There are a few ways in which to fit these, one is by the use of a special tool (yeah we all have on of them!), one is by the use of a hydraulic press, which not too many of us have access to, or another is by the use of heat (blowtorch). The latter will be explained here…
1. Having removed your old pistons make sure you con rods are clean and free of any oil or debris, also checking that the little end is undamaged and smooth.
2. Using a heat source start to heat the little end of the conrod. Here I’m using the gas cooker (don’t tell the missus) and a blowtorch.
3. Keep the heat on until the whole of the little end it cherry red.
4. Having already prepared the piston and gudgeon pin at the ready, offer the still cherry red conrod up to the piston.
***WARNING - The next bit you have about 5 to 10 seconds to get it done and there is no turning back ***
5. Using your other hand, push the gudgeon pin through the piston and little end and centralise using you finger and thumb, whilst also making sure the conrod also remains central to the piston…
(obviously the following sequence would normally have the conrod in there as well, but I have not developed a third arm yet !!! )
6. Once the gudgeon pin has been gripped, that’s it, there is no moving it and for a short while the piston will also seem as though it is fixed to the pin, this is normal, and as it cools, it will free.
7. After a couple of minutes, check that the piston has full movement on the pin, do this by holding the big end, this will be rather warm so protect your hand, and waggling the piston side to side and back and forth, don’t touch it IT’S HOT, it should move freely…. Leave to cool.
8. Repeat until all pistons fitted..
