Hi,
ORIGINAL: doxilia
The question that I have now is: Does the Hippo in these pictures have a RE Webra 60 or something else? Hard to imagine a model this size flying well on a 60.
The engine in the photo does appear to be a piped rear exhaust Webra Racing 61F or the long stroke racing 61F LS. It definitely has the Dynamix slide carburettor or something that looks very much like one! It's definitely a two stroke. Now .61cu.in. (10cc) was the two stroke engine capacity F3A rule limit in those days so the plane was definitely designed for, and flew well with, that size of engine.
Webra didn't make a rear exhaust two stroke aero engine larger than .61 in the early eighties when the last versions of the Tiporare were designed. But they did replace the Racing 61 F with a Racing 80F after the rules changed in the early nineties. The Racing 80F can easily be told apart from the Racing 61F by the much wider cylinder head and cooling fins. The engine in the picture is definitely not an 80F. I am told by the Webra representative here that the Racing 80F piston and liner can be retrofitted in a Racing 61F LS but have not verified this myself. It could be possible that the engine in the picture is a Racing 61F LS with 80F internals but I think that's unlikely. An 80 would need to spin a larger prop than the one I see in the picture, too. The one in the picture looks like a coarse pitch 11 prop as was used on 60 size pattern engines in the day.
Best regards.