[SBCfan04]

i know there are a lot of different opinions on breaking in an engine. I was curious what your opinions are on how to break in a new engine.

[Overdriv]

From my experience the rings are seated after the cam break-in time which should be at least 15-30 minutes at about 1500RPM steady in one setting. If it's still smoking after 30 minutes, you got a problem.

Let the engine cool down to ambient, then just drive it normally with no WOT banzai runs for the first 100-200 miles. Vary the speeds. Break it in slowly.

Change the oil and filter after 200 miles or so and again at 1000 miles.

The slower and easier the break-in, the longer it will last.

If you are using a flat tappet cam and especially one with a lot of spring pressure, you probably will want to change the oil and filter after about 25 miles.

Use an additive like EOS or Comp Cams break-in additive( not sure what it's called) till you get at least 5000 miles on the engine.

Everyone has there own ritual they follow but the main thing to remember is to have the engine ready to run without overheating or having to stop to fix fuel/water leaks etc for that critical time period of camshaft break-in.

Let your engine thermal cycle three or four times before any long trips. A lot of short trips with a mix of highway and town driving with a complete thermal cycle between them is good. Always let it warm up before driving, even in the summer months.

[68NovaSS]

Do a search here, there are many many posts about engine break-in in the knowledge database.

[GenYnNC]

If it is a flat tappet engine- make sure to use some oil with appropriate levels of z & p.

THis is my flat tappet break in ritual.

Assuming you have already primed the engine and have your timing 'near' correct.

I start the engine, bring to 3,000 rpm for the first 10 minutes consistently, and then vary from 2,500 to 3,000 for the next 25 minutes.

Change oil and change filter after the first 35 minutes.

Let engine cool COMPLETELY.

Crank again, bring to full temp, then makes some redline blasts, how many is up to you. I drive the heck out of the car for the next 500 miles.

THen change oil and filter again.

Then drive for 3,000 and chang oil and filter again.

my 2 cents.

I do agree with the statement above, if the rings are not seated in the first breakin (30 minutes or however long you run it) you got problems.

[tnovot]

[QUOTE=Overdriv]From my experience the rings are seated after the cam break-in time which should be at least 15-30 minutes at about 1500RPM steady in one setting. If it's still smoking after 30 minutes, you got a problem.
QUOTE]

I wouldn't run a steady engine speed at any RPM for cam breakin because oiling patterns and charasteristics are different at different RPM's. Most cam manufactures say to vary RPM from around 2000 to 2500 for about 20 minutes for breaking in a cam.
You have gotten lots of good advice from Overdriv and others about wearing in engine parts at different engine speeds and using heat up and cool down periods to "heat cycle" and season moving parts and engine block.
Don't baby it too much but don't keep sustained and steady high RPM's either. Several 1/2 to 3/4 throttle accelerations and coast downs will help seat the rings.
Also, I wouldn't start it up during breakin unless you can run it long enough to get it thoroughly warmed.
Terry