Repair Cost vs. Piston
 

i've never owned a rotary powered car, and am about to get the RX-8 in a week..just wondering how do the repair costs compare to the piston engines? would i expect to pay more for a comparable repair for a rotary or piston engine? if you got a "why?" reasoning, i'd like to know to..

thanks...

I don't know about maintenance but rotaries need to be rebuilt around 100,000 where piston engines don't need overhauls until long after that. The 8 may be different since its naturally aspirated. I think MSN autos or Edmunds shows the average annual repair costs for vehicles.

You need to know what you are talking about when you make a statement like "rotaries need to be rebuilt at 100k". There are a lot of old RXs with over 200k and even 300k without a problem. The model you are probably thinking about is the FD RX-7 (93-95), those problems are mainly due to ineffective cooling and a overly-complex twin turbo system.

I agree with you,
Now and then I check out rx7's 1st and 2nd generation on e-bay. Lots have over 150k on the motor.

Also, there are no "Repairs" to the rotary engine. A rotary engine needs to be rebuilt when there is a problem. The only real problem you could have is the coolant seals, oil seals or apex seal. The excentric shaft could get seized, but thats very rare. Any of those require a new engine or rebuild.

An FD reman goes for about 2100 + 1700 labor for install. Thats for a bone stock engine, not including any porting or fun stuff.

You cant directly say "how much does it cost rotary vs piston" As you may know comparing the cost of two piston engines can vary greatly also.

Theres so few bits in a NA rotary to go wrong (as opposed to a piston) they are more reliable, just a bigger job if they go wrong.

Think of a piston engine that only has piston seals , a cam and gaskets. ignore all the other stuff - thats not there to go wrong.

An old NA rotary came 2nd to a MB v8 desil in reliability tests in the 80's.

Aside from the engine, from the output shaft onwards the car is identicl to any other piston driven car mechanicaly. Just keep it toped up with oil and dont thrash it when cold it'll love you long time.

thanks for the info. i guess repair is the wrong word to use. however, i talked a buddy and he seems to know a lot about the RX-8...he gave me a scenario, if you need to replace a spark plug on a piston engine then you'd remove the wire, unscrew the plug, then replace, etc. he stated, that on a rotary, it's more complicated than that, and it's not something the average car enthusiasts would know how to do...probably costing above 200 bucks.

is there any truth to this? again, thanks to everyone who provided some information...

This is the TSB for the spark plug

http://www.finishlineperformance.com...h_rf04-04.html

they look like any other spark plug to me. The plugs are specifically designed for the Renesis and they are only made by NGK right now so they are more expensive than your regular plugs, something like $38 each. Other than the fact that they may be in a difficult to reach position, I don't know why your friend said it's more complicated than that.

Another point about repair cost is that the rotary has no timing belt or chain so you will never have to worry about changing that. That could easily be $500+ every 60k miles for a piston engine. Something to think about..

$38 for a spark plug!?!?!? :eek:

damn and I thought $8.50 per plug for my FC was expensive :(

The plugs are good for 100,000 miles aparently, and do spark more than piston engine cars.

Sounds like exactly the same procedure for a rotary. However, yes you do need to get *specific* NGK spark plugs, and they might be expensive for the time being.
It is generally true that a rotary costs more to repair when it finally decides to go out. When the engine blows, it's usually because of a seal (apex seal, side seal, oil seals, etc) This is somewhat the equivalent of a piston engine blowing a head gasket or ring seal or valve spring or timing belt. It's less expensive to repair a blown piston engine because you don't need to remove the entire motor to fix those types of broken seals - on a rotary the engine must be removed and the engine internals must be dismantled. Since it's removed, it may as well be replaced altogether with a freshly remanufactured motor since the amount of labor involved in rebuilding a particular rotary motor might cost about the same. So it might cost you about $3g for parts and labour on a blown rotary whereas a blown piston engine might cost about $300 to get running again.
In addition, rotary mechanics aren't as abundant as general mechanics who can troubleshoot and repair most piston engines; therefore a good rotary mechanic might not have as much competition for business. In fact, you might even have a hard time finding a mechanic willing to work on your car, let alone know what he's doing.
Aside of complete motor failure - which is no more common with rotaries in comparison to piston engines driven in the same manner - ancillary components such as starters, alternators, suspension, brakes, tyres, etc.etc.etc. are not specifically different from any other roadgoing car.
Does this sound bad? At least the RX-8 comes with a four year warranty... :D

ahhhh, that's precisely what i was concerned about...thanks to everyone, especially GiN for helping me understand the rotary engine a little bit more...you haven't eased my anxiety but, at least i'm a bit more prepared and educated to make a decision on what car is right for me....

as long as these repair costs are relatively similar, i think i should be alright...ummm, they are similar right?

Thanks again everyone.

They are similar. Many under-hood components are probably shared among other cars, and can be serviced by any competent mechanic, if not the dealership.

Rotary engines do not need to get rebuilt at 100,000 miles unless you put alot of mods on them. If you take care of it it will last just as long as any piston engine. What happened with alot of RX-7's was people would over boost them. People that would add alot of performance mods on the RX-7's needed to get the better apex seals (which would require a rebuild) if they didn't thats when they were blowing there engines at 80000-125000 miles. People with rotaries that aren't at the track or racing everytime you turn around normally can get between 150000-200000 miles on them. They are also cases of people getting 300000 miles plus.

I think that $38 a piece for Iridium pulgs are about normal

thanks DYT for the REAL info...i was getting worried