break in rebuilt engine

[slow84gn]

Whats the best way to break engine in? i have 200 miles on it so far. ive been fairly easy on it. except when a 2006 mustang gt wanted some.
My build
seal pro pistons 30 over
ported polished heads
three way valve job
ported throttle body
biggest cam postons had
t&d roller rockers 1.60
headers
think thats it on the engine

 

[Blown&Injected]

If that biggest cam is a flat tappet cam all the break in was done when you started it for the first time and followed the proper cam break in procedure.

If it is a roller motor, there is no break in.

Just change the oil a few times

 

[vacuum 6]

All motors need for the rings to seat. Since you already have 200 miles on it, the rings should be some what seated. Keep your eye on the oil consumption, see if the motor is using any if so the rings are still seating. IMO – I would not really get on it until 500+ miles. FYI - for the first 200 miles you should keep the rpm changing to help seat the rings.

 

[slow84gn]

it was my first rebuild so i dont know what kind of cam it was. im not at home to look it up. ill try an take it easy for five hundred. then im going to go through some tires. ha. thanks for the info

 

[Boost231]

so did u do the cam brake in procedures? or did u just start it and drive it?

 

[Blown&Injected]

The only break in is for the flat tappet cam - if that was not done there is a very good chance that it will wipe and put metal in your engine.

If the rings did not seat by now, they never will seat.

It is right or it is not right. At this point in time just change the oil and filter and go for it.

 

[BlackBandit]

If it's got a flat tappet cam in it and you didn't do a break in on it I wouldn't run it anymore. If you did break in your cam there's not allot left you can do at this point. If your rings aren't seated by now they probably never will. That 06 mustang may have helped you out though. Cylinder pressure (not ring tension) seats rings. When you step on the gas you increase cylinder pressure. This forces the rings against the cylinder wall and seals the combustion chamber. When the engine is fresh the cross hatch is rough and this causes the rings to "wear in" to their respective holes. The majority of cross hatch is gone reletively quickly. (I believe around 20 miles or so) This is why when you start an engine one of the first things I believe you should do would be to give it a couple of WOT "blips". Then break in the cam if it's a flat tappet and get it out to a place you can make a few WOT pulls ASAP. I'm not talking max boost/timing, but a couple of 12 psi pulls up to 4000-4500 rpm in third gear. Like 5-10 of them. That will seat the rings WELL and then give it the easy 500 miles. (oil changes at appropriate times of course) FWIW there have been allot of successfull racers that believed you should break in an engine how you're going to run it. I believe this to be why there theory worked. HTH james

 

[turbofabricator]

At this point.........Run it like you stole it! There is nothing left to do. ('cept for an oil/filter change). If all the machine work and assembly work is done correctly, all that needs to be done is to run it at 1,800-2,000 rpm for 20 minutes. Change oil and filter. Cut oil filter apart and check for debris. Re-start engine and let it warm up. Then put it in gear and slowly bring the boost up to about 4-5 psi against the converter.......Then slam the throttle home and let the tires break loose. Then take it to the track and run it. The rings will be seated as well as they can, and then there is nothing that should touch at this point. If it is built wrong, you should know at initial start up. After that, the crank rides in oil and should never come in contact with a bearing.