The new TR1 engine - squishing things together to make more power (part 31)

Aside from ruining perfectly good engines, there's some more that needs to be done in the advent of the upcoming season. The recent situation of detonation on one cylinder and the fact that the gap between squishband and piston was incredibly large led me to look for solutions to increase the effectiveness of the squish. And the best way to improve things was to get the piston and the squishband closer together by removing the cylinder base gasket.

First the baseline had to be established with some 2mm (super-soft) solder.

This came out as 1.71 to 1.75mm, which was just at what literature would consider the uppermost limit of squish-gap to still be working to a minimal extent.  Time to pull off the cylinder head and cylinder have a look at things.

Quite a few carbon deposits and signs of the engine running a tad richer than I would have hoped, but aside from that all seems to be well. After quite a bit of swearing because I haven't used enough grease on the base gaskets and lots of subsequent cleaning a thin bead of gasket sealer was applied and the engine re-assembled.

So which results did the whole process yield: The base gasket is 0.50mm thick when compressed and that's pretty much what the cylinder came down. Everything spins over freely and nothing seems to touch.

Theory says one should strive for a clearance of 1.00mm or even slightly less for achieving maximum effectiveness of the squish, but this leaves out of consideration that after all this isn't a racing engine and shall still work reliably even 30,000 or 40,000km after this overhaul and without any doubt, tightening up the squishband should help quite a bit in the future.