say that the different hp ratings were based different sized cams, but this remains to be proven

For unreal:

The 66 L78 and 69 L78 were completely different engines.
Different blocks, pistons, cams, intakes, heads, and different carbs. The only thing they shared was the crank shaft. Although the cams had the same part numbers, they had different intake and exhaust durations.

[Unreal]

Maybe I did not ask right. In 69, were the Corvette L78 and the Chevelle L78 the same, except for the manifolds? (and maybe the valve covers?) I thought they were, but I have "thought" a lot of things in the past that were incorrect.
Thanks,

[66 L78 ragtop]

1969 Vette L78?...No such animal

1965 was the only year that an L78 was offered in the corvette.

[Unreal]

[ QUOTE ]
1969 Vette L78?...No such animal

1965 was the only year that an L78 was offered in the corvette.

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OK, bad example.

You said that the L78 Chevelle was a different engine internally than the L78 Corvette. I know you said the L78 Corvette was only available in 65, but the car in question was a 66 Chevelle. So to stick to the question, would the 65 Corvette L78 be the same motor internally as the 65 L78 Chevelle? (Z16)

What I'm really trying to learn is if it was "normal" for same coded motors (eg L78. L72, etc) to be different from model to model. I would have thought (pure conjecture) that an L78 was an L78 regardless of the car it was dropped into. (manifolds aside for clearance reasons). I wonder why they would not call it a different "L" number if it were different internally.

So maybe a better example of my curiosity is whether the 69 L72 differed internally when the application was a Corvette, Impala, COPO Chevelle, or COPO Camaro. I sure thought they were the same, and assumed other motors would have been the same, too. Same curiosity would hold for other motors that shared "L" numbers, and were available across different applications.

[olredalert]

------Gary,,,For starters, a Z16 would have had a hydraulic cam and lifters. As a matter of fact the Z16 engine was the only square-port engine ever built for a specific option without a solid-lifter cam........Bill S

[lzdick]

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Cool story!..
Did you check the Vin listings..there's at least one DY Douglas sold Yenko car noted?.

https://www.yenko.net/ubbthreads/show...ge/0#Post76004

[/ QUOTE ]


Let's get back to the origination of the thread...before it was stolen.

I currently own the DY #578804 listed 4th on the VIN list. It is a non-vinyl top, 4-speed car. Purchased at J.D., the car spent its entire life in the Elgin/Carpentersville area until the late 90's when the Elgin owner moved to Madison, WI. I purchased the car from him in 2003.

[lzdick]

Quick85,

You should contact Rich Maksym at Coast-2-Coast Camaro Parts & Restoration (phone (248)933-0440) as he has spoken to the original owner of his DY car...which sounds like you know who that might be. His DY car is not on the VIN list (#649223) as it is a COPO car ordered/created by Jack Douglass, an '05D' car, sold 11/18/69. If you recall the two DY cars on the streets of Lemont in 1969, this car would be too late a build. The other give-away would be the endura front bumper...that would be recognizeable in the wreck. Good luck with your 'quest'.

[66 L78 ragtop]

[ QUOTE ]
------Gary,,,For starters, a Z16 would have had a hydraulic cam and lifters. As a matter of fact the Z16 engine was the only square-port engine ever built for a specific option without a solid-lifter cam........Bill S

[/ QUOTE ]

Unreal, here is some information that I hope you find helpful. Anyhow, if you have further questions, just send me a PM. Our discussion should probably take place at another location...

An RPO, such as RPO L78, designated a particular block, crankshaft , intake and cylinder head combo for a particular year.

Given the same RPO, the same model and the same year, the engine block stamp codes differed as a function of specific trans, carb and cylinder head combos.

So going back to your statement, you are correct in your understanding that an L78 is an L78 regardless of the car it was dropped into; the caveat being as long as you are comparing L78 engines from the same year. As you know, L78 engines are different and unique to their specific year of production.

The 396 in the 65 Z16 was RPO L37. The 396 in the 65 Vette was RPO L78. They were different in that they sported different cams, carbs and distributors. The cam on the Corvette was mechanical vs that of the Z16 which was hydraulic.

So addressing your inquiry regarding 1969 L72:

In 1969, the L72 was not available in the Corvette. Remember, the general rule of thumb is that the Vette always maintained its own unique set of RPOs. This was GMs way of maintaining the Corvette’s flagship status. The exception to this rule was the big Impala which borrowed the Vette’s big block engine in 1965 and 1966. GM likely felt this was acceptable because the huge Impala was a far cry from a threat to the sales of the Corvette. They were two different animals.

The only time the Vette and Camaro shared the same engine during the same year was when they were both chosen as the recipient vehicles for the aluminum ZL1 engine.

Anyhow, the COPO Camaros and COPO Chevelles were bare bone cars that came with the same crankshaft, heads, pistons, intake, and midyear 4 bolt engine block, cast number 3963512 that was designated for the special high performance passenger car.

The 1969 COPO cars essentially sported the passenger cars special high performance 427/L72. Just like when the Camaro was chosen as one of the recipient vehicles for the aluminum ZL1 engine, it again’ along with the Chevelle was chosen as the recipient of the passenger cars special high performance 427. The union of the lighter bare bones, Camaro and Chevelle with the omnipotent passenger car’s L72 was achieved via a central office production order (COPO). GM likely allowed the limited production of these COPO cars as they were designated for the drag strip as opposed to the Corvette which was heralded as the all American sports car vs drag car. Nonetheless, the COPO Camaro had the potential to compete with Vette sales so its production was closely regulated by GM.

Anyhow, I hope this helps

[camarojoe]

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The only time the Vette and Camaro shared the same engine during the same year was when they were both chosen as the recipient vehicles for the aluminum ZL1 engine.



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What about the 1970 LT-1?