4.6 Pistons, Rings & Gudgeon Pins

Out of stock

Product information

For sale in this listing is a set of 8 pistons to suit Rover V8 engines at 4.6L capacity. Supplied with the correct rings and gudgeon pins for you to assemble on to your rods (you can tell us whether you require standard or +20 thou oversize pistons using the drop down menu above). These pistons can also be fitted to 4.0 engines, but will lower the compression ratio. If you require 4.0l pistons please contact us

These pistons will give a compression ratio of 9.35:1 assuming all other components are as Rover designed them, however block deck height, head chamber volume, gasket thickness and gasket diameter on the bore all have an effect on compression ratio so all would need to be measured to know the true compression ratio of your engine. However please do not let this deter you from building your own engine as most engines we build with these pistons, our composite head gaskets and re-manufactured heads sit between 9 and 9.5:1 CR.

RPi Advice

  • Both 4.0 and 4.6l pistons are directional, look out for a dot or arrow on the piston, which should point towards the front of the engine
  • 4.6l rods have a single dimple on them, each of which need to face the other rod on the same big end journal. So rods 1, 3, 5 and 7 will back towards the back of the block while rods 2, 4, 6 and 8 will face forwards the front.
  • A few hours before you attempt fitting new pistons to your conrods, put the gudgeon pins in the freezer. The cold temperature will shrink the pins slightly, making fitting easier.
  • When installing the pistons and gudgeon pins, the small end of the conrod can be heated to assist fitting. As a guide the rods can be heated until they start changing colour slightly, but must NOT be heated to the point of glowing.
  • The big end bolts are stretch bolts and should always be replaced. New bolts are available from our shop here
  • When removing conrods, ensure that the big end caps are kept on the same conrod that they were removed from. Mixing up the big end caps will create issues.
  • Some 1st rings are directional, all 2nd rings are directional. Our advice is to check the packaging and the instructions the the rings come with as this will contain the information you need. Also be on the lookout for a stamped dot or "top" marking on the ring itself. 
  • Piston ring gaps are as follows:
    1st ring 10 to 20 thou
    2nd ring 16 to 30 thou
    Oil ring 14 to 50 thou

Weight 3kg