Name that sound!!!

[ProjectSQ]

Unfortunately I listened to the shop again and actually went nearly 500 miles on initial start up oil. I was only ok with this because: A) the shop said it would be fine fml. B) I couldn't find anymore VR1 10w-40. Normally I've changed the oil right after a heat cycle, again at 50, 500 then at normal 5000 mile intervals. (That's what I get for changing up what has worked)

When it comes to piston wall break-in you actually want a more aggressive approach. Whet I've done and have had solid compression numbers is for several miles even some times after first drive I would be on a long stretch and vary my speed around 20 or so mph putting load on the engine then full engine decel. This helps "seat" new piston rings to the cylinder walls.

[KiLLeR2001]

If I remember correctly, my procedure was...

- First start up, run it on conventional oil until it warmed up, then drain + new oil filter.
- 500 miles conventional oil driving normally, not babying it but not beating on it either. Drain + new oil filter.
- Switch to synthetic oil, drive it hard, baby it, and everything in between for 1000 miles. Drain + filter.
- From then on out 5000 mile intervals on synthetic oil.

This was all with 10w-30 weighted oil.

[Matej]

Anyway, back to the OP's inquiry, I am pretty sure the sound is caused by all that dust rattling around between the mating surfaces of your engine's components because you did not rebuild it in space.

[ixfxi]

matej...

dont be a crass sunovabitch....

building a motor in space still requires a hepa filter, possibly two... because of the cosmique dust. trust me, combine that with comets, sun rays, and alien pollution and foreign matter and youve got yourself a problem