The LA-Based Four Cylinder Racing Engine
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."
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:
-
- P5007467 drag race block (V8 flywheel housing for RWD transmissions) for P5 Hemi head; now discontinued
- P5007636 wedge-head race block (fits W8/W9 heads and V8 flywheel housing for RWD transmissions); now discontinued
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 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.
| Dressed midget motor, with cam-driven, dry-sump oil pump and distributorless ignition. |
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."
Unmachined: rear wheel drive flange for using an A727, A833, etc |