[Gasification] Engine knock

[doug.williams]

Hi Fredrik, and Colleagues,

You are correct.

> A compression ratio of 1:25 sounds very high. Can someone come up with 
> more
> information about this?

Duel fuel diesels will only work reliably with compression ratios of 16:1, 
as the spontaneous ignition temperature of producer gas is about the same as 
for diesel. You cannot control the engine over this ratio, as spontaneous 
ignition takes over. Engines with higher ratios, have a separate 
pre-combustion chamber, and these are well proven to be unsuitable for 
producer gas.

If you are setting up a spark ignition engine, the compression ratio has 
little merit over 12.5:1 as the increase in frictional forces consume any 
extra power that a high ratio might provide. this has been well researched 
and proven, my papers go back to before WW2.
Hope this clarifies the issue of compression ratios.
Regards,
Doug Williams.
Fluidyne Gasification.