Second Generation Camaro Engine/Induction/Exhaust FAQ

Which engines were available for the Camaro? Bowtie, or heavy duty (nickle) block identification Why were the horsepower ratings on engines often under-rated? Do I have "Dual Exhaust" or do I have dual tail pipes? Is the 400 engine a small block or big block? Emission Hose Routing How do I install a big block in my car? How to install electric fans Q: Which engines were available for the Camaro? A: Part of the success of the Camaro was the wide variety of engine options that were available. Here's a summary of the available factory domestic engines (other engines were used in export models and some dealer-modified Camaros (LS6)): Note: The yearly Camaro information has specific power team information available. L22 250ci/100HP L6 1BC - Base Engine, 1970 - 1979 LD5 231ci/110HP V6 2BC - 1980 & 1981, California Only, Buick. LC3 229ci/115HP V6 2BC - 1980 & 1981 L14 307ci/115HP V8 2BC - Base V8, 1970 - 1973 L39 267ci/120HP V8 2BC - 1980 & 1981 LG3 305ci/140HP V8 2BC - 1976 - 1979 L65 350ci/145HP V8 2BC - 1970 - 1975 LG4 305ci/155HP V8 2BC - 1980 & 1981 LM1 350ci/160HP V8 4BC - 1974 - 1981 L48 350ci/200HP V8 4BC - Horsepower varied, considered performance engine. LT1 350ci/330HP V8 4BC - Z-28 only 1970 - 1972 LS3 396ci/260HP V8 4BC - SS only, Q-Jet, 1971 & 1972 L34 396ci/350HP V8 4BC - SS only, Q-Jet, 1970 only. L78 396ci/375HP V8 4BC - SS only, Holley, 1970 only. Q: What is a Bowtie, or heavy duty (nickle) block and do I have one? A: Tin and nickel are two metals that are commonly alloyed with cast iron to improve durability, hardness and heat dissipation. Some production engine blocks have the numbers "010", "020" or both cast into their front face, just above the main bearing bore. (The timing cover must be removed for these numbers to be visible.) If both numbers are present, one about the other, it indicates that the block alloy contains 10% tin and 20% nickel. A single number, either a "010" or "020" represents the amount of nickel and indicates negligible amounts of tin. No numbers, other than the casting numbers that are typically found beneath the timing cover, translates to only minor amounts of tin and nickel being present in the block alloy. However, cylinder wall thickness is the overridering consideration - and a block with no tin or nickel and thick cylinder walls is generally preferable to a high nickel block with thin walls. Q: Why were the horsepower ratings on engines often under-rated? A: There's 2 reasons for this: Reason 1: Insurance purposes. Insurance bean counters look at tables and statistics to determine insurance rates for various cars. One of the factors in determining how to rate a car is "Factory advertised horsepower". The factory said the car makes 290 horsepower. In reality it makes closer to 350. Oops. Reason 2: Classification for Racing. In some forms of racing (Drag racing) cars are classified according to "Factory horsepower". Again, if the car is rated at 290 horsepower (but really has 370 horsepower) and it's going against a car that REALLY DOES have 290 horsepower. Oops. Q: Do I have "Dual Exhaust" or do I have dual tail pipes? A: There were several different exhaust systems offered on the Camaro. Performance cars generally have dual exhaust, which helps eliminate exhaust system back pressure. The catalytic converter made it's debut in 1975. No Camaro had dual catalytic converts (due to cost). Since only a single cat was used, each side of the exhaust dumped into a "Y" pipe and entered the cat. This right here turns the exhaust into a single system. Old dual exhaust had separate systems for each side of the engine. This would then go into one transverse mounted dual chamber muffler and exit out the back with dual tail pipes. Generally, all 6 cylinder Camaros had a single exhaust, single tail pipe. V8 cars had a single exhaust, to a single transverse muffler, with two tail pipes. The (1977+) Z28 technically had a single exhaust, with dual resonators. It's not uncommon to see dual mufflers under a car. These are aftermarket dual exhaust systems. Q: Is the 400 engine a small block or big block? A: Ah, here's a source of confusion. Chevrolet made a 400 cubic inch Small Block Chevy engine. It was considered for use in the 1972 Z28, but this was never done. The 400 was commonly used in full size cars, station wagons, Chevelles and trucks. Chevrolet also made a 396 Big Block Chevy engine. From 1970 to 1972 this engine was installed in some Super Sport Camaros. However in 1970 this engine was overbored .032" so it was technically a 402 cubic inch engine. It was badged as a 396 if installed in a Camaro. At the time, GM/Chevrolet had a policy or limit of "400" cubic inch or greater engines being installed only in mid or full size cars - not the Camaro. This is why the LS6 idea was deep-sixed as well. So there it is: Chevy DID make a 400 ci small block, but it wasn't used in the Camaro. Chevy DID install the 396 (actually 402) into the Camaro from 1970 - 72. This is a 396, or technically a 402 - but it was never called a "400". To say 400 IMPLIES the small block engine.