OK Mazda Rotary experts....what's wrong with this?

What would cause the lean issue? I assume the missing is most likely coils, right? For only $1000 does it have Challenge potential?

Marketplace - 2004 Mazda RX-8 | Facebook

Cats fail. Plugs, coils, failure to rev limit fix things.

Load is more important than RPM to a rotary.  Unfortunately, high load also kills side exhaust port engines because the heat destroys the side seals and warps the side housings at the exhaust port.

For $1000 if it isn't too crusty, I'd almost want to buy it and stash it until 2029 when it will be emissions exempt, and stuff one of my bridge port engines in it 

It's also an 04, which IIRC had the worst presets for the oil injection and all that, so I wouldn't be surprised if the owner's assumption about it needed a new motor was correct unless they ran it with some premix.

But yes, coils are a known failure point on these and there's a fair number of them out there that probably needed new coils and not a new engine.

I love how cheap so many of these seem to come up. Ive never driven over but I have big dreams for transplanting the subframes/steering/ABS into something..

In reply to classicJackets (FS) :

Don't do that....I had the idea of Miata rolling stock under an old Corolla and look how that got out of hand.

Seriously though, I did see a 3500 mile Miata ND-RF wreck for sale locally and had similar thoughts about putting all that drive train and suspension under some other shell. It might have worked under an RX-8 even.

In reply to DeadSkunk (Warren) :

Lol - I'm not bold or good enough to start with anything unibody!! Would love to do ND too

classicJackets (FS) said:

I love how cheap so many of these seem to come up. Ive never driven over but I have big dreams for transplanting the subframes/steering/ABS into something..

They rust horribly, though.  The plastic cladding is still attached, which is a good sign.

I bought an RX-8 a few years back with a popped engine and rebuilt the rotary. For some sick reason my brain thought this would be fun.

The video really sounds like this thing is running on one rotor. I'm actually surprised it started, usually if it's idling like that it really doesn't want to get going. Based on the ad "probably needs a new motor" "don't want to mess with it anymore" I've gotta believe that whoever owned it would have atleast tried to swap coilpacks to see if the miss followed.

PARTS cost to rebuild the rotary with used housings, all new mazda OEM seals, and a few "while you're in there" bits was over $3k for me pre-covid. Irons, rotors, and e-shaft were all good and would add a lot more if not. 

For how cheap these things are these days, I'd just spend a few thousand extra to get a running one that's got a good owner.

In reply to toconn :

It boggles my mind how expensive RX-8 engine parts are. Sure, it's been out of production for 10 years but it's a lot more recent than the FD RX-7 and they made more than twice as many. New Renesis rotors and housings cost about as much as a 13B-REW's.

In reply to j_tso :

It's the same part, just with some minor casting differences.

Mazda still makes 13B parts for GSL-SE, Turbo II, FD, and RX-8.

In reply to Pete. (l33t FS) :

That's what's so boggling about it. Mazdatrix lists GSL-SE housings at $670, all flavors of Renesis are over $1000, and FC-FD are in between. Manufacturing-wise I'd think there's less work to make Renesis housings since there's no exhaust port and insert, just more drilling for the oiling injectors.

I have always wanted to put a Mazda V6 K motor in one of these.  

j_tso said:

In reply to toconn :

It boggles my mind how expensive RX-8 engine parts are. Sure, it's been out of production for 10 years but it's a lot more recent than the FD RX-7 and they made more than twice as many. New Renesis rotors and housings cost about as much as a 13B-REW's.

The RX-8 was a neat platform but ultimately isn't worth the headaches and cost in my opinion. The renesis was never a highlight, just the last flicker of a dying flame. You gotta really like those specific cars to make ownership worthwhile in my opinion.

j_tso said:

In reply to Pete. (l33t FS) :

That's what's so boggling about it. Mazdatrix lists GSL-SE housings at $670, all flavors of Renesis are over $1000, and FC-FD are in between. Manufacturing-wise I'd think there's less work to make Renesis housings since there's no exhaust port and insert, just more drilling for the oiling injectors.

Well....

I bought new -SE rotor housings a couple years back.  They had casting flaws that they fixed with epoxy, and one of the exhaust port inserts was drilled wrong and I had to extract it and replace it with one from a dead housing.

j_tso said:

In reply to Pete. (l33t FS) :

That's what's so boggling about it. Mazdatrix lists GSL-SE housings at $670, all flavors of Renesis are over $1000, and FC-FD are in between. Manufacturing-wise I'd think there's less work to make Renesis housings since there's no exhaust port and insert, just more drilling for the oiling injectors.

Service order parts prices rarely have anything to do with perceived complexity. The two biggest cost drivers are  1) how  disruptive is the order to current production processes ,and 2) how many parts did the OEM order. A bigger order reduces the cost some. I used to run a parts plant and our parts were typically $8-10, but service order parts were 10-15 times more expensive , and everyone would get their shorts in a knot, but I could back up the real costs. The OEMs almost never buy a bunch of service parts at the end of regular production. Their inventory carrying costs are too high.

In reply to DeadSkunk (Warren) :

Mazda has a separate facility for rotary stuff, they never shut it down.

Neat thing about these engines, there are almost no suppliers. Mazda does everything in house.

DeadSkunk (Warren) said:

j_tso said:

In reply to Pete. (l33t FS) :

That's what's so boggling about it. Mazdatrix lists GSL-SE housings at $670, all flavors of Renesis are over $1000, and FC-FD are in between. Manufacturing-wise I'd think there's less work to make Renesis housings since there's no exhaust port and insert, just more drilling for the oiling injectors.

Service order parts prices rarely have anything to do with perceived complexity. The two biggest cost drivers are  1) how  disruptive is the order to current production processes ,and 2) how many parts did the OEM order. A bigger order reduces the cost some. I used to run a parts plant and our parts were typically $8-10, but service order parts were 10-15 times more expensive , and everyone would get their shorts in a knot, but I could back up the real costs. The OEMs almost never buy a bunch of service parts at the end of regular production. Their inventory carrying costs are too high.

Yea I worked for an OEM manufacturer and we were in the same boat. The equipment that made the parts for a 20 year old truck is the same equipment that makes parts for the new car that sells 300k units/year. On a normal production day we're building 1000 pcs and bringing in $50k / revenue per line. If an order for 100 service parts comes in and means we have to spend 2 hours switching over the line, run out the 100 pieces, and then spend another 2 hours switching the tooling back over - you'd better believe the accountants have figured out what that costs and are pricing appropriately. 

And that reality spreads all the way up the chain. Our cost to build the part is higher so we price appropriatley. The warehousing people that store the part don't move a lot of them so they charge more for the long sit time on the shelf. The resaler who sells the part doesn't sell as many of them so they set the margins higher. So instead of a $20 part going straight to an OEM, you've got a $100 part with an obscene warehousing cost and a massive end-retailer markup waiting to be tacked on. What the OEM pays $20 for the end user pays $250 for as a service part. 

Given the failure rate of RX-8 engines and the amount of cars out there, wouldn't more Renesis housings be produced or are people just abandoning them in droves?

I don't see as many people using GSL-SE housings compared to FC/FDs, or maybe there are more people cobbling together 13Bs with 12A irons like me than I realize. In 2019 I saved $300 on a pair by googling the part number and buying from a dealer in Florida.

Theoretically they can be used in a Renesis but require modifying the rotors and a custom exhaust. Mazdatrix did it years ago but I haven't heard much about it so it's probably not worth the effort.

In reply to j_tso :

Up here (Michigan) RX-8s are cheap. You're driving an older car, the engine goes south, and it will have rust.....so not worth the expense of fixing/replacing the engine. I keep wondering what a 2.5 NC derived power train would be like in an RX-8 shell, a southern one. It would probably suck because of the extra weight the RX-8 carries.

In reply to j_tso :

Apparently Mazda USA sells over 100 GSL-SE rotor housings per month.

DeadSkunk (Warren) said:

In reply to j_tso :

Up here (Michigan) RX-8s are cheap. You're driving an older car, the engine goes south, and it will have rust.....so not worth the expense of fixing/replacing the engine. I keep wondering what a 2.5 NC derived power train would be like in an RX-8 shell, a southern one. It would probably suck because of the extra weight the RX-8 carries.

That's what a turbo is for!

In reply to DeadSkunk (Warren) :

More power would help offset the weight. The RX-8 body is stiffer than the FD.

Pete. (l33t FS) said:

In reply to j_tso :

Apparently Mazda USA sells over 100 GSL-SE rotor housings per month.

wat *mindblown*

Controversial opinion?:

I own an RX-8, but it's not the look that sold me to it. And I think it's ugliness is what's causing it to be ignored by most people. Because rationally, it's simply a better car than the FD in almost everyway....except looks (and steering feel).

In reply to fanfoy :

The wheelbase is far too long for it to handle well.