Break In Motor Oil

[agro1]

Hey guys - They are getting ready to fire my new motor today (new short block), and I plan on running synthetic in it. The shop however, is telling me NOT to run synthetic in it for the break in (1000 miles). Is this correct ??? I mean lots of new cars come from the factory with Mobil 1. Any hlep would be appreciated.

Luke

 

[MUSKYMAN]

kendall 10/40

I have a friend that is a world famous engine builder....he swears nothing but nothing is better then "green slime" to break in the rings of a fresh engine.

the kendall is dark green like 2 stroke oil and its sticky like moly oils. also 1000 miles is pretty long, he always says 4 hours of run time then 8 hours on the second batch of oil then run what ever oil you want.

good luck with the new block

Thom

 

[agro1]

Thom - Yeah, I was thinkin' the same, at least in regards to break-in time. Lots of little particles in a new motor that I don't think should be circulating through there for 1000 miles. Thanks for the reply and the tip on the Kendall

 

[rover4x4]

I was always under the understanding just to use standard dino stuff for the first little while and change the filter a few times for the first 1ooo-2000 miles... then swap to the syn

 

[agro1]

rover4x4 - Thanks for the reply, I have always heard the same, but just wondered why it's better to break in with dyno oil as opposed to synthetic. Thanks again.

 

[Disco Mike]

Luke,
Do your self a favor and use regular oil of you choice for the first 6000 to 8000 miles. This way you will be assured of having the rings really seat in then switch to your synthetic. If you do it at 1000 miles chance are you won't have all the compression you want from your rings.
Good luck,
Mike j.

 

[agro1]

Mike - Thanks, I've heard the same thing from many mechanics as well regarding the rings. Why is it though, that dyno oil makes rings seat better than synthetic ? Is it because the dyno oil has more viscosity ?

 

[Disco Mike]

Luke,
Dyno lube is not nearly a perfect lube like the synthetic. Back in the 60's engines were actually shipped with a " break in oil" in them, the rings would seat in quickly and it was done. Most mechanics will tell you that if you start a new engine on synthetic it will never break in and you will burn oil and have less performance.
Mike J.