I've read this too and IIRC, it is 20,000miles. The car idles slightly higher before this mark.

The mileage switch is for emissions and automatic tranny breakin only, according to the service highlights document. There is no documentation indicating that noticeable engine performance is affected in any way by this switch.

https://www.rx7club.com/attachment.p...1&d=1238599163

https://www.rx7club.com/attachment.p...1&d=1238599163

strange how mazda had a break-in system for the AT but not the motor itself.

Well done. Good find.

So so true about the rebuilds and their larger ports. Also consider how most don't even have their injectors cleaned and flow tested after a rebuild.

There are so many other factors that can contribute to a rotary blowing that have absolutley nothing to do with how well the engine was broken in. Overall the only real reason to break a rotary is to break in the bearings. All the compression seals take thousands and thousands of miles to fully seat.

I broke my motorcycles in for about 1.2 miles..... however far it was to the first freeway on-ramp.

But when you have an engine and build that requires full tuning... I see break-in as being inevitable. You just are not going to slam the throttle until everything is dialed in properly. By that time, you have probably already gone through a significant break in.

You dont know how many times people leave my place with a fresh rebuild after me telling them to perform a 1,000 mile break in, only for me to hear them 2 blocks away ripping thru 2nd and 3rd gear.:wallbash:

Do I believe a break in is necessary, yes, but for a limited time really. I tell most customers to go 500 miles, change the oil and plugs and enjoy.

As for the comment about the original engine lasting the longest, there are a lot of reasons. For one, the parts are all new, which doesnt hurt. Secondly, most cars were stock until the late 90s early new millenium, that is when they started to blow left and right. Id say about 90% of fds out there have been modified at this point. Third, after about 40-50k about 1/3 of the fds had a properly working sequential system, very few had secondary boost, I cant even tell you how many fds I purchased over the years were the owner had no clue they had 0 boost on the secondary turbo, you will never blow the engine this way short of a coolant seal failure.

Lastly, everyone these days wants 500+ rwhp on a setup that was never designed for it, however, very few want to spend the money to do things the correct way. I see customers blow up engines on stock twins all the time who push the car too hard on an improper setup(tune, fuel, boost issues) and then I have customers daily driving 450rwhp fds for years. The owner of these cars decide how long the engines last( in most cases). These cars received there reputation as super unreliable cars because past owners purchased them for the looks, got hooked on how easy it is to gain near 100 rwhp then blew them up out of ignorance and blamed the car. :scratch:

I still didnt answer the question. If you dont have the patience to do a 500 mile or 1k mile break in, Im sure other issues will surface with your fd.

So sorry to revive this but whats quoted could not have been said any better. This should be a poll! My vote is for break in. Been doing it since I got my first car at 17, although I'm only 22 now and have only had 4 other cars it's still one of the things that you should consider after a rebuild/new engine...look at it as one of the many safety nets you can do for your investment.





~Shar

I thought engines are initially "broken in" before they even put them in the cars?

I know in the manual it states to break in the engine. But who the hell reads the manual when they buy a new car?

Also, there are also stories of people just ROMPING on it the day they get it, supposedly making the seals sit right away. Then performing the early oil changes etc etc.

I wouldnt do that on a rotary engine though.

Also, on this note. My friend gets loaner cars from BMW ALL THE TIME because apparently the fuel pump is an issue for the 335's. (he has a 335xi btw). So far in the slightly over 12 months of use, he has put about 30k miles. Yes thats alot, he drives everywhere, all day everyday, for no apparent reason. They have replaced his fuel pump about 8 times. I told him to get a new car to lemon law it or something. SOmething is wrong there.

Well anyway he gets loaner cars when he brings his car in for service. He once got a 335I with about 300 miles on it and was whipping it the day he got it, til the whole week was finished. I think he put about 1000 miles on it. And nothing was wrong. And when i say he romps on it or whips it. I mean as long as the engine is running, the rpms are being pinned 95% of the time. From light to light, stop sign to stop sign, highway to highway. Even idling he would just rev the shit out of it in neutral lol.

Its people like that that i think about when buying cars. I cant believe the abuse people put on cars these days, its kinda scary.

soo since this thread I finished building my motor. I stayed out of boost for 90 miles, then part throttle boost while rough tuning until about 450 miles. I think I hit 17psi part throttle because I was still fiddling with my boost controller. At 450 miles I started going WOT up to about 14.5psi or so, and have been boosting WOT at 15.5psi since 500 miles. I changed oil at 500 miles. I've got around 600 miles on it now. It's basically run the same since day one, except for improved driveability as I got it dialed in. Never flooded or anything. I wonder if I will notice stronger vacuum or more power as I break in further. I re-used the apex seals but replaced a rotor housing and the side and corner seals. Basically it pulls like a raped ape at this point with the T04R.

What I'm trying to say is, I didn't have the balls (or the money) to drive it hard almost immediately (after a couple heat cycles) just to see what would happen.

I am pretty sure mazda engines were run on an engine dyno before installation into the vehicle. Remans at least are all run at the factory. This is why you find oil residue in the oil pan and rust from the water they use in the cooling system.

At least on my 05 RX-8 doesn't. I got on it since it had 7 miles on it.

My brand new 82 GSL required a 1000 mile break in. At the time. that meant no hard acceleration, and no constant speed (rpm) driving. That engine had about 65K on it when I put it in my 79 RX7 (dedicated autocross car) around 1988. The engine ran great, and never smoked until the car was sold in 91. I don't know how many miles were on it at the time. I think the break in procedure definitely contributes to the life of a NA engine.

Most of our FD engines don't last long enough to die from worn out apex seals, and coolant seals require no break in. Those two facts would lead me to think that a break in period on an FD may be pointless. That being said, I was careful to follow the break in period on my rebuild.

Wait apex seals can wear out??? Like brake pads?

I always have thought that was a myth??

It's metal on metal. There is wear on both parts (housing and seals). They don't last forever. There are specific tolerances of wear specified in the FSM. So even if you don't blow the engine, you'll have to rebuild it at some point just from wear.

Reasons to break in:

1) peoples dirty hands have been all over the parts so it's good idea to wash them in engine oil during the 1st 250 miles and then change the oil. You'd be surpised how gritty this oil will be when it comes out compared to a normal oil change.

2) the apex seals are fresh metal, similar to rotors or any other medal that sees lots of heat you'd ideally want to cycle them from hot to cold to and not REALLY hot to cold to avoid warping :) Same thing for all the other new metal in the engine. This is also why it's better for break in to accur while running around town, back and forth to work etc... verses driving down the HWY for 500 miles, changing the oil and considering break in done hehe.

3) Bearings if new may take some time to settle and align well

probably 10 more reasons but the bottomline is break in is a very good idea if you'd like to give your engine it's best oppurtunity to succeed at the highest level.

O great, i guess something to look foward to lol

You know you're talking to an FD owner when he assumes that rotary engines always die from catastrophic failure

a lot of the n/a ones just wear and wear and wear until the compression is so low that they start flooding out etc. The Rx-8's do the same thing except at 50k because of Mazda's mistakes in their OMP calibration and design for the 04-08 models

Cool beans! The All Out Track Freak has spoken! Bottom line folks.........Just do it.
BTW Arghx, I was following your BW s475 build, so I guess you switched turbo huh. Hows it going with the new setup?






~Shar

i have heard that Mazda ran the engines before they went in the car. i always wondered if that were true cuz say a old lady went and bought a rx2 or rx5 (cosmo) back in the day, do u think a old lady buying a commuter car is going to know what a break in period is or about?? i think that there is a process or time in which the seals have to seal and you can feel that on a new motor as u put more miles on it it really dont take that long like 300-400 miles but i alwyas go 1000 cuz im sepersticous

You must have me confused with one of the other guys on here. I had a buildup thread but it was posted on a local forum. I am running a T04R with a very large streetport. On straight pump fuel it's not the fastest car around, but it's faster than anyone would ever need on the street. It also starts and idles very well now that I've figured out all the little tricks to ISC, PFC, and TB adjustment. The custom PFC boost control kit I made is working well too and holds a rock solid 15.5psi every time.

Wait so my engine will fail due to catastrophic issues before it fails from wear and tear??

lol damn even more things to look foward to.

If you notice most na rotaries last much longer than turbo verions. Mazda made major compromizes in the cooling sytems of this car. The radiator is way undersized, mounted at a poor angle, and the fans come on too late causing the motors to run too hot. A lot of this was done for emissions and packaging reason. On top of that, the stock intercooler essentially doesn't work.Once it heat soaks, it takes forever for the temps to drop.Excessive heat over time will kill colant seals, wiring, hoses, etc.High intake temps cause pinging and detonation. Most of the time you can't here it and over time the damage builds up. Its only a matter of time before a minor ping cracks a worn seal that has been heat cycled so many times. If you don't detonate you will eventually lose compression from engine wear due to an insufficient oiling system. Bottom line is people push more power out of their cars without upgrading components already insufficient for a stock car.

Ah, yes that was Gus. Whoops! I did read your custom PFC boost controller kit though :icon_tup: and yup adjusting is key for idling but man is it so frustrating!




~Shar

[QUOTE=1QWIK7;9397249]

Well anyway he gets loaner cars when he brings his car in for service. He once got a 335I with about 300 miles on it and was whipping it the day he got it, til the whole week was finished. I think he put about 1000 miles on it. And nothing was wrong. And when i say he romps on it or whips it. I mean as long as the engine is running, the rpms are being pinned 95% of the time. From light to light, stop sign to stop sign, highway to highway. Even idling he would just rev the shit out of it in neutral lol.
/[QUOTE]


Sounds like the way I used to drive my honda prelude Si, until my lead foot put a quarter-sized whole in the aluminum block. haha

Just because it ran fine when he was done with it, doesn't mean that he didn't significantly shorten the engine's lifespan.