Skoda Rally Blog

The bottom end of the engine is the un-heralded part of the engine – whenever people talk about tuning, it’s all heads and cams and manifolds. The bottom end does the unglamorous job of turning the explosion inside the cylinders into usable power, and it does this with a few simple (but precise and important) components. The main parts are the pistons, connecting rods, crankshaft and flywheel. Most of these need to be to the correct (near original) spec, again as defined by the FiA, and this means for most cars that they are modified original production parts. The engine I have has previously been built to a high standard, with a lightened flywheel (within the specs on the papers, again everything has tightly defined limits), and what looked to be slightly reworked standard connecting rods and pistons.

Bottom end of the engine

Once I’d dismantled it all, I found that the crank wasn’t badly worn at all, so a simple regrind will take care of this; it’s already been left at Magnum to have the work done. Separating the pistons from the con rods needed to be done even if the pistons are to be re-used; the reason for this is to weigh each part individually (as left together it’s possible that a heavy piston may have been with a light con-rod, leading to balance issues which wouldn’t be noticeable weighing the entire assembly all in one). It was nice to see that my first impressions of the engine (taken when I needed to swap the bearings before Rally GB 08) were right – each part had been balanced to within a gram, and close inspection of the rods saw nothing untoward at all. The pistons have some wear on them, so I’m trying to source some replacements (standard, as the current ones are standard and look absolutely fine, despite being taken to 7500 for over a year in my hands and no doubt plenty of time before), but the Skoda parts specialist I usually use is ill at the moment, so that may hold things up for a few days.