Limited Edition 427 zl-1 Big Block v8 for Sale – and the latest big block
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Latest 427 cu in racing factory GM big block engine is the 427 ZZ427, based on the design of the all-aluminum ZL-1 engine used by the CanAm racing cars. At the same time (2007) GM launched a similar engine but with a cast iron cylinder block, to reduce costs. Both engines develop 430 bhp and 450 lb ft, which is well below what the current 427 produces.
For example, the 427 engine in the Corvette develops 500 bhp, and can be tuned to develop a lot more power. Like all these GM V-8s, the new ones have the standard deswign that has been around in GM since WWII – a five main bearing crankshaft pushrod ohv and two valves per cylinder. And all except the ZZ427and the ZL-1 have cast iron cylinder blocks, despite that fact that considerable weight saving can be made with an aluminum V-8 – about 100 lb per block. GM is nothing if not conservative in development. Occasionally, you can find a limited edition 427 zl-1 big block v8 for sale, but it will cost more than these new engines.
These engines are designed to accept the front end ancillary drives produced by GM Performance Parts. Also, the engines have four-barrel carburetors like the originals, although the use of GMPP’s fuel injection system would make more sense. Only 427 engines will be produced to the ZZ427 design, and these should be capable of producing 550-600 bhp with the correct components like camshafts, fuel injection and tuned exhaust systems.
Despite their advanced design, the two new engines are similar to the original Chevy Big Block V-8, and the latest version the Chevy drag racing V-8. The original DRCE2 (drag racing) engine, limited by regulations to 500 cu.in, has since been modified many times, but retains the same basic layout as dictated by the drag racing regulations. The current engines have wider blocks for improved crankcase breathing, better lubrication and other improvements, but retain the original wedge-shape combustion chambers.
To improve performance at high speeds, the camshaft is mounted higher in the block, so that pushrods are shorter, thus reducing reciprocating weight, while this position also reduces bending of the block from the loads imposed by the high-lift camshafts.
The camshafts are carried in roller bearings, to reduce friction, and the main bearings are smaller in diameter for the same reason. The big block chevy crankshaft dimensions are bigger than the 2.50 inch diameter main journals, and the block height is 9.25 in. Overall, this is a very efficient engine produced at fairly low cost for a special purpose.
All these engines out-perform the famed high performance 396 chevy big block engine.
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Posted on: Wednesday, September 2, 2009 at 4:08 pm 
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