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How hard would it be to put a 1.8 motor and 6 speed tranny in a 1990 miata? alot of work or just bolt it in? what all would i need to make it happen? Thanks!
 

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Brah.
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actually i know quite a lot about it since i have done the swap.....


i dont know much about the 6 speed but you will need to wire in the reverse lights and you will need a 6 speed drive shaft.

for the 1.8 swap it really matters on what year you get. if you go with anything pre 2000 you will have no problem with the swap. DONT NOT BUY THE FM KIT overpirced bull ****.

if your 1.8 block has the brackets for motor mounts you wil not need new ones just new motor mounts would be a good idea. also the 1.8 will bolt up to the stock 1.6 even with the 1.6 clutch and flywheel. after you get the motor in its really easy just as easy as putting in another 1.6 you will need to install the CAS and extend the wires on it since on the 1.8 the CAS is on the other side of the motor. the 1.6 coilpacks will be needed but you will need a bracket to mount them to i would try to rig up the mounts for the 1.8 coilpacks before i went and spent money on the one FM sells. you will need to use the 1.8 injectors and 1.8 fuel rail also. after that you will need to use the old thermostat housing from the 1.6 on the front of the engine. i have the TB spacer you will need so you can buy that from me and save some money by not fooling with flyin miata. just plug the MAF up and intakepipe and you will be good to go!


i have helped a few people on the site with the swap so if you need more help just let me know.


ohh yeah DONT BUY FLYING MIATA'S KIT!!!!
 

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I'd say save money and skip the 6-speed and install a '99-'00 engine - more power, and significantly better breathing for any future plans (boost, irtb's.) Correct me if I'm wrong, but there's not much of an advantage to the 6-speed - it's mostly just for the "wow, it's a real sports car - it's got a 6-speed" factor. I suppose maybe if you used the lower final drive from a 5-speed car with the 6-speed it might be better, but I'm pretty sure you'd be better off with a 5-speed.
 

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BACK BY POPULAR DEMAND
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I bought my Miata with the 1.8 swap in it already, I recomend that. :)
 

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So you use a 1.8 ECU? It is plug and play ECU wise? I have a 90 as well and would not mind putting a 1.8 in, I want to just swap the motor as easy as possible, dont mind the 5 speed. My clutch and flywheel, everything bolts to the 1.8 motor you said?

I am new to Miatas coming from Honda's and 240's.

Thanks!
 

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BACK BY POPULAR DEMAND
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So you use a 1.8 ECU? It is plug and play ECU wise? I have a 90 as well and would not mind putting a 1.8 in, I want to just swap the motor as easy as possible, dont mind the 5 speed. My clutch and flywheel, everything bolts to the 1.8 motor you said?

I am new to Miatas coming from Honda's and 240's.

Thanks!
You still use the 1.6 ECU as the wiring to change ECUs is not worth the effort. The 1.6 ECU figures out the 1.8 good enough that it doesn't warrant the wiring to swtich them.
 

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CR.net Supporter
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I'm just scared of the short crank issue with my car and hey move up in size a TAD to fix it.... I dont know though.
Not all 1.6's had the short nose crank, just the 90 and early 91 models. There's a write up about the whole ordeal on Miata.net I believe, from what I gathered it seems to be more of an issue of the pulley bolt either coming loose, stretching from overtightening, or whatever else you can think of which in turn allows the key to not be fully engaged.

Here's a link to the write up: http://www.miata.net/garage/crankshaft.html
 

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Mufasa in Training
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I'm just scared of the short crank issue with my car and hey move up in size a TAD to fix it.... I dont know though.
If that's the only reason you want to go to the trouble of doing a motor swap, I honestly wouldn't bother. Long-nose cranks can fail just as readily as short-nose if not torqued properly. My 97 is an example :(
 

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I'm just scared of the short crank issue with my car and hey move up in size a TAD to fix it.... I dont know though.
If that's the only reason you want to go to the trouble of doing a motor swap, I honestly wouldn't bother. Long-nose cranks can fail just as readily as short-nose if not torqued properly. My 97 is an example :(
I agree, I have seen just as many (if not more) 1.8's with crank issues.
To me I'd skip the swap and put in a good running big crank 1.6
 

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To me I'd skip the swap and put in a good running big crank 1.6
Why? If he has a good running engine already.
There are thousands of small cranks with 200k plus and no failure.
Believe it or not, not everything on the pointyboard is true. :roll:
I too have seen more 1.8 fail than .6's
If you have issues certainly upgrade, but to swap because of the Miatadotnet hype.
I don't see it.
:IMHO: of course.
 

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To me I'd skip the swap and put in a good running big crank 1.6
Why? If he has a good running engine already.
There are thousands of small cranks with 200k plus and no failure.
I agree completely. I was under the impression that he needed an engine due to wearout or failure. I would run the 1.6 small crank until it dies, then replace with another 1.6

And for your info, I have defended this approach and the small crank 1.6 on m.net for years. ;)
 
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