RE: Shed Of The Week: Mazda RX-8

RE: Shed Of The Week: Mazda RX-8

Friday 31st October 2014

Shed Of The Week: Mazda RX-8

Mazda's rotary wonder falls into Shed's grasp. What was that about hot starting?



A can of oil is not normally the sort of thing you want to see in the boot of a car you may be thinking of buying. A can of oil in the boot of a brand new car should be your cue to run away at high speed, or at the very least to give the worry beads some seriously feverish frottage.

That's genuine Mazdaspeed bodykit. Honest
That's genuine Mazdaspeed bodykit. Honest
And yet, the sight of a tin of 5w30 was precisely what greeted hapless journos whenever they opened the boot of a Mazda RX-8 press car. It hadn't been left there by mistake: it had been put there deliberately, along with a tersely-worded admonition from Mazda UK to check the oil level every ten minutes. Actually it may have been every week, or every day. Memory plays strange tricks on the over-60s.

Whatever it was, it seemed like a curious (and in a strange way not altogether unpleasant) revisiting of the great old days of motoring when nipples had to be greased and trunnions had to be, er, trunnioned. For many muttering rotters, of course, maintenance was an alien concept. It was something you paid the ex. The possibility of touching any oily bits would only crop up if you found yourself on a press bash at somewhere like Spearmint Rhino. It's extremely doubtful that many scribblers would have used that can of lube for anything other than as a top up for their personal wheezing sheds, or possibly in exchange for a packet of gaspers.

For owners of many mid-2000s RX-8s it turns out that no amount of oil could stave off the now notorious RX-8 peril of null hot starting. This engineering failure was, and is, a massive shame as the rotary engine is a brilliant design, producing in the RX-8 unfeasible amounts of power (230hp) from a comically small swept volume (nominally 1.3 litres, though our lovely Government taxed it as a 2.6 on the argument that the rotary has one power stroke per rotor per output shaft revolution, versus one power stroke per cylinder for every other revolution on a piston engine - or something like that).

What can be seen here appears good enough
What can be seen here appears good enough
The hot start (or lack of it) malaise is caused by worn tips on the tri-lobed rotor that is the rotary engine's equivalent of a blockful of pistons. This single whirry lump layout bestows low engine weight and stupidly high revs, but the cost of repairing a Mazda rotary is even higher. Think a minimum of £3,500. Thus the classifieds are full of minters like this one, lovely cars that nobody will touch with a bargepole while wearing an ebola suit in the near-perfect vacuum of outer space.

The owner of this one tells us (and we have no reason to disbelieve him) that his car runs fine, while it's running. In the light of this, surely £1,000 is a derisory amount to risk on a great-looking and generally great handling four-seat coupe with clever doors, a leather cabin, Bose sound system and a host of pukka add-on body bits? Especially as you could get round the hot starting problem simply by not switching it off.

That's right: keep it running, quite literally. Shed is unsure on the laws about whether you have to turn your engine off at the filler pump, a location with which the next owner will become tiresomely familiar as RX-8s don't really do fuel efficiency. Especially if you never turn it off. Doubtless a wise PHer will know the score on forecourt etiquette and post it here.

This must be worth a thousand pounds to someone
This must be worth a thousand pounds to someone
Even if it is illegal to keep the motor ticking over at the pumps, Shed thinks this might be a better option than chucking the traditional bucket of murky garage water over the engine in an effort to hasten the cooling process for a successful restart. That sounds like a recipe for a slightly less poisonous version of the Fukushima meltdown. Obviously you'd turn the motor off once you reached your final-ish destination, vaguely confident in the knowledge that it would start in the morning. For some, such a motoring regime would be entirely workable.

Say you do buy it, are there any other options? The obvious question of course being, can you bung a different engine in it? Hmm, well your first difficulty there is finding something in the same weight bracket as the Renesis motor. Once you've given up on that one, you may as well look at more outlandish-sounding solutions like the oft-suggested LS1 V8 conversion. Here's one from Hinson Motorsport in Alabama. Others talk of inserting Nissan's SR20 2-litre four. For a full discussion on it, we can do no better than refer you to the massed wisdom of the PH experts.

Whatever you choose, there'll be plenty of fabrication work to do. Shed still thinks you should just run it as it is and simply rule out any situations in which the hot start is required. How hard can it be?

Here's the ad.

2005 Mazda RX8 231 PS
This is a very reluctant sale of my RX8, as you can see it is a very special car and is fantastic to look at. It has the very rare MAZDASPEED body kit and exhaust system on it so it not only looks great but sounds really nice too. This car is a dream to drive and will put a smile on the face of anyone who drives it. All four tyres have got loads of life left in them and it has just had its latest full service which included plugs, levels, filters, etc etc to go with the full service history the car already had.

It comes with a whole host of extras including xenon lights, heated leather seats, 6 CD multi changer, BOSE sound system, glittery metallic paint, black details. The list goes on and on.

With only 50000 miles on the clock, there is still so much life left in this car, it also comes with an MOT until July next year.

Unfortunately that is where the good stuff ends, this car has picked up the very common problem which seems to plague a lot of 2005/2006 RX8s. It has a hot start issue due to the rotor tips being worn out. This can be an expensive thing to put right as it requires the engine to be fully stripped and quite a lot of parts replacing, hence the very low price for this fantastic car. If you know somebody who can rebuild engines then this is the perfect car for you as a project.

The car will start perfectly when the engine is cold, and will continue to run for as long as you need it to. The problem starts when you switch it off and then try to restart it when it engine is still hot. It will start eventually after a few attempts as this allows the oil pressure to build. So its not a 'non runner' by any means but it has got problems. I sadly cannot afford to fix this car and am absolutely gutted to have to sell it, especially at such a low price.

Viewings welcome and if you want any more information, please just ask. As I said I am only selling this as I cannot afford to repair it so please no time wasters!

£1000 ovno

Author
Discussion

BFleming

Original Poster:

3,609 posts

144 months

Friday 31st October 2014
quotequote all
A guy at work owns one of these. When hot, he revs it to 4000rpm, then switches the engine off. He reckons that restarting is then pretty straightforward as unburnt two stroke oil is burned off! Seriously though, these things burn oil almost like a two stroke, and are very heavy on petrol. Expect at best low 20's, probably even late teens on short runs (not recommended given hot start issues).
A nicely built car, quirky without being fugly, and not bad to drive. Depending on what you want it for, it might be a good buy. They can be had cheaper though.

BFleming

Original Poster:

3,609 posts

144 months

Friday 31st October 2014
quotequote all
Also, there's a build thread on UKSaabs.co.uk about a guy who has put a Saab B204 engine into an RX8. It's a lot of work...
http://www.uksaabs.co.uk/UKS/viewtopic.php?f=35&am...

BFleming

Original Poster:

3,609 posts

144 months

Friday 31st October 2014
quotequote all
Kentish said:
Somebody I know has successfully put an Lexus LS430 V8 engine into his RX8.

He said it was quite straightforward, the worst part being the electronic engine management.
I like the idea of that, but does that mean he has a manual box, or a redundant clutch pedal for the Lexus slushbox?

BFleming

Original Poster:

3,609 posts

144 months

Friday 31st October 2014
quotequote all
KimJongHealthy said:
BFleming said:
Also, there's a build thread on UKSaabs.co.uk about a guy who has put a Saab B204 engine into an RX8. It's a lot of work...
http://www.uksaabs.co.uk/UKS/viewtopic.php?f=35&am...
Perfect way to ruin a car that's main feature is a high-revving, light and compact rotary engine.
I don't think anyone removes a healthy rotary lump & puts all that work into it just for the hell of it. Maybe your sentence should read "Perfect way to ruin a car that's main feature was a high-revving, light and compact rotary engine"

;-)