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1994 Mazda Miata rebuild - "The Black Widow"

1994 Mazda Miata

Mazda MX-5 (Miata)

My 1994 Miata - "The Black Widow"

Read the full write-up at My 1994 Miata - "The Black Widow" ↗

Photo: My 1994 Miata - "The Black Widow"

Reverting a 1994 Miata to stock power with a fresh engine rebuild

The owner, clarkma5, documents pulling a previously modified MegaSquirt VVT engine from a black-resprayed 1994 Miata and replacing it with a freshly rebuilt stock motor to satisfy California emissions rules. The thread covers engine dressing, a coolant reroute kit, clutch and flywheel work, bumper and tow hook jobs, and getting the car running again after over two years parked.

Specs

As stated in the original write-up.

Engine
Rebuilt stock 1994 1.6 liter Miata engine, reverted from a modified VVT setup
Flywheel
Exedy Pro-Lite flywheel
Cooling
QMax coolant reroute kit with 3-wire CLT conversion
Starter
TYC-brand starter motor for an NB
Wheels
Kosei wheels (gray)

Parts used

Parts named as used in the original write-up, grouped the way the Parts page groups them. Where one of the shops we index lists the same thing for this car, it is shown underneath with a link to the shop.

Engine 1

Cooling 1

Gearbox & Drivetrain 2

Wheels & Tyres 1

  • Kosei wheels

    Gray wheels on the car, cleaned during reassembly

Body & Trim 1

  • RSpeed valve cover bolts

    New bolt set used for the proper valve cover installation

Photos

23 pictures collected from the write-up, in the order they were posted, shown from My 1994 Miata - "The Black Widow". A picture opens larger here, with the way through to the page it is on.

clarkma5 · 2019-05-16T22:19:37-0400 3this post at My 1994 Miata - "The Black Widow" ↗

Land vehicle Vehicle Car Engine Motor vehiclePhoto: My 1994 Miata - "The Black Widow"
Engine Auto part Automotive engine part Vehicle MachinePhoto: My 1994 Miata - "The Black Widow"
Engine Motor vehicle Auto part Automotive engine part VehiclePhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-05-21T22:11:24-0400 1this post at My 1994 Miata - "The Black Widow" ↗

Land vehicle Vehicle Car Auto part HoodPhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-05-23T00:45:27-0400 2this post at My 1994 Miata - "The Black Widow" ↗

Auto part Metal Architecture Circle SteelPhoto: My 1994 Miata - "The Black Widow"
Motor vehicle Auto part Engine Automotive engine part VehiclePhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-05-25T16:43:52-0400 2this post at My 1994 Miata - "The Black Widow" ↗

Auto part Engine Automotive engine part Machine VehiclePhoto: My 1994 Miata - "The Black Widow"
Screw Fastener Pipe Household hardware MetalPhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-05-26T22:59:44-0400 1this post at My 1994 Miata - "The Black Widow" ↗

Motor vehiclePhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-05-27T02:53:06-0400 1this post at My 1994 Miata - "The Black Widow" ↗

Red Motor vehicle Bumper Auto part Automotive exteriorPhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-06-01T02:15:33-0400 10this post at My 1994 Miata - "The Black Widow" ↗

Auto part Tool accessory Machine Flange RotorPhoto: My 1994 Miata - "The Black Widow"
Engine Auto part Automotive engine part VehiclePhoto: My 1994 Miata - "The Black Widow"
Auto part Vehicle Engine Suspension part SuspensionPhoto: My 1994 Miata - "The Black Widow"
Auto part Clutch Clutch part Engine MachinePhoto: My 1994 Miata - "The Black Widow"
Clutch Clutch part Auto part Transmission part WheelPhoto: My 1994 Miata - "The Black Widow"
Motor vehicle Auto part Engine Vehicle Automotive engine partPhoto: My 1994 Miata - "The Black Widow"
Engine Auto part Motor vehicle Automotive engine part VehiclePhoto: My 1994 Miata - "The Black Widow"
Auto part Wheel Flange Alloy wheel RimPhoto: My 1994 Miata - "The Black Widow"
Alloy wheel Wheel Rim Auto part FlangePhoto: My 1994 Miata - "The Black Widow"
Screw Tire Automotive tire Auto part WheelPhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-06-02T17:22:27-0400 1this post at My 1994 Miata - "The Black Widow" ↗

Engine Vehicle Auto part Car Automotive engine partPhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-06-02T20:02:05-0400 1this post at My 1994 Miata - "The Black Widow" ↗

Land vehicle Vehicle Car Hood Motor vehiclePhoto: My 1994 Miata - "The Black Widow"

clarkma5 · 2019-06-03T23:34:38-0400 1this post at My 1994 Miata - "The Black Widow" ↗

Alloy wheel Tire Rim Wheel Automotive tirePhoto: My 1994 Miata - "The Black Widow"

How it was done

Starting condition

The Miata had been parked for over 30 months with a bad motor and had previously been set up for a MegaSquirt 3 with a wideband sensor and a higher-performance VVT engine. The owner decided to revert to a stock configuration to comply with California emissions rules. The car wore a black respray over its original red paint.

Engine removal and rebuild

The VVT engine was pulled with help from a neighbor, and a freshly rebuilt stock 1994 motor was collected from the builder. While on the stand the owner cleared and dressed the valve cover, fitted a new PCV grommet and oil cap, installed the oil pan, windage tray, oil cooler block, oil pressure sender, crank pulley, water pump pulley and new timing covers.

Coolant and wiring work

A QMax coolant reroute kit was installed along with a 3-wire coolant temperature sensor conversion, despite tool and fastener delays. The owner and his father resoldered the stock MAF lines and extended the CAS wiring to revert the engine bay to stock wiring, overcoming a failed soldering iron along the way.

Clutch, flywheel and transmission

A broken valve cover bolt had to be extracted by the original engine builder. The new Exedy flywheel needed its bolt holes filed to correct smashed threads from the first install attempt, after which an Exedy clutch was aligned and the transmission, starter and slave cylinder were fitted and torqued.

Bumper, tow hooks and bodywork

The front bumper cover was removed to ease engine hoisting, cleaned of extensive spider webs, and repaired where tabs had broken using epoxy and metal straps. Flyin' Miata tow hooks were installed front and rear while the bumper was off, and missing lower lip fasteners were replaced.

Reassembly and first start

The engine and transmission were hoisted back into the car and started briefly after about seven hours of work. Remaining tasks included adjusting the throttle cable idle, bleeding the clutch, fitting OEM heater core hoses, plugging a spare coolant sensor hole, and filling with coolant before seeking a temporary permit, insurance, smog check and registration.

A summary in our own words. The full account, with all its detail, is in the original write-up: read it at My 1994 Miata - "The Black Widow" ↗

Worth knowing

  • Check for broken-off bolts left in a head after an engine rebuild before reassembling it
  • Verify snap-ring pliers actually open wide enough for the job before relying on store advice
  • A good quality soldering iron saves significant time over a weak substitute
  • File flywheel bolt holes carefully if an aftermarket flywheel has misaligned threads
  • Choose fastener finish (color) to match the car rather than assuming a color will look discrete

My 1994 Miata - "The Black Widow"

forum thread: 1 of 1 pages and 10 of 10 posts inspected; 10 unquoted updates by clarkma5 used; 0 replies excluded on 3 November 2026. The original write-up and photographs remain with their creators. This page is a catalogue in our own words, and a signpost to the source.

Read the full write-up at My 1994 Miata - "The Black Widow" ↗

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