Verocious uses Raw Performance motors in all the Subaru vehicles we service that require a new long or short block assembly.

The following is Raw’s recommended Initial Start Up and Engine Break-In Procedures for Subaru Motors.

Short Block/Long Block without New Camshaft Install -

First, go back and double-check all hose clamps, fittings, and fluid levels. Even if you think you did it, check it again. It is also much easier if you have a second person helping you at this point.

Disconnect the big black and big brown multi-pin wire harness connectors. On turbo models these are located right behind the stock battery mounting location. On stock non-turbo cars, these are located on top of the transmission bell housing behind the intake manifold.

Make sure the engine is full of new non-synthetic oil (see oil suggestions below) and that the oil filter is also full of oil and hand tightened to the engine.

Turn the key as if you are going to start the car. You want to engage the starter for 10-15 seconds then release. Repeat this 5 times.

Disconnect the negative side of the battery and push the break pedal. This will quickly reset any codes you have stored in the ECU from cranking the engine with those connectors unhooked.

Reconnect all connectors and the battery. You are now ready to start the engine for the first time.

It should start right up, but if it doesn’t - don’t panic and try to start it again. If after 5-6 seconds of cranking, the engine does not start, it’s not going to. You need to go back and check everything again with the wiring and fuel system.

Once the engine starts, you IMMEDIATELY need to look at the engine oil pressure warning light and your oil pressure gauge if you have one installed. If the oil pressure warning light does not go out right away, turn off the car and recheck the connection to the oil pressure sensor. It is located on the front of the engine block underneath the alternator (stock location). If connection is fine, restart the engine.

If again the oil pressure light does not go out after 5 seconds, turn off the car. You need to go back and recheck your work.

Once you have the engine started and you have oil pressure, you want to run it at idle for a short period of time then rev the engine to 1500 rpms for 5 minutes. Hold it steady at 1500, try not to vary the revs too much.

Keep an eye on both water temp and oil pressure light or gauge if one is installed. Water temp should climb slowly and rest at just below mid point on the stock gauge. The second person should be checking for any leaks or uncommon noises coming from the engine during this time.

After 5 minutes, if you have no leaks and everything seems fine, let the car idle for a couple minutes and then shut the car off and let it cool down for 15-20 minutes. After it has cooled some, recheck all fluid levels again and you are now ready to drive the car, following the engine break-in procedure.

If you are only changing out the short block, and all other parts remain as they were on your old engine, you need to only recheck your air/fuel ratios. If you have changed any other parts with the new engine like ported heads, cams, turbo, injectors, intake, exhaust, etc, you need to be making ecu adjustments (if possible) to insure proper break-in. If you cannot make any changes, you need to source someone who can.

Engine Break-In Procedures

The first 300 miles should be driven with NO BOOST AND NO MORE THAN 4500RPMs. You want to do as much city driving as possible (lots of stop and go driving). As you are coming to a stop or slowing down, you should be downshifting and letting the engine do some of the braking work. If you do accidentally see some boost, that’s ok but try not to use any boost if possible.

New forged piston engines will use some oil during run-in. You want to keep an eye on your fluid levels at all times during the break-in process. Again, you will typically use some oil during the break-in process.

New forged piston engines also make more noise than stock engines do, so do not be surprised to hear more sounds coming from your engine. The sounds should be light tapping noises and start to settle as engine temp builds. If at anytime you hear anything that sounds unusually loud or gets louder as revs increase, do not run the engine until you can deduct what the sound is.

After 300 miles, change the oil/filter. Take a look at your oil. It will look dirty and probably have a swirl effect to it. That is the moly that is contained in the assembly lube. You should not have any metal flakes, chunks, etc come out with the oil. If you do, contact us ASAP and do not restart the engine. If the oil smells like fuel, that is a good indication you are over-fueling the engine and you need to do some more tuning to correct this. If you want, you can cut apart the filter to inspect for metal in the oil.

Install new oil/filter and recheck all fluids again. Now you can start running some boost and revving the engine a little higher.

Next 1200-1500 miles can be driven with boost pressures up to 10-12psi. This is usually wastegate set pressures for most turbos and external wastegates unless otherwise altered. Try to keep boost at no more than 10-12psi.

For every 250 miles you drive, you can increase the engine revs by 250. So at 550 total new miles you can now rev the engine to 4750 rpms. You want to follow these building steps up to your desired/new engine limited redline. It is suggested you set the rev limit at 7000 rpms at first.

As with the first 300 miles, you want to keep aware of your air/fuel ratios and make adjustments as needed.

After a total of 1500-1700 new engine miles, you should change the oil/filter again and can now have the car dyno-tuned if desired. Do not exceed any limits set for the new engine like RPMs and boost. The blocks Raw offers do not have a hp limit assigned to them, they only have rpm and boost limits. You must stay within those rpm and boost limits at all times. Enjoy your new engine and thank you for your business!

Suggested Break-In Oils

We like Shell Rotella-T 15-40 weight for all break-in mileage. If you are in an extremely cool climate, you will want to consider a lighter weight of oil like 10-40 or 10-30.

You can continue to use the Shell Rotella-T oil after completion of break-in if you wish. If you do switch to full synthetic, be sure to run a quality product.

Spark Plugs

For all WRX/STI 2.0 liter heads, we suggest NGK BKR7E plugs. For all US STI and turbo 2.5 liter heads, we recommend you use either NGK-LFR6A-11 or standard Subaru part NGK-ILFR6B. Plug gaps should be set from .031”-.035”. Spark plugs should be new at time of engine install and checked at end of break-in procedure and replace if needed. Do not run used and/or fouled plugs.