The Sky Shark 49 was a .49 cuin. sand-cast glow-plug engine which was produced in relatively small numbers between 1952 and 1954. Its manufacturer was a certain Mr. N. Haruyama, who had initiated the manufacture of a range of model engines under the Haru designation in 1946 and was to go on to manufacture the Sky Queen models during the mid to late 1950's. The Sky Shark was a forerunner of the Sky Queen line. It appeared in two distinct variants, although the differences were relatively minor. 

The Sky Shark was a bit of a lump at 11.87 ounces, also having a rather rough exterior finish. However, it was extremely well made where it counted - all internal fits and finishes were beyond reproach. Present-day testing has shown that the engine starts and runs very well, although its strong suit is low-end torque as opposed to high-end power. It appears to have been designed to appeal to those modellers who liked the power delivery characteristics of spark ignition engines.  

Full details of the Sky Shark and its relatives may be found in my earlier article on Ron Chernich's "Model Engine News" (MEN) web-site.