Searching for Net Calorific Value of Butene C4H8

[Mitch1]

Hi
I have tried to search through various books including perrys
Can anyone state the net calorific value (lower heating value) for butene C4H8 and the source if possible
It would be much appreciated
Thanks

 

[SteamKing]

There's this source:
http://www.engineeringtoolbox.com/heating-values-fuel-gases-d_823.html

under 'butylene'

 

[Mitch1]

Thanks mate