Hurt the 13B, but what is the diagnosis?

[StavFC]

Had some fun doing sprints and drag racing on Wednesday (119.5mph terminal speed using a tiny T04E 57trim, pretty impressed with that, esp as it a drift car, no drag racer), but I\'ve hurt the engine, but not sure what, and hopefully someone with more experience of dead rotarys can help diagnose...
 
The scenario---
Pre-compressor water injection jet fell off, meaning no water was being injected on one run.
Car started to missfire.
Swapped plugs for new ones but no change. Old plugs looked fine though.
Then became impossible to start and took serious effort to even push start.
Made horrendous metallic screeching noise from somewhere so shut it down again.
Had to try and get it home, so push started it and it was knocking from somewhere at idle and idling very low and lumpy as hell.
Drove ok, slow and lumpy, very low idle, but could cruise at 70 no worries and was ok in traffic.
Realised above about 5000rpm the missfire cleared up and it actually drove normally?!
Drove it home 100miles, and close to home I thought id try and finish it off as the damaged seemed to be done, so drove it at max revs and boost, and that didn\'t make it any worse and felt like it was at normal power above 5k.
Got home and it was still knocking from somewhere at idle and barely running.
 
During this whole time---
AFRs were still fine at the mid 10s.
Oil temp is fine.
Oil pressure is fine.
Water temp is fine.
Didn\'t use any water or oil, levels are same as at the start of the day.
 
Most of the above makes it sound like an electrical issue, but the horrible knocking and metallic noises, and the fact it happened on the run the water injection pipe came off, suggests mechanical.
 
Pulled the 100mile old plugs when I got in...
Rear rotor, black and rich and normal really

Front rotor, orange, almost, well, rusty

These plugs had done 100 miles, and were installed new AFTER the problem first started.
Did seem, under 5k anyhow, like it was only running on 1 or 1 and a bit rotors. Or maybe both, but not well.
 
Did a compression test using a normal Gunsons piston compression tester, how useful that is on a Rotary, im not sure.
Both rotors got near as damnit 5bar on a cold engine. No idea if thats good or not?
Heard rotary comp testing with one only works if you hold the pressure release button in, so did that too. The needle moves so fast you cant tell much, but just seemed to sump up and down in a blur to about 2-3bar on both rotors.
 
What does that tell me? I dont know. Probably broke though.
 
Any experienced diagnosis welcomed

[L18M]

sorry, cant help but any time figures for your 1/4 mile run and how much boost were you using
just curious lol

[m1tch]

Probably blown/chipped a tip - the higher the rpms, the more centrifugal force the seals have the better they seal.

If it sounds like a tractor on idle, you have probably blow the rear rotor, get a proper compression test done by mazda.

As you have kept driving the car it would have trashed the rotor, housing and probably both plates now....

[davehg]

sounds dead to me chap, time to pull it and rebuild it.

[Prof]

It\'s definitely a failed seal - and probably chipped/cracked as they do tend to \'go smooth\' again at higher revs.
 
As for how much damage is done - it would be really hard to tell without pulling it apart.  There is one test you can do - poor mans compression test - pull the lower plus, and also the \'EGI\' fuse from the engine bay - will stop the fuel and ignition systems.  Then have someone crank it with the foot on the throttle and listen for even whooshes from each rotor housing - 3 even whoosh sounds means it\'s probably ok - you are listening for 1 or 2 whooshes that are distinctly more \'flat\' sounding - meaning lost compression.  Get 2 on the one rotor and it usualy means an Apex seal - get 1 and it could be a side seal or corner seal.
 
You could have damage on front or rear or both rotors - but usually it\'s only 1 (usually the rear) that let\'s go.
 
I think it\'s rebuild o\'clock though
 
BTW - those plugs look a little odd to be in a rotary - normally the centre electrode cross type are what\'s used.
 
I\'d be worried about the rust on the plugs too - that\'s quite possibly caused by coolant - which means coolant seal failure.

[BlitzBoy]

Even though we had our arguments in the past dude , I feel sorry for your blown engine.
As been said by Mitch and from my past blowup 3 years ago, chipped seal symptoms on one of the faces it will run normally past a certain rpm due to centrifugal force.

You would have gone ultra lean when the WI stopped causing the det.

The plugs also indicate this as well with unburnt fuel making your plugs looks dark and dirty.

Get a compression test done with a Mazda comp tester.

[StavFC]

L18M- Low 12s with a terrible 2sec+ 60ft, lowest was maybe 12.3 I think? Would be mid 11s even with an \'ok\' 1.6 60ft by looks of it, not bad for a turbo thats meant to be maxed out at less than 400bhp on a Rotary.
1.5bar on pump fuel (holidng about 1.3 top end, turbo too small) thanks to my pre-compressor water injection setup, was happy for a good while now even on held top speed runs like that. But without the water it didnt even take a whole 1/4mile to kill it. My fault TBH, I shouldve secured the jet better.
 
Mitch- Being used for what its used for, it pretty much lives on or near the 8k limiter. Dunno about tractor, but does sound .....
Im not taking it to Mazda for anything though, its clearly broke and paying good money to get it there and back isnt going to help me
The damage was done, the minute that screeching noise happened that was clear. That stopped, the car drove, and got no worse all the way home, so im pretty confident the drive did nothing more than what had happed.
 
Dave- Does seem that way, but at the prices ive been quoted for rebuilds, I dunno...
 
Prof- Sorry, forgot to mention, I did the woosh test too. Didnt help really? Both sounded the same, and with regular wooshes. So either both are down to one tip (wouldnt run at all would it?!), all tips are ok, or my ears are rubbish.
The plugs are B10EGVs and are fine and used on countless big power and big boost rotaries worldwide.
And agree it kinda looked like rust, but its not used a jot of water, so not sure.
 
Blitz- AFRs stayed in the 10s even on the death run, I watched the LM2 all the way down. Im injecting 660cc a min pre-turbo and with or without water AFRs only change by about .3, but the difference to cooling and det prevention is on another planet, a planet that cant be seen by a AFR meter unfortunately.
Annoyingly I disconnected my charge temp gauge the day before to relocate it. Temps were low as hell with the water, but I wouldnt be surprised if they wouldve went high enough on that run soon enough that idve realised and let off. But who knows, no point looking at the past.

[BlitzBoy]

Edit

1.5 BAR without the WI working on pump fuel even though your afrs are in 10s will still cause the DET, UK pump 99 octane fuel is ok on a Rotary up to 1.2 BAR then it starts to get dodgy, T04E efficiancy map will change as soon as the WI stops working and you be pumping in a lot of hot compressed air at that boost pressure which would cause the det hence the chipped seal.

[davehg]

when and where was the engine built chap?

[StavFC]

Blitz-
Exactly that.
Just wanted to know what damage had been likely done as none of the checks has proven conclusive But \'chipped tooth\' is everyones reply so far, so its highly likely.
It was happy as larry like that for 5-6 1/4mile runs before that, all the sprint runs, and plenty of hard driving and even 150mph+ held runs other days too.
On that run it went iffy and soon as popped the bonnet could see the likely reason why- jet had fell out sometime in the run, meaning no water at all :Hammer
 
Dave-
Japan. Sometime 2007 or earlier IIRC.
BY ERC- http://www.erc-rotary.com/

[Prof]

Prof- Sorry, forgot to mention, I did the woosh test too. Didnt help really? Both sounded the same, and with regular wooshes. So either both are down to one tip (wouldnt run at all would it?!), all tips are ok, or my ears are rubbish.
The plugs are B10EGVs and are fine and used on countless big power and big boost rotaries worldwide.
And agree it kinda looked like rust, but its not used a jot of water, so not sure.

If it\'s only cracked / chipped - then it might not change the note enough to effect the noise - it\'s far from an accurate test.  A mazda compression tester on it would show up the problem.  Most of the rotary specialists would do that for about £30 or so.
 
The screeching was probably the bit that got chipped off being dragged around the housing - scoring a nice line in it for you - it\'s what happened on my number 4 engine and the symptoms exactly as you described.  I lost both front and rear - although front damage was far less than the rear - the rear cracked 2 apex seals, smacked a hole in the rotor - gouged out 2 tramlines in the rotor housing - all in an instant.  It ran well enough to drive to work - but the damage had already been done the instant the det happened.
 
Depending on your exhaust manifold - you may be able to take that off and have a look at apex seals through the exhaust ports - you can\'t see very ends - which is unfortunately where they tend to go - but if you have a borescope / mirror you may get a look inside.

[BlitzBoy]

Well the most likely damage will be one rotor housing,possible one rotor damaged,apex seals. The plates themselves will most likely survive as mine did when I chipped a seal 3 years ago.
You can get good second engine parts from Dragon or Tim from RX motors has loads of used good housings on the shelf

[m1tch]

Did you not have a backup WI system? If I was running something scary like 1.5bar in a rotary I would probably be doing pre turbo and pre intercooler lol What nozzle was it btw? Were you only running the one?

[ad4m1]

Gloucestershire isnt super far from hayward rotary is it? Just get a compression test done once and for all on it and save all the specurlation. You got options atleast - hayward, hurley prob have a tester or convince jit to go out there

[StavFC]

Mitch-
A backup? Not sure how? Any kind of backup would just be injecting too much water until something went wrong. Unless I had a special \'shoddy jet install\' sensor invented that could switch on another setup once the main jet fell out, but I reckon idve been better off just installing the current one better! (hindsight is 20-20!)
1.5bar is still girls boost in my opinion, but it was where id got to so far with the time I had. Was nice to have torque and drivability though, despite being on full boost by under 3k the original 0.85bar was appaling, despite decent top end power.
Personally I dont see the point of anywhere but pre-turbo TBH, there cars running 700@wheels and 2.5bar running just pre turbo and pump fuel, and my testing (i used to run post-intercooler) seemed to back that up.
Was running 660cc/min jet (10GPH), much more than most do for the turbo size (in the UK anyhow), single jet- more jets is more to go wrong.
 
Adam-
Its clearly broke regardless, the cost of transporting it somewhere is only worth while if I was then to 100% leave it with that place to do all the work to fix it.