1990 Mazda MX-5 Miata - Chevrolet 4.3L V6 Engine Swap

Mazda MX-5 Miata 1990 Description

I picked up this car in January 2015 from a nice gentleman in Dublin, A. He had previously purchased it from another nice gentleman in Florida who actually built the car. He definitely did a great job on the swap, ut there were a few things I had to adjust and replace in order to make it a more reliable daily driver (I drive it 60 miles a day).
Specifications:
1990 Mazda Miata

• manual windows
• power steering
• Hard Dog Hardbar rollbar in stainless steel (sells for $535 + shipping from Bethania-Garage)
• Nippon Racing Zen wheels, 5x6.5 et40 with 205/50/15 Cooper Tires
• Custom cowl hood

Chevrolet 4.3L (262ci) V6 engine

• 1986 block
• 0.60 over
• block decked 0.01
• 68cc GM 3.8L 90* V6 heads
• crank: 10 on mains and 10 on rods

700R4 4-speed transmission

• 1986
• regular lockup
• 10 vane pump

Nissan R200 rear differential

• 5-speed 280Z
• 3.55 ratio
• 4-bolt stub axles
• 3/16 steelplate to hub face
• stock Miata axles

Recently replaced parts:
Distributor cap, otor, oil, gnition module
Mechanical fuel pump replaced with an electric fuel pump
Radiator upgraded to 3-row, rossflow, luminum with 14" Spal fan
Left exhaust manifold
The positives:
Effortless torque
Lovely exhaust note
Lots of attention; people yelling at you from across the highway asking "what's in there?"
Nice interior with working gauges (tach recently went out though); great condition top
Very easy and cheap to work on; parts are on the shelf at most auto parts stores
I have a small spreadsheet with info on the car and the non-stock parts it uses
The title is clean and it does not require emissions testing in Georgia because it is 25 years old.
Things that may need attention:
When it's 97 degrees outside and you are in stop and go traffic for 2 hours it will run a little warm (about 2/3 temp gauge). This probably due to the small engine bay with a large engine in it and reduced airflow. The current radiator setup should be sufficient, ut I think the car could benefit from some ventilation mods. Note during normal driving and reasonable temperatures it actually runs slightly below half on the temp gauge.
I have recently noticed two small areas of rust on the rocker panels before the rear wheels on both sides (see pictures). This is the area where water drains to from theconvertibletop so it is notsurprising. This is the only real rust I can find on the body, ut I wanted to point it out in the name of full disclosure.
The car is setup with AC, ut the compressor is bad. I actually was going to de-AC the car though because I can only see that making it run hotter on days you would actually need AC. This should improve flow, y removing the AC condenser from in front of the radiator though.
Conclusion:
You won't find another swapped Miata for this kind of money, nd you'd be hard-pressed to build one yourself. The hard work has been done, o do like I did and improve reliability as you go along. As with any swapped car, would highly recommend that you are capable of doing your own wrenching in the garage. The car is not perfect, nd like I said I would not subject it to Atlanta rush hour in the height of the summer for more than an hour or so. However as a weekend toy, rag racer, r fun daily driver it does the job.