I have heard many different ways and I would like to know what you guys think about how to break in a engine. I would like to be able to get my engine broken in fast so I can finally see what a 350 has over a 2.8 V6.

Any suggestions or theories?

 

i start one with 30w oil, run it ant varying rpm, between 1000 and 2000. set timeing, check for leaks and change oil after 30 minutes or so, then drive it at various loads between 1500 and 4000 rpm for mayeb a hour. change oi lagain after 500 miles all with 30w oil, that's it it should be broke in with in the first hour or so. i liek to let it heat and cool a couple of times in the first 30 minutes, usually not hard to do with leaks, timing and such,

 

Here's what I do, everything stated by ede, but no more than 3,000 rpms's for the first 500 miles, then no more than 4000 rpm's until 3,000 miles and nothing over 5,000 rpm's until 5,000 miles. Then the engine is broken in and ready to tear. Change oil and every rpm change interval.
Have fun, Garrett

 

after teh initial 30 min. run, it is also recommended to do a couple of medium and WOT accelerations from 20 - 50 mph to seat the rings from what i heard.

 

This is what GM recommends on their crate engines for first startup..


Always put safety first. If your car is on the ground, be sure the emergency brake is set, the wheels are chocked, and the transmission cannot fall into gear.

Be sure to check the engine's oil level and prime the oil system.

Run the engine between 2,000 and 2,500 RPMs, with no-load on the engine for the first 30 minutes.

Adjust the distributor timing roughly by hand for a quick start-up and the smoothest idle possible.

Adjust the carburetor settings, if necessary.

After the engine has been running for 30 minutes, set the ignition timing (see install ignition section for timing specifications).

Drive the vehicle with varying speeds and loads on the engine for the first 30 miles. Be sure not to use a lot of throttle or high RPMs.

Run five or six medium-throttle accelerations to about 5,000 RPMs (55 to 60 MPH), then let off in gear and coast back down to 20 MPH.

Run a couple hard-throttle accelerations up to about 5000 RPMs (55 to 60 MPH), then let off in gear and coast back down to 20 MPH.

Change the oil and filter with 10W30SG oil and PF1218 ACDelco oil filter (PN 251605610).

Drive the next 500 miles normally, without high RPMs (below 5,000 RPM), hard use, or extended periods of high loading.

Change the oil and oil filter again.

Your engine is now ready for many happy cruising miles.

 

Should the inital 30min be run with the EST wire connected or unconnected before setting the timing for those of us with one?

 

Leave it connected and just adjust the dist for best idle possible, like it says above.