The early D-17's were an upgraded model of a WD45 with larger crankshaft journals and bearings, more power and side mounting. More had power steering.

I grew up on WD45's (and I still love to drive them), but my D-17's (early no series and Series IV) are much nicer, and safer, to use.

if you go and look at the nebreska tests for WC and UC,  it actually shows the wc pulling more than the UC, even with less power and weight.  Something isnt right there.

(was installing a new battery that day.) Note mine has wrong wheel colors, wrong grill color and wrong decals.

Belted to sawmill at our show 2018:

Ready to plow the garden this spring:

Stone boat pull at local Albion PA fair last fall. Nic at the controls:

Dirt track pulls:

Regards,

Chris

In short form, the 'most repeatable' power indication is PTO or BELT.  This is because the power transmission method's ability is very predictable, and the resulting load will be very consistent.

Drawbar horsepower depends on many variables, including, but not limited to ground conditions, tire diameter, ground speed, etc.

If you're interested in how agricultural ground traction calculations work, read the Wismer-Luth white paper on Agricultural Traction Prediction.  Harold identifies the math, but keep in mind that they didn't create the math, then perform tests to suit-  they performed thousands of tests, then extrapolated the math... it's an empirical data study, not an academic achievement exercise.

The short form answer, is that when weight distribution is set so that all but mebbie 5% of the tractor's weight is on the drive axles, ANY combination of tires, weights, etc., will yield a drawbar tension commensurate with about 30% of the tractor's weight.  Add more weight, drawbar tension will rise.  Reduce weight, it will fall.

Consider this fact:

Let's say a given tractor, with given weight, can pull 6600lbs 50ft in sixty seconds... that's 6600lbs*50ft=330,000 ft/lbs per minute.  33,000 is one horsepower... so that tractor is developing 10 drawbar horsepower.

To get more tractive effort, one could double the weight of the tractor, at which point, it could pull 10,000lbs, but in a lower gear, and only make 21ft in the same minute.  that's 10000*21= 210,000 ft-lbs in one minute, so only 6.36hp.

Let's say you drop it to 4000lbs, and pull it 310ft in one minute... that's 1,240,000 ft-lbs per minute, or 37hp.

Now,  lose more tractor weight... that reduces rolling resistance because tires aren't sinking as deep.  Reduce the draft load to 2000lbs, put it in road gear, and cover 1000ft... that's 2,000,000 ft-lbs per minute, or 60hp...

So you can see how varying the ballast weight, and the VELOCITY at which pulling occurs, results in 'horsepower' available.

And these pulls only last for a minute or so.

Compare that to a dyno:  You connect it, and put a load onto a machine, and that load is constant.  leave the load on for a long time, and the engine will start to get hot... and start to lose efficiency, and the lifespand will eventually start to erode quickly.  You'll eventually find a load-point where the cooling system cannot 'keep up' with the engine's waste heat generation.  At that point, the graph data above no longer matters, because the engine is on a rapid highway to hell... it will overheat... you've found the limitations of it's 'duty cycle'.  The maximum load level that can be used in ratings, is not the 'peak' horsepower, but instead, the 'continuous duty' rating.  A digital thermometer and graph paper is your friend here.

 Just get it! Looks pretty good from here!

Regards,

 Chris

these are good old machines and mine has done a lot of work.  check for psteering leaks.

power steering is nice with a loader mine has a 7.5ft bucket.  you couldn't steer it with out power steering...lol.   but aside from the power director popping out of gear i don't think there are any real issues with these machines and  unlike the older machines the engine should hold you back when going down hill a real plus on a hillside like mine. lol

 The 17 will be your work horse for sure! Start soaking that adjuster on the plow, then later some heat to loosen the rust. Tractor looks good! Have fun with your new toy!  Your collection is growing! You need to add a WD45 in there too!

I gave $3k for mine about 8 years ago.  Much like what you're looking at, all intact, not much 'mechanic modifications' done to it, paint ok and tires/rims were functional.  Currently in the process of upgrading my tires and rims.  I'd say good price and the blade is a bonus.

I've known this for a while, but never understood why the valve guides usually only let oil past them when opening the throttle. Can someone explain that? 

My initial thought was when opening the throttle, the increased "suction" from the pistons on the intake stroke is what pulls the oil through the worn guides, but I don't know if that's right. 

I can almost guarantee you will be happy with this addition.  We were still in business when the D-17 came out as dealers we were very pleased to see it.  Had good power and over time has proven to be an outstanding unit.  Very few problems.

Looks like you made an excellent purchase.  The D-17 came when we needed a larger, more powerful unit.  Was a "hoss" at the time. 

Let us know how it goes.

Good Luck!

Bill Long

Good looking tractor in it's work clothes!  I'm sure you will be happy with it.  Not sure that trailer is strong enough for that tractor though, lol.  What do you have to pull the trailer?

I would have to do a little more research but I believe the SC type implements should have the SC type lift latches for safety. If the bottom SC joint would ever open and or release the plows would push up on the SC latches and release the plow from the tractor.

Having it fastened tight might allow the plows to pivot around that point and end up on top of the driver. Now I am not in any way a expert on these, but I believe that is the design intent of the Allis SC (snap coupler) design. I believe you said your plows have been converted from a pin hitch to a SC. So that may have been the system used on the WD prior to the SC system. Hope others will chime in.

I really like your 17! Mine is still in its work cloths and the wife said it really doesn't look good with these other painted tractors! Maybe a hint of another project in the works??

Regards,

 Chris

Your doing good getting the electrical issues cleaned up. We used no rubber boot wires for years on WD series tractors. Dad would use a match book cover as a holder for the wire to allow the spark to jump and "clean the plug"! 

Just take a pair of pliers and squeeze the plug end a little till they fit tighter. Should be fine that way for a long time.

Regards,

 Chris

Another thing that contributes to this but doesn't get talked about too much is the wear in the snap-coupler system. If you step on the drawbar and it goes down several inchs, that's not good. The edges of the snap coupler 'bell' and the support it is pinned to wear over time, my opinion, the sloppier the more likely it is to uncouple. The spring in there is another consideration, if you're in there, replace it. They are not that expensive.

Using an implement that is snap-couple with pin-hitch lift links is a serious No-No. I'm sure a lot of farmers did it for years and got by. That pic  CTucker posted is good evidence not to do it.

 Loose plug wire shouldn't cause a serious problem. Assuming the plugs are good. Is it running rough?

Regards,

 Chris

 Your D17 has about the same patina as mine. I see you have the top link attachment added. Looks similar to what I built. I found that I would have liked to have my eyelets up on the top allowing a couple more inches for the top link. I could barely get my brush hog hooked up.

Regards,

 Chris