Mazda Rotary Club

General => Rotary and General Chit-Chat => Topic started by: richrx on April 02, 2012, 01:37:43 PM

Title: Rx7 \'engine unreliability\'
Post by: richrx on April 02, 2012, 01:37:43 PM
Hi

I\'ve been a massive fan of the rx7 for years, loving the way they look and the engine in them every bit as much for its uniqueness, noise and power, and I always found myself wanting to defend them and it\'s engine if any person would mention that the engine was \'unreliable\'.

However after my own experiance of the 3rd gen and many years on the forum often find that new owners to the marque, and often the \'better\' condition cars from Japan go pop after a new owner purchases them( confirmed by importers leaving the rx7 alone now and refusing to sell them)

Do people on this forum think that the Japanese cars are rebuilt badly, sold at the \'right time\' by the previous owners or do they not like the month on the boat being imported.

Or am I being harsh on these imported cars? Are the cars in the uk going Pop as often?

Are there many owners who give their car a thrashing often and have no issues with them? Or if youve rebuilt your engine and its been running for a few years has it been wrapped up in cotton wool?

I don\'t have an rx7 at present, however in a year or so I\'m hoping to get another, a late spec standard car, thinking that it will last as its standard and will be wrapped up in a garage... But after having a think I\'m not sure that even if looked after well the engine can last.

So what\'s your thought on the above and who\'s been running their rx7 for high miles whilst enjoying its performance on the road/track...

I realise my theres about 12 questions there, but it\'s a Monday and there\'s nothing better to do :p

All stories and thoughts welcome :)


Richard
Title: Rx7 \'engine unreliability\'
Post by: B.Martin on April 02, 2012, 01:45:59 PM
One reason for imported cars going pop could be the fuel, if inexperienced import owners are filling the car with 95 octane fuel then its inevitably going to happen as japanese cars are mapped for 100. I was reading a thread over on the RX7club today (granted its fc\'s) and there were 7-10 people so far, claiming their FC\'s were on 200k miles+ without a rebuild.

I think it comes down to how well the engine is looked after and how its driven as well, if its used to do the school run (which is a violation of the Rotary rights) and the oil is changed once every 2 years then its not going to end well. There is always a risk buying an imported rotary as with any car, you never know who has rebuilt an engine(if at all) or how well the maintance has been over there and what parts were used during a potential rebuild, if the tolerances were checked properly when being rebuilt etc.

As i said previously i think the difference in fuel is a big killer, there is also the chance that the car has not been \'shut down\' properly by the importer and neat fuel has been sat in the chamber for 8-10 weeks eating away at seals, which won\'t help in the long run!

I\'m no expert but this is my understanding of the situation.
Title: Rx7 \'engine unreliability\'
Post by: richrx on April 02, 2012, 02:01:56 PM
Yep

I understand about the fuel detonation and quality difference in the fuel. This may well be where an apexi comes in handy, especially on a stock car.

Surely there are other issues, with seeminly knowledgable importers having engine failures regularly( most importers stopping for this reason)

Richard
Title: Rx7 \'engine unreliability\'
Post by: Aubec on April 02, 2012, 02:10:09 PM
I don\'t buy that - who\'ve you been speaking too?  There is no one in Scoland that really touches RX7s, but that\'s not representative of the rest of the country.  I reckong most that go pop do so because the moment they\'re off the boat some muppet decats it and ups the boost- or the reason they went ON the boat in the first place was because they were at end of life...
Title: Rx7 \'engine unreliability\'
Post by: Brett on April 02, 2012, 03:20:47 PM
A lot of imports fail due to water seal failure.  This can be attributed to a prolonged period sat on a boat - especially if the car was run for only a few seconds to get it into its container or strapping point.  (Potentially leaving a fuel residue to sit in the bottom of the chambers, eating the seals...)

Otherwise simple logic dictates that the turbo RX7\'s are fairly high strung and frankly pretty old.  Most of the FD\'s are 20 years old now.  They were built to be fast - not to soldier on indefinitely.... (IMO)

Any high performance car of the era is probably long overdue a full overhaul.  People concentrate too much on the engine - its the ancillaries, the looms and the cooling that is really suffering now.

That\'s my 2p worth!

:wave
Title: Rx7 \'engine unreliability\'
Post by: richrx on April 02, 2012, 03:49:38 PM
Quote from: Aubec;818367I don\'t buy that - who\'ve you been speaking too?  There is no one in Scoland that really touches RX7s....or the reason they went ON the boat in the first place was because they were at end of life...

Lol I\'ve not been speaking to anyone inpaticular, it\'s all my own observations, and your final point was one of my original thoughts, can the Japanese owners of their cars recognise when their cars are on their last legs...



I suppose the truth is likely a combination of all the answers above, and a dose of general ignorance, I think the rx7 is about 10% specialist, I.e the engine, 90%( ancillaries and running gear) is the same as every other car. But it\'s the minimum knowledge that\'s needed to keep the engine running good that lets it down.

So how many owners have had an engine last 30,000 or say 5+ years whether after a rebuild or after purchasing the car??

Richard
Title: Rx7 \'engine unreliability\'
Post by: probedb on April 02, 2012, 09:15:06 PM
I\'ve had my car for 6 years...not standard, it\'s my only car so a reasonably daily driver and I don\'t drive sedately :) I swapped the engine not long after I get it but the engine I put in had over 30K on it.
Title: Rx7 \'engine unreliability\'
Post by: RyanT on April 03, 2012, 12:01:53 AM
I\'ve had my car a little under a year now and seems to be working fine. i use it as a daily driver and spank it on a regular basis. I\'m quite particular when it comes to maintenance tho and make sure i never leave it long before it gets a service. also its got 40k miles on it and too my knowledge has not had a rebuild and has a compression of high 8s all round.

i think a lot of people see these as cheap thrills without seeing the maintenance side of things and often basic care gets over looked. its easy to blame a car for its problems it can\'t fight back.
Title: Rx7 \'engine unreliability\'
Post by: leggysrx7 on April 03, 2012, 07:12:41 AM
Mines was rebuilt by previously owner, had it three years. Only one fault during those three years,O2 sensor. Ran brilliantly.

I used mine everyday. Couldn\'t afford a 2nd car, so ran the FD everywhere. I honestly belief that these cars need good attention in terms of oil, heating up, cooling down etc however I also personal believe that they need used regularly. Sitting about all week then brought out in the \'nice\' weather is no use, especially in Scotland! I\'d rather buy an FD that has been used regularly/every day, than one that\'s been sat about looking good.

My mate had a supra, ran brilliant....he used it everyday til he got a company car....months of trouble with the supra thereafter. High performance cars are meant to driven, not sat in a garage looking good, in my opinion.

I\'m either getting another FD or a Datsun 240/260z over the next 12/18 months :3gears-rh

If its an FD it\'ll be my everyday car :Ladys-man
Title: Rx7 \'engine unreliability\'
Post by: jpc on April 03, 2012, 08:24:51 AM
Quote from: richrx;818355Hi
I don\'t have an rx7 at present, however in a year or so I\'m hoping to get another, a late spec standard car, thinking that it will last as its standard and will be wrapped up in a garage... But after having a think I\'m not sure that even if looked after well the engine can last.

So what\'s your thought on the above and who\'s been running their rx7 for high miles whilst enjoying its performance on the road/track...


I recently posted on http://www.mazdarotaryclub.com/forums/showthread.php?t=75426 (http://www.mazdarotaryclub.com/forums/showthread.php?t=75426) about how reliable my 2000 RS has been. After 50K miles, compression is still at 7.0 and it recently dyno\'d at 265rwhp (~300-310bhp). Car is unmodified, fsh since new, always garaged. Mineral oil changed twice a year. Servicing £250/yr. Only thing that has gone wrong with it is a dirty electrical switch for the windows.

A previous owner took it round the Nurburgring and Croft. I\'ve done one track day in it. I hit the engine rev limiter most days.

The 99+ models had a number of reliability improvements, (intake cooling, oil injection). The R/RS/Spirit 99+ models got an extra oil cooler.

I wouldn\'t be surprised if the engine rebuilt before 100K miles. However, rotary rebuilds are cheap compared to other high performance cars.
Title: Rx7 \'engine unreliability\'
Post by: jetpilot on April 03, 2012, 09:18:41 AM
My first 1992 Rx7 was bought fresh from the boat (2002 ish), i was the first UK owner. It served me well and is now on its 4th UK owner without a rebuild in this country.

On the other hand, i bought a 96 and the engine expired (water seal) shortly after getting it.

I think i agree with some of the comments on here, time left on the boat with short stop/starts to move around, fuel and the almost immediate exhaust/air filter and boost and cane around dont help.

Its not just Rx7\'s though when it comes to imports, but perhaps because of its relatively low numbers compared to other Jdm sports cars, you will always here more when a 7 blows rather than a Skyline, Evo etc
Title: Rx7 \'engine unreliability\'
Post by: richrx on April 03, 2012, 09:55:05 AM
Quote from: jetpilot;818457Its not just Rx7\'s though when it comes to imports, but perhaps because of its relatively low numbers compared to other Jdm sports cars, you will always here more when a 7 blows rather than a Skyline, Evo etc


I agree with this, a friend worked at a performance garage, and his speciality was to rebuild blown skybus engines, although te cost of that with forged everything was 15-20+k :o
Title: Rx7 \'engine unreliability\'
Post by: jetpilot on April 03, 2012, 12:06:10 PM
A friend of mine is a small independent performance company. I have seen Skybus engines at his from a very well known engine builder that are supposed to have forged internals, new parts etc which have been thrown together with 2nd hand parts and no sign of anything forged which cost the owner as mentioned above in excess of £15k for effectively a badly put together 2nd hand parts bin lump.

He always has a chuckle to himself when the phone rings and the punter on the other end starts the conversation with, ive got a "-------------------" built engine with problems and its not anywhere near the 500 - 600hp i was quoted i could get!
Title: Rx7 \'engine unreliability\'
Post by: oyvindjs on April 03, 2012, 03:35:23 PM
I`ll give you a quick list of how to keep a rotary beating like the champ it is:
 
 
 1. Maintanance
 2. Money
 3. Knowledge
 4. Maintanance
 5. reliability upgrades
 6. Maintanance
 
 

Seriously...
The rotarys biggest enemy is, and will allways be, the owner!
Before purchasing an FD, you have to understand the FDs purpose and  origins.. It was a true supercar of the 90s, with a unique engine design  that is perfect for racing! Racing is expencive, it requires money to  perform over time. The FD is a car you basically can take from street to  track, and spank the living daylights out of most cars, even today 20  years later...!
So, how do you keep that beast happy? The list above...

Maintanance is kind of like feeding your own body... It doesnt cost all  that money, but you have to do it regularly, and it takes time. I have a  whiteboardlist hanging in my garage, listing dates and milage of when i  did the following:
Oilchange and filterchange, every 2500 miles
sparkplug change , 1-2 times a year
Coolant change , Every year
Filter change , inspect, clean and or change every year
Batterycheck , twice a year
Date and milage for last major checkup of the car, like bushings,  joints, shocks, springs etc etc.. Smells the coolant, inspect wires and  cables, inspects the oil, inspects the diff and gearbo oil, inspect for  corrosion in coils, plugs etc.. This takes me what..? 30 mins?  At least  4 times a year

Money. Maintanance cost money, upgrades cost money, work costs money. IF  you have knowledge, you can cut the work money, if you dont want  upgrades, you can cut upgrade money, but NEVER cut money on  maintanance..!!!! IF you cant afford simple basic mantanance, you cant  afford a working FD, it really is THAT simple..!

Knowledge:  The FD is the loud, obnoxious rascal on the side, not a part  of the piston conformity...! It is so out there in every way..!   Awesome looks, awesome sound, awesome performance... But all this also  puts it abit off when it comes to knowing how it works compared to a  banger-engine, and this also makes shops and people abit afraid to touch  it.. Knowledge about your car and how it works, is SO important when it  comes to the FD. Yes, it combusts petrol like the piston engine, uses  the same 3 main components + compression, but thats where it stops...!
One of the major issues turbo rotarys have when it comes to reliability,  is owners tuning their rotary like its a piston engine, cause that is  all they know, and that is what every other friend in the piston  community does...
" Hmm,m i want more power. What does my supra friend do?  Turbo back  exhaust, IC and boost controller, lets do it"...   POOP on the first  pull... Apexes are the weak point.. One ping is all it takes, worst  case..!
Rotarys need things done in a different order than piston engines. There  is PLENTY of rotary users that bang their cars for years without  problems, cause they are doing it right, in the right order.  Knowledge  on how a rotary works, is key, and there is really not a big secret to  it.. :)  This is something one can write pages up and down about, so i  wont elaborate now :)

maintanance: See first point

Reliability upgrades: This is all about fiing Mazdas shortcuts to make  the racing engine more usable for the un-knowing everyday FD driver who  doesnt give a shiet...
Heat kills rotaries
Ping(knock) kills rotaries

Oil is a major cooler in the FD... Get dual oil coolers
The radiator airflow and spec sucks when driving hard, upgrade it and set fans to come on earlier
Mazda used extra fuel to get the INSANE exhaust temps down. Fuel have a  cooling efficiency of what? 750 BTU?  So, more un-burned fuel is the  result, and this adds as  carbon on the apexes. Apexes get stuck...  Compresson drops... rebuild.  Water has a cooling efficiency of what?  7000 BTU? Water injection steam cleans apexes and internals. It lowers  exhaust temps. It kills knock efficiently...
Mazda used crank-case oil to lubricate the side seals and apexes, via  the Oil meetering pump... Nice for the knowledgeless driver, bad for  engine. Dirty crank case oil, burned in the combustion chamber..? Hello?  Either get a OMP that picks up clean oil from a separate tank, or  remove the piece of crap and go premix with 2stroke high-temp  lubricating oil.
The original fuel setup with the fuel pulsation dampener and the :censored::censored::censored::censored:ty  injectors sucks donkey! Did you know that injectors are to be serviced  every other year(ask an injector specialist) to be functioning within  specs? How many are doing this? How many as slightly upped to boost to  within stock fueldelivery maxlevels, with Apexi PFC and all reliability  mods, and still blown the engine? Do you think your stock injectors  really flow 550/800 after 20 years?  really?

The stock Ecu sucks, plain and simple. No control, no logging, no  nothing..! Apexi PFC plus logit is awesome and cheap. Nuff said.

Precat to get emissions down..? This lump of weight is a killer when it cloggs up.

A MASSIVE cast iron heat retaining turbosystem bolted to an engine that sucks heat to it like an icecold girlfriend  getting under your sheets to use you as a heating device? Shield that thing off with heatshields, and a gasket that is better at blocking off that heat transfer..! You have a blown rear rotor you say? It shows signs of overheating? Dont have significant heat shielding you say..?  

This list is long and can be elaborated further. Fix the shortcuts,and you "fix" your enginebays inehrrent problems...

Maintanance: You see where this is going..!

Owning a supercar is expencive! It is that simple!  If you cant afford  it, sell it to someone who can afford it. Life is hard, it sucks at  times, but owning a well performing and maintained rotary is ....... an  undescribable feeling..! EVERY friend i have, who has tried the FD...  cant put the finger on what thrills em, apart from the looks,  performance and sound..!
It start when you look at it, and REALLY get you all tingly when you sit down ,strap in and fire it up...!
FDs are a drivers car, it has soul! It does something to you that very few other cars does..!
Title: Rx7 \'engine unreliability\'
Post by: Will66 on April 03, 2012, 04:43:37 PM
This is good stuff.  Heat is the killer and it\'s why the turbocharged stuff that lasts for a while and produces consistent power and reliability have extensive cooling systems and often auxiliary injection.
Title: Rx7 \'engine unreliability\'
Post by: neil_jdmr on April 04, 2012, 09:27:35 PM
QuoteAre there many owners who give their car a thrashing often and have no issues with them?

Had mine coming up to 5 years now and put 25k on a jimmys rebuilt engine mapped at wgt to a safe 330fwhp. Its still running stock sequential and is a great street tuned all rounder. Not had a single problem with it and can honestly say its been the best car ive owned so me, personally doesnt buy that unreliable cack. If you treat it badly or dont research what upgrades you plan for it then yes she will bite the same as any other sports car.
Title: Rx7 \'engine unreliability\'
Post by: DJ Tommo on April 04, 2012, 10:06:39 PM
I bought my rex with NO receipts, just a previous MOT without viewing it off eBay.... :Typing

I have covered 15-20,000 miles in it since i bought it, have used it daily (and abused it daily).... :3gears-rh

I max out the injector duty reguarly (100% and 52deg timing) from over boosting, run it down to almost empty on fuel (risking injector blockage), ran it with less than the minimum oil level (as I forgot to check it for a few months, managed to fit 3 litres in!!!), havent changed the oil at all since I bought it, just the plugs and coolant...:guinness

I have even carried out a couple of mods (air pump removal, larger rad, BOV,) and its still running.... :rollin

The clocks reading 150,000 KMs and hasnt been converted to MPH yet so unless the clock has been changed that should be accurate....:Nono!

Unreliable....My arse....:rollin


Bring on the slating for my blatant abuse and lack of maintenence for my 13B;)
Title: Rx7 \'engine unreliability\'
Post by: Will66 on April 04, 2012, 11:08:48 PM
That\'s some abuse.  Try changing the oil a bit more and making sure it\'s warmed up before you try to kill it, it\'ll probably keep coming back for more.
Title: Rx7 \'engine unreliability\'
Post by: jetpilot on April 05, 2012, 07:48:35 AM
I\'ll bet this thread exists on every car forum globally no matter what car and i\'ll bet someone always says, at least you havent got a rotary, knowing nothing about the engine and imho the relatively low cost of repair comparatively.

I read a thread recently on Pistonheads with regard to 996 Porsche intermediate shaft or variocam issues. Apparently a common problem it would seem, but all the Porsche lovers dont want to acknowledge there is a fault and bury their head in the sand trying to blame the other owners for their driving style, history of the cars, dealers used, in fact, what ever they could blame apart from their beloved Porsche brand and admitting perhaps the design is flawed. The cost of repair is often more than our complete cars!

You cant expect a performance car to be bullet proof :)
Title: Rx7 \'engine unreliability\'
Post by: Will66 on April 05, 2012, 09:23:54 AM
It\'s quite telling the amount of rotaries that are involved in motorsport and the amount of engine mechanicals failures they don\'t have.  If you look after a rotary it will take immense abuse for the whole of its working life.  If you spend your time in a piston engined car nailing it at maximum rpm it will be scrap far sooner than a rotary.  Short of detonation or overboost when the rotary wears out and eventually stops starting when warm you\'ll just need to strip it, replace the warn out seals, put it back together, run it in and you can go again.
Title: Rx7 \'engine unreliability\'
Post by: oyvindjs on April 05, 2012, 12:50:07 PM
Here is a GREAT piece of rotary racing history by the great Howard Coleman.
from rx7club.com:
"
Back in 83-89 when i was racing rotaries versus factory backed piston  engines in SCCA GT3 class one of the most significant aspects of the  rotary was that it was bullet proof. The $20,000 four valve Toyota  engines that were the primary competition were running cams that were so  radical they had about 4 thou piston to valve clearance so as to make  enough hp to run w the rotary. Over-rev 500 rpm on a shift and you had a  bushel basket of shrapnel for your $20,000.

My Roger Mandeville or Daryl Drummond motors ran from 7000 minimum to  10,000 max for the entire 35 minute race. i remember at the 83 Runoffs  at Road Atlanta asking Roger after qualifying if he thought we should  throw in a fresh motor. The motor  in the car had run 12 National races,  plus two days of practice and two days of Runoffs qualifying... Roger  asked if the motor hot started O K and i answered in the affirmative. He  laughed and said that if we liked working we could change it but it  wouldn\'t add another hp.

Try that w a piston engine.... the valve stems would be loosey goosey  leaking oil into the combustion chamber, the valve springs would be  shot, the rod bolts would be stretching etc etc.

I ran 72 National races, 5 Road Atlanta Runoffs and had one blown motor.

The circumstance of my one misfortune was after the first day of  qualifying at the Runoffs I was fourth. I asked Daryl if we might put  one more tooth (Speedway Eng quick change rear end) in the overall gear  ratio for Q2. We were pulling 10,000 at the bottom of the hill after the  long back straight… the change would add an additional 400 rpm in 5th.  Daryl said it would be 50/50 the motor would live as it had been pulling  hard from the keyhole. I gave it a shot and the motor lost a seal at  10,400. Unlike a piston motor, most of it was salvageable.

Even when wounded, racing rotaries just keep on humming. i remember  seeing Chris Dembs at the (approx) 82 Runoffs pouring oil down his Weber  carb to get his rotary started and he blew off a very strong field...

Perhaps the most demonstrative example of rotary reliability was in the  24 Hours of Daytona. During the 80s Mazda racked up a huge number of  wins in GTU and GTO over Porsche.

At the end of the 24 hours all the Mazda racers would make a point of bringing their cars into the pits and letting the engines idle  while they leisurely extricated themselves. The engines (huge  bridgeports or peripherals) would just brap brap away like they had been  on a cruise.

Bullet Proof.

The piston engine cars still running after 24 hours would idle  at about 5000 rpm. They were total junk. I use the J word literally.  After a 24 hour race most piston engines are torn down and almost all  moving parts are discarded or sold for pennies down the food chain.  

Rotaries ruled the 24 Hours in the 80s. All from a shortblock that is  approx 13 inches by 13 inches by 13 inches... w no rods to bend, no  valves to crunch, no cams to screw with no windage problems in the  crankcase....

So what happened to the FD rotary?

Turbos happened.
"