Contrversial BREAK-IN READ!!!!!!!

[Big - D Racing]

Everyone check out this site and let me know what you think, I am by no means a professional engine builder but I do perform most of the work on my bike besides machine work. This break-in procedure is unlike anything I have ever heard from any engine builder before, but it sounds like it makes sense to me. Any engine builders what do you think about the article. Here it is:
http://www.mototuneusa.com/break_in_secrets.htm

[GPracer2500]

Mototune's ideas have been around for a while. I like to split the difference--run em' hard but not too hard.

[94F450SD]

i was always told to break an engine in the way your gonna run it.and i run everything hard.

[NacsMXer]

I asked Lazarus from GT Thunder about this and he had no objections to it. He told me that when he builds a fresh motor for his racers, they just run them like they normally would.

Of course you would also need to adjust the valves again at some point after everything is broken in. Proper engine pre start-up lubrication is also a must as well.

[honda460ex]

I have always been told by a couple friends who build race car motors... Run it like your going to run it... They say if its going to come apart or anything go wrong with it, it will happen regardless. I can understand not running it extremely hard just so you can break in the rings decently.

[400exrider707]

Thats how I break in my engines. Just make sure its nice and warm before you give her he11.

[phildogg]

thats the way I've always done engines..
phil

[jordan_m6]

im kind of partial. i start slow but before the end of the day im running 3/4 throttle. i have had no problems with my 400 it actually ran really strong.

[wilkin250r]

I'm in the middle.

Really, I think much of it depends on how the engine was built, your piston material, and your clearance specs.


The traditional method of slow-delicate heat cycles is better for the piston. If you have very tight tolerances and cylinder/bore clearance, you run a serious risk of seizure if you drop the hammer during break-in. You need to give it it time to expand and contract, work out all it's internal stresses, and wear into the cylinder properly.

The flipside is that high cylinder pressures are good for seating the rings, and those high cylinder pressures aren't going to happen at idle. And if you have a loose cylinder/bore clearance, you BETTER get a good seal on those rings.

So, I say your break-in depends on your motor setup and piston material. If you have a tight clearance, break it in slowly. With a tight clearance, ring seal isn't quite as critical, because your piston seals better. However, if you have a loose clearance, drop the hammer.

Just my $.02

[1fst400]

I actually broke my motor in 2 days ago. I ran it for about 2 min at idle. Then after that I got on it and did some 3/4 throttle acceleration in 3rd gear. Keeping the revs low.

after that I let er rip, but still havent really reved the pisser out of it.