why break in?
 

I have been argueing with my brother about this. i just got a motor rebuilt (currently has 250miles). im running a haltech and i opted to not mount IC pipes so i dont get any boost in the motor at all.
i was gonna follow he 1k mile no boost, no revving past 4k rpms (i even set a rev limiter in). btw i have new rotor bearings and am using atkins seals on used housings and premixing.

he calls me crazy and says in his race motor he redlines when he starts it up and its broken in. then even says that the dealer only suggest a 500 mile breakin for a new rotary. is that true?

any insight?

If you have new bearings, you must do a break-in.

If you have used housings without the seals that were used against them, in the same places on the rotors where they were originally used, you must break-in.

How *long* the break-in must be is a matter of debate :) I took mine to the dragstrip afer 400 miles of driving and rough-tuning. I kept it below 6000rpm before that time. Used everything except for Atkins cryo-seals, and the rotor housings and side housings were from a different engine that the rotating assembly came from.

The thing had horrible oil smoke problems for the first few hundred miles, but that is clearing up and is almost totally gone now (1200-ish miles). It had some flood start problems as well, partially due to tuning problems. It would never lose compression and fail to start, it would just fill the exhaust with fuel and smoke a LOT after startup. (But only after a cold shutoff, AKA "How to flood a rotary")

I am not bothering to do final tuning until these issues are totally resolved. Changes in rotor sealing mean changes in VE and combustion, and this alters tuning to some extent. How much, I don't want to experiment on.

Another thing... after I put it together, and for a long while afterwards, you couldn't turn the engine over by hand. You could with a socket on the E-shaft, but not just by grabbing the alternator or water pump pulley and twisting. First rotary I've had that was like that, and it had me worried. But it's also the first one I've put together with new apex seals and springs, and FD corner seal springs. After 900-odd miles, I could start to turn it a little bit. So there's definitely some "loosening-up" going on... I'm premixing around 100:1 for safety's sake.

PS - You have a turbo installed but no plumbing on the compressor outlet? What keeps it from overspeeding?

your turbo is going to explode.

what do u mean?
i kept my revs below 4k rpms, that can cause the turbo to explode?

Yes, your turbo is just spinning away with no load on it, even 4k can quickly kill it. Hook it back up and be easy on the engine for 500 miles, change the oil, gradually add rpms and load (boost) till you've reached 1,000 or so, change the oil.. now you can floged it.

~Mike..............

I like to flog it every now and then ;)

~S~

Lol

No you don't. I have personally broken down 4 engines with new bearings that never saw any breakin time, and those bearings looked like I just put them in. One of them didn't even get 60 yards on the new engine...

all though short on pla on 1,000 mile break in. no boost, and probaly no revving past 4k. then redline after 1,500 miles?

Some of you are jumping to conclusions about the turbo over rev thing. The only true way to tell in this situation is to use a turbo tachometer. Otherwise your just guessing.

Weird I didn't know the turbo could explode like that.

A turbo with full exhaust pressure from the engine, waste gate sealed and closed with no way for it to open (no boost reference to open it up because all the plumbing from the turbo to intake manifold is GONE), and NO LOAD on the cold side at all..... Wow, what a silly assumption on my part to assume he will over spin it. After all, what the hell do I know about turbo's and related systems :rolleyes: .... ohh... and what happens when he hits that only 4k rev limit trying to pull out in front of someone???? Rev limit = pop pop which means turbo rev rev. Maybe he would be safe, but why would you tell someone who is obviously in-experienced otherwise? Seems like a stupid risk to me. Most turbo's make positive pressures at or before 4 k, even sizable ones without needing to hit full load. Their spooling at this RPM with the turbo seeing a load on the cold side, what do you think it’s going to do with no load at all? Best advice is to hook it back up and be easy with your right foot, or pull the waste gate off and deal with the noise or make a temperary connection pipe from the manifold WG flange to the DP. Or... pull the turbo off the turbine housings leaving it on the manifold and hooked up to the DP, and make a simple block off plate to plug up the turbine housing now CHRA-less.

~Mike.............

ya im gonna try and put pipes on this weekend, using universal pipes.

Mike is right, I have seen it happen QUICKLY.......

no need to go past 1000miles. you should be at redline by 1000miles

Good for you.

Mazda, however, recommend a somewhat longer breakin period for engines with new bearings vs. old bearings (but still new seals). That seems to indicate that the bearings are a crucial factor, no?

They distort some when pressed in, even if the tool doesn't push up a high spot on the edge. That much is a given, and is probably why Mazda wants a longer breakin for engines with new bearings.

I had new bearings, housings, rotors, irons, and everything else you can think of and NEVER break in my motors. Three or four heat cycles is all you need. A piston motor, yes, a rotary hell no. What are you breaking in, slabs of steel??! Mine gets broken in with 25psi on the dyno and I have never had a failure. Only reason my 780rwhp let go a few months ago is because of my stupidity of not changing the fuel filters. Otherwise it would still be fine.

BooYa, thats what I'm talking about!! Build it and Boost it.

I was referring to a performance engine, one that is blue printed; not a production engine.

So was I. The breaking-in was meant to be done over a period of several hours on an engine dyno, slowly ramping power and RPM up until the final part where you were at full throttle and near max RPM for a specified length of time.

so far 750 miles on my motor. no boost yet nor revved it past 4k.its torture...

For what its worth...

I work for Ferrari/Maserati and worked at the Ferrari factory in Italy for 3 months. When building an engine, we assembled it, and then ran it on an engine dyno for no more than 1 hour. After that, it was installed into the vehicle which was test driven upon assembly completion. I promise you that none of the Ferrari test drivers do any less than beat the living $hit out of the cars for around 20 miles worth of test driving. The car is then ran through final inspection and shipped...

The point is, while they do ramp up power and rpms gradually, it's over a short period of time (under 1 hour), and the motor is ready to go in their eyes. The test drivers are encouraged to push the car to try and make it fail at the factory, and do. I am unsure as to why their motors would be an exception to what is acceptable when breaking in new bearings.

I know this to be true and thus will not shy away from a shorter break-in personally... I am open to suggestions as to why this may not apply to rotary engines, if anyone has any...

- Chris

OK, comparing 1 hour dyno time (which seems to be the standard for high end Motor Sports Teams) verses driving on the street.

That 1 hour on the dyno, I'm assuming like most Race Teams / high end engine builders starts off light load and low RPM gradually increasing till your at WOT with full load for a minimum of several minutes.

Now, go out in your car and TRY to duplicate this. Yeah, try and keep the RPM's low and low load and gradually add both (in traffic, with roads ending/beginning, those other pesky commuters in the way as well not to mention those annoying traffic lights/stop signs and the inconvenience of having to make a turn every so often). BTW full load would be top gear, uphill, head wind, and ohh.... hold that for 1/2 hour and see either how the road ended a State later or how Mr. Patrol man liked your "break in" procedure.

It sounds like you’re on the wrong side of the fence about this topic which is strange considering were you worked and what appears to be the obvious that I just pointed out (1 hour dyno verses miles on the street). After miles of mild break in, trying to add load and RPM on the freakin street can only occur a few second blast at a time not to mention cannot match what load a dyno can place on an engine, therefore more time doing so must be accounted for. And you work (worked?) for Ferrari / Maserati? Doing what exactly?

~Mike......................

Won't let me edit it, too late. But let me appologise if I come off as a bit harsh.

~Mike.............

Work for Ferrari/Maserati.... As a certified technician with factory assembly experience, and all English spoken training classes worldwide for Ferrari... Not that you care, but I also graduated from an automotive college as a top graduate with a 4.0, and have experience working/helping to work on vehicle's since I was around 5 years old... I could go on, but I merely wanted to point out that I am not just some kid claiming to know what they are talking about on the internet...

Maserati vehicles get the same test drive (beat the hell out of) without the same engine dyno break-in procedure (only 1 in 3 Maserati engines go on the engine dyno) without any troubles.... Didn't clarify before because I had no idea someone would try to tear apart a purely informative post that was merely meant to point out how 2 performance car manufacturers handle engine break-in from first hand knowledge.

You are correct in saying that you cannot duplicate the engine dyno "break-in" on the street, however, are you trying to honestly claim it would take 1,000 miles to equal this 1 hour engine dyno time? I wont bother to due the calculations, but I do believe it wouldn't take this long.... even if you were adding some miles to be on the safe side of things...

Your elaborate example of what would happen if you tried to duplicate the engine dyno time was a bit strung out and unnecessary :wink:

I agree on the fact that its not ideal to start the engine and go beat on it... I don't agree that a 1,000 mile break-in is entirely necessary though.

I say everything in this post with the utmost respect for your opinions and views on multiple subjects (I have seen you post on many other subjects). I too don't intend to sound harsh, but merely answer your questions and give reply's to your insinuations... Don't take my reply personally please...

- Chris