Turbocharging a Jinma 254 Build (Y385)

[California]

A turbo off of the 3 cyl would be to small as it is 1 liter.

You sure? I've read over-sizing a turbo is a common problem, and the turbo (for a tractor) should come off an application of no greater displacement. The article I saw used the turbo off a 1-liter 70 horsepower Smart Car for a 1-liter tractor, about the same cc as your Jinma.

Remember for a tractor what you need is torque midrange more than anything so you don't bog down when the going gets tough. Not peak hp like a car. A smaller turbo will reach target pressure at lower rpm.

Was that second turbo spec'ed for a car? What displacement was it specified for? If the tractor engine is turning 1/3 the rpm of the specified car engine then its only pumping 1/3 the volume of air compared to the car.

 

[ElectroTechnics]

Was that second turbo spec'ed for a car? What displacement was it specified for? If the tractor engine is turning 1/3 the rpm of the specified car engine then its only pumping 1/3 the volume of air compared to the car.

We ordered it off ebay: EMUSA Turbo Charger GT15 T15 Motorcycle ATV Bike Small Engine, 2-4 Cyln
0.35 A/R
1.75" Air Inlet
1.5" Air Outlet
Works for Small Engine, 2-4 Cylinder

It came in last week, not slop in the shaft, spins freely. We will be installing it this coming weekend. This is the same turbo used by a guy on youtube on the same tractor. We have a lot of instrumentation on the tractor right now to see how this new turbo works.
Exhaust temp
Water temp
Boost gauge
Turbo oil pressure gauge
Tractor oil pressure gauge
2 styles of tachometer (tooth pickup and mag pickup: we modified the front flywheel with a magnet)

We also plan to measure the compressed air inlet temp to compute charge density.

Another change to the OEM tractor will be replacing the OEM thermostat with a:
Murray Temperature Control Ultra - Ultrastat Thermostat - Larger than OEM opening allowing for up to 50% increase in coolant flow. Added bypass valve allows a small amount of coolant to circulate before fully opening

 

[Bob Rooks]

Remember that too much coolant flow will not allow coolant time in residence within the radiator to cool. Have you calculated your BTU absorption /dissapation?

 

[ElectroTechnics]

Remember that too much coolant flow will not allow coolant time in residence within the radiator to cool. Have you calculated your BTU absorption /dissapation?

That will be quite challenging to measure but we plan to when both of us are back working on it.
Right now with both the electric fan and mechanical fan we cannot get it over 176F unless cutting at least 2 minutes of heavy brush (outside temp 97F, humidity 80%), even then it only hits 180 - 181F

The plan was to disable one of the two fans, hit 180F after mowing briefly then time how long it takes at a set engine speed to drop the temperature X degree's under no load
repeat with: 2 fans, larger flow thermostat, etc.. then calculate how many BTU's we can dissipate with each setup.

One of us thinks we can run with only one fan and the larger flow thermostat... another thinks both fans are needed with an arduino monitoring the thermal load and ready to kick in the electric.
A science experiment if you will to determine our optimum setup :cool2:

 

[Bob Rooks]

Is that the same as saying you are monitoring Δ-T's? The difference between radiator inlet temp. and coolant pump inlet temp. This should not vary more than 12° to 15° F to reduce thermal shocking.

 

[ElectroTechnics]

You sure? I've read over-sizing a turbo is a common problem, and the turbo (for a tractor) should come off an application of no greater displacement. The article I saw used the turbo off a 1-liter 70 horsepower Smart Car for a 1-liter tractor, about the same cc as your Jinma.

According to an online engine CFM calculator a turbocharger 1.0l gas engine at 4500 RPM (max a 1.0 ecoboost can spin before the turbo starts to run out of breath) consumes 159 CFM of air. Whereas a 1.5l turbo diesel engine at only 2300RPM would consume 183CFM

So the turbo from a 1.0 ecoboost engine would be undersized. I know this is not accounting for pounds of air consumption, but we have already ordered the turbo and it should be a good match.

 

[California]

Your numbers sound good. I didn't know the Jinma was that much displacement.

 

[sd455dan]

Any updates on the new turbo -have you installed /tested it yet ??

 

[ElectroTechnics]

Any updates on the new turbo -have you installed /tested it yet ??

We will post more detail later, but I can give an overview of what we accomplished so far.

The GT15 turbo clone is installed. However, we are only getting 3 PSI boost max, typically it is closer to 2.5 PSI boost. This is from an oil-filled pressure sensor off the intake manifold (0-15 psi, after the turbo). The wastegate never activates, meaning we never hit 4 PSI

In terms of performance I brush-hogged the same deep grass, this time in 3rd gear without any drop in engine RPM. I could see the boost pressure rise up to 2.5PSI when I entered the deeper brush, and instead of having to shift down to 2nd gear I could stay in 3rd the entire time.

We have an engine exhaust temperature probe in the exhaust manifold prior to the turbo.
In the heaviest mowing I saw 500F, but typically it was around 400-420F with 375F in lighter grass.

The temperature was 180F max after 45 minutes of brush-hogging. We discovered the OEM thermostat was "stuck", after un-sticking it we measured 170-180F while mowing.
The high-flow thermostat did not allow the engine to warm up.... it stayed at 147F max with that thermostat in. Though we only rev'ed it up and didn't drive or mow with it while testing that high-flow thermostat.

We are still thinking about why our max boost is 3 PSI
- one small leak in the pressure sensor hose was uncovered and fixed (minor improvement), other pressure leaks?
- fuel adjustments - ****** fuel timing? Typically as boost pressure rises on a diesel you ****** up to 24 degrees before TDC
- other?

We will update with video's and pictures later, it was a busy weekend getting it all plumbed in and ready for testing.

 

[petar]

You don't need more boost, EGT indicates that you have far more air than you need.
EGT's that low are an indication that you need more fuel. For factory turbodiesel engine max sustained EGT's are 650 *C (1200 F), 800 *C (1400 *F).
Also on a diesel without fuel you simply can't make boost.
So you need to turn up the full load fuel screw on the injection pump governor until you hit 1000 *F ( reduced from 1200 just to be safe since the engine was never designed to cope with increased thermal load) under sustained heavy load.
DO NOT ****** TIMING!! It can only worsen the perfomance UNLESS you were way over advanced in the first place but you would clearly hear the engine knock a lot more.
Once you increase fuel you'll notice a drastic improvement in perfomance without more boost. Then if you wan't more perfomance turn up the boost and fuel more.