So a couple of weeks ago the engine in my 8 blew, thanks to some kind people on this forum I was able to find out that I had spun the bearing in rotor 2. Since then I have been looking at motors online and I cant really find anything that doesn't honestly look like a scam.

So here's my question.
Would it be better to rebuild the motor myself, and if so where would I find the parts to do so.
or
Would it be better to buy a reman engine from Mazda and maybe do some porting to make up for the hp loss that the us engine has from the jdm one.

Pros and cons of each method, is doing it myself possible?

Any responses are greatly appreciated!



I just want to drive her again!

 

DIY rebuilds don't always result in success.
If you can afford it your best bet is a professional rebuild or reman, imo.

https://www.rx8club.com/series-i-tec...engine-231883/

 

https://www.rx8club.com/rx-8-discuss...ilders-265177/

 

DO NOT REBUILD the motor yourself
you CAN remove the motor and ship it off to a rebuilder
and they can also port the exhaust for you
then you can reinstall it yourself to save money

but really, you should just find a decent shop to do the labor for you unless you really enjoy working in the garage
time is money, right?

 

The JDM and rest of the world motors are the same. The differences in HP are from the way they measure it...and slightly different software programming.

For what you get for the price a Mazda motor will likely be the best bang for the buck. You can't buy the parts for the cost of the engine

There are some good rebuilders on the forum.... look around and read the reviews... some are a lot better with customer service than others

Porting without a way to tune it won't do much except make it run poorly so figure that into the cost of the rebuild as well

A DIY rebuild is good if you can do it....It's nowhere as easy as it looks based on the number of parts

Good luck

 

Yes, to rebuild or not to rebuild: that is the question. . One which h/b discussed ad nauseam on the forum.

So, the money answer is NO.
- If you have to ask...,
- if you're finding it difficult to purchase one complete engine vs. eval in spec /out of spec... and potentially purchase multiple major components,
- etc;
...self rebuilding may not be for you.

That's ok b/c as others have said you can easily purchase a rebuilt engine for about the same price as rebuilding it yourself w/out the hassle. Before undertaking a rebuild...you need to clearly assess... do I have:
- resources ($$$)
- space
- time
- all required tools
- ability to measure & modify multiple seals to tolerances as tight as 0.00XX"
- confidence to complete the disassembly & assembly
- the ability to stomach if it's FUBAR on completion... to possibly start again...

Really only you can provide an answer to your question. I rebuilt mine...self taught, and am currently at ~18k miles turbo'd, and going strong. I was able to answer yes to the above questions, did considerable research, and stuck to Mazda tolerances. Having done so...when time to rebuild, I will purchase a reman and go from there.

It c/b a great learning experience, can save a good deal of $$... depending what needs replacing... , and can result in a solid engine. It also shouldn't be undertaken lightly..., is not for the faint of heart, finances, patience, or attention to detail, and c/b a nightmare.

So, the question to YOU is should YOU undertake rebuilding your engine?

All the best.

 

how many times does it have to be said; do not port a Renesis engine, just cleaning up the port edges is sufficient

 

Thank you all for you responses!


Thank you for the response, The part about getting a rebuilt engine for about the same or less price then a rebuild. Where would one look to find said rebuild engine? My main goal is to save money with this so I would very much like to look into this.

 

Any particular reason why? I know the ports on them are pretty big from factory, but what would it hurt, would there be any reliability problems ect.?

 

If the correct research is done and the proper tools are obtained, Why is it just a flat no? Any specific reason?

 

If you would have read the rebuilder's thread I linked for you, you would have seen at least one source.

https://www.gossettparts.com/oem-par...e-n3h302200rv0

 

If you would have read the first thread I linked for you, many reasons are given for not doing it.

If you won't read 2 threads about it when someone is trying to help you, you're going to have a hard time.

 

There are things that can happen during a rebuild that are problematic and are hard to solve if you don't have the specialized tooling for that specific issue. For example, balancing rotors or finding a torque wrench that goes to 300 ft/lbs and a 2 3/4" socket. Also ensuring side seal tolerances, apex seal placement, port polishing and many other fun things, its quite a lot to figure out for a first timer. Not something I've ever personally felt like doing myself based on the research I've done.

 

O.P., TBH when I joined this forum... many were MERCILESSLY FLAMED for asking similar questions as you have without having availed themselves of searching and reading the enormous reservoir of information contained here. Thankfully, forum culture has improved greatly in that respect. That said... already clear, concise guidance and links h/b provided to you.

I respectfully advise that you w/b helped by ...reading more, posting less.

All the best.

 

It all depends on how comfortable you are with risk. If you want to learn and are OK doing another rebuild within 10k, and have no problem affording it, sure. If, however, your goal is to save money, this is not the savings you're looking for. By the time you buy the special tools, replaceable parts and potentially replace your worn big parts, you're not saving anything. That's the real variable here: if your housings are worn beyond spec you either need new ones for $1000+ or ypu rebuild with what you have and we have this conversation again next year.

​​​​​​

 

I did read the thread, I was simply asking for more clarification. Thank you for your time.


Ahh, this makes a lot of sense actually. I really appreciate you giving me a in depth response, and will take this into consideration.

Thank you for putting this in a way that does not sound hateful, I appreciate it. And in the future will do some more looking before posting.

This is pretty much the answer I was looking for, thank you very much.



Thank you for the responses everybody, I appreciate it very very much. Im probably going to end up buying an already rebuilt motor as Im only about 1000 off and its not worth the risk. Thank you everybody for your time.

 

Great decision to just do the swap. This way you know the engine will work and it won't be nearly as difficult of a project.

 

A lot depends on how quickly you need the car and how reliable you need it to be. I'm leaning toward rebuilding myself, but I may change to a complete swap out like you. Time will tell.

 

I already got a donor car with an engine to use till I can rebuild the original one. I hope you get it figured out too!