Rotary and Reliability: Same Sentence?
08-14-12, 03:06 AM
#1
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Rotary and Reliability: Same Sentence?
So I'm somewhat New to rotaries I used to own an RX8, had no issues with it until some guy decided my car would look better with his sandrail wedged halfway into my engine bay. Then I ended up picking up a g35 for a daily, later grabbing a project 240. So as my mechanical know how grew, I never lost my love for rotaries. I recently came across a once in a lifetime deal on a FD (which is why I'm here in the first place) and since then I've been obsessivly nerding out on everything rotory. Earlier tonight I engaged in the oh so popular rotary vs. Piston argument and the concept of reliability came up. Now in my limited knowledge I defend ed these misunderstood little guys as best I could but I wanted to ask for some concrete evidence or stories to rub in their faces and help ease my own mind. So anyone who knows please just have some friendly conversation regarding reliability of rotories as daily use as well as hard track abuse. Which is what I plan on doing with this car. They seem to think I'm going to lose my motor every other month I want to be able to defend my motor with hard evidence.
08-14-12, 11:42 PM
#2
The bad reputation comes from a few main sources:
1) The engines are less forgiving when stupid people or novices modify them improperly. Turbo engines in particular. It takes very little knock to break a seal.
2) The FD has a seriously under-built cooling system from the factory, but it can be remedied with aftermarket parts. The 3rd gen FAQ has a list of reliability mods.
3) Early RX-8 engines had an insufficient metering oil system, which lead to many engine failures. The later model engines got a redesigned system (1 extra injector per housing I believe) to correct this. Premixing oil into the gas tank would also correct this.
NA engines can pretty much last forever. Turbo engines tend to get modified, which has mixed results depending on the owner's budget/intelligence/skill level.
1) The engines are less forgiving when stupid people or novices modify them improperly. Turbo engines in particular. It takes very little knock to break a seal.
2) The FD has a seriously under-built cooling system from the factory, but it can be remedied with aftermarket parts. The 3rd gen FAQ has a list of reliability mods.
3) Early RX-8 engines had an insufficient metering oil system, which lead to many engine failures. The later model engines got a redesigned system (1 extra injector per housing I believe) to correct this. Premixing oil into the gas tank would also correct this.
NA engines can pretty much last forever. Turbo engines tend to get modified, which has mixed results depending on the owner's budget/intelligence/skill level.
08-15-12, 03:53 PM
#5
*Very few oil system related failures on a streeted rotary.
*65psi? Thats rediculous.
To the OP....... FWIW I've owned my car for 10 of it's nearly 20 years and it has never left me on the side of the road. Numerous long distance trips include a 1800 hard mile mountain drive in 5 days. Also includes numerous Autocross events.....in addition to those of the previos owner. Yes I baby the car like any other enthusiast...but I drive it too.
Buy the right car and be smart. The bad news is, it's not a civic. The good news is...it's not a civic.
08-15-12, 04:04 PM
#6
many strides have been made in recent years with reliability and these engines, many shops putting together specific parts aimed at the reliability issues of the engine and making more than stock power for longer periods of time.
the largest issue i have come across with these cars and reliability are the hands they pass through. some younger people rebuilding the engines, porting them, using cheap or used parts that shouldn't be reused causing the engines to either not last or never run right again.
in short, many of the stories are caused by cheap repairs by people on extremely limited budgets. this gives the cars/engines a bad name. the engines themselves do have a shelf life though, keep in mind these engines are only sealed by rubber o-rings and 25 years is about all you can expect from an original rotary engine.
i doubt he translated 65psi correctly, most turbos won't even get near that figure before the engine twists like a pretzel unless built for that kind of boost(nor will most turbos even be able to push that much air to even reach that psi).
the largest issue i have come across with these cars and reliability are the hands they pass through. some younger people rebuilding the engines, porting them, using cheap or used parts that shouldn't be reused causing the engines to either not last or never run right again.
in short, many of the stories are caused by cheap repairs by people on extremely limited budgets. this gives the cars/engines a bad name. the engines themselves do have a shelf life though, keep in mind these engines are only sealed by rubber o-rings and 25 years is about all you can expect from an original rotary engine.
i doubt he translated 65psi correctly, most turbos won't even get near that figure before the engine twists like a pretzel unless built for that kind of boost(nor will most turbos even be able to push that much air to even reach that psi).
Last edited by RotaryEvolution; 08-15-12 at 04:09 PM.
08-15-12, 05:31 PM
#7
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Thanks for the quick support! I tried to hold the built with time and care arguement down. Bc with any motor carelessness leaves you scratching your head. I watched my friend's (good friend, feel bad for calling him out but he was one of the naysayers?) RB that he rebuilt, a motor everyone loves for it's aility to take abuse, develop a rod knock. Then i watch him rebuild it and hammer in the wrist pins with a 3/8 socket welded to and extention and a hatchet/hammer... I wouldn't say an RB was unreliable. I would just say HIS RB was unreliable. He sold it running, next owner thought he should redline it everywhere, and subsequently those wrist pins gave and decided they'd make more power outside of the block.
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08-15-12, 05:45 PM
#8
cheap and quick builds yield cheap and unreliable cars.
i have had more than a few people ask how much it would be to simply reseal a 13B, i scratch my head to think about it and say "i don't reassemble dirty engines so you'd be looking at a basic rebuild of $1450, less if you feel like cleaning". carbon kills rotaries as well, worn parts yield undesirable results, cheap start ends with a cheap result.
i would rather pass on a job than do it half assed just for a few quick bucks.
i hear still owners say shops simply won't touch these cars, that lack of support is what leaves them on the side of the road as well, with owners putting them in scrap yards, kids just getting their licenses picking them up for pennies on the dollar, painting them with primer and putting gaudy body kits on them, repairing them without any knowledge and buillding up this reputation. why do those shops not touch them? because they are filled with people who are afraid of anything out of the ordinary, people who refuse to learn about anything new even though they are always learning something new when newer cars come in. it doesn't make sense to me either.. these are grown men afraid of something mechanical that teenagers have no qualms tearing apart to learn.. these are people who still to this day do not know that these engines do not have a crankshaft or camshaft.. these are people who have had a wrench in their hand daily for many many years.
i have had more than a few people ask how much it would be to simply reseal a 13B, i scratch my head to think about it and say "i don't reassemble dirty engines so you'd be looking at a basic rebuild of $1450, less if you feel like cleaning". carbon kills rotaries as well, worn parts yield undesirable results, cheap start ends with a cheap result.
i would rather pass on a job than do it half assed just for a few quick bucks.
i hear still owners say shops simply won't touch these cars, that lack of support is what leaves them on the side of the road as well, with owners putting them in scrap yards, kids just getting their licenses picking them up for pennies on the dollar, painting them with primer and putting gaudy body kits on them, repairing them without any knowledge and buillding up this reputation. why do those shops not touch them? because they are filled with people who are afraid of anything out of the ordinary, people who refuse to learn about anything new even though they are always learning something new when newer cars come in. it doesn't make sense to me either.. these are grown men afraid of something mechanical that teenagers have no qualms tearing apart to learn.. these are people who still to this day do not know that these engines do not have a crankshaft or camshaft.. these are people who have had a wrench in their hand daily for many many years.
Last edited by RotaryEvolution; 08-15-12 at 05:56 PM.
08-15-12, 06:43 PM
#9
anyway, i'm sure i have nothing NEW to add to this discussion. it's just that people irk me with stuff like this. i can honestly say that every rotary i've ever killed was due my doing something dumb! there are exceptions to every rule, but in this case, not many at all. most rotaries die because of owner/tuner retardeness or else you're operating at such a high level of tune and modification (pronounced: real racecars) that there is a real learning curve to deal with. that's all there is to it.
the stigma partially comes from pride and not accepting your failures as an owner/tuner. also, most "mechanics" make mountains out of mole-hills in the sense that they're afraid of rotaries and simply won't use the phrase "i don't know" so they end up creating problems that may not even have been there. as was said before turbo rotaries are less tolerant of detonation and other tuning evils. in general N/A engines are much more forgiving, but believe me they can break, too. however, as with your friend's Nissan, i've seen people blow up everything from Hondas to Toyotas. how unrelaible are they considered to be?
08-15-12, 07:04 PM
#10
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About the only way to kill a N/A 12a rotary is to either overheat it, or run it without oil. Other than that, they run for a very long time. I bought my car at around 180,000 miles from the original owner. I drove it daily, and raced it weekends until it hit 213,000 miles when it finally coughed up an apex seal.
Nice thing about 12a motors is that they can be found cheap. $200.00 for a replacement and I was up and running again.
Rotaries + boost = an entirely different story...
.
Nice thing about 12a motors is that they can be found cheap. $200.00 for a replacement and I was up and running again.
Rotaries + boost = an entirely different story...
.
08-15-12, 07:06 PM
#11
well, i've seen and owned a handful of original engine boinger cars from the 60's and 70's. you won't see the 2nd and 3rd gen 13B engines breaking into that territory even if they are very well maintained. you have to accept that these engines do need to be cracked open periodically to refresh the internal seals.
many original engines from the 2nd gens i pull apart, the seals have almost no elasticity left in them whatsoever. the engines are almost held together simply by corrosion.
for turbo applications you definitely need to sway away from the stock or aftermarket hard apex seals, many companies are now offering soft bendable seals but their lifespans i would say take the compromise. then you have engine twisting issues, which many companies dowel and stud engines. i'm planning on offering 1/2" titanium studs in the near future to alleviate that issue as another company already has.
many original engines from the 2nd gens i pull apart, the seals have almost no elasticity left in them whatsoever. the engines are almost held together simply by corrosion.
for turbo applications you definitely need to sway away from the stock or aftermarket hard apex seals, many companies are now offering soft bendable seals but their lifespans i would say take the compromise. then you have engine twisting issues, which many companies dowel and stud engines. i'm planning on offering 1/2" titanium studs in the near future to alleviate that issue as another company already has.
Last edited by RotaryEvolution; 08-15-12 at 07:12 PM.
08-15-12, 09:14 PM
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I've been looking into an FD for a while now, which i want to be reliable. I've been watching how to video's on rebuild's and i honestly don't mind diving in. I just want to make sure i build it properly is there somewhere I can find usefull info other than youtube? The point is to do it myself because I wanna learn.
And REvolution do you attend Sema? I'm almost positive I'm attending this year I'd love to hear some stories or little insider tips if you wouldn't mind sharing. Maybe I'll have my FD by the time i get out there.
As for the apex seals. What is a good option? you said not hard, is there like a medium range material or is it a one or nothing type of ordeal? I was reading into engine twisting and people tapping the motors for studs and doing something to reinforce the dowel pin area to avoid excessive load on those particular pieces
And REvolution do you attend Sema? I'm almost positive I'm attending this year I'd love to hear some stories or little insider tips if you wouldn't mind sharing. Maybe I'll have my FD by the time i get out there.
As for the apex seals. What is a good option? you said not hard, is there like a medium range material or is it a one or nothing type of ordeal? I was reading into engine twisting and people tapping the motors for studs and doing something to reinforce the dowel pin area to avoid excessive load on those particular pieces
08-15-12, 09:21 PM
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you have a very ... hmmm ... entertaining ay of putting things and i like it.
anyway, i'm sure i have nothing NEW to add to this discussion. it's just that people irk me with stuff like this. i can honestly say that every rotary i've ever killed was due my doing something dumb! there are exceptions to every rule, but in this case, not many at all. most rotaries die because of owner/tuner retardeness or else you're operating at such a high level of tune and modification (pronounced: real racecars) that there is a real learning curve to deal with. that's all there is to it.
the stigma partially comes from pride and not accepting your failures as an owner/tuner. also, most "mechanics" make mountains out of mole-hills in the sense that they're afraid of rotaries and simply won't use the phrase "i don't know" so they end up creating problems that may not even have been there. as was said before turbo rotaries are less tolerant of detonation and other tuning evils. in general N/A engines are much more forgiving, but believe me they can break, too. however, as with your friend's Nissan, i've seen people blow up everything from Hondas to Toyotas. how unrelaible are they considered to be?
anyway, i'm sure i have nothing NEW to add to this discussion. it's just that people irk me with stuff like this. i can honestly say that every rotary i've ever killed was due my doing something dumb! there are exceptions to every rule, but in this case, not many at all. most rotaries die because of owner/tuner retardeness or else you're operating at such a high level of tune and modification (pronounced: real racecars) that there is a real learning curve to deal with. that's all there is to it.
the stigma partially comes from pride and not accepting your failures as an owner/tuner. also, most "mechanics" make mountains out of mole-hills in the sense that they're afraid of rotaries and simply won't use the phrase "i don't know" so they end up creating problems that may not even have been there. as was said before turbo rotaries are less tolerant of detonation and other tuning evils. in general N/A engines are much more forgiving, but believe me they can break, too. however, as with your friend's Nissan, i've seen people blow up everything from Hondas to Toyotas. how unrelaible are they considered to be?
Yea i definitly know what you mean about the pride issue. Sometimes I wish companies took more pride in their work. I had to completely redo my 240's engine harness bc the shop that originally did the work felt that butt connectors were a professionalyy acceptable way of securing wires together. Im talking 12 butt connectors in the Maf alone.. I ended up delooming the harness back to the ecu plug and shortening, repairing and generally cleaning up their mess. Another little fun fact. The car the motor originally came from, was built for the owner's wife..... Let's just say this thing was hastily put together at the least. If i were the wife, I'd file divorce paperwork for the Hubby knowingly stuffing me in that beater.
08-15-12, 10:30 PM
#14
I've been looking into an FD for a while now, which i want to be reliable. I've been watching how to video's on rebuild's and i honestly don't mind diving in. I just want to make sure i build it properly is there somewhere I can find usefull info other than youtube? The point is to do it myself because I wanna learn.
And REvolution do you attend Sema? I'm almost positive I'm attending this year I'd love to hear some stories or little insider tips if you wouldn't mind sharing. Maybe I'll have my FD by the time i get out there.
As for the apex seals. What is a good option? you said not hard, is there like a medium range material or is it a one or nothing type of ordeal? I was reading into engine twisting and people tapping the motors for studs and doing something to reinforce the dowel pin area to avoid excessive load on those particular pieces
And REvolution do you attend Sema? I'm almost positive I'm attending this year I'd love to hear some stories or little insider tips if you wouldn't mind sharing. Maybe I'll have my FD by the time i get out there.
As for the apex seals. What is a good option? you said not hard, is there like a medium range material or is it a one or nothing type of ordeal? I was reading into engine twisting and people tapping the motors for studs and doing something to reinforce the dowel pin area to avoid excessive load on those particular pieces
Rotary Aviation super seals tend to be the most popular for a mix of street driving and relatively high abuse scenarios. for sole high mile commuters seals like Atkins and OEM are best or if you have deep pockets get ceramic for a seal that will outlast your car and save the housings(Pettit or Ianetti). for cars that see little miles but gobs of abuse Goopy or ALS have a set of seals for you.
i swear these guys should be paying me to advertise for them instead of the other way around.
Last edited by RotaryEvolution; 08-15-12 at 10:33 PM.
08-16-12, 12:35 PM
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New to the Rotary World as well. FD
I am new to the RX7 Rotary World as well. I just bought an incompleted project from a friend that has a 20B NA Conversion. Still have a long way to get it up and running hopefully it will run with Zero problems. Will save up and Do a 20B NA with high Compression Rotors.
08-16-12, 05:04 PM
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@Rotary Evolution I appreciate all your help and input. It's rare you see a vender actually offer good information for free without somehow directing my wallet to your bank account. Props on being a good person and a good rotary consultant. If i am able to follow through with this project, I already know one vender who seems quite trustworthy.
Everyone else Love the mass info your all sharing, especially with the from factory cooling issues, gauge issues, these are all things potential owners who aren't familiar with the cars could be ruined by and potentially making the rotary rep worse.
@loco blade Good luck with the N/A build, those things sound MEAN, I kinda want an N/A rotary build on the side, but i think i'm starting to get carried away with all these projects.
Everyone else Love the mass info your all sharing, especially with the from factory cooling issues, gauge issues, these are all things potential owners who aren't familiar with the cars could be ruined by and potentially making the rotary rep worse.
@loco blade Good luck with the N/A build, those things sound MEAN, I kinda want an N/A rotary build on the side, but i think i'm starting to get carried away with all these projects.
08-17-12, 07:02 PM
#19
Since the OP seems to have been helped and it shouldn't hurt anything to go a little off-topic, I'll post up a public appology of sorts to Kaaarl12a for doubting his 65psi statement. He PM'd me enough info on the car in question that I was able to google a short video of a 6 sec. pass this car made that would seem to substantiate his claim. If this was the car, I was right about it being a dedicated drag car, but apparently wrong on the level of boost it was running. IIRC, it was reported to be something on the order of 1300 hp.
Here's the vid: la otra rx7 - Bing Videos
Sorry Kaaarl12a, it would seem I'm now standing corrected.
Here's the vid: la otra rx7 - Bing Videos
Sorry Kaaarl12a, it would seem I'm now standing corrected.
08-17-12, 08:03 PM
#21
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Been daily driving mine for 3 years, still going strong.
Like everybody said here, do the build right, maintain it, and there wouldn't be reliability issues.
I've had tonnes of people questioning me about my FC, and I would bring up the comparison of poor maintenance vs. proper maintenance. Most of them wouldn't argue by that point.
Like everybody said here, do the build right, maintain it, and there wouldn't be reliability issues.
I've had tonnes of people questioning me about my FC, and I would bring up the comparison of poor maintenance vs. proper maintenance. Most of them wouldn't argue by that point.
08-17-12, 09:13 PM
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08-18-12, 09:43 AM
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Bought a kit car with a 13rom the 3rd or 4th owner, he had tried to race it and had no clue that it had no oil injection, I ran it at least 1000 miles before even looking real hard at the engine. OMP was not hooked up and was leaking a bit . Removed the OMP and started mixing, it is still running strong with about 5k miles more. My bad. Have had several FCs and no problems except hot start, it is common knowledge that rotarys want to stay cool, need clean air, and good oil, Wish that I had discovered this site long ago.