Big M

Let me explain. There is a scarce amount of goodies for my 1990 Protege LX. That, or I'm not looking hard enough.

Anyway, I know there's a lot for Miatas. So, is my LX motor significantly similar to any Miata motor?

I know I could probably make due with the available LX stuff, but just humor me...For the sake of argument, what would be compatible between the two?

Bruce95fmla

just use the search function for , looking for mods. there are tons of conversations about mods..

protejay

the 94+ Miata has basically the same 1.8 DOHC as ours(see below). the problem is the miata is RWD - thus the engine is mounted longitudinally. our FWD 1.8 is mounted transversely. thus headers, intakes, turbo kits for the miata do NOT interchange.

engine parts such as cam gears, pistons, valves, rods, etc DO interchange.

the good news is that our FWD pro was offered as a turbo model overseas, thus you CAN get turbo stuff for the pro.

a side note....our 1.8 came *stock* with a MBSP - Main Bearing Support Plate. AFAIK the 1.8 miata didn't get it until '01
the miata 1.8, though, over time got hotter cams, a better head, and solid lifters.

bpt323

just wondering exactly ....which 1.8l motor you are implying when you say it came stock with the main bearing support plate.... Are you implying the LX model 1.8l's or are you implying the turbocharged 1.8l???

UCSBgeek

Bruce, normally, solid advice, unfortunately the seach engine is NOT returning everything ...

http://www.protegeclub.com/forum/sho...=240777&t=2051

The US LX had the MBSP. I think even my SOHC has one.

protejay

yep, as Chastan said, the us LX model - and IIRC, even the SOHC (the only thing it doesn't have stock is the oil cooler).

evidently mazda just decided to 'build' them all the same way; and top them off with different pistons and heads depending on whether they were na or fi...

bpt323

1.8l's in U.S> stock form has a 3 stage stock oil cooler....the GTR block has a 5 stage.....Double check your sources

kcbhiw

The head from a Miata will not work in the Protege (easily anyway). The Miata uses a DIS type ignition system for one. In addition to that, the thermostat housing is on the wrong end of the head (front on the Miata, back on the Protege)

bpt323

What is the DIS ignition system????
AND what about the CAS being removed? 99+ models

kcbhiw

After further research, I have discovered that a Miata head WILL work. Castings are available on both ends of the head for the thermostat housing. You would need to plug the coolant passage on the front side (cam gear side) and unplug the coolant passage and possibly tap the bosses for the thermostat housing on the backside of the head (distributor side).

However, only the head from the 94-97 MY Miatas will work. The heads on the 99+ MY Miatas are taller and the intake/exhaust ports are a bit different.

I appologize for the mistake.

bpt323

Hey im really interested in trying towards putting a 99-00' miata head on my DOHC pro block... but im looking for advice and more research information....Is anyone willing to help me out....
looking for as much nformation as possible...
thanks