So my gsr head has new valves, seals and guides and has been shaved. The bottom just has new piston rings. How must i break in the engine?

 

bump

 

Stock Valvetrain? How much milling did they do on the head? Are you running a stock computer? On a completely new motor (valvetrain to bearings) I just checked the AFR's, ran it for about 30mi. and then changed the oil, rechecked the AFR's and beat the **** out of it since then. Perfect Comp. & Leakdown #'s.

Or you can just baby it for 500 miles like alot of the older guys say.

 

well from a few articles i read they say to do a lot of hard accel and braking for 20 miles then change the oil(non syn.). After that, drive normal for about 200 and change it again. Then switch to syn. at around 1500mi...Any other opinions?

yes its stock

 

I would stay away from synthetic until 5k+ miles, no need for it that early. What is your compression ratio? If it is raised from stock you need to make sure the car is not running lean or you will hurt the rings.

 

compression is stock(it wasnt shaved mucH). How do i drive it after the first 20 miles of hard running?

 

Idle to redline a few times, running regular oil, change ur oil do it again,

basically all this hype about breaking in motor softly is completely overrated / wrong
when you do this, you wear down your rings do they dont seat propertly if u want me to find a extact layout thats fine i can do so, but becasiclly about 5 times from idle to redline, go change ur ip do it again, then u can drive it regular, using syn for breakin is a no no, it doesn't ally things to seat propertly, after ur done with about a 100 mile break in, go ahead change ur oil, to syn..mobil 1 ftw.

 

btw, if u dont have anything other then a stock ecu, dont even start up ur car until u get awideband in there..to make sure ur not running too rich or too lean.

 

its all stock....I bent 6 exhaust vavles so i decided to do all this since i had the motor apart...The rings arent in yet but will be by tomorrow. So basically beat on it for the first few miles, then change oil?