I Still Hate My Tractor

[milkman636]

Fred, This might help some. As you are aware, Bobcat used the V2003T (56 HP) in some models but in same frame without Turbo they used the V2203 (46 HP). So I can't be positive of the specs on V2003 aspirated engine. Comparing specs of V2003T vs V2203 almost everything matches (injection timing, compression, valve lash, etc.) except valve timing.

Compression test in Bobcat specs. fall in line with your findings:

View attachment 349270

Here is valve timing the V2003T;
View attachment 349271

Here is valve timing on the V2203;
View attachment 349272

Injection timing on both is 18 BTDC.

A problem I have run across occasionally on Kubota engines with power complaints was governor spring setting. Spring were set so engine RPM had to drop well below the normal 150 - 200 RPM decrease before governor would release the fuel rack. Caused the engine to lug down too far that it could begin to recover, just a thought to check.
Turbo will definitely add more power but might as well check everything while you are at it.

Great input here. Hopefully this thread has taken a turn for the better and will quiet down and get easier to filter through and learn a little. I am glad Fred is sharing his trials and there are members who can share some good insight to help him in his quest. So how does one test a governor spring setting?

 

[milkman636]

Yes that!!!

Probably zero chance of video until it's all back together and running. Even then I'm guessing Fred isn't a guy that videos himself very often.

 

[The Fred]

Thanks for posting real help. I will go back and recheck installed cam intake centerline because I may have one of those specs wrong, bad info in = bad info out. Gotta stop today too much to do. I want to monitor boost pressure, ex temp before turbo, intake temp, oil engine oil temp. Any ideas on a panel or one stop shop for a setup? I see BD Diesel has a similar setup. I don't want gauges because once I realize everything is ok I'll take the panel out anyhow.
Lots to do, so far the only hackjob is the A/C compressor mount. I bored a hole (milling machine with holesaw) for the air cleaner pipe. Also will need to add an oil cooler most likely behind the oil filter but then I will have to hack the right side panel to extend the oil filter through the side.
Not happy about that. Any ideas?

Again, thanks for real help. I searched high and low for Bobcat service info but Google came up dry. To attain 20 BTDC looks like I will need to subtract a substantial amount from the fuel rack shim.

Fred

 

[Bluegill2]

Dang Fred, you just might pull this off!

 

[aczlan]

Also will need to add an oil cooler most likely behind the oil filter but then I will have to hack the right side panel to extend the oil filter through the side.
Not happy about that. Any ideas?

Remote oil filter mount with an inline oil cooler? Something like: http://www.summitracing.com/parts/trd-1113/overview/ perhaps?

Aaron Z

 

[TexasBoy]

,,,,but I'm from a family of mechanics and seen enough blown engines, transmissions etc. to know sometimes even experts can wander down the wrong road.

Ive been racing on the dirt track for over 30 years and we have fab'd every imaginable engine mod conceivable looking for more power, and we've grenaded plenty of mills in the process. Sometimes it works, sometimes you end up with a big piece of cast iron yard art.

 

[TripleR]

Ive been racing on the dirt track for over 30 years and we have fab'd every imaginable engine mod conceivable looking for more power, and we've grenaded plenty of mills in the process. Sometimes it works, sometimes you end up with a big piece of cast iron yard art.

The mechanical gene skipped right over me though I know the basics; when you get very far off into engine modifications, I am lost, so many things that sound good can go wrong if you don't account for it elsewhere. I admire those with such mechanical skills as it oftn seems as much an art as a science. My uncle grew up in grandpa's garage and got a degree in mechanical engineering and could keep a car running forever, but couldn't get any more power out of one than it had when it rolled off the assembly line.

 

[Chilly807]

I wouldn't do too much with timing just yet, if it's correct I'd wait and see what it acts like. I try to change one thing at a time. 18 degrees is probably pretty good for a turbo engine, if you can find out what the specs are for a similar size/rpm Kubota engine with a stock turbo that would be a good reference point. Someone that has a 5740 or 5140 can look at the valve cover, it's usually listed there.

Good point about intake temp, much over 70 degrees C and you can melt piston crowns. Do the turbo Kubotas have intercoolers?

Sean

 

[sd455dan]

I'll admit I like everything I own to work perfectly and strive to make it like that. I should have tried before buying but didn't. I jumped on this because there were no more larger 40 series tractors around, they are gone. Took 2 hours this morning and set up a degree wheel to the front pulley becuae the loader frame covers the timing port in the clutch housing. Sidenote: I would bet real money that no dealers check the timing and tear thse things apart. What a PITA.

Anyway here's my notes from this morning:
12-7-2013

Compression (cranking) 400 psi. all 4 cylinders (factory spec 520-580). WSM discrepancy?
Wrong manual for the tractor? WTFKnows
Checked Snap-On gauge against Nitrogen tank regulator gauge and both match closely.
Fuel Timing check #1 cylinder 17 degrees BTDC.
Leakdown test : #1 cyl. - 2%, #3 cyl.-3%, #4 cyl.-6%, #2 cyl.- 3%. NO leakage through valves.
Valve adjustment varied from .003"(#1 cylinder) to .007" (most others).
Adjusted all valves to .008".
Checked installed camshaft position, with overlap split degree wheel right on TDC #1 cylinder.
All valves checked at .050" lift.
Intake valve opens @13 degrees ATDC. Closes @170 degrees BTDC.
Exhaust valve opens @147 ATDC, Closes at 19 BTDC.
Intake and exhaust valve lift is .305".

View attachment 349026View attachment 349030View attachment 349031

Any other things I could check? Fresh out of ideas. Other than the timing being of MAYBE 2 degrees retarded and the tight valve adjustment I see nothing wrong with this. Tractor has 50 odd hours running time. Air filter minder hasn't moved. It just acts like more air is needed.

Thanks, Fred

Fred It still looks to me as if that cam MAY be installed in a retarded position.

When I read your post saying intake opens @ 13* ATDC- I read that as 13* AFTER Top Dead Center to make things worse Some Asian and European manufacturers use nomenclature that defines ATDC as in ADVANCE of Top Dead Center-
Either way all the specs I have seen where the words are written out have The Intake valve opening BEFORE or in ADVANCE of the piston reaching top dead center,

Which from what you posted leaves my wondering IF the intake is IN Fact opening IN ADVANCE of Top Dead Center - THEN the Camshaft is Installed in the correct position

BUT If it is opening AFTER or BEHIND Top Dead Center then there is a problem and the cams centerline is in fact installed in a very Retarded position- and would result in low cranking compression and a very poor running engine, unless it is running near wide open- because retarding cam installed position (results in shifting the power band higher in the REV range)
With the way you have described how this new Kubota runs I am actually hoping this engine was built with the cam being installed in the wrong position Because it would at least solve some of the problems you have reported .
I still think a 120? Cubic inch engine is very small for the rated horsepower-

Hope to hear about whether the cam is in the correct installed position - or not

and how all this pans out Including a TURBO installation :thumbsup:

 

[Chilly807]

All the diesels I work on are turbocharged, some in conjunction with a mechanical supercharger, and all are also intercooled to keep the intake air to a safe temperature. Aluminum pistons start getting soft above 1200 degrees F exhaust temps, some of the stuff we have has composite pistons with aluminum skirts and cast iron crowns for that reason, not to mention oil cooling jets aimed at the bottom of the piston crowns to keep them from melting.
6 psi boost is very mild, and may not hurt anything.
Some heavy medium to high speed marine diesels have the waste gate set at 45 psi, although boost levels around 20 psi are more common.

Sean