Looks like I am ready to fire up my new motor.

First, I have gone back and checked the previous posts on the subject,, It seems the biggest agreement is to use a decent non synthetic oil and change it very often for the first 3000 miles.

There seems to be some dissagreement when it comes to the break in proceedure though.. What has been found to be the most successful way? Some say go easy, others break them in hard.

I would love to hear from some engine bulders or others that have gone through this in the past.

My motor by the way is a Darton block 427. I would like to do it right. Way too much time and money invested to screw it up now..

Thanks in advance for your input.

 

What did your tuner tell you?

 

It greatly depends on what you are going to be doing with the car.

Most importantly, before you start the engine remove the spark plugs and remove the fuel pump fuse. Crank the engine over several times to make sure you have oil pressure.

If you have oil pressure, start the engine and let it idle to operating temp. Shut off and let cool. This will give all the internals one heat cycle. After it is cool, at least change the oil( changing the coolant is also good ). The oil change will remove out all the assembly lube used in the engine build. The assembly lube is import for all the internal parts until the oil system is up and running. After that, it is good to get it out of the engine.

After the initial oil change, do one more heat cycle. It is good for the internals to go through a couple of heat cycles. It is also good to do another oil change, but it is not totally necessary.

Now is the important step of seating the rings. To do this, do several hard accelerations and decelerations. Do engine braking as much as possible and avoid using the brakes. This will cause the rings to be forced agasint the cyclinder walls and be "filed" by the hone marks to match the cyclinder walls. This is very important and should be done within the first 20 miles of the motor.

For the first couple of oil changes use non synthetic oil. After a fair number of heat cycles and miles( 500+ ) you can switch to synthetic if you want.

Keith

 

Hey Keith..
This may be old school but don't they break the cams in anymore? Say 2500 RMP for 5 or so minutes?

 

True, but it is important to give all the internals( Rods, Bearings, Valve Springs, Rocker Arms, etc ) a couple heat cycles if they are new parts. I think the old scholl thought of running a engine at 2500 rpms for a given amount of time is not really needed any more. A couple heat cycles, seat the rings, and you are good to go.

Keith

 

The reason for THAT type of break in was applied to flat tappet cams and lifters. The cam lobes are splash lubricated by oil thrown out from between the connecting rods and crank bearings. The RPM's needed to be that high upon initial start-up to make sure there was adequate oil lubrication "thrown" onto the cam to remove the black protective coating on the lobes and break in the mating surface on the bottom of the lifter. It isnt such an issue with roller cams for obvious reasons.

As for breaking in the engine in general, start it up, let it idle, check for oil pressure first thing, check for leaks, make sure operating temp stabilizes at thermostat temp, open the radiator reservoir to get all the air out of the system and top it off. If all that looks good, then drive it around, vary the speeds and RPM's for a 1000 miles, change the oil, and then have fun. I would put in synthetic oil from the start. Thats how all engines come from the factory anyway. The "old school" reason for using non synthetic oil was because it isnt as slick as synthetic and would break the rings in faster. With all the thousands of LSx engines out there that came with mobil 1 synthetic from the factory are running just fine and the rings were designed for it anyway.

 

I agree with everthing said except I still think a steady RPM of maybe 1800 would still be better than idle for the first heat cycle. Isn't there less load on the connection rods/bearings with a low RPM-1800.
Doesn't this also sling oil onto the cylinder walls.

yes constantly watch that oil pressure/temp and water temp/level.
do the first run with the water bottle cover off so you don't trap air and you can add as needed.
startup was always stressful for me.