How big a pistons in a WC block?

 

One night there was an Allis up at 380-390 inches.  The fellas who built it were verry good with engines and knew their stuff.  THey had flywheel dynoed the engine to be at 170 HP, now it's been a few years and I can't say an exact number, maybe it was 176 or 171, doesn't matter.  It had a fabricated manifolding and ran at a pretty good RPM.  They hooked in 3rd gear that night and put down a good run.  We had hours to talk before we pulled and we talked quite abit about different things in the engines we had, I don't beleve that any of us were hideing anything from each other.  It turned out that I bought a few parts from them and ran into them a few times over the years.

 

I knew I didn' have the torque to hook 3rd but went in 2nd.  UP against 170 hp I figured I was in for a good butt kicking.  I snuffed mine in 2nd that night, but I was 80 feet, that's right 80 feet in front.  THe sled pulled just hard enough that I could hang on, but the ones with torque boiled the tires.  The larger engines made more torque but did it at a slow enough speed that they had lost a lot of momentum.  In the times we pulled, the big one never won.  There were a few smaller engines at 280, 310, 360 that were really tough, one at 410 that wasn't tough

 

Another time when I locked up the engine and scored the pistons, hence the smoke, in Northwood Iowa.  3600 pound class and they ran a floating finish line.  We all chewed a long ways to something like 360 feet.  To long to run a dry engine, or I should have had a little more skirt clearance, when the engine came down I hit the clutch and it just died.  Pulled the starter rod and it just shook the exhaust pipe.

 

It cooled off and I figured it was already trashed so I hooked in the 4500 class, there was a 540 inch Olliver 88 there with a "Gengrich" (sorry on the spelling) engine.  We both pulled through and there were a few other allises and 460 farmalls, M's etc that couldn't quite make it.  When we re pulled the Olliver spun the tires with good authority, I snuffed mine but it was about 18 feet in front.  It gave all it could give but it was wound so tight that the ground speed was pretty high when the load came on.  Momentum saved me, cubic inches and torque did no favors that night.

 

Another night a Olliver 77 that didn't have much power just keept on lugging and dieing down, I came through blazing away and spun out, totally got my butt kicked by several tractors that couldn't go near as fast.

 

 

And another time we ended up with a 10 mph speed limet, I got waxed, couldn't get the engine up in it's powerband to take off well.  It just stumbled. bumbled and wasn't going to do anything.

 

My point is that you don't have to outpull them, you just have to outrun them on a modern type sled, most of the time, but it doesn't alwayse work.  But if anyone thinks that they can be dominent it doesn't happen.  We all got allong and could laugh and joke about things and see who was going where the next weekend

 

How much torque would it take to spin the tires in a given situation in a certain gear?  Now drop a gear and see how much torque it will take.  Now figure out how much faster an engine has to turn a gear lower to achieve the same ground speed.  It also does not need to have the torque reserve as in a higher gear and can maintain the high speed longer. 

 

Look at how much happens in the last 3 seconds of a run.  How many revolutions of a crankshaft happen in the last 3 seconds?   By that time the run is over, it's already been made.  Say the typical group of tractors in a class is spinning out at 275 feet.  By 230 feet you can tell who is going to win, the one going slightly faster, or has the ability to maintain a higher speed for longer.

 

I've seen a lot of guys sling shot it to the front of the pack.  When debateing what gear to run in, alwayse pick the higher one, it may not be right, but it's usually less wrong than the lower one would be.

 

On another note,

If someone wants to see a neat video or likes Minne Mo's, search on youtube for "tom larsen-draggin-rose".  I was messing around and found it.  An old friend and heck of a good guy with a UB moline he worked hard on, it runs verry well.