I always wonder what would happen to break-in threads if the motoshmotousa.com thing didn't exist? The Internet may just collapse inside its own bowels.

OP, as you're thinking of an engine build, I'd suggest following the builder's recommendations. Good luck.

 

The engine builder referred me to that site.

Was looking for second opinions as I have only been exposed to the old "1k miles and EASY" break in mantras.

 

On a new car a lot of components break-in, so maintaining a given process for XXX number of miles makes a lot of sense. On an engine build, well, pick your side.

 

Well heres my thinking-- if you go full ***** deep on the engine build... it might be GOOD for the rings, but wont it be BAD for new cams/springs/valvetrain/timing chain?

 

^This.

On a brand new car there are a lot more things to break in other than piston rings.

On a freshly rebuilt engine, let 'er rip.

 

Once again, this is ONE website from an unproven source. I'm not saying the hard break-in theory is wrong; I'm saying touting some guy named "MotoMan" who broke in motorcycle engines as gospel is downright irresponsible.

Here is a counter-article that cites actual car engineers.

http://www.motortrend.com/features/e...e_performance/

 

Everyone is going to have a different opinion on this subject. Take the advice from someone you trust. The last motor I build was a Honda B-series block capable of 55Lbs of boost. It was a daily driver that I kinda over built. I had different tunes running 500-700hp for two years and never an issue until it was stolen.

I run a non detergent/non synthetic oil for 250-500 miles and then swapped to Royal Purple Straight 30W Synthetic. Why because I took the advice of some one who has been building cars 20 years longer than me. Other honda guys will build a motor do a 5 min warm up drive around the block and straight to the dyno and It works. No one way is right.

 

Sorry guys. Have to close this. This topic has been beaten to death every way imaginable. A simple search will pull up every argument ever had on this topic.