Discussion
i have a rx7 running just under 500fwhp and recently i also had an rx8 which i bought with low compression and got the engine rebuilt at rx motors. i did loads of investigating regarding issues,causes,prevention etc
the rx8 renesis rotary is very different from the 13b turbo engine found in my rx7 the renesis was developed to rev higher but to manage this mazda redesigned the rotor tips making them shorter and harder than earlier 13b engines. the problem with this is that it reduced the amount overall wear the tips can handle, this wouldnt really of been an issue if they hadnt made the amount of oil the omp system injects into each rotor marginal at best causing the tips to wear even more quickly. this wear is what causes the tip to break or just wear so thin it no longer seals causing low compression. the lack of oil is something they addressed in the later r3 engine by adding and extra oil injector. most enthusiasts get round this by adding a 100ml of low ash 2 stroke oil to every fill up. so tbh not great development on mazdas part with that one.
the coil issue is just stupid and mazda should of sorted this by now they have updated it so many times but still it seems to be an issue. you can check to see if the coil is going by checking on the underside for shorting and discolouring but its not easy to do and joe bloggs isnt going to know to do it anyway so as a matter of course replace every 30k. the shorting causes lack of power from incomplete combustion which if you arent pre mixing will cause seal issues with lack of lubrication through washing and also bugger up the cat pretty quickly.
main engine bearings wear excessivley this is mainly due to the engine not being warmed completly before high revving with low oil levels or poor quality oil being contributing factors.
the final golden rule for any rotary is once its warm you must rev it to the redline at least once every trip this will ensure no carbon builds up on the seals or tips and helps prevent them from sticking which can also cause failure, low compression or high wear to the housings.
as far as cost is concerned rxmotors in blandford will do a drive in drive out engine rebuild for 2k they will strip and replace anything that is not within tolerence with rotor tips,main bearings and seals always replaced as a matter of course. this is what i did with my rx8 and it also comes with a 12 month warranty.
if you buy an rx8 no matter what the mileage a compression test is a must but it will not of course show up any incompetence of the previous owner regarding the warm up reving etc
my advice if you want a nice handleing car and go into ownership with your eyes open go and buy one with low compression for less than £1500 and get the engine rebuilt that way you start from a known point of wear and use and can take precautions to keep it healthy for a long time.
its a shame the track 8 here went bang with the list of issues here there was a 50/50 chance how it was going to go and its not going to get a harder test than going round the ring all the time.
as far as my rx8 is concerned i bought it as i was taking the rx7 off the road to work on which i no longer have to do so i gave it to the wife who didnt like the fueling cost to comute in it so it was sold today. the person who has bought it has got a 100% sorted rx8 and if he does all the things to look after it he shouldnt have to spend any money on the engine for 30k when the coils will need doing again
mind you i took the rx7 for a spin this evening and there really is no comparison
the rx8 renesis rotary is very different from the 13b turbo engine found in my rx7 the renesis was developed to rev higher but to manage this mazda redesigned the rotor tips making them shorter and harder than earlier 13b engines. the problem with this is that it reduced the amount overall wear the tips can handle, this wouldnt really of been an issue if they hadnt made the amount of oil the omp system injects into each rotor marginal at best causing the tips to wear even more quickly. this wear is what causes the tip to break or just wear so thin it no longer seals causing low compression. the lack of oil is something they addressed in the later r3 engine by adding and extra oil injector. most enthusiasts get round this by adding a 100ml of low ash 2 stroke oil to every fill up. so tbh not great development on mazdas part with that one.
the coil issue is just stupid and mazda should of sorted this by now they have updated it so many times but still it seems to be an issue. you can check to see if the coil is going by checking on the underside for shorting and discolouring but its not easy to do and joe bloggs isnt going to know to do it anyway so as a matter of course replace every 30k. the shorting causes lack of power from incomplete combustion which if you arent pre mixing will cause seal issues with lack of lubrication through washing and also bugger up the cat pretty quickly.
main engine bearings wear excessivley this is mainly due to the engine not being warmed completly before high revving with low oil levels or poor quality oil being contributing factors.
the final golden rule for any rotary is once its warm you must rev it to the redline at least once every trip this will ensure no carbon builds up on the seals or tips and helps prevent them from sticking which can also cause failure, low compression or high wear to the housings.
as far as cost is concerned rxmotors in blandford will do a drive in drive out engine rebuild for 2k they will strip and replace anything that is not within tolerence with rotor tips,main bearings and seals always replaced as a matter of course. this is what i did with my rx8 and it also comes with a 12 month warranty.
if you buy an rx8 no matter what the mileage a compression test is a must but it will not of course show up any incompetence of the previous owner regarding the warm up reving etc
my advice if you want a nice handleing car and go into ownership with your eyes open go and buy one with low compression for less than £1500 and get the engine rebuilt that way you start from a known point of wear and use and can take precautions to keep it healthy for a long time.
its a shame the track 8 here went bang with the list of issues here there was a 50/50 chance how it was going to go and its not going to get a harder test than going round the ring all the time.
as far as my rx8 is concerned i bought it as i was taking the rx7 off the road to work on which i no longer have to do so i gave it to the wife who didnt like the fueling cost to comute in it so it was sold today. the person who has bought it has got a 100% sorted rx8 and if he does all the things to look after it he shouldnt have to spend any money on the engine for 30k when the coils will need doing again
mind you i took the rx7 for a spin this evening and there really is no comparison
My engine is a german straight 6. It works perfectly.
This is a thread about a Mazda rotary owner that is going to a BMW saloon after reliability woes. I have owned both types as longterm sole dailys and done the miles and held the spanners in both instances. The BMW is still my daily car to this very day.
So not trolling in the slightest, this is informed opinion based in actual (and ongoing) experience from a fellow PHer!
I actually really like your GTE btw, but you do understand that in a thread about a guy who blew his RX8 doing laps of the Ring placing a pic of your old Astra was, erm, brave!
This is a thread about a Mazda rotary owner that is going to a BMW saloon after reliability woes. I have owned both types as longterm sole dailys and done the miles and held the spanners in both instances. The BMW is still my daily car to this very day.
So not trolling in the slightest, this is informed opinion based in actual (and ongoing) experience from a fellow PHer!
I actually really like your GTE btw, but you do understand that in a thread about a guy who blew his RX8 doing laps of the Ring placing a pic of your old Astra was, erm, brave!
Edited by LotusAlfaV6bloke on Thursday 30th August 22:32
Edited by LotusAlfaV6bloke on Thursday 30th August 22:34
Well you brought up the Astra ownership..?
The Vauxhall 20XE redtop has been used widely on the racetrack over the years by amongst others Lotus & Caterham. I seem to remember a guy called Cleland doing rather well in the BTCC with it. It's absolutely bullet-proof, was an extremely advanced design for its time, retains factory performance & is easy to maintain.
The OP had his wankel compression tested, he bought the car with a full service history, he took it out on the track & it went pop.
Can't say I'm surprised.
The Vauxhall 20XE redtop has been used widely on the racetrack over the years by amongst others Lotus & Caterham. I seem to remember a guy called Cleland doing rather well in the BTCC with it. It's absolutely bullet-proof, was an extremely advanced design for its time, retains factory performance & is easy to maintain.
The OP had his wankel compression tested, he bought the car with a full service history, he took it out on the track & it went pop.
Can't say I'm surprised.
zygalski said:
So what's the agreed best practice for maintaining one of these mass-production coupés?
Come on RX-8 types, I could use a laugh
Easy, don't keep it past 20,000 miles. I owned 2, loved them to bits, never had a single problem, made sure I got rid of them before they were out of warranty and on the wrong side of coil pack problems.Come on RX-8 types, I could use a laugh
cyman said:
the rx8 renesis rotary is very different from the 13b turbo engine found in my rx7 the renesis was developed to rev higher but to manage this mazda redesigned the rotor tips making them shorter and harder than earlier 13b engines. the problem with this is that it reduced the amount overall wear the tips can handle
RX8 is supposed to be able to do 150,000 miles before the tips need looking at.The OP didnt mention what mileage it had done already.
My RX8 was fine but then it was new when i got it and I only covered abut 40k miles in it.
LotusAlfaV6bloke said:
My engine is a german straight 6. It works perfectly.
This is a thread about a Mazda rotary owner that is going to a BMW saloon after reliability woes. I have owned both types as longterm sole dailys and done the miles and held the spanners in both instances. The BMW is still my daily car to this very day.
So not trolling in the slightest, this is informed opinion based in actual (and ongoing) experience from a fellow PHer!
I actually really like your GTE btw, but you do understand that in a thread about a guy who blew his RX8 doing laps of the Ring placing a pic of your old Astra was, erm, brave!
You were the one that tried to be a internet hardman and show how much better you were than someone who "only" had a Astra. This is a thread about a Mazda rotary owner that is going to a BMW saloon after reliability woes. I have owned both types as longterm sole dailys and done the miles and held the spanners in both instances. The BMW is still my daily car to this very day.
So not trolling in the slightest, this is informed opinion based in actual (and ongoing) experience from a fellow PHer!
I actually really like your GTE btw, but you do understand that in a thread about a guy who blew his RX8 doing laps of the Ring placing a pic of your old Astra was, erm, brave!
Edited by LotusAlfaV6bloke on Thursday 30th August 22:32
Edited by LotusAlfaV6bloke on Thursday 30th August 22:34
Pathetic move which rightfully backfired on you.
really appreciate the comment from cyman.
all others bashing on the rotaries your entitled to your opinoins. (spelt wron i know but im an engineer cant write)
show me an engine that can deliver so much performance for so little cash. yes they dont last as long as a piston but thats the deal.
check this out
7 secound rx3.
all others bashing on the rotaries your entitled to your opinoins. (spelt wron i know but im an engineer cant write)
show me an engine that can deliver so much performance for so little cash. yes they dont last as long as a piston but thats the deal.
check this out
7 secound rx3.
Lukeschwantz, it's not a for or against issue.
If the Renesis wasn't problematic Mazda wouldn't have set up that facility in the US to replace or repair them.
The engines do expire and there are two firms in the Midlands looking at putting the VAG 1.8T four pot in them because of the sheer availability of RX-8s with dead engines and the ubiquity and affordability of the VAG 20V 4 cylinder turbo.
It reminds me of Jags That Run that includes info. on LS1 RX-7 conversions:
http://www.jagsthatrun.com/
If the Renesis wasn't problematic Mazda wouldn't have set up that facility in the US to replace or repair them.
The engines do expire and there are two firms in the Midlands looking at putting the VAG 1.8T four pot in them because of the sheer availability of RX-8s with dead engines and the ubiquity and affordability of the VAG 20V 4 cylinder turbo.
It reminds me of Jags That Run that includes info. on LS1 RX-7 conversions:
http://www.jagsthatrun.com/
RobDickinson said:
cyman said:
the rx8 renesis rotary is very different from the 13b turbo engine found in my rx7 the renesis was developed to rev higher but to manage this mazda redesigned the rotor tips making them shorter and harder than earlier 13b engines. the problem with this is that it reduced the amount overall wear the tips can handle
RX8 is supposed to be able to do 150,000 miles before the tips need looking at.The OP didnt mention what mileage it had done already.
My RX8 was fine but then it was new when i got it and I only covered abut 40k miles in it.
I think the main problem with the RX8 was Mazda selling it as a car anyone could buy and own - like Mrs Jones next door who bought one 'because it looks nice' after her fiesta and uses it on the school run every day, doesn't warm it up properly, doesn't rev it, doesn't check oil.... you can't treat an RX8 like a normal car because it isn't.
I do think that if warmed up properly, revved correctly, Royal Purple oil used, coil packs checked annually and changed every 30k you can have one that will be reliable. I personally think that buying a low comp and getting it rebuilt is a good idea as you know then it will be spot on.
I would definitely have another, particularly an R3 (although these seem to suffer gearbox problems)...
I do think that if warmed up properly, revved correctly, Royal Purple oil used, coil packs checked annually and changed every 30k you can have one that will be reliable. I personally think that buying a low comp and getting it rebuilt is a good idea as you know then it will be spot on.
I would definitely have another, particularly an R3 (although these seem to suffer gearbox problems)...
Dale Lomas said:
My car had 76k miles, fsh and I ran pre-mix. I hadn't fitted a Sohn adaptor. Oil and water levels perfect.
Yes, but you don't know how it was used by the previous owner do you? That's why I think a rebuilt one would be the way to go.Edited by Dale Lomas on Friday 31st August 09:13
Mr Colonial - I wasn't trying to be an "internet hardman", I was being fair. The other chap's very first post about this whole article was a very trolling "So what's the agreed best practice for maintaining one of these mass-production coupés? Come on RX-8 types, I could use a laugh"
A very simple check reveals he has a mass produced Vauxhall. I was right to use this in response to his childish first comment. Tell me how all that is wrong? It didnt backfire on me at all all
He then links his old Astra to motorsport heritage out desperation, a bit like if Dale had linked his own car to the 787 Mazda that won Lemans!
A very simple check reveals he has a mass produced Vauxhall. I was right to use this in response to his childish first comment. Tell me how all that is wrong? It didnt backfire on me at all all
He then links his old Astra to motorsport heritage out desperation, a bit like if Dale had linked his own car to the 787 Mazda that won Lemans!
robsa said:
Yes, but you don't know how it was used by the previous owner do you? That's why I think a rebuilt one would be the way to go.
That applies to any used car. How many other used cars routinely need their engines recon'd or replaced as a matter of course because the previous history is unknown?
900T-R said:
Don't forget, though, that the reason it's scrap now, is that it was only £2.2K in the first place.
Many on here will have paid more for a major service than the £3K or so quoted for a rotary engine rebuild including removal/installation...
That's my point though - if it had the 2.3 MPS Turbo or a 6 cyl the RX8 would never have dropped to £2k after 8 years and now be scrap. I would say they still be fetching £6-8k after 7 years.Many on here will have paid more for a major service than the £3K or so quoted for a rotary engine rebuild including removal/installation...
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