rotary engine?

[Zanity]

so i was looking at some prices for the rb26 and sr20 engines and then i would look at the 13b twin turbo rotary engines and i can't help but realize...they are so much cheaper than the sr20s or the rb26s.

so i'm thinking, what kinds of things would need to be done do to make a 13b twin turbo or maybe a 20b? transferable to a 1973 240z?

i'm thinking with the money i can save getting the rotary engine, i can pay for the mods necessary.

just a thought for the future.

when i know enough to actually do this i'll be sure to let you all know and updated but it may be a year or two.

[Mike kZ]

PM Auxilary ...http://forums.hybridz.org/member.php?u=8034 . He is building a rotary Z .

 

http://www.rotaryz.com/

[Gollum]

I'll save a bit of time. I kinda feel bad for aux always having to answer tons of rotary questions.

 

First off, realize that they need to be rebuilt semi-often, usually around 60k. Reason being is that the apex seals are under constant friction and hard load and just plain wear down.

 

Next, the stock twin turbo exhaust manifolds don't clear, by quit a bit. The RX7 and RX8 engine bays are very wide compared to the S30 (actually... most cars have a much wider bay) and as such you NEED to go with an aftermarket exhaust manifold setup. While you're at it you might as well convert to single turbo imo.

 

You also have to decide if you want to use the factory oil adding function. Rotary motors are fuel lubricated, so they NEED oil in the fuel. That's just the nature of how they work (much like a 2 stroke). So either you need to adapt the stock system, or remove it and add oil to every tank in precise amounts (that's what aux plans on doing).

 

Personally, I think if there was a NA 3 rotor that costed less than 2k for a complete motor + sensors + ECU that had more than 250hp, then I'd strongly consider it for a swap. But the 3 rotors are turbo motors and extremely expensive. And I'm overal not sure I'd be willing to deal with the headache of a rotary swap.

[Zanity]

yeah, i know all the downsides of rotary engines but i also know all the upsides.

a 20b would not be cheaper, i hope to build a 20b or a 26b engine in my future as well.

i just would like to be able my two favorite things in all cars...a Z and a rotary engine.

so the headache would be worth it.

[Juarez88]

if you haven't heard of it.

 

http://www.diy-re.co.nz/

 

 

I would probably buy that if I planned on building a 2 or 3 rotor.

[Zanity]

if you haven't heard of it.

 

http://www.diy-re.co.nz/

 

 

I would probably buy that if I planned on building a 2 or 3 rotor.

 

yeah, when i'm ready to i plan on getting that.

[rxKaffee]

A good turbo 3 rotor install in an FC was quoted to me at around 10k$. This was for the total package to be installed into the FC GXL that I had at the time. I'm sure it could be done for less yourself but it'll take alot more fab on a Z.

 

You can get a coustom E-shaft from a couple different people, to make your own 3 rotor. I believe most if not all of them use older 12A parts though.

 

A well-tuned N/A 3 rotor should put you WELL over 200hp. A good tune on a moderate-to-heavily modified series5 n/a 2 rotor will get you to 200hp.

 

Only people with poorly tuned or highly abused rotarys have to rebuild every 60k mi... My s4 had over 180k on the original engine and still pulled hard, with verifiable compression numbers for each seal. Only the oil rings needed replaced, but hey, just meant I could smoke it up like a diesel when I wanted

 

Premixing isn't that big of a deal either if you decide to plug up the factory oil injection. It doesn't have to be precise, just close. Most people don't even drain their tank all the way down before refueling.

[Zanity]

hm, thats good to know.

i'm pretty sure i'll be abusing my car some if i get a rotary.

 

i was actually just planning on getting the 3 rotor from a eunos cosmo.

or from a site like this

http://www.jdmtigerjapanese.com/

[Gollum]

Only people with poorly tuned or highly abused rotarys have to rebuild every 60k mi... My s4 had over 180k on the original engine and still pulled hard, with verifiable compression numbers for each seal. Only the oil rings needed replaced, but hey, just meant I could smoke it up like a diesel when I wanted

 

 

 

Well is your engine NA or Turbo? Most of the people that talk about having to rebuild every 60k no matter what are the guys putting 400+ wheel HP down on turbo motors. NA rotary engines last forever by comparison.

[MazterDizazter]

I'll save a bit of time. I kinda feel bad for aux always having to answer tons of rotary questions.

 

First off, realize that they need to be rebuilt semi-often, usually around 60k. Reason being is that the apex seals are under constant friction and hard load and just plain wear down.

 

Next, the stock twin turbo exhaust manifolds don't clear, by quit a bit. The RX7 and RX8 engine bays are very wide compared to the S30 (actually... most cars have a much wider bay) and as such you NEED to go with an aftermarket exhaust manifold setup. While you're at it you might as well convert to single turbo imo.

 

You also have to decide if you want to use the factory oil adding function. Rotary motors are fuel lubricated, so they NEED oil in the fuel. That's just the nature of how they work (much like a 2 stroke). So either you need to adapt the stock system, or remove it and add oil to every tank in precise amounts (that's what aux plans on doing).

 

Personally, I think if there was a NA 3 rotor that costed less than 2k for a complete motor + sensors + ECU that had more than 250hp, then I'd strongly consider it for a swap. But the 3 rotors are turbo motors and extremely expensive. And I'm overal not sure I'd be willing to deal with the headache of a rotary swap.

 

The reason why most twin turbo rotary engines need to be rebuilt (or to the best of my understanding) is because most stock FD RX-7's have inadequate stock cooling systems. Some simple upgrades to the cooling system (one of these being a big uncramped engine bay such as one in the Z) should work wonders for a rotary engine. The older single-turbo 13BT's are known to last around 120k and I suspect that's because of the increased space and proper cooling.

 

You can pre-mix the oil in the gasoline, or there should be an oil injector adapter available; my '90 RX-7 Turbo II had an external oil resevoir which I filled with two-cycle oil every couple hundred miles. Try checking http://www.rotaryaviation.com.

 

The most cost-effective turbo rotary swap I think would be the 13BT - $1500 will get you a series 5 motor/trans complete with ECU and all accessories, which makes 202bhp and 182lb/ft. 13BRE, 20b, and Renesis motors are considerably more expensive. You're best bet is to read aux's thread, and go on RX7club.com and read, read, read all you can.

 

I really hope this works for you; rotaries kick ass!!!

[Zanity]

i always thought that the fd engine bays were actually spacious enough.

all that plastic seemed to direct air to where it needed to go better.

but maybe i was mistaken.

I know when i see the engine it seems to only take up about half of the engine space provided.