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Assembly and Break in Instructions for SOHC EJ25

Subaru SOHC ARP Head Stud Install Steps:

1. Clean the deck surface of the block and cylinder head with brake clean and a clean lint free towel
2. Install dowel pins if they are not already installed
3. Put the head gasket on block, making sure the oil passage hole is on the correct side
4. Clean the Head studs with brake clean
5. Apply motor oil to the bottom thread that goes into block
6. Thread the 2 middle studs into block hand tight
7. Put the Cylinder head on to the block being careful of the deck surface and making sure it is seated all the way down on dowels
8. Clean stud washers, and put into cylinder head making sure there is no lube on the bottom side towards the cylinder head
9. Put the outer 4 head studs through the washers and head tightening hand tight
10. Use a small brush and apply ARP lube to the top side of washers and stud threads
11. Clean Head Stud nuts, apply ARP lube to them and thread onto the Studs
12. Torque to 30-60-90 ft-lbs in OEM sequence

Valve Lash:

After Heads are torqued down, you will need to set valve lash to 0.008” intake and 0.010” exhaust. You do this after torquing the heads down because it changes with the heads torqued down. We have a detailed YouTube video for Valve Lash, Link below.

https://youtu.be/L29hgaE5jRM?si=xgNXvcl2Y24kIlTs

Timing Belt install video:

https://youtu.be/NSlB747MfpI?si=ecv88LGiSjy6QbUs

Break in Procedure:

We recommend using Driven Break in oil BR30 and Six Star Magnet oil filters:

1. Prime the engine oil before the first start of the car by unplugging the cam sensor, crank sensor, and removing the spark plugs. Once these are unplugged/ removed, you will crank the car to build oil pressure and circulate oil through the engine. It can take multiple 30 second cranking intervals for the oil pressure light to go off.
2. Plug cam and crank sensors in and start the car, run the engine at 2000-3000 rpm for 30 minutes with no load. Make sure the engine gets up to temperature, and check for leaks. Make sure the fans kick on and kick back off and the coolant system has been burped of any bubbles. 
3. Change oil to new BR30 and drive the car for 500 hundred miles, just normal driving varying load. Don’t beat on it yet.
4. Change oil again for the new BR30 for 1500 miles.
5. The car is ready for regular oil and hard driving. We recommend Driven GP-1 oil 10W30 or 10W40. If you have an oil cooler, you can hook it up after the engine is broken in.