Part Number: 20000160, 20000161, 20000162, 20002503, 20002504, 20002505, 20002506, 20003488, 20003489, 20003490, 20007211, 20007212, 20007213, 20007705, 20007706, 20007707, 20007708, 20007709, 20007710, 20007711, 20007712, 20007713, 20007714, 20007715, 20007716, 20010271, 20010272, 20010273, 200010274, 20010275, 20010276, SB8008 Applications: Subaru STI EJ25 (2.5L) Disclaimer and Warranty A vehicle modified with Cosworth competition and or racing performance products will not meet the legal requirements for operation on public roads and highways. It is the purchaser s responsibility to check and comply with all local, state and federal laws prior to operating vehicle. Installation and use of performance products may also affect and void warranty and insurance policies. In general, Cosworth Performance Parts carry no warranty. Cosworth, LLC and Cosworth Ltd. shall not be liable for direct, indirect, incidental or consequential damage or injury to persons or property that might be claimed as a result from the installation, improper installation, and failure of part including claims for delay, loss of profits or labor. There are no Index 1. This Page 2. General Installation 3. Before Starting and Engine Break-in 4. General Maintenance, Warranty, and Product Disclaimer Parts List 1 - Complete Subaru STI EJ25 Assembled Long Block 03/24/10 EH v1.0c 1
General Installation Congratulations, you are the new proud owner of a Cosworth built Subaru STI EJ257 long block. A complete engine package which mates the Cosworth EJ257 short block with the Cosworth Big Valve CNC Ported Cylinder Heads using Cosworth high performance head studs and gaskets. Factory valve covers are included and we also install one of our blue-printed, high pressure oil pumps for maximum lubrication. The Cosworth EJ257 short block uses ALL new parts including block castings, crankshaft, connecting rods, pins, piston rings, bearings, etc. The engine is painstakingly blueprinted and assembled by the same engine builders that assemble F1, Champ Car, Formula Atlantic, ALMS, and other professional motorsports engines. The blocks feature Cosworth forged, lightweight, aluminum pistons; billet 4340 connecting rods; and heavy duty tri-metal bearings to handle the stresses of high horsepower. The Cosworth Big Valve CNC Ported Cylinder Heads are brand new Subaru castings, feature a 4-angle intake, and radiused exhaust valve job. They include our proven S2 camshafts complete with valve lash set to our specifications. The Cosworth heads are pressure tested, deburred, ultrasonically cleaned, serialized, and assembled with the highest quality valve train components available. Many hours have been invested in engineering the port design and valve seat angles providing you the highest flowing and most complete Subaru Cylinder Head assemblies available. Your Cosworth Big Valve Subaru Cylinder Heads are capable of supporting over 1000hp. It is strongly recommended that this long block is installed by an experienced tuning shop or mechanic. Your Cosworth long block is intended for off road applications only and not intended for use on street operated or emissions controlled vehicles. This engine is NOT designed for professional motorsports or extreme high horsepower applications. If you require a racing engine program and have a significant racing budget, please contact Cosworth for further details on an engine program. Specific applications (STI) Since this long block is based on the Subaru factory castings, it is designed to be a direct bolt-in replacement for OEM long block. An air to oil cooler using -10AN hoses is strongly recommended to keep oil temperatures below 110 degrees Celcius. For high horsepower applications, the factory water to oil cooler is next to useless. Please take a few minutes to inspect the long block for any sign of damage from shipping. 03/24/10 EH v1.0c 2
Before Starting During the break-in process, we recommend using a high quality API SJ or newer mineral 20W-50 engine oil. We also recommend using a genuine Subaru oil filter. Do NOT use a synthetic or synthetic blend during the break-in process. Replace the oil immediately after the break-in procedure or 500 miles (whichever comes first). We also strongly recommend priming the engine s oil system before starting. To do this, make sure there is no fuel or spark by disconnecting either the ECU or by removing the appropriate fuses and/or relays. Then crank the engine until there is oil pressure registering on an oil pressure gauge (you or your mechanic must install one). When first starting the engine, be sure to keep the engine speed above 2000rpm to ensure the tappet buckets and cam lobes have adequate oil. Engine Break-in It is critical that your Cosworth engine is not started with an excessively rich fuel mixture. An excessively rich mixture will wash away the oil in the cylinders and the rings can potentially never break-in causing excessive oil consumption, crankcase blow-by and lower power output. This damage is permanent. If the engine will be broken in by driving the car, we recommend you keep the engine speed below 4000 rpm. Drive the vehicle at various loads, speeds, and throttle positions while keeping engine speeds below 4000 rpm for approximately 1000 miles or 1660 kilometers. The longer the engine is broken in, the better your results will be. If breaking your engine in on an engine dynamometer, follow the break in procedure detailed below. You can use the guideline for a chassis dynamometer as well, but load readings will differ. If using a chassis dynamometer make sure to keep water temperatures below 95 degrees Celsius and oil temperatures below 110 degrees Celsius. Run at 2000rpm @ 50-60 lbf-ft. load for 20 minutes Run at 3500rpm @ 90-100 lbf-ft. load for 20 minutes Run at 4250rpm @ 100-110 lbf-ft. load for 10 minutes Run at 4250rpm @ 125-135 lbf-ft. load for 5 minutes Run at 5500rpm @ 125-135 lbf-ft. load for 5 minutes Run at 5700 rpm @ WOT for 2 minutes (not to exceed 300 lbf-ft.) During the final break-in stage, the boost should be limited so as not to exceed 350 lbf-ft. of torque. Some initial ECU calibration activity may be required to complete break-in with proper air fuel ratios. The engine should be calibrated to achieve an air fuel ratio rich enough for the type of fuel you are using. Consult with a professional tuner if you are unsure of an air fuel ratio the engine requires. Boost should be regulated so as not to exceed 300 lbf-ft. of torque during the break in process. Once ECU calibration is complete up to 7000rpm, the short block should be ready for a WOT, full power run throughout the entire power band. 03/24/10 EH v1.0c 3
Warnings: PLEASE READ AND UNDERSTAND ALL BEFORE INSTALLING ENGINE!!! 1. We have seen a considerable amount of camshaft lobe failures on cylinder #4. Cylinder #4 is the furthest cylinder from the oil pump. Lobe failures can be caused by excessive cranking of the engine prior to starting, the oil pump not priming quickly enough, and/or by not revving the engine to 2000 rpm immediately after start up to break in the cams. 2. Excessive smoking, blow-by, and high oil consumption are often caused by incorrect fueling on start up with a new engine. Excessive fuel in the cylinders can also wipe the oil layer off of the cylinder bores leading to premature piston ring failure. Once this occurs the rings are permanently damage and can sometimes ruin the cylinder bore as well. The only cure for this is to send the engine back to Cosworth for the repair work. 3. We have seen valve failures at the #2 cylinder due to valve to valve contact when the belt and cam pulleys are installed by an inexperienced mechanic. Follow the directions in the factory Subaru service manual for the correct timing belt installation procedure. We recommend the use of breaker bars to rotate the camshafts so the camshafts cannot rotate in one direction as with a ratcheting wrench or spanner. If a camshaft rotates at any time and valve contact is made, the valve that made contact MUST be replaced to prevent catastrophic damage at a later time. Warranty In general, Cosworth competition and/or performance parts carry no warranty. Cosworth LLC and Cosworth Limited shall not be liable for direct, indirect, incidental or consequential damage or injury to persons or property that might be claimed as result from the installation or improper installation and failure of part, including claims for delay, loss of profits or labor. There are no Disclaimer and Warranty A vehicle modified with Cosworth competition and or racing performance products will not meet the legal requirements for operation on public roads and highways. It is the purchaser s responsibility to check and comply with all local, state and federal laws prior to operating vehicle. Installation and use of performance products may also affect and void warranty and insurance policies. In general, Cosworth Performance Parts carry no warranty. Cosworth, LLC and Cosworth Ltd. shall not be liable for direct, indirect, incidental or consequential damage or injury to persons or property that might be claimed as a result from the installation, improper installation, and failure of part including claims for delay, loss of profits or labor. There are no 03/24/10 EH v1.0c 4
General Maintenance Your Cosworth long block should be maintained more often than a factory engine. Obviously, it is dependent upon how the engine is used, but the harder you use the short block, the more you will have to maintain it. Follow the guidelines below: Immediately after break-in, refill with Mobil 1 Extended Performance 15W-50 engine oil. Use a genuine Subaru oil filter. Use NGK Iridium spark plugs, heat range 8 or colder. Use a low temp thermostat whenever possible. Do NOT remove thermostat from cooling system. Product Disclaimer Your Cosworth long block is much stronger than a factory Subaru engine. However, pre-ignition and detonation will destroy the strongest of engines. During the engine calibration pay attention to knock levels very carefully. Always use the fuel recommended by your tuner and consult your tuner before making any changes to your engine configuration. A vehicle modified with Cosworth competition and/or racing performance products will not meet the legal requirement for operation on public roads and highways. It is the purchaser s responsibility to check and comply with all local, state, and federal laws prior to operation vehicle. Installation and use of performance products may also affect and/or void vehicle warranty and insurance policy. Warranty In general, Cosworth competition and/or performance parts carry no warranty. Cosworth LLC and Cosworth Limited shall not be liable for direct, indirect, incidental or consequential damage or injury to persons or property that might be claimed as result from the installation or improper installation and failure of part, including claims for delay, loss of profits or labor. There are no 03/24/10 EH v1.0c 5