Pop Pop Boat Engine - Large. Large engine for boats up to 12" (30cm). £3.75 Out of stock New Large Boiler. PLEASE NOTE - Not for the faint hearted. The boiler and pipes measure 15cm (6") overall. The boiler itself measure - 7.5cm (3"approx). Ideal for installing into your own home-made boat. This engine will run on either candles or olive oil (or something stronger) with a piece of wick added. If you try one of these larger engines, please email and let us know the best type of fuel you used - we are predicting solid fuel tablets (Gellet or Marmod). No mention of meths. whatsoever. The underside of the boiler and the pipes are made out of steel and may show signs of light surface rust. This can be removed by lightly rubbing down with wire wool prior to installation. Fitting and Running instructions here Try using one of our engines, and send us a photo of your finished project. We'll show your masterpiece on our new page - "I built my Own Boat"