WD-45 engine overhaul to D-17 specs

docmirror

Well-known Member
OK, I'm about ready to order my parts for the overhaul. I am starting with the WD-45 case and head. I will be going to the D-17 overhaul kit. The two options are center-thrust bearing or end thrust bearing. I presume the center-thrust is the older style, similar to the WD-45 but I will confirm that once I have the crank micced.

Other than the piston/ring difference for 7.25 C/R over the 6.45 C/R change, I"m wondering if there is any other change made? I've been informed that the gov springs will be different to make 1650 RPM, and of course the carb will be slightly larger bore, but if there are other engine differences, now would be a good time to know.

Cam profile? Valve train, or valve size? Head casting? etc.

If anyone has done this before please chime in before I go making this up. If there is a difference in valve train, I will make a hybrid and re-use my WD-45 head and valves, and get the best perf I can out of what I have in terms of head/valve flow.

I'm ordering the parts through here, unless anyone has had trouble with parts from this seller.
 
Pretty sure you will need rod and main bearings for the WD45 crank. I am about positive the D17 had bigger journals. Cam is identical as is the valve train. I guess I haven't looked into valves to see if they have the same sizes.
Aaron SEIA
 
Agree. D17 was center thrust, WD45 was end thrust. WD45 still used shims on the main caps, D17 did not use them. Be absolutely certain the engine kit you are getting is 7.25:1 CR. Most aftermarket kits, especially the overbore 4 1/8" ones are 6.5:1 CR. AGCO kits are still 4" kits but apparently their availability has become limited in recent years. If you do get a higher compression kit, it might be 8:1 CR like the 170 or Late E/EIII Gleaner combine. Hopefully Dr. Allis will be along with a more detailed response. Mike
 
Pistons and sleeves are all interchangeable between WC-WD-WD45-D17-170-175. Each set of pistons and sleeves are supposed to be a different compression ratio, which to some degree dictates the end HP. Rods bearings are the same for all of these engines. Get the size that matches your crankshaft re-grind ( .010", .020" .030", etc). WD45 uses no shims on the rod caps. Main bearings are 3.00" diameter on all D17-170-175 and use no shims. They are smaller diameter on ALL the older engines and have shims on the main caps. You'll probably have to order pistons/sleeves for a D-17 and mains/rods for a WD45. Camshaft grinds are all the same. Carb size is the same between WD45 and D17.
 
The cylinder head and valves/guides/springs, etc. are pretty much all the same when it comes to performance. The later D-17 engines had 3/4" reach spark plugs because the head was thicker on the deck surface to resist cracking at the spark plug holes. Many heads were replaced over the years and you might find a WD or WD45 with a newer D-17 3/4" reach spark plug holes, because all the older castings were discontinued and you got upgraded to the newer cylinder head.
 
(quoted from post at 13:14:40 06/29/18) Pistons and sleeves are all interchangeable between WC-WD-WD45-D17-170-175. Each set of pistons and sleeves are supposed to be a different compression ratio, which to some degree dictates the end HP. Rods bearings are the same for all of these engines. Get the size that matches your crankshaft re-grind ( .010", .020" .030", etc). WD45 uses no shims on the rod caps. Main bearings are 3.00" diameter on all D17-170-175 and use no shims. They are smaller diameter on ALL the older engines and have shims on the main caps. You'll probably have to order pistons/sleeves for a D-17 and mains/rods for a WD45. Camshaft grinds are all the same. Carb size is the same between WD45 and D17.

Well, this is great, great info. I'm now re-thinking the upping HP plan, as I will have the smaller crank journals. Since it's a 3 journal main, and I've already seena broken crankshaft, it might be smarter to just stick with the WD-45 build and deal with that, or go up to a Gleaner/D17 case and crank.

Thank you Dr, may have saved me another busted engine. If i can push it with the WD-45, I'll go to the D17 plan.
 
I haven't done this for over 30 years. I do think I remember the dealer sold me a different govener spring
when I did mine. Someone else please comment on this.
 
WD45 governor spring gets you 1700 RPM and a D-17 gets you 2000 RPM wide open. Many WD45 crankshafts have been reground by machinists who don't really KNOW how to grind a tractor crankshaft correctly. I'll bet your broken crank was a .030" x .030" ??? Try and find a better crank to begin with and have a real pro who does diesel cranks re-grind it leaving the fillet radius a fat as possible.
 
Actually, I bought the grader with the broke crank engine and don't know anything about how it broke. All I know is it broke at the back of the center main journal.

Most grinders know the journal fillet radius rules. I don't know how big it's supposed to be, but I'm going to discuss it with the crank grinder once I get the kit in.

The other issue that is almost universal is when the power is increased, something else will finally break. It may not be the crank, it might be the spider gear, or the input shaft, or a chain in the chain box, but more HP will find the weakest link. I wanted addl HP because I'm going to be using it at high elevation as well as near sea level.

This leads me back to the turbocharge kit which will bring it back to sea level power when used at 8400'. I can adjust the manifold pressure reg to keep it around 30" Hg at WOT, and not overstress the rest of the drive components.
 
(quoted from post at 04:28:49 07/05/18) Any combine salvage yards in your area? An engine off a Gleaner E would most likely be a more economical way to go.

Well, found a Gleaner E engine, but it's 1000 miles from me. Still sounds like a good way to go with the added HP. Also, I don't have to mess with the rebuild on my WD engine. Maybe I can get away with just rings, and a bearing kit rather than the whole deal, and put the WD45 engine in a tractor.

Grrrr, wish it was closer.
 
Pistons for WD and WC are not the same as for the rest, for a given compression ratio. The reason is because the
stroke is only 4? on those engines. Some of the WC/WD pistons will work in a 4-1/2? stroke engine, but the
compression ratio will be much higher, and in some cases might be unworkable.
 

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