Motor Oil for break in

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word

Senior Member
Why do people always say use non synthetic non detergent oil for break in? The rings and bearings are broken in after 20 minutes of driving......why not use synthetic oil if it lubricates better?

someone please give me an explanation. i'm thinking about using castrol syntec 5-30W for my newly rebuilt motor (12:9 compression)

thanks
chris
 
Originally posted by word@Sep 18 2004, 12:46 PM
Why do people always say use non synthetic non detergent oil for break in? The rings and bearings are broken in after 20 minutes of driving......why not use synthetic oil if it lubricates better?

someone please give me an explanation. i'm thinking about using castrol syntec 5-30W for my newly rebuilt motor (12:9 compression)

thanks
chris
[post=391891]Quoted post[/post]​


The rings and bearings are not broken in after 20minutes of driving, and even if they were that 20minutes with a synthetic would make it harder for the rings and bearings to break in properly.

You are only supposed to use a non detergent oil if your engine was rebuilt in a clean room. Otherwise just use a regular nonsynthetic oil.
 
the reason you dont use synthetic on a rebuilt motor for break in is because the rings and cylinder wall must have some sort of wear pattern, the synthetic oil doesn't let the rings score properly. just use regular oil whatever viscosity you plan to use change it at 500 miles and 3000 miles and switch to synthetic if you want ;)
 
i've read that site, but my engine is NOT tuned yet and I'd hate to have any pinging on a new block. I'll be using 93 octane gas and some octane adder from autozone, retard the timing and crank up the fuel pressure to keep the detonation to a minimum.


I guess I'll use Mobil 1 5-30W non synthetic, the motor was assembled in a garage.

thanks a lot!

chris


Originally posted by h82w8+Sep 18 2004, 02:46 PM-->
@Sep 18 2004, 02:36 PM
http://www.mototuneusa.com/break_in_secrets.htm
[post=391939]Quoted post[/post]​

:suprised: :eek3: :eek3: :eek2: :eek:
...seems like something I would test on a chainsaw or something first!
[post=391944]Quoted post[/post]​
 
Originally posted by word@Sep 18 2004, 05:42 PM
I guess I'll use Mobil 1 5-30W non synthetic, the motor was assembled in a garage.
[post=391981]Quoted post[/post]​


:thumbsup:
 
Originally posted by word@Sep 18 2004, 05:42 PM
I'll be using 93 octane gas and some octane adder from autozone, retard the timing and crank up the fuel pressure to keep the detonation to a minimum.



That would be the stupid thing to do, when starting a fresh engine, you should have stock fuel pressure of 42 psi, stock timing of 16 degrees BTDC, and i dont recommend using octane boost.

I just started my motor last week and have put 350 miles on it so far with the slow break in, and did a compression test and i got 180 psi across the board. Im running low comp pistons thats why it seems relatively low.
 
i'm not sure how the engine will idle, i'll have a 255lph fuel pump, FRP, 310cc injectors, and a stock p28.

I guess under closed loop it'll be okay because the ecu will adjust the fuel curve by the o2 sensor readings.....but anything higher than 25% will send the ecu into open loop and i'm pretty sure the fuel map is not sufficient for the new motor.
 
I'd change the oil a bit sooner than 500 miles. Get one of those magnetic oil pan plugs too, It will keep the ring and wall material that wears down from cycling through the engine and clogging the filter. Using synthetic oil is not going to keep your motor from pinging, if it IS going to ping, it will regardless of what motor oil you use. 12.9 is kind of high, maybe you should just invest in a couple gallons of race gas to break it in with, that way you can run stock timing and fuel maps and have no worries.
 
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