TD020: Tapered grind or not?

balogh Sun Mar 23, 2014 10:24 am

I have several TD020 engines some with grooved type cylinder, some with thick wall cylinder. I assume these latter are younger than the grooved type. The grooved types also do not have their top fin milled to acommodate the wrench, while the thick wall cylinders have their top fin milled..

Question: were the older, grooved type TD 020 cylinders made with tapered bore?

Because my TD051-s with grooved cylinder do have tapered bore, but the younger TD051-s with thick wall cylinder do not, I assume the same goes with TD020-s too,i.e. grooved cylinders were made with tapered bore.. I read once that COX abandoned the tapered bore design to cut production cost, at least on the TD049 and 051 engines. Does it imply that once the TD 020-s with grooved type cylinders were also made with tapered bore?

My experience with tapered bore is very positive as far as the longevity of engine compression is concerned.
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