I love the Mazda Rx-7 for the sence of style and the sence of style and the speed im trying to get a messed up one and fix up the engine and all. But I was told that Rotory engines aren't reliable. Is that true?

 

It doesn't have any valves or camshafts, or timing belts/chains, or connecting rods, not to mention pistons. It's got less things to break. Rotaries are way more reliable than piston engines from that standpoint.

Of course this is biased information coming from a guy (myself) who probably knows a bit more about rotaries than whoever told you that they aren't reliable.

You are open to new ideas though, and that's great. Just stick around here and you'll learn everything you ever wanted to know, and even discover new things. It;s really cool.

 

They are very reliable, and have gained their best racing reputation in the endurance classes. The problem is that they are a little expensive to repair, and it is difficult to find a good mechanic. This means that people tend to hold off on repairs, and/or attempt repairs on their own that they maybe shouldn't, both of which have adverse effects on what would otherwise be a reliable engine.

 

I would say that just like with any other engines there are a lot of factors that make up reliability. Basically if you want reliable, then don't modify it. Rotaries are very fragile though, so unless you really want to learn how to tune them up yourself, it's best to let some one else do it that has experience. As far as building one, you can build one for almost no money just to have it driving around, however, if you want performance there are no short cuts there!

 

The rotary engine in and of itself is very reliable. It's all the **** Mazda bolts onto it that makes them unreliable.

 

I couldn't agree more
Rotaries were designed to be driven hard. It's actually more damaging to papmper a rotary! Apparently you end up with carbon buildup on the ports if you never rev the engine very high.

 

since ima newb i have a question. Why are apex seals designed to be so thin?

 

I'm not an engineer, and there are a lot of people here who know a lot more about why the rotary engine works the way it works and why somethings are the way they are than I do... but it's my understanding that they're so thin because of friction. The thinner the seal is, the less contact with the rotor housing, means less wear on the seal and the rotor housing.

Go look for a "3mm versus 2mm apex seal" thread and you'll see both sides of the arguement for that with some good explanations as to why the seals are the way they are.

 

Thinner seals seal better at higher RPM.

 

since there is more heat at higher rpms how would it be better?

 

It's not just rotaries, boingers also have to be reved up sometimes or they will carbonate. I've heard from a mechanic about some old lady bringing a car because it didn't perform well, all he had to do to fix it was to take it out on a highway and floor it. Oh and it's usually the seals that get carbonated.

 

That's like asking if a lime is to a lemon and a lemon's to a lime, why do cherries taste better... all the time?

Basically, the thinner seals would stay cooler because there is less friction.

 

So you guys are saying its always good to get out there and have a little high reving fun with your rotor. To help cut down on carbon buildup?

 

What's the point in owning a sports car if you don't wail on it from time to time?

Granted, I don't have an RX-7 at the moment... but if I drive my car anywhere and I don't hit redline at least once there's probably something wrong with the car that's keeping me from being able to do that.

 

Rotaries suck, dont get one. They break all the time and you will regret it. Besides, if you get one that leaves less for me to get.

 

I don't know if you would call a 74 repu a sports car. :P

 

The REPU isnt much of a sports car, but my 93 RX7 is. The REPU will have to be my sports car when I get around to autocrossing again, it is the only think I have that I can fit in with a helmet.