Why Run In?

[John Yorke]

Most stock engines die as stated from water seal failure thats because of poor maintenance, modified? well thats another matter, its all well and good having a nice shiney newley built engine which is just as likely to go pop if you have crap wiring, poor ignition, blocked rad ect.
In a perfect world there is no need for the 1-2k runin period, as Ant has said give the new bits a couple of hundred to bed in and away you go.

[Oedipus Rex]

there is an argument that if you thrash it straight after you build it you will end up with higher compression.

[kev-yorks]

Well 107 views so far and no reasons for a excessive running in period yet posted i suppose that tells a story.
Kevin

[RemarkLima]

Have a read of:
http://www.mototuneusa.com/break_in_secrets.htm

Basically this is the way all the racers I know breaking engines, it\'s not mean but has purpose! Then they last and make good power for their whole lives.

Now rotaries don\'t have the same hatching on the housing I assume to bed the seals onto the housings, but I don\'t see why it would make much difference if you just make sure verything\'s up to temp and then give it some decent load so that the seals do infact bed in better due to more pressue IYSWIM.

[Jit]

my idea of running in is simply to use the car as if using it for normal day to day driving...no WOT. thats how im running mine in. mild boost and no more than 6k rpm.

[Oedipus Rex]

Have a read of:
http://www.mototuneusa.com/break_in_secrets.htm

Basically this is the way all the racers I know breaking engines, it\'s not mean but has purpose! Then they last and make good power for their whole lives.

Now rotaries don\'t have the same hatching on the housing I assume to bed the seals onto the housings, but I don\'t see why it would make much difference if you just make sure verything\'s up to temp and then give it some decent load so that the seals do infact bed in better due to more pressue IYSWIM.

that was pretty much what I was reffering to.

According to Mazda a proper bedding in period will lead to a better service life and a more even power output across the rev range but I\'ve never heard htem actually say why.

Mazda official advice for breaking in new engines is gradually increasing power for the first 200 miles, but not approaching redline and then short birsts of redline for the next 100 miles, after that change the oil and you\'re away.

[88GT-R]

Well 107 views so far and no reasons for a excessive running in period yet posted i suppose that tells a story.
Kevin

Although none of the builders have have commented. A warranty no doubt plays into this, and also the fact that there are different driving standards..ie some know more about rotaries than others, so treat their engines accordingly.
I won\'t be going too lightly on the new spec engine during it\'s initial couple 200mile run in, but will be treating it with alot of care and attention.

John

[RemarkLima]

Pretty much would be my feelings on the matter, make sure you load the engine as well, full throttle up some hills etc... Even in a higher gear at low RPM, but get full breath into the engine IMHO.

Bearings and such like are so precise now they really don\'t need any kind of breaking in etc... They\'re gong to be pretty much like that until they fail

The only difference I can see is the rotary nature of the engine... But if, for example, the apex seals have a softer tip which only lasts a few hundred miles for that inital bedding in then surely it\'s exactly the same principle?

[iaint]

It\'d depend somewhat on the tips used - softer metal seals need less running in to form a \'perfect\' seal.  Ceramics (as I\'m currently running in) need a little more - they don\'t wear as much as they wear the housing (although less than steel as they\'re much lighter).

Ant - there is a massive difference in the acceleration forces involved at 8k vs 4k.  IIRC from my physics A-level (failed :

F = ma (Force = mass * acceleration)

as mass is constant force increases with the acceleration which (unless the square rule applies meaning we have an exponential increase) it\'s a linear relationship - doube the revs and the forces involved double.

[RobbieRX-7]

http://www.mazdamotorsports.com/webapp/wcs/stores/servlet/Tech?storeId=10001&subject=misc

[banned advertiser]

Cool
Only 300 miles, huge difference to the 2000 I have done in the past.
I guess at the end of the day if you built it yourself then do as you please, but for warentee sake you will ave to stick with what your builder asks.

[TRex]

Shocking...
 Here we have people that give advise on a regular basis, also build and play with engines, But questioning and Cannot understand the reason for breaking in an engine!
 Sorry I thought this was basic engineering principles/knowledge...
 Shocked....... :Hammer

[Martiny]

What if your intention is to maintain the colling system correctly, and actually get MORE than 50/60 k miles?

[kev-yorks]

Shocking...
Here we have people that give advise on a regular basis, also build and play with engines, But questioning and Cannot understand the reason for breaking in an engine!
Sorry I thought this was basic engineering principles/knowledge...
Shocked....... :Hammer

Nothing shocking about it at all just some of us are willing to think outside the box and what is perceived technical knowledge all opinions where just that and the thread has achieved its goal in that people are now at least thinking about it. Hence the starting comments "opinions only and the goal was to start a debate" if you want to stick with the old school of thought because it was always done that way then fair enough. Just to throw another spanner in the works once again personal opinion only the reason we have so many water seal problems in the UK could well be down to the way people start there cars and won\'t drive them until they are up to temp, just leaving them ticking over for 10/15  Min\'s or so. Instead of starting and driving straight away (off boost) to get everything up to temp within minutes.
Regards Kevin

[TRex]

Old school of thought?

 My friend it\'s basic knowledge that new materials need time to work/bed in!  A most important factor among others on the subject.

 With regard to engines not seeming to last, agreed thats possibly down as you said to peoples choice of opperating styles, meaning their warm up and cool down procedure and also their driving style!

 I can tell you one thing, it\'s been noted that there is a lot and I mean alot of people doing their own rebuilds now...  this is worrying, I mean fair play, have a crack...  but you won\'t get me ever buying a car that has had a homer done on it...
 
 This again will only add to the unfortunate ever increasing bad rep of the Rotary engine and the Cars overall value! :3Confused

 Rgds