The Mark IV - James Copeland

June 13, 2012 - PRLog -- In 1966 the 427 cubic inch version of the Mark IV engine was introduced as a production engine option for the full-sized Chevrolet’s and Corvette’s. The bore was increased to 4.25 inches with varying power ratings. According to James Copeland there were smooth running versions with hydraulic lifters suitable for powering even the family station wagon. Chevrolet manufactured the Big Block 427 until the mid 1990’s. James Copeland goes on to mention that the only 427 available from 1972-1995 was a truck version that was used in General Motors medium duty trucks like the Kodiak and the GMC Top Kick. From the years 1988-1995 the throttle body electronic fuel injection was used on the 427.  Things weren’t always that easy because not every version of the 427 was available in every car. If you wanted to order the highest performance version that would mean sometimes having to add or delete other options form the car. This difficulty with engine configuration and vehicle options gave the 427 the nickname: “racing taxicab” because the car was minimally equipped and plain looking like a taxicab. The Big Block was also known as the “Bisquick” adds James Copeland. The Bisquick was a popular engine often used in the Corvette. You can read more by visiting James Copeland’s blog-site at: http://todaysmusclecars.com/the-427/ .

Once again the big block was expanded for 1970 to 454.2 cubic inches.  In 1970 the Chevy Corvette LS5 version of the engine made its debut with a powerful 390 horse power engine. The LS6 had a horsepower of 450 and some folks say that it was under rated. People believe that the LS6 actually had a horsepower of well over 500. The problem was that there was no way of proving the claim. According to James Copeland the AHRA ASA Class record holding Chevelle LS6 for the 1070 season posted a best of season trap of 106- that’s 76 miles per hour 350 horsepower for a combination of driver and 3,900 pound car. Super Chevy magazine had their say and conducted a chassis test of a well tuned line stock 1970 LS6 Chevelle and recorded 283 horse power at the wheels. According to James Copeland this lines up with the previously referenced 350 SAE$ Net horse power figure. Another model was deigned but never made it to production-the LS7 which was 465 horse power and 490 pound version of the 454. The funny thing was that a few LS7 intake manifolds were produced and actually sold by a few Chevy Dealers as performance parts. To read more log on to: http://todaysmusclecars.com/the-454/ .

The LS7 was one of those engines that could be considered a true muscle engine. Did you know that this engine was later offered as a crate engine from GM and advertised at 500 Gross horse power? Now that’s one powerful engine adds James Copeland! You can read more about muscle cars by visiting James Copeland’s blog-site at:  http://todaysmusclecars.com/ .