...anything that'll mate to a Ford Type 9 gearbox. The prop shaft for that is available off the shelf at Canley's making it a fairly simple conversion -
http://www.canleyclassics.com/?xhtml...sl=product.xsl
That gives you the option of some cheap, small, light, tuneable and (relatively) powerful engines like the Rover K series or Ford Zetec 1.8/2.0. My choice for another Spyder build would be a 1.7 Zetec SE/Sigma motor from a Puma. At 81kg's and 123bhp it'd be perfect for an agile sprint or hillclimb car.