I was told by someone that by design, it's physically impossible for a wankle rotary engine to detonate, forced induction or naturally aspirated. Any truth to this?

 

Who ever told you that needs to be kicked in the nuts.

 

Absolutely untrue. If that were true all the "unbreakable apex seal" threads would never happen. The truth is rotaries are absolutely intolerant of detonation. While a piston engine can tolerate some small amounts, one good ping is all it takes to wipe out a rotary.

 

Uderstanding what detonation really is is the jfirst tool in knowing why a rotarys prown to detonation. below is a quote from the man himself...my boss and mentor Paul Yaw of www.yawpower.com



We tend to think of combustion inside of the engine as a series of explosions, but in fact the combustion occurs at a very slow rate, at least compared to an explosion. In the absence of detonation, the mixture in the vicinity of the spark plugs is ignited first, and the "flame front" travels from that point, through the rest of the mixture in a fairly controlled manner. Detonation occurs after the combustion has initiated, and the pressure, and temperature in the chamber rises to the point that the remaining mixture literally explodes. Anyone who has ever experienced detonation understands that it certainly is an explosion! Detonation is caused by a combination of heat, and pressure, and so it stands to reason that excessive exhaust gas dilution, (remember these are hot gasses) will increase the likelyhood of detonation. As most of you know, detonation will destroy a turbocharged engine in a big hurry.


Hope this helps in your quest for info....


Glen Weaver
www.azrotaryrockets.com
info@azrotoryrockets.com

 

I need to take a shower.

 

I wish my last two motors knew that!

 

I would agree a rotary engine can not detonate.(If you want it to still run that is)

 

Perhaps a study into the differences between detonation and pre-ignition is warranted....

B

 

hahahahahahahaahahahahahahahahahaahaha thats ****** funny as ****. but i know what you mean man. this is my 3rd motor.

 

i was hoping someone would get a kick out of that. Im actually at the point where im about the purchase a blown motor just to rebuild it for WHEN this motor goes. lol. Of course i ask a lot from my motor (25+ psi), so i really cant complain.

 

wait a second, I had also heard that you could take the CAS on an NA 1-2nd Gen NA and twist it back and forth and it would still run and not detonate? agian this is hear say...

 

WOW! Someones smokin some goooood ****!!

Tell them to pass that **** this way when they are done...

 

lol....I'll take some too!

 

pre-ignition is something that is very rarely spoken around here, oddly enough i would say almost half the engine failures were cause by it rather than detonation but detonation seems to always be at blame.

 

http://www.streetrodstuff.com/Articl...ne/Detonation/

 

I wouldn't bet my "APEX" seal's on it. ! ! !

 

complete and utter bullshit! i suggest finding the person that told you that and kick them in the head as HARD as you can ... then tell them it can't hurt.

 

Rotaries are really hard to detonate from running lean, at least in N/A trim. You could say that it's impossible.

Now, if you get your distributor put in backwards or get ignition crossfire on the trailing plugs or suffer from preignition or otherwise end up with *severely* advanced timing, then you can run into detonation with an N/A. In an N/A it is usually harmless, other than horrible noises and immediate loss of power while it's occurring.

I'm fighting this right now in my 203k mile 12A. Something in the ignition isn't happy, and at WOT at around 4k-5k I run into some hefty detonation. I'm thinking it's a crossfire issue, as my timing is pretty conservative (was at 22, now at 18deg and I'm running premium for time being) I've had maybe 5 separate instances of heavy preignition/detonation where it knocked at least a dozen times. 203 thousand miles old, still has awesome compression too. (And it's only been severely overheated about a dozen times in the past 50k!)

Once you put a turbo on it, all bets are off. Detonation tends to be swift and excruciating with a turbo rotary, just like in a turbo piston engine, although it tends to be cheaper in a rotary. Break a piston in a boinger and the carnage generally distributes itself throughout the engine, taking out the cylinder heads as well as the block and the turbo, so a complete engine is pretty much required. A new "beefular" rotary costs much much less than the equivalent in a piston engine, I don't hear about too many $20k rotaries that don't have "3 rotor" or "4 rotor" attached...