I guess I should have prefaced this thread like my others....
first.... I'm Alaska.... no tractor racing up here, second, not likely I'll ever get to one of your events to meet people that race (though it's interesting) third, I'm not building a tractor engine... it's for my hovercraft
and get real.... there are several companies producing long rods and as far as I can tell, no one has posted data on what this product will do all by itself.... removing the effects of the compression increase that comes with the required piston change.
I'm 63, I raced motorcycles in the 70's when the long rod was still a new idea and considered a must have in the day.... you just did it. now.... I'm researching this and there is a lot of different opinion, and some of it makes sense. every mod is a trade off.... I don't want to trade my low RPM power..... I want to increase it, and frankly, the long rod looks like it could be the wrong thing to do. I'm looking for peak power at 3000-3300.... whatever that is, yes I know more RPM means more power, but my props limit the engine speed. anyway, if I wanted only to increase C/R.... no problem, I know how to deal with that. btw, I'm a licensed aircraft mechanic (40 years) with a machinist background among other industry experience.
p.s. - "opening the checkbook and doing the math" is no problem.... I also have an airplane.... that will stress your checkbook, even though I'm licensed to do all work on it
right now the math says there is no reason to pursue the long rod for my application. that based on the fact that no one can show me that it does anything positive at my RPMs (or any RPM for that matter). (bearing in mind that I built long rod motors in the early '70s)