Jim and Brian's 1973 240Z Father-Son Restoration
240z Father Son Project
Photo: 240z Father Son ProjectFather and son rebuild a barn-find 1973 Datsun 240Z
Jim and his son Brian bought a 1973 240Z that had sat on a Stockton farm for 11 years, expecting light work but ending up stripping and restoring nearly the entire car. The thread covers bodywork, a built L-series engine with SU carbs, drivetrain rebuild, wiring, interior and suspension, with later updates on drivetrain upgrades as the car racked up miles. It is a long-running, partial record of a hands-on family project.
Specs
As stated in the original write-up.
- Engine block
- N42 block (2.8L)
- Cylinder head
- P90 head, milled 0.080 in
- Compression ratio
- 10.2:1
- Carburetors
- 4-screw 1970 SU carbs with modified needles, built by ZTherapy
- Ignition
- 280zx electronic ignition distributor, restored by Advanced Distributors
- Camshaft
- Isky cam, 0.480 lift, 280 deg duration
- Headers
- 6-2-1 headers
- Gearbox
- 5-speed manual transmission, rebuilt
- Exhaust
- Motorsport exhaust system
- Front suspension springs
- Tokiko illumina variable rate springs
- Interior trim
- New plastic panels and vinyl from Motorsport
- Sound deadening
- Be quiet sound deadening material
- Weatherstripping
- Weatherstripping kit from Motorsport
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 5
- N42 engine block
Base block used for the rebuilt 2.8 litre engine
- P90 cylinder head
Milled 0.080 inch and rebuilt with new valves, seats and springs to set compression and squish
In the shopsCylinder Head Gasket (N42 Block) ↗Motorsport Auto (The Z Store)· $39.87 USD
Cylinder Head Gasket Set (Rover V8 Carb) ↗
bpnorthwest.com· $59.99 USD
L28 Standard Valves for N42 Cylinder Head ↗
JDM Car Parts· $59.00 USD - Flat top pistons
Swapped in place of dish pistons to achieve target compression
In the shops
Piston Set Flat Top .040 ↗bpnorthwest.com· $342.82 USD
Flat Top Piston Set .060 (Mini 1000) ↗bpnorthwest.com· $342.82 USD
Piston Set - Mini 1000 Flat Top 9.75:1 ↗bpnorthwest.com· $342.82 USD - Isky camshaft
Chosen for a daily-driver profile, 0.480 lift and 280 degree duration
In the shops
Isky High Performance Racing Camshaft ↗
Z Car Depot· $659.00 USD
Isky Stage 3 Racing Camshaft for Nissan L28 Engine ↗JDM Car Parts· $663.99 USD
Isky Performance Camshaft (Datsun L16/L18/L20B) ↗Z Car Depot· $449.00 USD - 6-2-1 headers
Fitted as part of the engine build running 10.2:1 compression
Fuel & Ignition 2
- 1970 SU carburetors (4-screw, modified needles)
Built and set up by ZTherapy for the stock-looking build
In the shops
Carburetor Metering Needle ↗
Moss Motors – Triumph TR6/TR250· $29.93 USD
Carburettor Needle Adjusting Screw ↗James Paddock Ltd· £8.95 GBP
Carburettor Needle Retaining Screw ↗ - 280zx electronic ignition distributor
Restored and modified by Advanced Distributors
In the shops
Electronic Ignition Distributor Cap (65D Distributors) ↗bpnorthwest.com· $17.98 USD
Pertronix Electronic Ignition (Lucas 59D4 distributor) ↗bpnorthwest.com· $170.91 USD123 Ignition Electronic Distributor (Jaguar XK 6-Cylinder) ↗
MGOC Spares· £369.95
Gearbox & Drivetrain 3
- 5-speed manual transmission
Bought used for $150 and rebuilt with a Drivetrain.com kit
In the shops
5-Speed Transmission Case Dowel Pin OEM (240Z/260Z/280Z/280ZX) ↗Z Car Depot· $4.29 USD
Transmission Shaft Snap Ring (240Z/260Z/280Z/280ZX, 4/5-Speed) ↗Z Car Depot· $4.99 USD
Transmission Shaft Woodruff Key (240Z/260Z/280Z/280ZX, 4/5-Speed) ↗Z Car Depot· $3.99 USD - Rear end rebuild kit
Rebuild kit from Drivetrain.com used on the rear end
In the shops
Rear Hub Rebuild Kit ↗
Triumph Special Tuning (TST)· £83.33 GBP
Rear Caliper Rebuild Kit ↗
Flyin' Miata· $54.99 USD
Rear Cylinder Rebuild Kit ↗Moss Motors – Triumph TR6/TR250· $14.75 USD - Subaru R180 differential
Purchased by Brian to replace the worn rear end
In the shops
Stub Axle Set for Subaru R180 Differential Conversion ↗JDM Car Parts· $498.00 USD
Subaru R180 LSD Stub Axles Set ↗
DTSN.eu· 399.00
OEM Differential Axle O-Ring R180 ↗Z-Services· €2.30 EUR
Suspension & Steering 1
- Tokiko Illumina adjustable front springs
Fitted to the front suspension, later planned to be cut for ride height
Body & Trim 1
- Motorsport weatherstripping kit
Fitted around doors and hatch, though found too stiff to seal easily
Interior 2
- Motorsport interior plastic panels and vinyl kit
Used to retrim the interior, with panels trimmed to fit
In the shops
Interior Panel Kit - TC ↗MGbits4U· £812.22 GBP
Interior Panel Kit (Black) ↗bpnorthwest.com· $783.19 USD
Black Interior Panel Kit - Midget 1970-1979 ↗bpnorthwest.com· $660.95 USD - Be Quiet sound deadening
Applied to door panels, roof, floor and hatch to reduce vibration
In the shops
Hushmat Sound Deadening Insulation Kit ↗Z Car Depot· $349.00 USD
Sound Deadening Kit, hood ↗Moss Europe (UK)· £37.00 GBP
Bitumen Sound Deadening Pad ↗
Newton Commercial· £8.00 GBP
Other 1
- Motorsport exhaust system
Installed but later judged to hang too low at the 2-1 junction
Photos
90 pictures collected from the write-up, in the order they were posted, shown from 240z Father Son Project. A picture opens larger here, with the way through to the page it is on.
JCan · 2012-10-11T07:07:54Z 16this post at 240z Father Son Project ↗
JCan · 2012-10-11T07:24:21Z 12this post at 240z Father Son Project ↗
JCan · 2012-10-11T07:39:34Z 12this post at 240z Father Son Project ↗
JCan · 2012-10-11T15:43:38Z 14this post at 240z Father Son Project ↗
JCan · 2012-10-11T23:59:32Z 12this post at 240z Father Son Project ↗
JCan · 2013-01-10T19:00:37Z 6this post at 240z Father Son Project ↗
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JCan · 2024-06-01T03:47:51Z 2this post at 240z Father Son Project ↗
How it was done
Starting condition
The car was found on a farm in Stockton after sitting 11 years. It looked solid at first, but once stripped down the floor pans, a rear quarter panel and the front right area were found to need repair.
Body work
The car was stripped to the frame, sand blasted (which warped some thin panels) and powder coated. It was taken to Marck Motors Body Shop where replacement floor pans, a quarter panel, hood, hatch, headlight cover and a door were sourced and fitted, followed by filler and paint prep.
Suspension rebuild
The suspension was disassembled, powder coated, and rebuilt with new bushings, bearings and shocks.
Engine and drivetrain build
A used 5-speed gearbox and rear end were rebuilt with Drivetrain.com kits. The engine was built around an N42 block with a milled P90 head for 10.2:1 compression, flat top pistons, an Isky cam, SU carbs from ZTherapy and a restored 280zx electronic distributor, machined at Valley Head Service.
Reassembly
After the body came back from paint, the wiring harness, brakes, fuel lines, gas tank, rear end and half shafts were installed, followed by mating the engine and transmission, dash wiring, pedals, heater and an exhaust system.
Interior and finishing
New vinyl and plastic panels, sound deadening, carpet and a weatherstripping kit were fitted, along with replated door hardware and a CNC-machined spare tyre trim. The car was shown at a Motorsport event with about 200 miles on the rebuilt engine.
Later updates
Years later, after roughly 60,000 miles, the transmission and rear end needed replacing. Plans were made to fit a Subaru R180 limited-slip differential and a CD009 gearbox, with the Subaru diff purchased for installation; a further turbo L28 build was being considered.
A summary in our own words. The full account, with all its detail, is in the original write-up: read it at 240z Father Son Project ↗
Worth knowing
- Sand blasting warped thin body panels; media blasting would be used next time instead
- Powder-coated wheel bolts and parts should be fully assembled with bumpers and dust covers before judging suspension completeness
- The Motorsport weatherstripping kit was too stiff, requiring doors and hatch to be slammed shut
- The 280zx 5-speed gearbox proved to be the weak link in the drivetrain after repeated rebuilds