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My Answer To Technical Trivia Question
Well, several folks got pretty close to identifying one of the model years and/or engine which used a unique-to-that-model year timing set or component thereof. One of the engines was, indeed, the 1996 LT4. Below, I'll respond to each of the 5 elements of the question that I posed above in order to try to make this as clear and concise as possible:
1) What were the model years?
The model years were 1966 and 1996.
2) What were the engines?
The engines were all 1966 small blocks, including the Corvette small blocks, and;
For 1996, ONLY the LT4 engine used in Corvettes only.
3)What was the specific unique component or components for each of the 2 model years?
For 1966 small blocks, the specific component was the camshaft timing sprocket
For 1996 LT4, the specific components were the entire 3 pieces of the timing set.
4) What was the configuration of the unique component or components?
For 1966 small blocks, the camshaft timing sprocket was a nylon-toothed, "wide" sprocket design.
For 1996 LT4 the timing set was roller timing set. A true, single roller timing chain was used with sprockets designed for said roller chain. Both cam sprocket and crank sprocket were steel and the cam sprocket was specially balanced.
5) What made them unique to that model year?
All 1955-66 Chevrolet small blocks used in passenger cars and light trucks used "wide tooth" timing sprockets and timing chain. Sprocket tooth width was 0.58". However, the 1955-65 camshaft timing sprocket was a ductile iron piece. For 1966 ONLY, the camshaft timing sprocket was changed to the nylon-toothed, aluminum design with sprocket width the same as the previous ductile iron. The timing chain and crankshaft sprockets were the same as earlier. For 1967 and later, the nylon/aluminum camshaft timing sprockets continued to be used for small blocks. However, the camshaft sprocket and other timing set parts were changed to the "narrow tooth" design (sprocket tooth width was 0.525"). So, the 1966 small block was the only model year that ever used the "wide tooth", nylon/aluminum camshaft sprocket.
As far as 1996 LT4 goes, keep in mind that ALL 1992-97 Gen II small blocks used a special design camshaft timing sprocket which included an integral sprag gear which provided waterpump drive through a secondary gear. However, all 1992-1997 LT1 engines (and, the "B" body Gen II smaller displacement engine) used a Morse-type timing set (otherwise known as "early-link" or "silent chain"). A Morse design timing set was the type used for all 55+ Gen I small blocks installed in passenger cars and light trucks. Also, the camshaft timing sprocket and crankshaft timing sprocket used for LT1 (and "B" body engine) were manufactured of powder metal.
The timing set used for 1996 LT4 ONLY was a roller design timing set, utilizing a single, true roller chain. In fact, it was the very first use of a roller chain in any Gen I or Gen II small block installed in a passenger car or light truck. And, it was the very first use of a TRUE roller design timing set in any PRODUCTION small block.
Not only were the chain and both sprockets different due to the roller design, but the sprockets were manufactured of steel and the camshaft sprocket was specially balanced. The LT1 (and "B" body engine) shared NO timing set parts with the LT4. The LT4 was a one-year-only engine as far as PRODUCTION installation in any passenger car and it was unique to the Corvette application---it was not installed in Camaros or any other passenger car. Even for Corvettes, it was used only for 1996 models with 6 speed manual transmission.
And, there you have it!
I'll be posting some other information when I get a chance regarding timing set parts used for both big blocks and small blocks over the 1955-2007 period.
Well, several folks got pretty close to identifying one of the model years and/or engine which used a unique-to-that-model year timing set or component thereof. One of the engines was, indeed, the 1996 LT4. Below, I'll respond to each of the 5 elements of the question that I posed above in order to try to make this as clear and concise as possible:
1) What were the model years?
The model years were 1966 and 1996.
2) What were the engines?
The engines were all 1966 small blocks, including the Corvette small blocks, and;
For 1996, ONLY the LT4 engine used in Corvettes only.
3)What was the specific unique component or components for each of the 2 model years?
For 1966 small blocks, the specific component was the camshaft timing sprocket
For 1996 LT4, the specific components were the entire 3 pieces of the timing set.
4) What was the configuration of the unique component or components?
For 1966 small blocks, the camshaft timing sprocket was a nylon-toothed, "wide" sprocket design.
For 1996 LT4 the timing set was roller timing set. A true, single roller timing chain was used with sprockets designed for said roller chain. Both cam sprocket and crank sprocket were steel and the cam sprocket was specially balanced.
5) What made them unique to that model year?
All 1955-66 Chevrolet small blocks used in passenger cars and light trucks used "wide tooth" timing sprockets and timing chain. Sprocket tooth width was 0.58". However, the 1955-65 camshaft timing sprocket was a ductile iron piece. For 1966 ONLY, the camshaft timing sprocket was changed to the nylon-toothed, aluminum design with sprocket width the same as the previous ductile iron. The timing chain and crankshaft sprockets were the same as earlier. For 1967 and later, the nylon/aluminum camshaft timing sprockets continued to be used for small blocks. However, the camshaft sprocket and other timing set parts were changed to the "narrow tooth" design (sprocket tooth width was 0.525"). So, the 1966 small block was the only model year that ever used the "wide tooth", nylon/aluminum camshaft sprocket.
As far as 1996 LT4 goes, keep in mind that ALL 1992-97 Gen II small blocks used a special design camshaft timing sprocket which included an integral sprag gear which provided waterpump drive through a secondary gear. However, all 1992-1997 LT1 engines (and, the "B" body Gen II smaller displacement engine) used a Morse-type timing set (otherwise known as "early-link" or "silent chain"). A Morse design timing set was the type used for all 55+ Gen I small blocks installed in passenger cars and light trucks. Also, the camshaft timing sprocket and crankshaft timing sprocket used for LT1 (and "B" body engine) were manufactured of powder metal.
The timing set used for 1996 LT4 ONLY was a roller design timing set, utilizing a single, true roller chain. In fact, it was the very first use of a roller chain in any Gen I or Gen II small block installed in a passenger car or light truck. And, it was the very first use of a TRUE roller design timing set in any PRODUCTION small block.
Not only were the chain and both sprockets different due to the roller design, but the sprockets were manufactured of steel and the camshaft sprocket was specially balanced. The LT1 (and "B" body engine) shared NO timing set parts with the LT4. The LT4 was a one-year-only engine as far as PRODUCTION installation in any passenger car and it was unique to the Corvette application---it was not installed in Camaros or any other passenger car. Even for Corvettes, it was used only for 1996 models with 6 speed manual transmission.
And, there you have it!
I'll be posting some other information when I get a chance regarding timing set parts used for both big blocks and small blocks over the 1955-2007 period.
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