Depending on lots of variables, it is quite possible for any engine to overheat without the thermostat. This generally occurs with a long lower radiator hose which has no reinforcing wire. The thermostat prevents such a hose from being sucked shut, which shuts off the collant flow from the radiator to the block. Having had this occur, I still tend to replace extremely long lower radiator hoses with 2 short ones, and a piece of metal tubing.
Another instance (although not occuring with stovebolts) had to do with Smiths thermostats. One feature of many English vehicles was a bypass to allow quicker warm-up. The Smiths thermostat had a sliding ring around its perimeter that would slide into a position to close the bypass as the thermostat opened. Failure to include a thermostat or using a non Smiths thermostat would definately cause overheating.
Here is a link showing one of these:
http://abouttimespares.com.au/showpartslist.asp?cat=46&sub=979 Scroll down and look at part number Part No: X85025/80. The outer ring is the slide.
Jon.
