Is it possible to break in an engine by letting it idle at 3 to 5k rpm for "X" amount of time?

I suppose it's possible, but I wouldn't call it ideal. Your motor should see varying degrees of rpm and load while it's breaking in, starting off pretty light early in the breakin process and ending pretty heavy. Is this for a race car? If not, just drive the car! (That is why you have it, right? https://www.nopistons.com/forums/pub...DIR )

Blue TII and I had a lot of fun breaking in his last motor. We just went for a 4-hour drive every night for a week and it was done! https://www.nopistons.com/forums/pub...#>/biggrin.png

Yeah I did buy it to drive it https://www.nopistons.com/forums/pub...IR#>/smile.png.I was thinkin' that I could do some sort of mix of the two. Like 1/2 and 1/2. I do realize that you have to actually drive it so things settle in place. Any technical reason why I shouldn't do a partal High Idle breakin?

if you want to somewhat speed up breakin.. you can try to drive around the highways in 4th and 3rd gears rather than 5th,

There are as many ways to break in a motor as there are to build one up.



Rob at Pineapple will advise you to break in a motor very gently and gradually.



He builds a very tight motor w/ sideseals clearanced just enough to move and everything else tight as well for good compression. Looks like his ports are set up for fast closing/good dynamic effect, but the sideseals need to burnish in the plates.



Ito has stated he breaks in his motors w/ a burnout.



He has written here that he runs higher sideseal clearance especially on turbo motors and really pays attention to being easy on the sideseals at the top/closing line of the port despite the trade off in ultimate power.



So, how does YOUR engine builder recommend the engine is broken in?

ito acutally breaks his car in by driving to the bronx and back, about 55 miles... then the burnout and tuning.... but of course he never ever recomends it for anyone......

The break in on my Reman was simple. No 5th gear for the first 750 miles. Low boost, light throttle, below 3500 RPM for the first 300 miles, then change the oil. Same thing but below 4500 for the next 200 miles, then change the oil. Then I can get into boost and be a little harder on it for the final 250 miles, 6000 RPM Max, then change the oil. I didn't really push it until I had hit 1000 miles, at which point it was ok to switch to synthetic oil.



The most important factor on engine break in of any type is to constantly vary the RPM. DO NOT set the cruise control, and try to float the speed +/- 5 mph for at least the first 500 miles.



My motor was done up over a year ago by a certified Mazda Rotary Tech at a dealer, he owned a 3rd gen and advised me of this break in procedure.

I recommend "driving like you have a cop following behind you" for a thousand miles. If you have new gear & rotor bearings, definitely nothing over 4krpm for atleast 1,000 miles if not 2000.



B

I asked Leonard Hughes of Candies and Hughes about that for my boat motors that I have gotten. He said its the load that is produced on the seals and friction surfaces and the reason to vary is so that the seals scuff is not shaped at one rpm and torque load. Its kinda of like sharpening a lead pencil but only rubbing one side. You want the seals and surfaces to break in equally through out your rpm range and torque load.If broken in over on a small rpm range and sam torque then the seal would not be as effective outside of that. drag racing they clearance the seals so they just go.

FYI

if its built right it won't break from day one.....