Around 2009 I installed my home self-built unforged L28 stroker into my Datsun 240Z. Since installing the motor it has been in continual development and featured in my YouTube channel. I have made an overview video if watching something more your thing!

The heart of an L28 stroker

The basis of a stroker motor is the use of a crankshaft to increase the stroke of the piston. Historically stroking a Datsun L6 was done using an LD28 ‘V07’ crankshaft from Nissan diesel motor. In 2007 my LD28 V07 crank cost $150NZD and twice that to ship to Australia. Nowadays (and in the future!) it is likely to be more cost effective to modify an RB30E crank or purchase a billet kit.

My L28 stroker

When I set out to build this motor myself it had to satisfy the universal car law of you can only pick two from power, cheap and reliability. I chose cheap and reliability. With that in mind I spent endless hours searching catalogues for suitable off the shelf items, some from different engines. The fruits of my labour are listed below.

The bottom end

The base engine used was a barn find – literally! The donor engine was from a late 80s Nissan patrol and was swapped out for V8 in the 90s being stored at the back of a hay shed. Apart from a little long term surface corrosion the engine was a very good example of factory motor. The pistons I select is what I am most proud of. They are cheap, sufficiently strong and readily available. The bottom has all the fast rotating components so I had the rotating assembly balanced for 10,000 rpm. Overkill? Not really when it cost no more at the machinist!

  • L28 F54 block, standard deck height of 207.87mm
  • LD28 V07 crank, knife edged and nitrided
  • L24 factory connecting rods
  • Mitsubishi 4G64 L300 eutectic pistons +20 thou over (87mm) and machined for zero deck height
  • Hastings piston rings
  • Ross Performance harmonic balancer
  • Balanced L28 flywheel
  • Exedy ceramic cushioned clutch
  • Factory L28 oil pump

The head

Engine head setups make and break performance. The head I used was to factory spec and in good condition that came with the F54 block. At the time my own porting skills were limited so I kept head work to the basics. I kept to the basic match porting and unshroud the valves for a bir extra low lift flow. My head specifications are below:

  • N42 head 44.6cc chambers
  • 292 duration .495″ lift cam
  • Ferrea +1mm oversized intake and exhaust valves
  • Bronze valve guides
  • Crow Cam single valve springs and retainers

Assembly of the L28 stroker

I assembled my L28 stroker in much the same fashion and to the specs as a factory L28. I clearance everything that the stroker crank affected. In the end some slight grinding of the inside of the block for conrod clearance was really all I was required to do.

One thing I did do was dummy assembly and blueprint the engine, really verifying the piston to valve clearance to confirm my ‘design’. This was done with a lump of soft air drying clay coated in a bit of engine oil (to stop sticking) on top of the piston. Cylinder 1 from crank to cam was assembled and rotated a number of times. Using a standard thickness head gasket the clearances measured 3.5mm to the Exhaust and 3.3mm to Intake valves to give a guide. I was comfortable with this clearance.

Next the last caps over the valves need my attention. Using various combinations of copper shiming plate I was able to determine the required lash cap thickness. If I can recommend one place to purchase shims, it is Precision Shims in Australia http://www.precisionshims.com.au/

Recommendations for an L28 stroker

As a result of many years of ownership and development there are a number recommendations I feel that I am qualified to make on an L28 stroker long engine:

  • paint the internals of the block with an insulating enamel, such as Glyptal ‘Red’, to shed oil faster
  • use a high volume or turbo L28 pump
  • adjustable cam gear

Other useful information

Ignition upgrade guide: https://builtonpurpose.co/ignition-upgrade-guide/

Recommended parts and tools: https://builtonpurpose.co/recommended/

Check out my youtube channel: https://www.youtube.com/builtonpurpose