I googled BTU per pound of cherry pits and found this site. You many be interested in it.
http://listserv.repp.org/pipermail/stov ... 02305.html
This site reports a BTU value between 9 and 10 thousand. Although not as high as coal, it is higher than wood, and any other grain including corn.
I won't be able to test the 20% mixture coal/cherry pits until this coming season, but I'll be sure to report my findings.
If one were to have a good supply of cherry pits, AHS has a wood boiler called the wood gun that can be retrofitted with an air lock delivery system that would be perfect for burning pits.
Fellas, I truly appreciate these discussions. I have read more in the past two weeks than the time I spent in college - both times!