This too contributes a little to the "charm" of everything that was invented according to criteria that at the time might have seemed solutions that, perhaps, could have had developments in competitions or at industrial production level. Although they actually had a nice fantasy ...All I can say is "Why?" ... were they trying to cheat around a non supercharger rule?
Otherwise just chuck a belt driven roots supercharger on the side. Job done and all the weight down low ... This appears to be another example of Alfa Romeo deliberately finding the most overly complex solution to a simple problem, lol
Here is the GTA SA story:Question on the turbines. Did Alfa make them from scratch or were they repurposed from some existing use?
Hi Andrew,Question on the turbines. Did Alfa make them from scratch or were they repurposed from some existing use?
The only existing data on the bore and stroke of the SA engine were measured in Loris Paone's Turbo Motor workshop in Cesano Maderno, on three "surviving" engines, and correspond to the known values of the atmospheric aspirated GTAs, that is, 78x82 mm. However, to declare ignorant Fusi, Tabucchi and the others that in period indicated 86x67.5 mm as a value, is ridiculous. It was certainly not the people who did not know the subject. It should be noted that the measurement is only performed on three of the approximately 12 motors prepared for racing. For the other engines (majority) data do not exist. However, it is known that there have been constant changes on the SA (switching on the transistors for example) and also from the photos of the period it is visible that the engine was different from car to car (just note different oil pans). Everything could be changed because the engines were partly produced in Settimo and processed on site. The data discrepancy remains one of GTA SA's unsolved mysteries.In regard to the bore/stroke dimensions of the GTASA, most likely was the traditional 78x82. Even the picture in Fusi's book of what is presumably an official factory photo, shows the distance above the water pump to the head as that of the normal dimension, as Alleggerita pointed out in a previous post. The larger mono-bore/shorter stroke version has no height distance in this area and is easily identified from the front.
This is what Teodoro Zeccoli told to Maurizio Tabucchi during interview in June 1991:To my knowledge the turbines were sourced quasi in-house from Alfa Romeo Avio (Aeronautical division).
The GTA-SA had some issues. I name a few that I know of.Let's face it, they built 12 one off engines. It is possible they tried 12 variations before righting canning the, interesting to us now, waste of time.
It is the V16 BRM of saloon car racing. Both projects failed because the wrong supercharger was selected.
I would agree with the observations Vince made.My assertion that 78 x 82 was the most likely dimensions used dose not exclude the possibility that the short stroke version may have also been tried. All I am concluding is that so far, in all published pictures of GTASA engines, the block height corresponds to the normal dimension, not the short stroke version. I would think that they would have at least tested the short stroke version, but so far have never seen a photo an actual engine of this version.
Olaf, certainly in Fusi's book the dimension listed for the GTASA is 86 x 67.5. However, on the accompanying page showing a picture of the engine it displays the normal block height, not the 67.5mm height. So there is still some discrepancy between figures and photos.I would agree with the observations Vince made.
I'll check if I can find a reference to a short stroke GTA.....