An error was found in the balancing book in the table on pgs. 80-81 by Luca Landoli, a good engineer in Spain. The cylinder offset listed for the Fulvia does not yield the listed % of reciprocating weight to be used to balance the crankshaft. He is right, but the story is a bit confusing. Basically, the % is correct, the wrong value was listed for the offset, which should be 18.94, not 19.34mm as shown. When run through the formula, it will give the reciprocating % of 21.5%, as listed (see below calculations).
The explanation is as follows: When most of this work was done in 2016, I drew (in CAD) all the angles and dimensions and derived any missing information, including finding an offset for the Fulvia as 19.34mm. However, a 1963 Fessia writeup stated the offset as 18.94mm, which was used to calculate the 21.5%, but mistakenly, the previous offset was listed (incorrectly) on the table.
Here are the correct calculations used and the CAD drawing for the Fulvia (on the drawing, the offset is labelled as B1):
K = ½ * (1-e/L * (cot (crankpin offset angle))) K = ½ * (1 - (18.94mm/153mm) * (cot (12.27))) K = ½ * (1 - ((.1238)* 4.597) K = ½* (1 - .5691) K = .215 or 21.5%
Another (minor) error was found on pg. 35, in the text of the CEMB formula: listed is crankshaft angle, but it should be crankpin angle.
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