Steam Engine Twin Cylinder Maxwell Hemmens. Twin cylinder engine , ideal engine for a small boat , with change over valve and lubricator. Dimension: 120 mm x 55 mm x 80 mm high. See photos for more detail.Feel free to contact me for further information/pictures etc. And I will get back to you ASAP. All items are sent as Registered Post. The item "Steam Engine Twin Cylinder Maxwell Hemmens" is in sale since Sunday, April 14, 2019. This item is in the category "Toys, Hobbies\Powered Toys\Steam Powered". The seller is "gerlinger74" and is located in Gordonvale, QLD. This item can be shipped worldwide.