Interesting facts about JD 2.9 3cyl...so how much power can I get????

kentuckydiesel

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I was doing valve adjustments on my '95 5200 yesterday when I started looking at how "beefy" the head/block appeared to be. I decided to go back and check the specs on rod journals, crank journals, wrist pins, bore/stroke...then compare them to my 7.3 Powerstroke which has been putting out about 350hp for the past 200,000mi...maxing out at 35psi with the stock turbo (now having 345,000mi) with no internal engine or turbo issues to date.

To my surprise, Like my 7.3, the Powertech 2.9 has forged rods. The crank journal, rod journal and wrist pin specs are within thousanths of the 7.3, the bore/stroke is just a slight bit over that of the 7.3, and the 2.9 has a 17.2:1 compression ratio, vs 17.5:1 on the powerstroke.

If I have reliably made 350hp (43.75hp per cylinder) for this long, why shouldn't I be able to turbo the 2.9 and be able to produce the same 43.75hp per cylinder, bringing it to 131.25hp? It is direct injected...though I might need a larger pump than the little Lucas-CAV pump which I already have turned up almost all the way (and it still only smokes grey on hard acceleration at lower RPMs)

Unfortunately I haven't been able to find the Int/Ext valve sizes on the 2.9, so I can't compare that, but surely it's close.

Thanks,
Phillip
 
3 cylinders + 4 stroke = 1 compression event every 240 degrees. Research, moment of inertia.
 
Just throw a little hx35 on it and see how it goes! Only one way to
find out.
 
3 cylinders + 4 stroke = 1 compression event every 240 degrees. Research, moment of inertia.

This is a good point, and I had thought about it...but wouldn't this come into play more in comparing a 7.3 litre 8cyl to a 7.3 litre 3cyl of the same HP? That, and the 3cyl not having quite the RPM potential.

What is it rated at originaly?

Original rating on my tractor was 45hp. The 5300 has the same engine/injection pump with different fuel settings making around 55hp. I estimate that mine is making 55-60hp with current injection pump settings.

Here are the injection pump model numbers:
5200 (45.6hp): Lucas/CAV DPA2-3239F200W
5300 (55.9hp): Lucas/CAV DPA2-3239F210W
5400 (turbocharged-68.4hp): Lucas/CAV DPA2-3239F220W
Deere Industrial (turbocharged-79hp) Stanadyne DB4327-5

On a side note, Deere put 1.378" diameter wrist pins on the naturally aspirated engines and 1.614" diameter wrist pins on the turbocharged models.
While some say that the N/A engines shouldn't be turbocharged due to "undersized" wrist pins...I have to believe the increased wrist pin size was only done because these engines are also sold for generator and marine applications where they will see constant load and RPMs.

Thoughts...Ideas???

Thanks,
Phillip
 
My personal thought, opinion and idea.

Thought...it's a little farm tractor so a few extra ponies could be cool, but more than 60-70 hp is probably not ideal considering the trans will probably start to suffer.
Opinion...the engine will likely die early at near triple the HP rating.
Idea...buy an old 4020 deere and hop it up, go have fun at the local tractor pulls!

I'm pretty sure that is a Yanmar engine, not a genuine Deere, however I could be wrong about that.
 
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My personal thought, opinion and idea.

Thought...it's a little farm tractor so a few extra ponies could be cool, but more than 60-70 hp is probably not ideal considering the trans will probably start to suffer.
Opinion...the engine will likely die early at near triple the HP rating.
Idea...buy an old 4020 deere and hop it up, go have fun at the local tractor pulls!

I'm pretty sure that is a Yanmar engine, not a genuine Deere, however I could be wrong about that.

I'm going with yanmar too. My deere has one.
 
I'm going with yanmar too. My deere has one.


Nope, this is a JOHN DEERE engine.

Powertech 3029...smallest engine Deere makes. No offense to those who have them, but I wouldn't have bought the tractor if it was a Yanmar engine. See below link:
Industrial Diesel Engines on Product Finder from John Deere


I also would have never would have purchased a little 45hp tractor, but this one is the same platform (transmission, axles, etc, etc) as the 5510 and 5520, both of which had 89hp. The only difference was the fact that they had the Powertech 4045 4cyl rather than the 3029 3cyl (along with a larger radiator, longer MFWD driveshaft, longer hood, and a slightly bigger fuel tank).

Breakage at a bit over 100hp should be a non-issue.

We used to have a 1970 4020 and I loved it. I would have bought another one, but my place is very hilly so I needed something lower to the ground with MFWD that I could widen like crazy to keep me from going wrong side up. Current tractor sits 8' 2" wide with 18.4-26 "rice and cane" rear tires. It will climb/push/pull just about anything even as it sits now.

-Phillip
 
Been clearing 20-30yrs of cedar growth...just pushing it down the hill with the bucket.

IMAGE_158.jpg


-Phillip
 
how many head bolts per cylinder? How does it compare to your 7.3?

7.3 has (17) 1/2" bolts per head (4.25 bolts per cyl)--torqued to 95 ft lbs

Deere 2.9 has (14) 1/2" head bolts (4.67 bolts per cyl)--torqued to 110 ft lbs

All said, with the number of head bolts at higher torque, the 2.9 ought to be able to hold more boost than the Powerstroke. The head is a heck of a heavily built piece.

Also, I found out that Deere has basically the same size exhaust valves as the Powerstroke (deere:1.69, Powerstroke:1.68), and it has LARGER intake valves (deere 1.85, powerstroke 1.68).

Hmm...

-Phillip
 
my 4 cyl JD motor is a bit higher compression than yours, and I was told to leave it alone and be happy, or mess with it and be ready to fix it. I have a 91 1070 for food plot work.
 
7.3 has (17) 1/2" bolts per head (4.25 bolts per cyl)--torqued to 95 ft lbs

Deere 2.9 has (14) 1/2" head bolts (4.67 bolts per cyl)--torqued to 110 ft lbs

All said, with the number of head bolts at higher torque, the 2.9 ought to be able to hold more boost than the Powerstroke. The head is a heck of a heavily built piece.

Also, I found out that Deere has basically the same size exhaust valves as the Powerstroke (deere:1.69, Powerstroke:1.68), and it has LARGER intake valves (deere 1.85, powerstroke 1.68).

Hmm...

-Phillip

I just did a quick google search for images of headgaskets and it looks like both use 6 per cylinder (some are shared between cylinders).

I say go for it...
 
my 4 cyl JD motor is a bit higher compression than yours, and I was told to leave it alone and be happy, or mess with it and be ready to fix it. I have a 91 1070 for food plot work.

Thats actually a Yanmar 4TN84 in your tractor. Should be a fair difference between the inherent strength of the 400lb yanmar 1.9 liter and the 700lb deere 2.9 litre engine. Top factory hp rating on the yanmar was about 43...top factory HP rating on the deere was around 79
 
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