Allbon Spitfire MKI 1cc Rebuild Story

Allbon Spitfire MKI 1cc Rebuild Story

Starting with a bones example (missing its piston, connecting rod and mixture control needle) we start out to produce another fine runner of this rare little British engine.

Below is a picture showing the Bambi, the Dart and the Spitfire from my collection.

Below we have a replica box and and manual for the engine.  

The biggest problem we face with this rebuild is the missing piston and connecting rod to use for scaling the dimensions for making the new items. Using pictures of a disassembled engine we constructed dummy parts for working out the porting and final piston and rod sizes.  

The tank was made from cigar containers which I got from a tobacco shop around the corner.

After a lot of work the fits are actually not that bad; I added a few nice touches including a ball end on the mixture control needle.

According to published test data I should expect to produce somewhere close to 0.087 horsepower and turn up 12,000 to 14,000 r.p.m. I mounted a 8X4 propeller and this one screams like a banshee: must be because of my improved porting, that I developed for this specimen.

Watch the clip below of the first run of this rebuild engine with a tight fitting piston which will require a least 5 or 6 more runs with extra oil before parts will be acceptably run in for normal use.

Watch the rebuilt engine during one of its first bench runs.

https://drive.google.com/file/d/0Bw2P1xgqAWCudkt6UFFvUU1XMEE/edit?usp=sharing

Published on 10 Nov 2013 Another lovely small diesel what I bought recently. Missing a lot parts but a good basis from which to build up this great small screamer. Allbon engines are one of my favorites.Very well made from proper materials and with excellent fits all over the engine. The 3 transfer ports are similar to the style of Oliver Tiger, pointing at a 45 degree angled upward. Straight in the higher cylinder chamber. excellent scavenging and therefore high output with excellent starting characteristics. I only smoothed down the channels a bit as at the beginning were there were sharp corners. So the gasflow is now even more efficient.sub-piston induction and also a good peak performance. When they got together with D.C. the quality became less than before, but the price was decreased so more engines were sold as "DC" engines. Allbon engines are fairly rare today and highly desired by collectors. I will not show all the details of the rebuild, as its nothing new for my viewers. But as I wrote earlier, rare exceptions will be caught on film. I hope that you like the background stories too. I put it the stories,as it helps with the understanding of the history and development process of the particular engine. Many thanks again for Ron's Model Engine News website for the endless treasures of information.