why break an engine in when nobody broke in the original engine?
 

Let's face it. For most of these cars, either a salesman, a tech, or the original owner must have gone WOT or driven the car hard when there was less than 50 miles on it at least once.

Who would buy a sportscar that costs over $50k in inflation-adjusted dollars without dropping the hammer at least once? I mean I know some people do in fact do that, but if they restrained themselves, the previous guy who testdrove it didn't. Surely Mazda didn't design a motor that would fly to pieces if the shop detailer or oil change bitch went joyriding before delivery to the customer?

So from a technical perspective why is breaking a new engine so important, at least if you have one of those "brand new" Ray Crowe engines or a rebuild with new housings? I mean even the older 2nd and 1st gen motors which lasted longer than FD engines were probably driven hard at some point during the first 100 miles, and those typically lasted 100k+ . I would like an answer beyond "so-and-so trusted source recommends x breakin." Because most of the original motors were not driven with such discipline.

Breaking a motor in is not a mandatory requirement. It is a highly advised recommendation. You could do everything right, break it in for 1000 - 2000 miles and then boost and pop the engine or you could never break it in and drive it like a bat out of hell the first day and the engine lasts for 80,000...

People highly recommend it for obvious reasons given how the seals, side seals and springs work. You have 5,000+ posts so I dont think it is necessary for me to explain how the rotary engine works but the idea and concept is that you just want everything to "seat / sit" properly so you get an even seal on all faces.

I personally did not break my motor in, I boosted after 100 miles and I felt comfortable that everything was functioning properly. I didnt boost to redline but I was getting on it. My engine has been fine so far :)

Don't the Renesis engines have a pre-programmed function to essentially force this issue?

back in the day when i was kicking the tires on a 94 fd new on the lot, the salesman told me that the secondary turbo does not begin to kick in on the sequential system until an x number of miles was recorded on the odometer (in the 1500mi range iirc).

I test drove the car, but at the time was far from educated on the 10-8-10 boost pattern and the way the twin setup was suppose to feel. Was the salesman (who was actually the owner of the dealership) full of shit, or did he know what he was talking about? I had no choice but to believe him but have wondered this ever since.

Maybe some original owners can shed some light on the secondary turbo not coming on line when new?

this is a good ass question i was just thinking about this last night. i know if i were old enough to drive in 93 and was able to buy an FD and were uneducated about them i would have been beatin the brakes off it.

I wonder if Gordon, DjSeven, or maybe Goodfella, might have some insight on this. They seem to be very knowledgeable regarding this jank.

+1

a properly broken in engine (apex seal/piston ring) will seal better, ultimately produce more horsepower in the long run.

The longest lasting engine on most cars is the one off the showroom floor. The one that is least likely to have a disciplined breakin is also that first one. I'm not saying there is a cause-and-effect relationship, nor am I saying we should all go beat the piss out of new/rebuilt motors with good condition parts. But do people make too big a deal out of breaking in a car with good condition rotor housings?

Is there proven long-term harm from neglecting a breakin? I'm not talking about racing a new motor or the opposite which would be never boosting it. I'm talking about just regular old "medium" street driving like you would do under normal circumstances. Is a solidly rebuilt rotary engine sensitive enough that a few WOT pulls or high rpm runs with say 40 miles on the clock would result in a long term loss of compression or engine life?

I don't think comparing a rebuilt engine to a new engine is comparing apples to apples. With a new engine, by definition, everything is new spec. A rebuilt engine is usually mating substantially used parts with new. It's also a matter of heat cycles too.
And I'm also guessing that dedicated race engines, like those in a drag car, have different tolerances than we're used to dealing with.

The argument I've always heard in regard to piston motors, which I feel probably applies somewhat to rotaries, is that it's kind of a matter of luck. Sure you could take it out and beat the piss out of it, but if something isn't seated correctly you run a higher risk of failure. Whether or not that same failure would have occurred with a proper break in would be hard to determine, but that is one part of the argument I've always been presented with. The other part is that if you start beating on it before everything has seated properly you run the risk of reducing the overall life of the engine. So while it *should* have lasted to 100K, maybe it only lasts until 60K. Could this be explained by the majority of FD's needing rebuilds around that mileage? Maybe... Some FD's seem to do fine past the "normal" mileage that the engine starts to break down, by product of the original owner observing a proper break in period? I think it's logical personally. The proponents of "beating on it right out of the box" that I've talked to never seem to care about longevity, they are using motors in race cars, weekend warriors, etc, cars that likely won't see 60K miles of use while they own them, which I guess is a perfectly alright situation for them.

I'm with Gordon though, I would like to see someone like Rich or Ihor weigh on in this, Chris from Banzai?

I am going to call bullshit on this one. From my understanding of the sequential system it is all regulated by vacuum (turbo control solenoid / actuators etc.) -- i guess the only plausible possibility is that they have some kind of semi retarded function entered into the ECU that keeps the car from reaching full boost levels but I find this possibility highly unlikely...

I guess the only people that could really answer this are the people that owned one off the lot.


And again, in reference to the break in - I doubt there is any real conclusive evidence (empirically researched) to support this hypothesis... The real question instead should be, "what do I have to loose by not beating on my engine for the first 1000 miles, even 500!" Probably, if you looked for statistical correlations on engine lifespan in conjunction with the driver / owner of the vehicle, you would be able to draw more validating information than speculation on the effects of the break in. For instance, the individual who practices less restraint and control over his "heavy foot", to resist the temptation of hauling ass on a new motor is probably more likely to be the individual that drives the car like a maniac in all instances, does doughnuts in shopping center parking lots and likes to do launches at every red light he has a chance to just to be seen. Where as the more mature, reserved and in control individual will be more conscious of his driving style and the engine's limits (water temps, oil temps, egt's considered etc.)

Now I have no knowledgeable basis for this statement but from a personal standpoint, I feel this argument is kind of null for the rotary engine in comparison to a piston engine that has substantially more moving parts, seals and gaskets (like the head gasket), bearings, cams that must set... or, the only reason that I could think of that this would be recommended by the manufacturer is in regards to the silicone or glue that is used to seal up these engines... When I got my new motor from Ray, there was still wet silicone in the holes where the engine mount mated with the engine - possibly they just want those heat cycles to help all the silicone properly dry and seal? I dunno

He may be right to some extent. The FSM does state that there is a mileage switch that gets triggered at a certain mileage. Now what is changed and what mileage, I have not a clue. Mazda does have a history for putting these mileage switches in rotary's.

Don't jump the gun hear about calling BS. It is actually very easy for the ecu to be programed to not ground specific solenoids. Simply put if the ecu was programed not to ground the solenoids that controls the secondary turbo control door and the pre-spool door, these doors will stay closed so you have no chance to spool the secondary turbo.

Well guys, Like i said. I was told this buy the owner of the Mazda Dealership, He is a family friend and has no reason to lie to me. Maybe he was misinformed? I would like to know if it is true aswell. We need some original owners to chime in on this. (possibly they might not even know)

I would say if your going to drive slow or normal on a stock clearnced motor break it in before driveing some what fast, but if your going to push a race clearenced and balanced motor tune it on the dyno and let it rip your as ready as it gets!

Whats dumb is to push a stock motor past were its built to go and have a poor tune and rip it everywere you go, that fucks shit up and give rotarys a bad rep!:)

That's not true because a Mazda built stock motor can handle alot more than most people think. What's giving the rotary a bad rep is all the ignorant people who decide to crank up the boost past the stock ecu programing threashold. I don't care how well a rotary engine is built, you start running boost levels higher than the boost levels that was originally programed, you will blow the engine end of story.

^^^^^^^^^^Thats what i was trying to say when i said tune, then theres the balance and clearence difference in stock and race! But your right wrong tune and blow up a new motor!

(sits refreshing the page every 5 minutes waiting for howard to chime in with his AI speech :D )

And atleast you have the peace of mind should it blow that you did everything you could, and took all the recommended precautionary steps to prevent it.

when it comes to this car and all the time/money ive put into it, i will always take the precautionary steps.

Exactly... It is the peace of mind knowing it wasn't your fault. No regrets.

If you follow every precaution; break it in slowly, install AI, and have chrispeed tune it, and then you STILL blow the motor. Hell, even I'd go v8 after that experience.

To be honest, most times when a low mileage motor is blown, it can be traced to something wrong with a peripheral system or a lack of judgement. I haven't seen too many "blown motor" stories that didn't have some solid reason WHY the motor blew. Just because it isn't a 2JZ that can be pushed way beyond reason, does not make it unreliable.

One story comes to mind: Someone posted about a blown motor, then someone asked about their boost level, to which the OP replied "Oh I've been running 19 psi for a year with no issues." Then he was asked what AI he had. He said "What's AI?" ....... That sounds like a reliable motor with an unreliable pilot to me.

This topic comes up on any forum concerning a motorized vehicle. And there are lots of different opinions.. Here's a question: Did they run the motors at the factory during testing? What RPMs? What Load? Boost?

I know that in jap motorcycle production they take every motor beyond redline, at the factory.

I'm not saying we should skip break-ins. What I'm trying to do here is suggest that we should consider giving Mazda more credit than is normally given to them. Did Mazda design a hand-built engine that would be seriously harmed by the inevitable person who doesn't know or care about taking it easy on the motor? Did they design an engine that would be significantly harmed by the one test drive from the guy who is wondering whether this thing is worth his $50k equivalent? Maybe not.

Believe it or not, I find myself more and more impressed with the durability of the rotary every day. When I tore down my engine I was surprised just how good of shape it was in for having been overheated, detonated multiple times (apex seals survived), and run on half [sic] a quart of oil by my dumb ass.

All ferraris are raced on a test track and beaten the shit out of them before them reach the showroom. Could have mazda done something similar back in the day? maybe. Like someone said, a brand new engine with all new parts isn't the same of a newly rebuilt engine with a mixed of old and new parts. Also about 90% of all rebuilts aren't stock ports and aren't going to be pushed to the same 10psi as the stock engine is. So take this in consideration.

For my peace of mind, i broke in my engine for about 900 miles. No regrets.

Also imagined you bought a brand new rx7, and right out of the dealer you pushed it to the limit and broke the engine. You would come back to the dealer and say "this sucks, it just blew". the mechanic would take one look at the odometer and said "well....it wasn't broken in proberly and by doing this you have void the warranty".............

I think I remember Ihor telling me he used to do this when he worked with lambos (or ferraris, I forget which). Must have been alot of fun. It would be awesome if mazda did this as well but I honestly don't think they did. Those expensive exotics are just that, expensive. Im sure they made enough money to take the time to abuse the engine before it was rolled out and not worry if it will blow or not. I don't think the same could be said for mazda.

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

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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.