Are the new Thunder Tiger 40s actually 46s?
We had an engine at a race recently that the pilot stated he had recently bought new from a lhs that said it was a 40, but checked out to be a 46. We did not question what the pilot claimed as he is well know and liked,but thought maybe someone had bought it and messed with it and then returned it to the hobby shop.
Today I became aware that our local hobby shop also had a new engine that appeared to be a 46 rather than a 40. Note this was not the same hobby shop that sold the first engine.
I went to the hobby shop and was allowed to examine the engine in question. We compared it to a 40 that I had and a used 46 that the shop owner had. Measuring the stroke through the glow plug hole the new "40" with a digital caliper it measured the same as the used 46 and 1mm longer than my 40.
The first tip off was a quarter would fit between the cylinder head and the crank case onthe 40 it will not.