Kings Lynn Model Shop
0 item(s) in basket - 0.00
View Basket Checkout
Home Special Offers Contact Us Log In My Account Checkout
Secure Ordering - Secure 128bit Encryption
More Info

PLEASE NOTE: Currently we are open for Telephone and Internet Orders Only

At present some suppliers are closed, and some deliveries may take longer than usual.

Telephone Hours will be 10am-3pm, Mon-Fri till further Notice. 

 ***Petrol 10cc,15cc and 20cc Twin Engines - Now Instock ***


Unfortunately this product is no longer available, please try searching for a similar product in case we have re-listed as a special combo or the product has changed.

O.S. OS FR7-420 Sirius 7 Radial Engine [L-OS37010]
FREE Delivery on this product!

Since 1986, O.S. owners have enjoyed the unique experience of owning and operating the fabulous FR5-300 Sirius 5 cylinder radial. Models have become bigger over the years and O.S. wanted to release a new radial engine to cater for that market. The result is the gorgeous FR7-420. With 7 cylinders and a capacity increase to nearly 70cc, the FR7-420 offers a dramatic increase in both torque and power. In keeping with the scale image set by the Sirius, the new FR7-420 has been styled in the same way with front pushrods and separate rocker boxes for the inlet and exhaust valves. These totally new cylinder heads are not just about ‘style’, they offer a more efficient design that contributes to the power output. That neat frontal appearance is maintained by keeping the single, dual needle carburettor at the back and hidden in the centre of the engine mount. The prototype engine shown here will have some detail changes (cast cylinder heads etc) made before release, but the general style will be similar. It would almost be a crime to hide it away in a cowling!

Quality and style this good is something to be proud of owning. The wide range of large propellers
recommended makes choosing the right one for your model simple. At these sizes, they could be close to scale!


Weight:3167g (111.71oz)
Propeller Range:22x10-12, 23x8-12, 24x8-12, 26x8
Displacement:7x 9.95cc (0.607)
Bore:24mm (0.945")
Stroke:22mm (0.866")
Practical RPM:1500 - 7000 rpm