Some of the super stock methanol tractor pulling engines are around the 24:1 ratio. They've got more money in one engine than I've ever seen in my life tho.
Diesel's notoriously hard to ignite. There are Natural gas pipeline pumps that run with spark plugs, but diesel doesn't appear to work that way.
They suck alot. Stock light truck applications push 20psi/650cfm daily. Modified apps run twice as much or more. Also, the diesel's biggest enemy is exhaust temp. Generally the bigger the exhaust housing is, the lower the EGT's you can run towing a heavy load.
brandon.