Fishey

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Luis de Prat:
<strong>Actually, it appears that the balance shaft concept was invented by an Englishman named Frederick Lancaster in 1911. Mitsubishi simply refined the concept and patented its own version, which Porsche found more suitable for the 944 engine.

Read more here under "Vibration Control":

<a href="http://www.geocities.com/MotorCity/3322/eng25.htm" target="_blank">http://www.geocities.com/MotorCity/3322/eng25.htm</a></strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">This is ver true but porsche took it to a whole new level with 2 shafts per engine. Also porsce refined the shafts so they didn't steal hp the way they did in mitsu's design.

Fishey

I also have read that the reason the 944's are limited to only 6,500 rpm is these shafts are moving at 2x the crank rpm, so like 13,000rpm (I dont know if this is true but that would make it hard to go above that in the rpm range)

Olli Snellman

Don't you know , dad's are always right ! As Luis wrote it was old english trick which was later improved by Mitsubishi. There's no need to invent a wheel again if there is a good system available !

Waterguy

Did Porsche patent the part where, instead of sticking them inside a specially designed block, they simply bolted them onto the outside of the block using seals that would later leak?

When Porsche tested them, they found that they stole 4 to 5 hp out of 143 in the original engine. This was considered an acceptable trade-off for the benefit of the smoothness they provided (924s were criticized for having a rough engine.) How many hp did the Mitsubishi design steal?