Engine Break-In - A few questions?

[modifiede30]

We'll the engine is in and has about 200 miles on it now. Before its driven too much more, I'd like to get some recommendations on breaking it in the rest of the way.

What is a recommended oil weight for a new engine?

I know you're supposed to take it easy, but what does this really mean? Should it be held under 4500 rpm, or something lower/higher?

Since its driven on the highway, is there a speed that should be set as the max until after breakin - say 70 mph or is something higher/lower more appropriate?

I've also noticed that the head is ticking - this surprised me since everything is new which made me think it was somewhat normal with a performance cam (274/275 with 11.4mm lift). Does a performance cam typically make more noise, and what is a recommended lash setting? I was told between .011 to .014 and set mine to .012. I assume the range is necessary to account for piston/valve clearance issues in cars with varying compressions and "squish" clearance. Given that this is a relatively low compression stroker (around 9.4:1), the clearance shouldn't be much of an issue. Anyway, should they be ticking and if not, should I reduce clearance or increase it?

[M-technik-3]

Light weight oil to medium weight oil. If you want a fast engine drive it like you stole it. If you want durability keep it under 4500 or 2/3rd throttle.

Cessna's use mineral oil for break in process but they also dont have a oinl filter and run better gas yet are still carbed.

The cam will need adjustments to get noise to go away. Remember it just went in you haven't even done an oil change so Let it get broken in then do adjustments to quiet it down.

[Stu]

Break it in on 10-30 conventional oil. Go to synthetic after the first 3000 miles.

For the first 500 or so miles, keep the revs under 4500, but constantly load the engine. Make plenty of full-throttle runs up to 4500. Once you get about 500 miles on it, buzz it occasionally in the lower gears (1st, 2nd, 6000+ rpm), but keep it below 4500 in the higher gears. The reason for not revving it in the higher gears is to keep the rings from getting hot and forming to inconsistencies in the bore (assuming the motor was bored out).

Do that until about 900 miles, then do as you please

[ChocolateKrackers]

A magnetic oil filter sleeve to collect micro metal particals. It'll save your bearings atleast untill it's thurougly broken in.

[modifiede30]

Here are some interesting veiws on the engine break-in process. Hmmm.

http://www.mototuneusa.com/break_in_secrets.htm

I did some searching on the subject and most if not all articles indicate that you're better off driving it hard in the first few hundred miles than soft, to ensure the rings seat properly. Thoughts?

[ChocolateKrackers]

Agreed. If it's going to wear out after a rebuild it'll do it practically imediatly rather than if you baby it. Who did your work?

[M-technik-3]

You need to set the rings gently not abuptly. If not you will have increased oil consumption and loss of compression due to blow by. The drive em like you stole it method does not work for me.

just my opinion.

[decay]

If you want a fast engine drive it like you stole it.

i always wondered about that. when i got my new gti-vr6 a couple years back everyone told me to take it easy; but being a 20-year-old with his first compact six-cylinder car, i beat on it like i was trying to break it from day 1-

20k miles later i killed another VR6 guy visiting from seattle- his car had all the bolt-ons i did, plus headers and schrick cams...