Welcome along Michael, what sort of thing interests you ? Pre-war motorcycles for me but I do like to see some of the models. Some very skilled people on here.

Welcome to the Forum.

Are you a member of a local M E Club?

If not, find one and join. There you will find like mined people, and a mass of experience, and advice, should you need it.

Also "Junk" sales are often a good source of material, measuring equipment (if you are careful ) and things "That will come in handy one day".

As an instance, I found a metric plunger clock which seemed too good to pass up, and was eventually built into a Jacques Maurel Bandsaw Blade Tension Meter. It was a good move, greatly improved the saw's behaviour, and blade life.

Howard

Two strokes tend to be sensitive to the induction and exhaust systems, since they rely on the pressure pulsations within the systems to provide scavenging with minimal loss of charge.

Life is simpler with diesels, since when, and how much, fuel enters the cylinder is controllable.

Often on diesels, removal of exhaust residuals is aided by a scavenge blower,although this can still make the torque band quite narrow.

The Commer TS3 and Foden FD4 and FD6 had little low speed torque, or torque back up, and needed to be kept spinning at a suitable speed. (The Foden lorry transmission used a three speed range change box as well as the normal four speed box. If you have ever driven one and encountered a rising a gradient, you will be pretty good at quick gear changes! )

General Motors perfected turbocharging two stroke diesels for their locomotives, and the engines powering ships, such as the Emma Maersk are not only prodigious in size but in output,

The single cylinder two stroke diesels in Marshall tractors were very much narrow speed band units.

Although, in Rail and Marine applications. the engines are intended as more or less as constant speed units, making tuning the systems for optimum results is easier..

A loop scavenged petrol engine in a motor cycle or car, (Wartburg for instance ) with varying speeds and loads, is quite a different proposition.

Decreasing back pressure may produce a little more power, but at a greater cost in fuel consumption, or tractability!