|
G/MAN
08-19-2007 17:32:05
|
|
Re: Why cant there be a stock tractor pull in reply to older puller, 08-17-2007 08:55:09
|
|
| |
If common repairs, rebuilding and parts replacements that are done over the course of a tractor's working life are to be considered "modifications", then it's highly unlikely that there is a 100% "stock" antique tractor to be found, be it at a pull, parade, show or in the field. If that's your definition, then even substituting a different brand and heat range of spark plug and gapping it a little wider is a "modification" and will make the tractor not longer stock. Don't foo-foo that - spark plug heat range and gap can easily affect power output. How many tractors are running with plugs that are identical to what they were built with? As for cylinder overbores, that's kind of a hollow argument, too. Overboring cylinders was done to increase the service life of cylinder blocks long before it was done to increase displacement, and yes there is a displacement increase with any overbore, but with any reasonable overbore, the actual displacement increase is minimal as a percentage of total displacement. Taking a 412.5 stock JD "G" out .045" increases displacement by about 6 cubic inches, or about 1.45%. Even a "big" .125" overbore leaves you at 429.5 cid, which is still only about a 6.5% displacement increase. Is that worth tearing down an otherwise sound engine, dropping $400 plus on new aluminum pistons or tracking down a set of .045" over "stock" Deere cast-iron pistons or a NOS or good used standard-bore block, and paying for machine work and additional parts in order to gain those few extra cubes and a nominal horsepower increase that probably won't even show up on a dyno? And if it DID result in a measurable and repeatable horsepower increase, is it all due to the displacement increase, or was the ring seal improved substantially, maybe even over what the factory achieved when the tractor was new, with a fresh bore and new rings? Heck, seems like even normal cylinder wear results in slightly oversized bores and an increase in displacement. Shall tractors with worn-out stock cylinder bores, pistons and rings be outlawed in "stock" classed because they have more displacement than they had when new? As for decking blocks and heads just to true the surfaces, I've never seen any warped so badly to require .100" of material to be removed, and I don't know of a decent machinist that would ever do so unless specifically asked to. Replacing worn-out valve seats and increasing valve protrusion, or replacing the valves themselves if they happen to be of a slightly different design with more material above the seat will all decrease chamber volume and increase compression. So do thinner-than-stock head gaskets, so does a simple cylinder head rebuild WITHOUT porting and polishing constitute a modification that should make the tractor non-stock? Should a tractor be DQed if it has an aftermarket "stock" head gasket that's slightly thinner than the factory gasket? How about "factory" performance-enhancing parts, like genuine Deere hi-comp "gasoline" pistons and cold manifolds for a "G"? They're Deere part-numbered parts from the OEM and are specifically designed for that tractor in order to increase performance, so are they stock or not? How about putting gasoline pistons in an otherwise stock "A" that left the factory as an all-fuel tractor. Those are stock parts that were being installed on tractors the same day the all-fuel tractors were built in the same factory on the same line, but are they not "stock" because the tractor didn't come with them? As for Power-Blocks, they're legal as stock replacement parts in many areas, because they were initially made to improve performance of field tractors and were sold on that basis, so most of the time, there's no way to "catch" a guy cheating if the part is legal. And if they're NOT legal, they're pretty darn easy to spot and identify. I doubt there are many guys running Power-Blocks and are "cheating" in a "stock" class where Power-Blocks are illegal and are getting away with it, at least if anyone else at the pull has much of a clue. I'm playing devil's advocate and a lot of this is nit-picky stuff, but the bottom line is that I've never seen a "stock" antique tractor in my life, and you'll never get the kind of rules in place, the necessary steps to enforce them or pullers willing to adhere to them, so you either pull in "stock" classes against whatever else is there and can't be proved otherwise and take whatever you end up with, or you sit on the side of the track and watch. When you get down to it, is it really that embarassing to get beat by some real, classless cheater that wants a $3 trophy bad enough to go to all sorts of trouble and expense in order to win it? I don't think so, and people that do cheat like that are more worthy of pity than disdain.
|
|
|
