1.6 to 1.8 Miata Conversion Motor Swap Thread.

[Demon I Am]

So there is a lot of this info available in the internet about this swap, but a lot of it is not very useful. While doing my own 1.8 swap, I found a load of dead links, and "Search noob!" posts that were not too useful. Much of the "good stuff" started looking good, and then end incompletely. I wonder if we can piece together a valuable resource for people who wish to do this in the future. An "idiot's guide" so to speak. Please feel free to contribute pics or experiences as relevant.

I have a friend who is beginning to accumulate parts for this swap, and came up with a pretty comprehensive list to help him. My swap was using a NA8 (94-97) motor, which is the easiest of the swaps. I do not have info on things needed for the NB motor swaps, but hopefully they can be added to the thread by other users.

Parts needed:

1.8 motor
1.8 mounts (optional, but yours are probably old and floppy)
1.8 exhaust manifold (or header and cat/test pipe. You will either need the EGR pipe, or to buy an EGR block off kit. this kit should have a cap and a plate. You can probably make the plate yourself for cheap, while you have the exhaust mani off of the car. The cap size is supposedly a m22x1.5, but this has not been trustfully verified. BEGI and Flyin Miata offer both pieces for $15 each).
1.8 intake manifold
1.8 injectors-(if you get used injectors, you can clean them and buy injector rebuild kits from www.injector-rehab.com for cheap. Be sure to order an extra single rebuild kit, in case you break something. There is a special method to doing it right.)
1.8 fuel rail
1.8 timing belt/WP kit
----should have Timing belt, Idle pulley, tension pulley, VC gasket, water pump & gasket, cam seals (2), crank seal, water neck o-ring)
1.6 CAS o-ring
FM Swap Kit:
----EGR plate, throttle cable bracket, coil bracket, motor mount cups, throttle body adapter, electrical parts needed to extend your CAS wiring. *You may be able to save money by buying your motor mount cups from the net, or a local scrapper. You probably have wire and butt connectors (or solder/gun) and electrical tape to lengthen the CAS wiring*
1.8 Coolant Hoses (or reuse 1.6, if they are fresh, but plan on at least replacing the heater core hoses. They are easier to slice and remove, than to keep intact. The heater core pipes that they mate to are soft copper and crush easily. You may have to make some custom water lines (the small diameter ones), if you do not replace them all.)
1.8 Front main seal, rear main seal
Transmission seals (should be 3 of them, optional, but you might as well, while you are in there),
Exhaust gaskets (3) (motor to header/mani; Manifold to the DP; and DP to Cat. If you go with a header, you can skip the second one)
Intake Gaskets- 1.8 Intake to motor & 1.6 throttle body,
1.6 alternator belt- the one that comes with the kit is a 1.8 ribbed, you are transferring the 1.6 wp pulley and need the v-belt.
Main Crank Bolt- (optional, but supposedly they stretch)
Clutch, Flywheel, Pilot Bearing, Throw Out Bearing, Clutch Tool (Optional, but if yours is old, this is the best time to do it)
Clutch line -this is optional, but I highly recommend switching to a long length ss braided line. It makes slave cylinder swaps so much friendlier
1.8 Spark Plugs
1.6 Plug wires (optional)
Thermostat and gasket (t-stat is optional, but might as well. Gasket will be needed regardless)
Transmission fluid- 2qt GL4 75w90 - (do not forget that you will need some in the shifter turrett after re-installation of the transmission)
Diff fluid - 2qt GL5 75w90 (Optional)
Motor oil
Oil Filter
Anti-freeze/distilled water
Black RTV sealant
Locktite blue and red
Zip ties
Vacuum line caps (large variety pack)
Worm hose clamps Variety of sizes (replace those dangerous and often-failing spring clamps while everything is out of the car, you will thank me later)
Sandwich bags, sharpie marker, masking tape (if you are forgetful, labeling your connections, bolts, brackets is quite helpful.
Brake Cleaner, PB B'laster, Simple-green (optional but will make life easier)
Gloves-It can be a dirty job