photographs of specific CO2 motors

[g_kandylakis]

Czech Modela, late 70s

[g_kandylakis]

later model Modela "S"

Gasparin style cylinder with O-ring and four smaller exhaust holes instead of 3 large ones.

Filling valve on this one is of the older standard type.

[g_kandylakis]

GM 300

[g_kandylakis]

GM 63BB (ball bearing)

[g_kandylakis]

GM 63

(photos to be added later, basically similar to the 63BB except for the thinner crankcase)

[g_kandylakis]

Gasparin GMW 73 BB

competition motor for F1K class

[Flygrimm]

Here's a Gm-160 and a 12oz CO2 bottle filler adapter I purchased from Gasparin in 2013.  The motor came with a small bag of replacement parts and the filler came with an extra very small ball.  Don't lose them!

[Nigel_M]

I thought folks might find useful a comparison of some of the various Sodastream CO2 'bottle' adaptors they might find at a swap meet or maybe wish to buy new. All of these have the traditional thread. The last I heard, the Derek Knight adaptors were not currently available but they are listed on his price list at www.kpaero.com. The latest Gasparin evolutions are to the best of my knowledge available at http://www.old-engine-model.com/en/ although the example in my photos is somewhat older and different in appearance, it is perhaps more likely to be the style found at a swapmeet.

There are two different K&P or Knight Pridham or Derek Knight types; the original and the latest Derek Knight design. The differences can be seen from the diagrams in the instruction leaflets scanned below. The newer design has a plastic insert at the bottle end comprising the filter whereas the older K+P design has a single steel shaft that runs right through. The latter looks like a bolt with the head ground down to me, but what do I know. Both have 3 o-rings. One big one to seal against the neck of the sodastream bottle, one small one inside the nozzle, the third internally which seals the shaft to the brass housing. The K+P design has interchangeable inserts in the nozzle which have very slightly different bore diameters to allow use with different motor tank filler nozzles. The overall Gasparin design will no doubt be similar except perhaps for the interchangeable inserts.

In the photos, the newer Derek Knight design is on the right with the lesser shaft diameter, the Gasparin is in the centre, the traditional K&P design is on the left.