EJ25 Shortblock Assembly | Stage 1 (Subaru WRX/STI)PART# MAP SUB-SB-25-S1
$ 2,749.99 $ 3,099.99
Stage 1 EJ25 Shortblock Assembly
Modern Automotive Performance won't settle for anything less than the best when it comes to our engine building program and our reputation. Only the best quality components along with specialized machining and assembly techniques for each individual platform are used to ensure the best possible performance and longevity. When it comes to Subaru engines, MAP makes no exceptions.
- Crankshafts are never cut / turned and receive a micro-polish treatment and balancing specifically for high performance applications.
- The First step in the machining process is resurfacing. We pride ourselves on the surface finish (RA) we achieve as it is of the utmost importance in regards to head gasket sealing.
- Next, we bore the sleeves square to the deck surface. EJ25 specific torque plate is used to ensure roundness. The overbore is followed with a four step plateau honing process that provides the absolute best cylinder wall finish and ultimate ring seating.
- OEM Main and Rod Bearings (except for used cores which include ACL or King race series engine bearings, also available as an upgrade for new cores)
- Stock EJ25 Connecting Rods
- Forged Pistons
- Crankshaft: We use standard size OEM crankshafts most frequently as we have not had a crankshaft failure to date. However, we realize that there are weight advantages and stroke options available with some aftermarket crankshafts so we will happily build your shortblock accordingly!
- Pistons: We offer our two most popular pistons Manley and Wiseco as options. If you would like to go with a different brand of pistons please give us a call.
No core? No Worries! Simply select a new OEM EJ25 shortblock below for us to use as a starting point. New OEM shortblocks require much less cleaning, preparation and machine work compared to used shortblocks, so even though a new shortblock purchased separately would be $2000+ the difference in price here is just $835!
Why Choose a MAP-built Engine?
We won't settle for anything less than the best when it comes to our engine builds. We utilize quality components along with specialized machining and assembly techniques for each individual platform to ensure the best possible performance. If we see a gap in regards to acceptable product offerings on the market we often times develop our own like the Ultimate Duty Connecting Rods. We thoroughly inspect, blueprint, clean and assemble our engines in a clean room and most of the machine work is performed in house to satisfy our stringent requirements. We have had great success in building countless motors for every imaginable application from the weekend warrior to the all out race car.
Please note that this product is built to order. Based on fluctuations in demand build times may vary throughout the year. Please contact an MAP sales representative for current estimations.
Ready to start your new engine? Check out our Engine Break In Procedure for the proper way to break-in a fresh engine!