Press fit Cozycarbs

Previously I realised that the press-fit process would stay well inside the elastic deformation limit of both the aluminium comprising the cozycarb as well as the carburettor. So the exact method of pressing the cozycarb home was less important than the final result. I decided that preheating the cozycarb, or cooling the carburettor, would not be necessary. Of concern was the uncertain effect of extreme cooling on possible non-metallic components within the carburettor, and the uncertain effect of heating on the loctite-type sealant which was prescribed to be placed on the mating surfaces. There was also the issue of the partially fitted surfaces rapidly coming into thermal equilibrium and possible jamming together and leaving me with no opportunity to restore the temperature differential. A transition to a cold-pressing process would be required to complete the fit. So I decided to do a fully cold-press.

Finally, I received confirmation from Fisher aviation products that the dimensions of the carburettor and cozycarb were also fully to specification - the 0.13mm diameter difference (0.065mm radial interference) was perfectly normal. They also stated that no problems had occurred with other customers. This, and the fact that the deformation remains fully elastic even with this level of interference assured me that I could achieve this press-fit.