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

 

[k0ua]

I am not going to comment one way or another about Freds modifications, as I don't have the experience to make any meaningful contribution. but something he said did make me do a test today as I was out pushing snow.

Fred mentioned that he saw a tremendous drop in RPM going up a hill when he raised or sent his hydraulic pump into relief.

So I went up the steepest hill I have, and let me tell you it is plenty steep in MED with my 3 speed hydrostat and tried it at various RPM's and this is what I got. All of these tests are with the hydro pedal mashed to the floor.

At about 2400 when I raised the loader the tach would drop about 50 rpm and regain 2400 almost instantly (govenor kick in I guess). When I deadheaded the pump by pulling into curl all the way. it would drop about 100 and stay there.

At 1700 when I would raise the loader the tach would drop about 50 to 75 and regain 1700 When deadheaded the pump it would drop about 175 and try to regain some back. I did not hold it very long, as I don't like to actually deadhead a pump.

Overall the drops in RPM were very minimal and except for sound note of the engine you could hardly tell it.

My 38 gross horsepower Kioti is sure not the same engine, but the tractor with loaded tires, my 850 lbs of ballast on the back, and loader is just under 6500 I believe. This may or may not be pretty close to Freds Tractor, but I am thinking pretty close. I am no mechanic either, but I am still having trouble understanding such a big drop on Freds machine unless the governor is not working right. I know that hydrostatic transmission, have much greater losses than a gear machine but guys they are not that much. I wish I could help and offer some assistance, but unfortunately I cannot. Carry on, good luck.

James K0UA

 

[ovrszd]

I am not going to comment one way or another about Freds modifications, as I don't have the experience to make any meaningful contribution. but something he said did make me do a test today as I was out pushing snow.

Fred mentioned that he saw a tremendous drop in RPM going up a hill when he raised or sent his hydraulic pump into relief.

So I went up the steepest hill I have, and let me tell you it is plenty steep in MED with my 3 speed hydrostat and tried it at various RPM's and this is what I got. All of these tests are with the hydro pedal mashed to the floor.

At about 2400 when I raised the loader the tach would drop about 50 rpm and regain 2400 almost instantly (govenor kick in I guess). When I deadheaded the pump by pulling into curl all the way. it would drop about 100 and stay there.

At 1700 when I would raise the loader the tach would drop about 50 to 75 and regain 1700 When deadheaded the pump it would drop about 175 and try to regain some back. I did not hold it very long, as I don't like to actually deadhead a pump.

Overall the drops in RPM were very minimal and except for sound note of the engine you could hardly tell it.

My 38 gross horsepower Kioti is sure not the same engine, but the tractor with loaded tires, my 850 lbs of ballast on the back, and loader is just under 6500 I believe. This may or may not be pretty close to Freds Tractor, but I am thinking pretty close. I am no mechanic either, but I am still having trouble understanding such a big drop on Freds machine unless the governor is not working right. I know that hydrostatic transmission, have much greater losses than a gear machine but guys they are not that much. I wish I could help and offer some assistance, but unfortunately I cannot. Carry on, good luck.

James K0UA

Good test James. Wish you had tried it at something closer to 1/2 throttle rather than 3/4 throttle. Maybe another test at 1500, then 1200, then 1000. I'll run a test on my Brother's L3240 in a couple days and report findings.

 

[k0ua]

Good test James. Wish you had tried it at something closer to 1/2 throttle rather than 3/4 throttle. Maybe another test at 1500, then 1200, then 1000. I'll run a test on my Brother's L3240 in a couple days and report findings.

I am sure it will drop more with lower throttle settings. but Heck I would never go up that hill at less than 1700, especially in Medium range.. Now if I was in HI range, it might of stalled.

 

[Chilly807]

A mechanical governor will drop rpm slightly as the engine is loaded, and will maintain that new rpm setting within the capability of the engine. This is not a result of an overload condition, simply an inherent trait of a mechanical governor. To the best of my knowledge, there's no way around that (this is what I do for a living, btw). In most cases it's not a problem anyway, and in the situations where you need more accurate speed control there are hydraulic or electronic governors that can be adjusted for zero speed droop.
An overload condition is quite different, as the speed drop is not controlled, and the engine will actually stall if the excess load is not removed or reduced. With an overloaded engine, the fuel rack goes to it's maximum position and stays there until load is reduced, and there's usually black exhaust smoke, which is also present in cases of air starvation.
When Fred increased the fuel setting, the engine couldn't burn the extra fuel efficiently, so it dumped it out the exhaust as black smoke, essentially unburnt fuel.

Sean

 

[buickanddeere]

I'm concerned that our resident OCD tinkerer has tweaked so many items on the tractor that finding a baseline to measure from will be difficult.
As previously stated if the engine really is down on power. It's either due to cam timing, injection timing or some strange phantom assembly error. And/or a heavy parasitic load from a hydraulic pump fighting a relief valve.
iirc the typical diesel opens the intake valve somewhere between 15 degrees prior to TDC to TDC. If measuring modern cam timing at 50 thou lift then of course those degrees change.
Any access to a thermal gun to check exhaust temps on all cylinders? This engine could have a cylinder riding along doing nothing?

 

[sd455dan]

Fred, This might help some.
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.


Turbo will definitely add more power but might as well check everything while you are at it.

Thanks for posting this information , it is helpful looks like they added a small amount of duration on the turbo cam...

 

[the old grind]

A governor trying to keep rpm up would add fuel & should make more smoke doing it, no? (.. clean burning at most speeds when unloaded? ..)

Fred's intake opening event should align with whether factory specs consider cam rotation before the .050" he timed at. Show me 30^ of 'ramp' (take up lash) and/or to get that .050", and Fred's '15^ after' could be someone's '15^ before'. (Cam is ok if so?) Gotta be sure where lobe center is and where it's best measured in crankshaft degrees.

I've seen oil 'coolers' that were just long lines out into the airstream somewhere and back vs finned or thru a core. See the boneyard for odd shaped/sized coolers/cores with various inlet/outlet openings. Inter-cooler volume can add to lag (think Kubo robo-throttle) so he'd want to keep inlet air temps down as compactly as efficiently. IMO it'd be great to have that.

Fred, I was just explaining old-school 'doodlebug' to a young friend. With cab on & hood off the look would be there for ya during all the development/test work, .. and alterations. Would put any bodywork on no matter what/where add-ons do for now. (Didn't really think you'd start choppin' just yet. ) 'Remoting' can add to plumbing but also ease servicing. Can you get going with a cheapo point & shoot digital temp gauge, like if you're rtr & still shopping for a better monitoring setup? (don't know which happens first ..)

 

[milkman636]

Thanks for posting this information , it is helpful looks like they added a small amount of duration on the turbo cam...

I was thinking a new camshaft might be required myself.

 

[crazyal]

Look forward to seeing the turbo in operation once it's complete. I think it's a cool mod to do. There's no question you haven't been happy with your tractor, maybe this will change that. Maybe along the way you'll solve what ever issues that may have been causing a loss of power.

I do have some questions about your Meteor though. We haven't had much snow so you shouldn't of experienced any power loss. Were you loosing power or was it more a case of it just wouldn't throw snow. If it just wasn't throwing snow then you may have an impeller clearance issue. I almost never run at more than 2000ish with my blower. Being a front mount with a mid PTO I should have less HP going to it.

 

[Chilly807]

Thanks for posting this information , it is helpful looks like they added a small amount of duration on the turbo cam...

It's typical to do that to promote scavenging of the cylinders, since the intake manifold is under pressure any time the engine is loaded. Once the intake opens, air under pressure rushes in and carries spent gases out the open exhaust valve until it closes, after that the cylinder is pressurised until the intake closes.

Sean