ive got a customer that is wanting a good reliable caar and had bad luck with a forieghn import engine so they bought a brand new short block straight from subaru.

 

im being paid to assemble and install the motor. I had them order subaru genuine headgskets, cam seals, and oil pump, ngk pugs and wire, felpro valve cover gasket set, fuel filter ect.

 

it just had a gates timing belt kit put on it with a new ntn tensioner, and subaru high flow water pump and a subaru thermostat.

 

what i would like to know is what is the install prcedure for a new short block? do i need to use any special kind of oil for a break in period? is there a break in period oil change interval?

I would follow the same procedure for breaking in a completely new motor. Wont hurt the used stuff but will help the new. I seem to remember the owners manual of my wifes 2011 (with SOHC EJ25) having a break in procedure to it.

Use 5w-30 conventional oil. All you're really doing is breaking in the rings, so they need lots of oil. No special additives, just clean oil. Don't let it idle for long until you get it up to operating temp. Keep the RPMs between 1,500-2,500 to keep from fuel washing the cylinders.

 

I usually change the oil after the first hour or so of running, then at 100 miles of normal driving. Then again somewhere between 500-1,000. You can change to synthetic after this if desired. No long steep hills or heavy acceleration, but don't drive like grandpa either.

Keep the RPMs changing so the rings see different pressures while they're breaking in.

Make sure the cooling system is full before the first start so you don't get an overheat condition waiting for the thermostat to open. Fill the block with coolant through the upper hose.

 

If the tensioner is the one peice type I would replace it. Those don't take well to being re-compressed and re-used.

 

Also on the first start, if you can, leave the plugs out and unplug the injectors. Crank the engine over with no load until the oil pressure light turns off.

Pre-fill the oil filter so you don't have to wait for the pump to fill that before the engine gets oil.