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emdmat1981

523Dxi DM950D or DM850D Diesel Engine

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Was wondering if any of the 523Dxi owners or experts have insight into the differences (pros and cons) of the Briggs Vanguard (Daihatsu) 3/LC DM950D and DM850D.

 

I recently acquired a low serial number (around 125) 1998 523Dxi with 350 hrs on the meter and was surprised to see it had the larger 26.5hp DM950D (model # 582447) vs the "standard" 23.6hp DM850D  (model # 522447).

 

According to the Toro parts site the DM950D was the only engine used in 1998, while both the DM950D and DM850D were used in 1999, and only the DM850D thereafter.

 

Interestingly enough none of the "glossy" literature or marketing material I have found mentions a 27hp diesel powerplant (either standard or optional) ... even though the Toro parts site confirms its existence).  

 

I would be interested if anyone can expand on the differences or knows why the switch in engines by Toro / Wheelhorse.  

 

Thanks!

 

IMG_0302.jpg

Edited by emdmat1981
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I don't know much about the engines myself, but if they are diesel then I would guess that they figured out that the HP was a little (OP) Over Powered  for the size of tractor and that the fuel consumption of the 950D was to much in comparison... With the same fuel tank size (I'm assuming by the SOP) the 850D would be obviously be able to run longer on the same amount of fuel. So they fazed it out shortly thereafter possibly for those reasons...

 Disclosure: These views above are nothing more than just my thought and do not reflect factual info from the manufacturer.... :) A guess.
 Hope this helps.

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You raise an interesting question. The 523Dxi was originally developed  for the European market and then also sold here in the USA. Regarding the switch, it could be that the DM850D was less stressed for the application with less cubic inches and/or cheaper so it began to be substituted. Another reason could be a change in regulations, here or in Europe, regarding horsepower. I seem to recall  that ROPS began to be required around this time period. Keeping a 23 horsepower rating may have been under the requirement. Then there is Toro also using the same engine in their Groundsmaster mowers and Workman Utility so that could also factor on the switch. The Groundsmaster mowers actually switched to a Kubota diesel but kept the Daihatsu gas version later on.

 

My 523Dxi is also a 1998 with serial number 890556 with the DM950D engine. It has around 620 hours.  I have to admit that I never noticed the difference in my paperwork regarding the horsepower. I have both a 1998 and a 2000 5xi brochure with both showing the horsepower as "23 horsepower" for the 523Dxi. Considering that the Daihatsu DM-series engine was also developed as a gas engine with the same external dimensions, I'm surprised that Toro produced the 520Lxi with the Kawasaki engine. A Daihatsu gas model would have simplified the parts inventory.

 

I believe (could be wrong) that Simplicity used the DM950DT in their Legacy model although it was advertised as 27 horsepower so now I'm not sure if it was just the DM950D.

 

 

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2 hours ago, Mastiffman said:

I don't know much about the engines myself, but if they are diesel then I would guess that they figured out that the HP was a little (OP) Over Powered  for the size of tractor and that the fuel consumption of the 950D was to much in comparison... With the same fuel tank size (I'm assuming by the SOP) the 850D would be obviously be able to run longer on the same amount of fuel. So they fazed it out shortly thereafter possibly for those reasons...

 Disclosure: These views above are nothing more than just my thought and do not reflect factual info from the manufacturer.... :) A guess.
 Hope this helps.

 

The DM850D may actually consume less fuel than the DM950D with 6.3 cu.in. less displacement. Considering that some of these may have been purchased for commercial use, that would make a difference. But the DM950D consumes way less fuel than the Kohler Command CH gas engines in the 5xi. I can mow almost four times compared to just over two times with my 518xi. 

 

Here is the current brochure on these engines: http://www4.briggsandstratton.com/miscpdfs/RNT/vanguard_3lc.pdf

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That's what I was thinking. Just in the last few months of owning my two WH tractors (90' 520h and 95' 312-8) I've been using the 312-8 for mowing and now for plowing while using the 520h for Snow blowing. I've starting thinking about a diesel engine for the 312-8 and possible a swept front end with trailer hubs/ bearings and adding some hydro... 

 But today was my first really good run on the 520h after fixing the surging issue (loose Gov. Arm Linkage clips) and I ran it for a little over 2.5hours and only used about half a tank. Granted this wasn't one straight shot of full HP snow blowing but I cleared 5 full 55ft s car wide driveways, full block on side walk, cleared 2 intersection corners (one twice on account of a second pass of a city plow) that end into my street and cleared city snow plow "walls" created on 10 driveways in this time... So the fuel consumption seemed fair.

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41 minutes ago, WVHillbilly520H said:

John I know this is bit off topic which xi mule drives were the better ones? Any pics?,Jeff.

 

Jeff,

 

I have both but really don't notice a difference in function. The newer version is easier to adjust and tighten as the arrows are in front. It also changes the size of one of the belts required on one of the mower decks.

 

John

 

 

43 minutes ago, Mastiffman said:

That's what I was thinking. Just in the last few months of owning my two WH tractors (90' 520h and 95' 312-8) I've been using the 312-8 for mowing and now for plowing while using the 520h for Snow blowing. I've starting thinking about a diesel engine for the 312-8 and possible a swept front end with trailer hubs/ bearings and adding some hydro... 

 But today was my first really good run on the 520h after fixing the surging issue (loose Gov. Arm Linkage clips) and I ran it for a little over 2.5hours and only used about half a tank. Granted this wasn't one straight shot of full HP snow blowing but I cleared 5 full 55ft s car wide driveways, full block on side walk, cleared 2 intersection corners (one twice on account of a second pass of a city plow) that end into my street and cleared city snow plow "walls" created on 10 driveways in this time... So the fuel consumption seemed fair.

 

I have a C-105 (my DC-105) with a Chinese diesel. It is my "show" tractor but I use it for pulling a cart or my lawn spreader. It definitely is a viable engine but finicky when the weather turns cold to start. I think using a heat gun to force warm air down the intake would help. The glow plug is just in the intake plenum as opposed to the cylinder as on my 523Dxi. I have a C-145 with hydro that I would like to put another diesel engine in. 

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Thanks to all for their thoughts and perspectives as there is not a whole lot of info out there on the 523 diesel engines.  

 

I was really confused about the DM950D engine at first and almost didn't go through with the purchase from the PO since I thought the engine had been replaced. 

 

I guess in the end those with an already rare 523Dxi tractor may have an even "rarer" 27hp variety if they have the DM950D (with another 12% more HP and 10% more torque over a DM850D). :-) 

 

Perhaps the reason we got the DM950D initially over the DM850D was just due to availability of the engine thru Briggs / Daihatsu.   I'm thinking we may never know for sure.

 

Anyway ... a couple more questions:

 

1) does anyone have estimates or insight into the number of units produced by model number?   Would be interested to see the number of Dxi's (and other models in the Xi series) produced.

 

2) what would you say is the average life expectancy of a Briggs / Daihatsu Diesel?   Would have to assume the unit was properly maintained, no overheat conditions, "modified" oil fill process followed, etc 

 

3) any other pain points or things to watch out for with the Diesels?

 

Thanks Again.

 

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On ‎12‎/‎17‎/‎2016 at 6:42 PM, shallowwatersailor said:

I have a C-105 (my DC-105) with a Chinese diesel. It is my "show" tractor but I use it for pulling a cart or my lawn spreader. It definitely is a viable engine but finicky when the weather turns cold to start. I think using a heat gun to force warm air down the intake would help. The glow plug is just in the intake plenum as opposed to the cylinder as on my 523Dxi. I have a C-145 with hydro that I would like to put another diesel engine in. 


 Interesting. I've only seen videos of them. Nothing in person. The Cold start seems to be frustrating for some of the owners in videos. Takes a bit to get them going initially. But they seem solid once warmed up. So yours is only a single cylinder. Do they make twin diesels? I was watching a video of a 1982 Ford 1100 with a tiny little 0.7 liter water cooled 2 cylinder diesel in it, yielding about 13hp... THAT would be a cool little engine to slap on a 312-8.... IF a place for the radiator could be safely made and the PTO could be matched up to the WH drive pulley some how...

Tractor Data of the Ford 1100

http://www.tractordata.com/farm-tractors/000/2/4/245-ford-1100.html

Edited by Mastiffman

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21 minutes ago, emdmat1981 said:

Thanks to all for their thoughts and perspectives as there is not a whole lot of info out there on the 523 diesel engines.  

 

I was really confused about the DM950D engine at first and almost didn't go through with the purchase from the PO since I thought the engine had been replaced. 

 

I guess in the end those with an already rare 523Dxi tractor may have an even "rarer" 27hp variety if they have the DM950D (with another 12% more HP and 10% more torque over a DM850D). :-) 

 

Perhaps the reason we got the DM950D initially over the DM850D was just due to availability of the engine thru Briggs / Daihatsu.   I'm thinking we may never know for sure.

 

Anyway ... a couple more questions:

 

1) does anyone have estimates or insight into the number of units produced by model number?   Would be interested to see the number of Dxi's (and other models in the Xi series) produced.

 

2) what would you say is the average life expectancy of a Briggs / Daihatsu Diesel?   Would have to assume the unit was properly maintained, no overheat conditions, "modified" oil fill process followed, etc 

 

3) any other pain points or things to watch out for with the Diesels?

 

Thanks Again.

 

 

I too am curious about production numbers. The diesel is probably the rarest of the five models due to the original selling price.

 

Well, I have twice the hours on mine as opposed to yours. :)  There is a used DM850D for sale on eBay right now with 1,530 hours! I'm sure that it isn't like the GM Oldsmobile diesel of the 1970s. The fuel pump appears to be one of the more expensive parts to replace.

 

Drain the fuel-water filter every time you use it - and never run it out of fuel.. I found a larger capacity WIX/NAPA oil filter to help add a few more ounces of oil, and added a magnetic drain plug. Find a good diesel fuel additive to use and buy fuel where they turnover their stock regularly. When mowing in the summer, it does collect quite a bit of grass chaff on the screens and screen in front of the radiator. Keep them clean. Otherwise, just the usual 5xi maintenance. 

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The larger DM950 doesn't necessarily have more horsepower. On a diesel, power is largely a product of the specific fuel rate delivered by the injection pump and can be set wherever the manufacturer wants within limits. The DM850 may not have the volumetric airflow to go to 27hp, but there is no reason that the DM950 could not be set down to a 23hp setting. Those engines came with quite a few hp ratings to suit the different applications that they were installed. I'm guessing that the DM950 was first used because of availability, then was later changed to the DM850 because they only needed the smaller engine to make 23hp. Ratings are often just that. I replaced a similar turbo engine in scag z-turn. Briggs/Diahatsu rated it with several ratings between 34-36 hp, but scag rated it at 31hp. Neither was correct because the fuel pump had been turned up. A 72 in deck was no problem at 7-8 mph.

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8DCCDE16-90A0-4D02-B42B-553B35DB30B7.jpeg.fc55afc5f01ade51163539348f56e4f0.jpeg

 

C519DF1C-743D-42D0-A5F4-C0A2B937DFAF.jpeg.58608cc3d56f355fa8353a378babcab4.jpegI know this is an older thread but rather than start a new one, I’ll build on this one. Has anyone come across reliable production numbers on these machines?  You would certainly think that Toro would have the total production numbers somewhere on these.  Do any of the forum members currently work for Toro?  We could send you on a mission:ph34r::ph34r::ph34r: to find out how many of the Dxi models were produced.  

C4A5E618-7A0D-4552-9617-A28796EFD73A.jpeg.fb6196885c48db061fb622204ae32894.jpeg

My wife’s is apparently an earlier version with the DM950D in it.  It now has just over 1162 hours on the meter and still seems to be a strong runner.  I think I have a glow plug that is getting weak but I’ll be looking into that later this week.  

 

6051A18B-146A-4A7C-9AA6-C052FD0C8A90.jpeg.f14daf46f49e387ec0360da9b2ccf03f.jpeg

I know that it uses a little more fuel than my Kubota powered (640B) Cub while doing similar work but still quite a bit less than any of my gas tractors. Both have 60” decks, hydraulic lift, power steering.  The Cub is rated at 17 and the Dxi at the afformentioned 27hp.  The Horse starts way better in the cold than the Cub does even with new upgraded glow plugs. We’ve owned the Dxi for about 2 and a half years now and I really like it.  Hopefully we can keep it for years to come.  When it comes to serious work load at my property, these are my two go to tractors...

 

9895B9B6-7C49-4598-9410-CB72C5BCFF79.jpeg.3873b3fff916e6b46c669da8d7f862ea.jpeg

Oh yea, don’t buy one of these unless you have a big space to put it, they aren’t small machines!

Edited by PeacemakerJack
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The dxi model 73551 and 73550 was made in 1998 only. 

The dxi model 73552 was made in 1999 and 2000 only and model 73590 was made in 1999 thru 2004.  

After 1998 the engine was still Briggs & Stratton but became model # 522447-0106-E2.

A friend of mine that I worked with at Toro is retiring and I'm going down to visit him on his last day. I will see if I can find an answer to production numbers while I'm there.

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Thank you for clearing that up.  I’m looking forward to any production numbers that you may be able to obtain for the xi series—especially the Dxi in my case.  It is so cool that you worked on the development of these tractors.  Thank you for the valuable information...:bow-blue:

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You are welcome.

It will be fun to see some of the people I used to work with and the new product being developed. It's hard to believe its been16 years since I left Toro.

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Time fly’s doesn’t it!  Hard to imagine that my wife’s 523D will be “officially” an antique in a couple of months!  I check her tag last night and it read model 73550 serial number 8900570. That means @shallowwatersailor That your tractor was produced only 14 units before ours!  

 

Until I read this thread, I didn’t realize that the 950 was factory installed in the 523D.  I just assumed that someone had transplanted that engine in there. @Dennys502 do you know if that engine was released in the tractors with its full power rating or did the “detune” the pump to put it closer to the 23hp rating?  

78FE0A27-13EF-4180-9DAB-4E169A8CA08E.jpeg.2da296b5d46303fd57c114e66bea0616.jpeg

 

I believe that ours was purchased new by a local TV and Appliance store and owned by them for a little over a decade.  They likely used it primarily for snow removal as my snow blower seems to have quite a bit more use than my mower deck.  The next owner was a service repairman for a small engine shop and he used it for double duty like we do.  He said that he really liked it but needed to move into a compact tractor and therefore gave me an opportunity to own a “rare find”! 

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The original specs for the build called for the DM700D which was rated at 19.5 hp. The only thing done to the engine was the rpm's were limited by the governor. If I remember that is where the 23hp came in. It's not so much the horsepower as it is the torque with these engines and the most torque was usually in the middle of the curve.

I can't insert an image of the torque chart but there is a pdf with a torque chart here              rodscontracts.com/docs/DieselEngine/vanguard_3lc-3.pdf                    Just copy and paste the URL and it will download the pdf

 

 

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Go here for service manuals

 

 

Edited by 19richie66
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12 hours ago, PeacemakerJack said:

Time fly’s doesn’t it!  Hard to imagine that my wife’s 523D will be “officially” an antique in a couple of months!  I check her tag last night and it read model 73550 serial number 8900570. That means @shallowwatersailor That your tractor was produced only 14 units before ours!  

 

Until I read this thread, I didn’t realize that the 950 was factory installed in the 523D.  I just assumed that someone had transplanted that engine in there. @Dennys502 do you know if that engine was released in the tractors with its full power rating or did the “detune” the pump to put it closer to the 23hp rating?  

78FE0A27-13EF-4180-9DAB-4E169A8CA08E.jpeg.2da296b5d46303fd57c114e66bea0616.jpeg

 

I believe that ours was purchased new by a local TV and Appliance store and owned by them for a little over a decade.  They likely used it primarily for snow removal as my snow blower seems to have quite a bit more use than my mower deck.  The next owner was a service repairman for a small engine shop and he used it for double duty like we do.  He said that he really liked it but needed to move into a compact tractor and therefore gave me an opportunity to own a “rare find”! 

 

Interesting on how yours is a bit younger than mine. :)  I just received a second Tiny Tach diesel tachometer for the 523Dxi. I had bought one for it two years ago but ended up installing it in my re-powered DC-105 to assist in breaking in the engine. That way I could monitor the rpm. I will check it against the chart.

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