What are the best rotary swaps pros and cons
 

I've been looking everywhere trying to find info on swaps, i see the 20b swap and looks like alot of work and time,
I have a 2004 AT rx8 and was told my engine was going bad i'm just looking for a complete swap and turning it into a weekend type car although looking for some reliability
If i get flamed for this that's fine( i've looked everywhere but never understood why people did the swaps ie performance/reliability/exclusive/unique?) i just want good info on the options that are there i want to stick with rotaries but all ideas (options) are great to see.

:confused:

an engine swap is not something to go into lightly. you're looking at a huge time and money commitment and even then there is no guarantee. If you're not comfortable wrenching yourself and/or you don't have a bottomless wallet I would suggest replacing the engine (mostly free if it's under warranty).

also, who told you it was going bad, did they do a compression test, how many miles?

I was told by a mechanic (napa) but i knew it needed a tune up so i pulled my plugs and wires and put on new coils, the plugs were just shot, and one wire was burnt (not fire just not supplying enough power using the voltmeter reading was about 75% i guess you'd say) anyway he said it was the front apex seal, which i know isn't a farce but i understand the money and time thing kind of looking for a project that would give me more power in the end and something to do because trade in values and selling are horrific plus i still love the car despite all the problems.

it's got roughly 79K miles

engine is still under warranty, take it to a dealership asap

as far as mechanical experience i have a decent amount, alot of tools and have done alot of work on piston cars just not rotaries as far as rebulding but i've been reading and got a few videos on rebuilding them and it doesn't look to bad i'd hire someone to help me tackle the project but now i'm in the planning stages, plotting what type of swap and finding parts in japan through friends and business guys i work with there, plus through canada.

i don't think it's under warranty because of the years not mileage though

it's mileage

i have a 04 AT, 39k miles.
YOU ARE UNDER WARRANTY.
Engine: 8yr/100k miles

Truth.Still under warranty! I suggest get the engine replaced, and if you want to work on it, go FI.
But, if you're set on swapping, the I look forward to the build thread :smoker:

yeah but unless u take your car to mazda to do all oil changes or have documented u can kiss that warr goodbye, because the engine has a warr until 100,000 miles, i had had 79,000 when my engine had went out, but i wasnt covered under warr, i pretty much came out of pocket for a rebuild, if u are under warr i would have mazda replace it and then get it rebuilt again just my opinion because my relpacement was shit, cuz when i got ready to break it down some of the bolts were already loose. but just know u if u wana go first class you gona pay for the ticket and u get my point get what u pay for. just ask a buch a questions but smart ones...

On a cost comparison basis, since everything has to replaced anyway on an engine swap, you're better off spending the extra 2~2.5k and swapping a 20b. You can find running front clips for $3000.

i can get a 20b for roughly 2000dollarsUS shipped to the states but how much more money would be to get it all swapped? i figure now with so many people doing it their are short cuts or parts made for the swap cheap am i right?

It's not wise to use an used block without any prior rebuild. A 20b costs around 3 times more in decent conditions and we're talking about the core only.

that was the point to get the engine and then go threw complete rebuild

not here it doesn't. They go for $2500~$3500 here. 13b-rews go for $1700~$2000. So you're looking at around 2x the cost at most, but that 2x only amounts to $1000~$2000.

That's why I said you're better off just swapping out a 20b because you're going to need aftermarket EMS, and everything else anyway.

Sooo... based on power goals.
400HP or less: Go turbo Renesis
400+HP: Go 20b

I'm not with you, sorry.
It makes absolutely no sense to start such a great project with an engine whose conditions are unknown.
Tear it down, replace what needs to be replaced (housings, bearings, seals and gaskets) and see how much you have just spent. Housings are around 700$ each, you need 3 of them.
Finding an used block in known conditions is hard and requires time and effort.

I guess that we have different approaches to such projects :)

Wait the napa guy told you your engine was going bad! How did he come to that determination? Was a compression test done on the engine? Take the car to a dealership and have them look at it. Chances are the napa dude has no clue!

buying a used motor and then rebuilding it is the simple and inexpensive part of the swap.

exactly, they charged me 100 bucks i didn't want to take it there because i know my car really well actually i knew i just needed a tune up, it's been roughly 21K miles since one, plus he said he did a compression test and told me rotaries only have 3 cycles unlike a piston engine it has 4 so right when he said that i knew he was a liar, if he did a compression test he would of seen the cracked plug, instead he said " to get rotaries started you gotta pour oil in the intake of the engine" right then i said o god damn what did you do, did you do this? he said yea a little so i'm going to take him to court i've got 5 lawyers on retainer for free from my dad so it's free, it was only 100 dollars but i haven't driven the car since and am documenting everything to show in court for damages.

reddozen your right that is kind of why i started this thread, i wanted to see what was possible and also show everyone else interested in this what's possible, money isn't really to much of a big deal i've kind of accepted this is a project car for the last year of what i want to do to it, i've just researched things and the main problem for me is people show the swaps but never really explained why they went that route, i like to have a plan and right now i don't have one

I didn't say not to rebuild it. A 20b rebuild kit is only a couple hundred more than a 13b rebuild kit. The only 2 parts that really matter are the thick center iron and the eshaft. I was only referring to the raw cost of the engine. As for housings... I would never pay $700 for a housing. A low mileage housing with no notable wear is good enough for me. I can't see that the difference in longevity for a street driven motor would be that noticeable. If it was a race engine in a race car, then I would understand. I also wouldn't care if they were 13b housings instead as long as they all matched.

I put less than 10,000 miles a year on my daily driver, and when it was running, my RX7 did good to see more than 1,000 miles a year. Brand new OEM hard parts aren't always necessary. That being said, a FULL rebuild is always important. all seals and gaskets should be replaced every time. no questions asked.

That is perfectly understandable but that was the best case scenario. What if you buy one of those junkyard import whatever engines and discover that the centerplate is close to the end of its life? What if you have to replace a sideplate or two?
Anyway an engine alone won't be cheap, add the ancillaries and the transmission and you're screwed lol :)
There's one 20b in the FS section right now that could be an interesesting and very cheap starting point though!

$5000 is NOT cheep for a used 20b here in America. Like I said, you can get running front clips here for $3000 with all accessories, harnesses, etc. Hell, you can call pineapple racing and get a rebuilt 20b for $6000 ported any way you want it.

Lets say your thick center is damaged beyond repair (not likely on a stock 20b cosmo clip), you can get another one for $1500~$1800. At $3000 initial + $1800 you're still less than $5000. I will laugh my ass off at whoever is foolish enough to pay that guy $5000 for a used 20b. I would just assume for the same cost spend another $1000 and get one the way I want it from a reputable rotary shop ready to set in the car.

Ebay's prices flux between $2500 and $4000. Right now there are 4 motors for $4000. I wouldn't pay more than $3500, and most likely could get one tomorrow for $3000 with a front clip.

And RX7 trannies are like $150...
$400 clutch...

If you're trying to build some bullet proof setup to make 900HP, then sure, it's going to be pretty expensive, but if you're smart about what you buy and how you set it up, and can do it all your self, its really not that bad. It's still the best option IMO to swap if you want more than 450+HP.

That makes sense, 6000$ for an engine is what I wrote in the first place :)
The ancillaries like turbos etc would need to be rebuilt and that's why i don't think that it is so cheap. We're agreeing on the price so everything is fine.
Maybe i'm just too precise when doing car stuff :)