Written in 2002, revised 2010 and 2017
The A-4 is a racing engine based on the LA 5.2/5.9 V8, available for years from Mopar Performance. There are three major blocks:
These A-4 aluminum blocks use many Chrysler small block components, with corrected valvetrain geometry (a problem with the LA since it was designed) and a shorter deck height. They were dyno tested and factory sealed for consistent output.
The midget block was listed at $6,121 (we found it for $5,600) in 2010, with cast iron sleeves, billet steel or billet aluminum main caps, a main cap stud kit, and mounting hardware. It had an unfinished 4.130 in. bore with 8.40 in. or 9.00 in. deck heights; it accepted W9 raised-port aluminum cylinder heads for sprint or Midget racing.
The drag race block listed $5,217 in 2010; it now shows up as having been discontinued. The wedge-head race blocks, listed as being designed for USAC Midget and drag racing, ran $6,644, list, in 2010, and now shows as being discontinued. Both came with steel billet caps, ductile iron sleeves, and a hardware kit.
The block top deck is extra thick to allow for O-ringing and forced induction. One racer said, “People using this engine are walking away with all the marbles over the GM ‘Iron Duke’ based engines. Coupled with a Hewland EGT series transaxle, this engine in a lightened Neon (prepped like Gary Donovan’s 10 second Reliant), should be able to dip into the mid to low 9 second ET range in the quarter mile due to lighter potential weight and higher rpm capability.”
The racer continued, “A pair of turbos, sequentially fed through proper charge air cooling, should push the motor to over 600 hp and have far more durability that a 2.2/2.5 or 2.0/2.4 engine, and a higher rpm range.
“The Hewland transaxle mentioned earlier is $16,000 - the price of being the best. A race car of this type costs anywhere from $35,000 to $85,000 to be competitive. NASCAR cars cost from $80,000 to $160,000 each, if not more.”
When this article was written, the cost for the block (semi machined) was about $1,000 and the Hemi head was about $800 bare and semi-machined. These pieces were released in the 2002 Mopar Performance catalog. The cool looking magnesium valve covers were on page 116.
As far a this engine ever being a “production car piece”... it was intended strictly for racing, and does not meet EPA standards for street engines.
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