ROTARY RELIABILITY - The facts!

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Delanor
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ROTARY RELIABILITY - The facts!

Post by Delanor » Wed Apr 08, 2009 6:37 am

I did consider posting this information in the members only section as my research has been on behalf of the club but as the car is the reason we are all here in the first place and it will benefit the reputation of the RX-8 I have posted it here.

It has become more noticeable recently that RX-8 engines have been failing, not in any great number to my knowledge and I have been around here for quite a while now and it has now arguably become a contentious issue but there is no denying it is happening for owners old and new with varying mileage so with this thought in mind I decided to speak to the experts the guys that know Rotary engines.

Hurley Engineering based in Coventry have 30 years experience in connection with the Rotary Engine originating with engine conversions to the notoriously unreliable Wankel engine that was fitted at that time to the NSU Ro80 through the era of the RX-7 to the latest generation - the Renesis so I gave them a call to get the facts straight from the horses mouth so to speak.

After a lengthy chat to Mick Hurley believe me this guy knows what he is talking about he is passionate about the virtues of the Rotary engine and as he admits will sit there all day to talk about them he is very knowledgable and accomodating in that respect.

Anyway the facts: Hurley repair/recondition Rotary engines their work comes from all quarters - private individuals to Mazda dealers up and down the country to date they have rebuilt 8 Renesis engines since Christmas and costing is usually £3200 for an engine turn around but at the moment the cost is £1,995 plus £545 fitting plus the inevitable VAT and for that you get a 2 year/24,000 mile warranty.

Mick has informed me that the Rotary engine in his experience is a very reliable and forgiving unit quoting the many occasions that they have stripped an engine that had still been running but that was displaying a problem to find that the engine was in such a state that it was hard to believe it was still in use compared to a piston engine that would have packed up long before.

When questioned further Mick revealed that by far the majority of engines and I did say majority not all that they have stripped the cause of failure has been the lack of correct maintenance the signs being severe blueing due to heat build up from lack of oil - the signs are immediately noticeable and as I said he does know what he is talking about, another failure contributor that they are now seeing more signs of is due to the failure of coil packs in the event of this happening if the condition is not immediately diagnosed increased fuel wash will soon cause a point of failure for the engine so make sure your engine is kept in tip top condition with respect to this.

Another fact that was interesting to learn (certainly for me as an engineer) is that the Rotary engine is a relatively easy unit to work on due to it`s simplicity - Mick informed me that no special equipment is needed and if you are handy with a set of spanners you can rebuild an engine which for my part was an interesting fact to learn as I have always carried out my own repairs in this respect on piston engines so anyone want to lend me their engine and I`ll have a play. :lol:

Mick did voice his concerns that he hopes history will not repeat itself with the latest generation of Rotary engine as the undeserved reputation that the RX-7 was labelled with (they have a wealth of experience with this engine) caused by several reasons but not solely down to the unit itself which incidently he confirms in power output levels the Renesis engine will never achieve quoting the 600 bhp Rotary powered monster that he has driven as a road car. :shock:

The general concensus being which I for one am in full agreement with is that the RX-8 is used by by Joe public, company reps drive them, leasing companies supply them, uncaring unknowledgable owners drive them and critical oil levels are not maintained and as the car ages and it becomes more financially attainable it will inevitably end up in the wrong hands, as Mick says it is a lot of performance car for not a lot of money if they are not driven and treated with respect (as I said maintenance of oil level is critical) the engine failures will increase, this is not a failure of the engine design or reliablity but as Mick says if you don`t treat it correctly it will turn round and bite you.

Another question I put to Mick was on the subject of oil a good quality mineral based oil is recommended no particular brand just make sure it doesn`t get low - with respect to the so called special Rotary engine oils he doubts that they offer any real benefit which will only be revealed after long term trialing has been carried out quoting the many engines he has seen with 100K+ mileage on them that have been run solely on the oils as stated.

Pre - mixing fuel - no benefit to be gained, that is not to say it will not help just that if the engine is looked after correctly there should be no need for it.

So lets hope these facts from a knowledgable business that knows the Rotary engine inside out will demonstrate that the engines are not unreliable and I know that is no comfort if you have suffered a failure but certainly in the case of second and third time buyers it demonstrates that you need to perhaps be a little more choosy in which car you buy and just to complicate matters a little more just because there is a full service history from a Mazda dealer is no guarantee that the car has been treated with the respect it deserves another fact that Mick and myself are in full agreement of.

Need to know more? as Mick said he will sit there and talk Rotaries all day long in fact he has invited me round for a look at their operation as Hurley are local to me that is an invite which I most certainly will be taking up as soon as I can so I finally get to see the nuts and bolts of a Rotary with some expert knowledge at hand as well, I have learned a lot already just on seals alone.

So there you have it when pub talk raises the subject of so called dodgy Rotary engines tell `em the truth is out there - you just need to look in the right places.

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Del.
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Re: The truth is out there - Rotaries finally!

Post by MarkR_VX » Wed Apr 08, 2009 8:05 am

Thank you very much for taking the time to collate and distribute this information Del.

It's a very informative piece and should certainly be the first port of call for any new buyers concerned about engine reliability.

Well done and thank you =D>

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Re: The truth is out there - Rotaries finally!

Post by Soul » Wed Apr 08, 2009 8:10 am

Very informative mate thank you =D>

Worth stickying or adding to the FAQs?
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Re: The truth is out there - Rotaries finally!

Post by I am Spartacus! » Wed Apr 08, 2009 8:56 am

great post and thanks for talking to the chap (and also for him chatting with you).

I have heard a lot of rx7 owners state that if the rotary engine is left standard as it left the factory, looked after and treated right, it can go way beyond the 60k recommended rebuild mark :)

And again you are right about owners not knowing what they have, I'll always remember the woman on the multi-storey car park who asked me about her "fault light".....it was the oil light and she was unaware that it needed monitoring and topping up on occassion [-X

Another occassion I saw a winning blue rx8 (whilst searching for an 8) that was owned by a doctor.....he had been using diesel oil to top up the car :shock: :shock:

so just in the above 2 scenarios are two rotaries waiting to die due to poor maintenance #-o

Again, thanks for the post Del :)
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Re: The truth is out there - Rotaries finally!

Post by MetA » Wed Apr 08, 2009 9:42 am

Add my thanks for this research Del :)
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Re: The truth is out there - Rotaries finally!

Post by SeanP » Wed Apr 08, 2009 4:02 pm

Great post Del, cheers =D>
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Re: The truth is out there - Rotaries finally!

Post by willard » Wed Apr 08, 2009 7:58 pm

well done dell ,a very interesting read =D>
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Re: The truth is out there - Rotaries finally!

Post by Knighty » Wed Apr 08, 2009 8:22 pm

Good read, thanks =D>
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Re: ROTARY RELIABILITY - The facts!

Post by Bassmanrex » Wed Apr 08, 2009 10:25 pm

+1 from me too, great read, thanks for posting it Del

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Re: ROTARY RELIABILITY - The facts!

Post by beaniebike » Thu Apr 09, 2009 3:56 pm

Me too! Thanks for that. I usually begin to nod off when reading lengthy posts - but not today! Very interesting. =D>

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Re: ROTARY RELIABILITY - The facts!

Post by essexgirlracer » Thu Apr 09, 2009 5:54 pm

Cheers for that makes my mind rest easier, as there is a post on mrc that got me worried saying engines over 50k will have damage something to do with oil ports, and some guy saying you need to pre-mix the 8's? if that was the case mazda would tell you to, id rather listen to the advice from mazda/rotary specialist.
We premix the 7 but thats a completly different car
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