Technical Information on a ROTAX 912 engine with black cylinder head cover

un motor 912 con las tapas est un 80CV . 

Ademas, el # 3792,575 es del ano 1990 y el 100 CV empieza en 1999.

Y no se puede convertir un 80Cv en 100CV.

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edit:  in english

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a Rotax 912 with black head covers is the 80 HP version

moreover, # 3,792,575 is of mfg year 1990 and the 100hp started in 1999

no, you can't convert a 80hp into a 100hp

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et voilà

reminder: forum rules require ALL posting here is to be done in English language (or at least pasting in a Google Translation alongside).

see also

https://www.mentalfloss.com/article/55677/what-universal-language-skies

https://simpleflying.com/english-aviation-language/

http://www.aviation-esl.com/ICAO_English.htm

https://www.baatraining.com/language-of-the-sky/

http://language.aero/en/about/aviation-language

Translating for the OP (Pedro):

"They asked me to inspect a Rotax 912 engine, which had not been operational for about 4 years.  Judging from the black rocker covers, it is possible that this in an 80 hp engine.  

There is no reliable documentation (no logs) for the engine.

The serial number on the identification plate is 3792575, which corresponds to a model number of 309120010.

My question is whether this data corresponds to an engine that is actually 80 HP, since the operator told me it was a 100 HP 912.

As we know, there are 80 HP components that are neither allowable or compatible with those of a 100 HP 912, and I'm trying to confirm that a "cannibalization" hasn't been carried out to somehow convert an 80 HP engine into a 100 HP engine.

Thanks"

Hope that helps...

S.N 3792575  is a very early Rotax 912UL 80hp engine that was produced 07/06/1990

S.N 3792575 es uno de los primeros motores Rotax 912UL de 80 CV que se fabricó el 07/06/1990

Some people have put the larger cylinders and pistons on the 80 hp thinking that they will then have a 100 hp engine.  What is important to know is that there are other differences.  The 80 HP has a 79.5mm bore, the 100 HP has an 84mm bore.  In addition the heads have some slight change for the 84mm bore with a relife just at the valve to allow better breathing with the larger bore size.  

The camshaft has a different duration, the 100 HP cam has a longer duration of opening to help flow.  

Compression on the 80 HP is 9 to 1 and on the 100 HP it is about 10.8 to 1.  

Due to the higher compression it is important to use the high torque starter rather than the small standard starter.  With this the 100 HP engine should also have the overload clutch fitted to help prevent backlash on starting.  

Regards

Google translate for you:

Algunas personas han puesto los cilindros y pistones más grandes en los 80 hp pensando que luego tendrán un motor de 100 hp. Lo que es importante saber es que existen otras diferencias. El 80 HP tiene un diámetro de 79,5 mm, el 100 HP tiene un diámetro de 84 mm. Además, las cabezas tienen un ligero cambio para el orificio de 84 mm con una vida útil justo en la válvula para permitir una mejor respiración con el diámetro más grande.

El árbol de levas tiene una duración diferente, la leva de 100 HP tiene una mayor duración de apertura para ayudar al flujo.

La compresión en el 80 HP es de 9 a 1 y en el 100 HP es de aproximadamente 10,8 a 1.

Debido a la mayor compresión, es importante utilizar el arrancador de alto par en lugar del arrancador estándar pequeño. Con esto, el motor de 100 HP también debe tener instalado el embrague de sobrecarga para ayudar a prevenir el contragolpe al arrancar.

Saludos