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Rotary and Reliability: Same Sentence?

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Old 08-18-12, 10:40 AM
  #26  
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If you have a cat, and take care of it like a dog, it will die. Vise versa.
People buy roataries and treat them like piston engines, ergo, they don't do very well.
Old 08-18-12, 10:59 AM
  #27  
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Anyone have an idea or any experiences with a bad idle like this? i took the UIM off and looked over all the lines in the rats nest and they look fine, intakes look clean too. Could it be in the Y-pipe or the turbos?? I dont know where else to cheak for something loose
Old 08-18-12, 11:18 AM
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Originally Posted by joelkarlonas
Anyone have an idea or any experiences with a bad idle like this? i took the UIM off and looked over all the lines in the rats nest and they look fine, intakes look clean too. Could it be in the Y-pipe or the turbos?? I dont know where else to cheak for something loose
back out your idle set screw about half a turn and see if that helps.
Old 08-18-12, 12:16 PM
  #29  
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Like a few people have mentioned, cheap parts will render cheap build. Also depending on how you maintain the engine it will reward you back by running well
Old 08-18-12, 01:13 PM
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Originally Posted by RotaryEvolution
back out your idle set screw about half a turn and see if that helps.
i see there is a slight space between the screw and the lever underneith it, backing it out would just increase the space,
something else? it just happened when i boosted for the first time that high
Old 08-18-12, 11:09 PM
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Originally Posted by joelkarlonas
i see there is a slight space between the screw and the lever underneith it, backing it out would just increase the space,
something else? it just happened when i boosted for the first time that high
then your cold start assist is stuck.
Old 08-19-12, 07:49 AM
  #32  
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Originally Posted by Kentetsu
About the only way to kill a N/A 12a rotary is to either overheat it, or run it without oil.
you'd think so, but not necessarily true. i somehow managed to flatten the springs on two 12As and chip the ends off the apex seals on one. in the engines' defense i was doing some really weird (and dumb) **** with timing and maximum RPM so .... i got what was coming to me. i also used street race back then, so they lived pretty hard lives.

i did overheat one, but that was special situation where i let anger rule the day instead of common sense. again, my fault, not the engine. i've always been pretty meticulous about maintenance.

on the flip-side i have had a few 150,000+ 12As, so i've lived on both ends of the longevity spectrum in my 25 years of rotaries.
Old 08-19-12, 09:16 AM
  #33  
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as a mechanic i couldnt wait to get my hands on a rotary the promise of a new challenge was so tempting i love it every time one comes in and now i own one reliability is all in the quality and skill of the builder
Old 08-20-12, 01:56 PM
  #34  
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I get soO sick ANNNNNND tired of people saying rotaries aren't reliable!!! The FACTS are rotary powered rx-7's have more race WINS than ANY other car!! (and rotary powered race cars in general!!) The Rx-3's absolutely ENDED Skyline ("Gojira"!) domination in racing back-in-the-day. Rx-8's are currently dominating in 24hr races.... people seem to OVER-look the fact that u DON'T win races w/o RELIABLE engines/cars!!!!! Talk to/read about people who have raced in spec7 series & never needing to do a rebuild for a WHOLE race season or MORE! BMI Racing's 4 rotor did 18 months of competition WITHOUT ONE SINGLE ENGINE ISSUE!!!! They only took it apart just to see how it was wearing and guess what?! It was perfectly fine NO ISSUES!!!

Star Mazda Championship presented by Goodyear
Old 08-20-12, 02:48 PM
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racing and daily driving are 2 completely different things though, the rotary does have weaknesses compared to many piston engines when using them for short trips over long periods of time.
Old 08-20-12, 02:57 PM
  #36  
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Originally Posted by fbse7en
I get soO sick ANNNNNND tired of people saying rotaries aren't reliable!!! The FACTS are rotary powered rx-7's have more race WINS than ANY other car!! (and rotary powered race cars in general!!) The Rx-3's absolutely ENDED Skyline ("Gojira"!) domination in racing back-in-the-day. Rx-8's are currently dominating in 24hr races.... people seem to OVER-look the fact that u DON'T win races w/o RELIABLE engines/cars!!!!! Talk to/read about people who have raced in spec7 series & never needing to do a rebuild for a WHOLE race season or MORE! BMI Racing's 4 rotor did 18 months of competition WITHOUT ONE SINGLE ENGINE ISSUE!!!! They only took it apart just to see how it was wearing and guess what?! It was perfectly fine NO ISSUES!!!

Star Mazda Championship presented by Goodyear
There's a difference between a racing prepped motor that professionals work on versus your average Joe doing cheap/free mods to it. Reliability is in the build, and when you put the two together and see which motor will hold out the most, the difference is noticeable. Personally, the best start you can do is buy or download a factory service manual and read, read, read. If there's something you don't understand, ask on here. Though the help is somewhat questionable (aside from Aaron cakes), it's usually spot on, if not in the ball park. Remember, the only stupid question is the one not asked.
Old 08-21-12, 12:30 AM
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Originally Posted by fbse7en
I get soO sick ANNNNNND tired of people saying rotaries aren't reliable!!! The FACTS are rotary powered rx-7's have more race WINS than ANY other car!! (and rotary powered race cars in general!!) The Rx-3's absolutely ENDED Skyline ("Gojira"!) domination in racing back-in-the-day. Rx-8's are currently dominating in 24hr races.... people seem to OVER-look the fact that u DON'T win races w/o RELIABLE engines/cars!!!!! Talk to/read about people who have raced in spec7 series & never needing to do a rebuild for a WHOLE race season or MORE! BMI Racing's 4 rotor did 18 months of competition WITHOUT ONE SINGLE ENGINE ISSUE!!!! They only took it apart just to see how it was wearing and guess what?! It was perfectly fine NO ISSUES!!!

Star Mazda Championship presented by Goodyear
^ I agree. The big rotory winners that you see are not the same Joes like you and I. They're funded by serious wallets. The amount of time, money and research that goes just into those motors alone is probably over $100k. The budget allows them to see what works and what doesn't. Something regular people can't do. It's like comparing the le mans 787b to our cars. That 4 rotor is a whole different animal. Apples to oranges. With that being said, I hope to be won over by the rotory. I picked up an fd (running shell) a few months back and now I am doing a 13b swap. Wish me luck!
Old 08-21-12, 02:12 AM
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Originally Posted by joelkarlonas
Anyone have an idea or any experiences with a bad idle like this? i took the UIM off and looked over all the lines in the rats nest and they look fine, intakes look clean too. Could it be in the Y-pipe or the turbos?? I dont know where else to cheak for something loose
1993 Rx7 efini vacuum leak - YouTube
For the Video Guy, Me and My friend could be 100 percent off on this one but check your map sensor. The idle issue happens alot with honda's when their map sensor's go out.
Old 08-21-12, 04:56 AM
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Originally Posted by Talex37
...I picked up an fd (running shell) a few months back and now I am doing a 13b swap....
You have a running car now, but your swapping the 13bREW for a 13b?
Old 08-21-12, 11:05 PM
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Originally Posted by Sgtblue
You have a running car now, but your swapping the 13bREW for a 13b?
Lol. Sorry for not being clear. I purchased a shell with everything, minus the motor and tranny. Just recently, I dropped in the 13b REW
Old 08-23-12, 12:17 AM
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ive seen plenty of people with even 2jz's, a toyota motor, and blow them right out of the box, hell ive even seen brand new jeep wrangler motors die after 50,000 miles(critical engine failure), on the other hand, ive seen rotarys just built and then explode on the dyno, never even got to drive on the road! but you know what, i have a 162000mi fc and that thing still runs strong and is my daily driver. its all in the knowledge of how it works, how to fix, and how to tune that makes up a motors reliablity, rotary or piston.
Old 08-24-12, 01:26 AM
  #42  
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Understanding of the rotary is a big step toward long life. It's the only engine that you can take to the redline on a daily basis without feeling guilty. They are race engines, and if you baby them they tend to die young...



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Old 08-29-12, 09:49 PM
  #43  
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I would love to learn how to rebuild a rotary, they are vary interesting to me.
Old 08-31-12, 03:04 PM
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does adding a 3mm apex seal really add to the reliability, or just performance?
Old 09-03-12, 10:54 AM
  #45  
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Originally Posted by Xpelspoon
I would love to learn how to rebuild a rotary, they are vary interesting to me.
These videos will help you in the process of rebuild a 13B or 12A engine. While they deal with an older 13B from an RX-5 Cosmo, the engine internals are basically the same for any 12A or 13B. The only real difference is that on engines newer than '85, the coolant o-rings are in the irons instead of the housings as shown in this video.

The first video is engine removal. While it is an RX-5 Cosmo, an car that few will ever see let alone work on, the process will give you the general idea of an engine removal. Steps are similar for most rotary vehicles, it's the details that differ.


The next video is engine disassembly and some cleaning. This is an old carbureted 13B so the accessories bolted to the engine are different than newer engines. However the process of externally disassembling any rotary is about the same. Covered here is also flywheel removal (same for any rotary) and engine parts cleaning.


Cleaning of all engine parts continues in this video. Provided here are examples of how this is accomplished with a minimum of tools and supplies. It's a lot of labor to clean old parts until they are looking new again. At the same time, parts should be inspected.


Finally, here is the engine assembly. This video includes clearancing side seals, assembling all the seals onto the rotor, then assembling all the parts into a 13B short block.




Originally Posted by NorthWest7
does adding a 3mm apex seal really add to the reliability, or just performance?
No, neither. 3MM seals are used when 2MM rotors are worn past the point of being usable. The grooves are milled out, and 3MM seals are installed. Actually, due to slightly worse sealing, the 3MM seals actually perform marginally worse than 2MM. And they aren't appreciably stronger.
Old 09-03-12, 02:01 PM
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My experience.. rotary projects are reliable when kept within the limits to which they are designed and tuned, to a point, and when all components are addressed like cooling, fuel, etc. However, rotaries do not respond well to adverse conditions to which they are not prepared for. You don't often get second chances with rotaries when conditions are not ideal, as compared to some other engines. I love rotaries! But they need attention to detail and control.
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