Hi there,

I am wondering if it is possible to rebuild a 20b at home for a 750hp engine. I know you can pay people to do the rebuild, but I feel any person with the money can do that. I want to have the satisfaction of doing it myself. Is it possible to do everything on you're own? I was originally gonna do a ls1 conversion. But personally seeing soMething so amazing and rare as a rotary, seems much cooler. I've always wanted to make something that no one has seen before. I hate doing the same as everyone else. So I guess that brings me to another question if you guys have any ideas to make this project unique I'd like to know. Time and money aren't an issue. As this is a side project that I'm in no hurry to mess up. I am gonna plan every detail first. So if anyone has answers or suggestions let me know.c

 

Firstly, I think you are my long lost twin, because we think exactly the same!! I want to build an N/A 20B for 350hp by myself at home - I wouldn't pay to have it done, because than it's bought, it's meaningless! I'm trying to plan out every detail before I do anything just the same. I love the engine for its uniqueness too, no one has ever heard of this amazing, very capable engine. So, you are basically me. Anyways...

When I had the idea the first thing I did was buy the 13B rotary rebuild video from atkins rotary. Its like a 25 dollar DVD showing how to rebuild a 13B step by step including all the little pieces in the rotors and such. Granted a 13B is not a 20B but it's the perfect place to start!

After that I've gone through rebuild threads, and tried to find out what a worn part looks like. Than I researched to see what parts I should use to achieve my goals in terms of rotors, bearings, etc.

I'm begging gtorx7 to show me how to build it up but I've had no luck so far

I would start with the DVD and than obtain a parts list from Mazda. Than look for a 20B Cosmo technicians manual.

It's entirely possible! What we're both missing is the hands-on experience, and I wouldn't touch anything to do with an engine block until I've seen some built in person.

Here I'll save you some time - From what I can see, the actual assembly isn't the hard part. Things have to happen for 750hp turbo or 350hp N/A, careful porting, balancing the assembly, clearencing everything, lightening everything, fabricating manifolds - all things that require expensive, specialized tools and experience using them. For 750 turbo you'll need 3mm apex seals too which means machining rotors grooves to accept them - a delicate process - you can f ck your motor really badly if something comes loose and chews up $6,000 in housings and probably the rotors too. You need a special tool to pull out the eccentric shaft which is also pricey. There is a way to do it without the tool, but you could end up f cking your e-shaft, $.

Good luck, long lost twin!

 

welcome to the board!

1. yes, you can do it at home!
2. i wouldn't recommend you trying it until you read and research enough to do so.
3. people usually pay someone because they're not capable/knowledgable enough to do it themselves.
4. you don't just need knowledge of the 20B. you NEED knowledge of how they work and how to tune them. and sorry to say ... if you're asking on this board, then you're probably not ready for this.
5. since you're paying for this ... learning still doesn't hurt.

 

I do agree with you. I know I'm not ready, mostly I wanted to see if it was worth it to find out how to do the rebuild or if because of the work involved it is better to have someone do it. By the sounds of it it may be worth it to get someone to build the crate and I do the rest. It's nice to see that I have someone in the same kinda state of mind. And thanks for the welcome. I think I'll probably start being a regular here soon enough. Rotary FTMFW.

 

There is a dvd set you can buy from kiwi-re.com that covers everything you need to know about the 20B

 

Hey I checked out kiwi-re.com but couldnt find anything about a dvd set. Is there something im missing?

 

Sorry about that was thinking about something else the correct address is diy-re.co.nz good luck

 

are the 20b videos available now? looks like you can only the 13b videos on their site.

 

I've seen that site before - if there was any way to buy it I would have bought it as soon as I saw it.

I'll be calling them I guess.

 

yes, you can do it yourself.

The problem is, for 750hp youre going to want to do some fairly aggressive porting, and it is easy to ruin an engine if you arent familiar with porting. I would recommend that you build a 13b first, so you get the hang of it, and if you screw up a port on that you can get a used iron for cheap money. Once you get that under your belt you can think about a 3 rotor.

Aside from porting rotaries are actually easy to build...significantly easier than piston engines.

As for unique... If you want to spend the time and money, learn to weld and then put the 20B in something cool. Ferrari 308 maybe?

 

Yep, what he said with the porting. That is one thing you might want to take to pros. You can still do the build. Oh yeah, don't forget tuning, it could be pricey if you tuned it wrong.

 

QFT. If you want, once you take the motor apart, you could take the housings and irons to a shop and get them to do the porting while still doing the assembly yourself. That's what I'd probably end up doing if I was looking to get a 20b.

 

Yah im thinking I will do like you guys said with porting. Or maybe do that and work on a 13b as well. But ya i think ill get a shop to do that part. Maybe if I do a 13b ill do some mild work and use it as a daily driver backup. But for now im just in the planning stages. Im not gonna probably start work on this project till summer next year.

 

You should check out RX-7 specialties (http://www.rotaryengine.com). They're relatively close to you and have extensive dealings with rotaries.

 

Sweet to see that there is a 20b specialist near where I am. Now im just trying to think of a sweet car but maybe Ill stick with the FD RX-7 put a 20B in and use the veilside kit. I want to build something thats good for drag, track, and daily use. but I want to deisgn it good for even show use. But have a awesome sound system and electronics setup that rivals the space shuttle lol.