I wont be waiting the full 500-1000 miles to break in this motor I built. I'm almost to 250 and plan to have her at redline before the next 100 miles. Anybody got some horror stories to talk me outta my plan?

 

Why? Why not enjoy and savor the anticipation? Do your self a favor, break it in right. Looking at the bigger picture, the breakin period is just a nanosecond in the overall life of the engine. Do it right and enjoy the engine for a lifetime.
of course that's just my opinion, I could be wrong,
hanman

 

I don't know ****, but it seems pretty dumb to ignore the proper break-in procedures. Just my opinion.

Why don't you take a nice trip on the weekend? Go for a long scenic drive and those 750 miles will disappear before you know it

 

Ok, common sense, the tried and the true; I'll give you that much. But who has actually not broken a motor in "properly" and had something bad happen? I figure the period is excessive anyway, 3 hours dyno time is hardly equivilent to 1000 miles anyway.

 

Its important to vary the engine speed between 2000-4000rpm for the first 500miles. That does NOT mean reving it hard from 2-4KRPM though. This helps the apex seals conform to the rotor housings imperfections and whatnot. Then at 500miles then bring it up to 5000rpm and generally make just a occational redline here and there some and at 1000miles you can generally go ahead and give'r hell. Oh yeah, a couple oil changes during this... Racing Beat's catalog is simialer to this.

The important difference on a brake dyno is you can vary the engine speed much easiler and load it easier as well properily to break it in fast.

 

I once rented a Kia Sephia and and after driving a while I noticed it only had 75 miles on the odometer. This was, of course, after I had redlined it to all hall while trying to get it airborne.

Right on.

 

did you get it to yump?

 

Thats funny. And actually break-in is less critical in newer engines with better tolerences and metalurgy that allows little or no break in period and provide 200,000miles of internal failure free usage. I learn in auto research class that some new engines have some outer layers of seals and cylinder, are made with the purpose of sealing better with regular driving from day 1 instead of following any particullar procedure.

I personally wouldn't do that to my own Kia with so low miles,....which I wouldn't buy anyway.....LOL

 

Hey nimrod you said you rebuilt it?. What seals did you replace and what seals didnt you replace?. Did you have the housings lapped?. Where the rotor housings new or used?. The motor im rebuilding is only getting new apex seals and racing corner seal springs!. I dont plan on going through a break in period, just taking it easy for the first 100 miles or so.

 

Speaking of lapped housings...What is it and what does it do? I assume its like having your head planed on a piston engine? Like they re-surface the sides of the housings or something to make them sit better? Maybe? Am I close?

~T.J.

 

New parts:
1. 18 springs
2. Everything rubber

Used parts:
1. Everything else

not lapped but streetported (mildly)

 

hey isnt' the break in period 3k and not 1k?

 

Break it in hard and it will go hard! But seriously, why risk damaging your engine by not breaking it in correctly. The first hundred or so km's should be very light load and nothing over 4000rpms. Then gradually increase the revs and load every couple hundred km's or so and make sure you cruise at varying rpm's. You'd be suprised how quickly you rack up those kilometers anyway. Only took me about three weeks.

 

I can only imagine the temptation to try out a fresh rebuilt and ported engine, whether 12a or 13b. But by the same token, won't it be that much more rewarding to just cruise around right now and teasing all the ricers. You know, as they try to race just look at them and smile. Then, after 1k, go cruising again and give em hell.
When I rebuild my 13b, I'm actually looking forward to getting used to finding my comfortable cruising range and nursing the engine that I've poured countless hours and barely countable dollars on. Besides, I doubt it's worth the chance of breaking something that is constructed mainly of your sweat.
Oh, and the reason no one on here has a horror story is because those people sell their RX-7s the day after they blow the engine because they didn't treat it right.
Savor the time with your car right now, rev the f*ck out of it later.

 

haha, speedturn pointed out my blatent mistake of not listening to the factory's recomendations. And the fact that I read them in the catalog just a few days before I put the motor together makes it that much worse.

Mazda says....

I'm behind schedule as it is, so I started in on those 25 miles at 6k today. It was fun.

 

bah, just do it right.. take it out for a 500 mile drive around town, doing plenty of laps, I'd do it at night, less stoppages.. go back and forth on the freeway, go down sidestreets looking at houses and what not, whatever..

by the way..
1000 POSTS!!!! WOOOO!!!

 

My first engine I had rebuilt, I was never told about the break in period and the engine went in under 30k. The second engine I had built by another comany told me it was critical to keep it under 70 for the first 1k miles if I wanted to have good compression throughout the life of the motor, and get a good 185 - 200+ miles out of the engine.
recap
500 miles change oil, keep it under 4k
1,000 miles, I changed it again and kept it under 70, very speeds, got it up to 5k
4,000 miles, I changed the oil again, got it up to 6k
after that I opened it up and it runs great.

 

To all of the above, I add this--->patience is a virtue... attributable to Confucious, but he's not actually the originator of the saying...

 

Mazda knows what they are talking about. They have built millions more engines than anyone else, so I'll just follow what they say is best for my motor.

 

If you are going to follow what mazda says why did you say you are going to redline before you even get 500 miles on the car????????

 

YEAH!! What he said!! Mazda don't recommend redlines for fresh enjuns last I recalls...

 

I built a motor to race with, my redline is 8500 not 6k, and I'll break it in the way mazda says to:

25 miles at 6k
25 miles at 7k
25 miles at 8k
25 miles at 8.5k

Here's the link that no one went to apparently. It explains the break in procedure.

http://www.mazdamotorsports.com/weba...1&subject=misc

 

Ah so, the motor isn't expected to last even 20,000 miles since it's going to be a race engine never bound for daily street use. Everything is much clearer now! Tear 'em up at the track, hot dog!

 

bye bye to a nice engine is about all i can say

 

Hey, bigjim, this tread is about 2 years old. Why did you bring it up?