I doubt everyone here keeps track of this sort of thing. I certainly have not but am curious like in other cars where certain cylinders are problematic, is there a rotor that seems to blow more often?

I know there was talk about the LIM not having even flow and the excessive or a JDM LIM without emissions would resolve that.

Like to have some discussion on the topic and if one fails more often than the other, is there an answer for why?

Please participate in the poll. If you know the reason your engine failed please list it in the thread also. I'll start it off, the car I bought came with a blown rear rotor, no compression on it which means at least 2 of the 3 apex seals are not functioning. The reason for the failure was switching from a high flow cat to a midpipe, without tune I believe. Likely the there was a boost increase that was not noticed or the mixture became too lean.

Thanks

 

Front only, 1 apex cracked and another bent @18PSI with water/meth. Bad tuner; learned my lesson.

 

Fist time engine went pop was at 18psi stock 2 piece seals had bit to much timing felt it pop
Drove home i new it was dead

It was rear rotor corner of apex seal cracked raped housing and rotor probly could have used it again but got another set

Ive gone threw other engines my own errors ether to lean or to much timing

 

Air flow to rear rotor is less turbulent because it's more straight because of the lim design. Also the rear rotor gets hotter due to the coolant path. The side effect is as overall leaner conditon in back. You can tune out this imbalance with an after market ecu and dual egt sensors. When my stock set up blew from over boosting, it was the rear that blew.

 

Let's see if the poll shows the same

 

Had a couple blow. Was always the rear. On the stock motors I've blown. I believe you will find that with the overwhelming majority of motors that blow from apex seal failures.

 

You can vote more than once for two separate engine failures.

 

Motor I just had opened had a stick side seal on the front and burnt up the oil control ring

 

I think most motors that fail damage the apex seal, but few if any fail because of the apex seal. its almost entirely something else. like the heat around the spark plug raising the metal in the area which ruins the apex seal. Or detonation which causes the apex seal to break, or a jacked up input into the engine which ruins something, or a coolant seal goes out, or overheat.

 

Wish some more voting in the poll

 

At the end of the day, it doesn't really matter. A blown motor is a blown motor. If someone found a magic recipe that made the rear rotor run at the same temperature and get the same airflow as the front rotor, then you'd just be up to a coin toss as to which one blows.

If the engine is running lean, too hot, old with thin apex seals, etc. a motor will let go. Rebuild and move on.

Dale

 

That doesn't make much sense.
If the rear rotor fails 80% of the time and you're able to resolve the issues that cause it than you are still driving on that motor and it may never fail or will now have a longer service life. You definitely want to take a look at such prevalant data and use it to your advantage. I'd say don't look at anomalies and extremely rare occurrences that rarely cause motors to fail.

 

Seems the magic recipe is that equal length lower intake manifold by Xcessive that is meant to do just that. But as you mentioned it doesn't rectify the fact that the seals are still vulnerable to damage if you have any of a few dozen other peripheral systems fail. Water Injection is also another system that can combat that heat. These 2 things may have taken some strides towards a more reliable rotary. A lot of motors may have been saved from poor turning or boost creep if they were running those 2 products. The new "super seals" help to save a lot of internal parts from damage seals breaking and taking out the hot side of a turbo and or the rotor housing.
Still means the motor has to get R&R'd; you can just reuse more of the parts after the failure. Still expensive and labor costs can hurt if you don't do it yourself.

 

If you fix the root cause of most of these problems, rebuilds won't occur very often.

To me there are a few things that need to be ironed out and there will always be some risk in the system. You want to find the risky areas and make them as robust as possible.

Identify the items which have catastrophic failures and ensure you have insanely good maintenance at those spots and those that degrade over time but can be caught through other means you do so that way.

Also designing a system that is way overbuilt. a fuel system that can handle 25% + of turbo output. a turbo that isn't pushed too hard to make the power wanted, good safety factors all over the place. Good maintenance, overbuilt cooling systems.

Tune the car where inputs could change 5% and the system laughs at it. where AIT's are super low and only run at 14PSI max.

etc.etc.etc.

 

Yup I agree. Mazdas build was so cheaply done that it couldn't even support the factory HP let alone double that most of us expect.

I'd like to add that proper warning gauges be in place. I think everyone should have warning lights and buzzers for airfuel, water temp, air temp, boost

 

Except a bigger Radiator or Remedy waterpump or even EWP , there is not much to do to improve coolant..

I've seen before on Xtreme Rotaries (website now closed sadly )

They came with a bracket & some machining to add straight coolant passage around the spark plugs on each housing, it was pretty bad-*** but for the cost.. I can totally see the benefits of preventing warps on the top side of the housing but man....