More Horsepower, Same Cubic Inches?

[SkyPup]

Combustion in these Kubota's is limited by the fuel-air supply, specifically to meet current Tier 1 and future Tier II Federal emission levels for agricultural tractor engines. Generally, there is quite an excess of air even in a naturally aspirated diesel since it operates over such a large air-fuel ratio (1:10 to 1:100) depending on the load. An increase in fueling by 20% should be atainable before too much smoke and soot occur from overfueling. Long term operation under extremely heavy load (>4-5 minutes at a time) with increased fueling would also be something to watch as increasing the fueling will directly increase EGT with correspondingly higher piston, upper ring, and exhaust valve temps

Kubota has redesigned these diesel engines to incorporate their new TVCS (Three Vortex Combustion Chamber). The D-1503M engine in my 2004 Grand L-3130 also has their most recent TVCS-E series combustion chamber design to take advantage of the three vortex induction swirl configuration with a newly designed tapered injection throat to force more air into the specially concave recess on the new piston head to obtain better combustion efficency i.e. less emissions (soot, hydrocarbons, and carbon monoxide). This engine series also has new injection nozzles with smaller orifices to match this low emission combustion chamber design as well. Perhaps the larger injection nozzles from older engines in the model series would fit the bill?

The D-1503M engine series also has a new metal head gasket and different coolant passages to reduce the upper most piston ring operational temperature by >25 degress Centrigrade for cooler operation and longer life (also the piston is coated with molybdenum oxide to reduce friction considerably). This has helped to limit the high temperature flame front to contact with the piston recess area, reducing metal fatigue and stress on the entire combustion chamber.

I've contacted some professional FIE engineers in Europe to investigate the injectior and nozzles utilized by NipponDenso on this engine series and will see what they can find out about upgrading these nozzles to a higher fueling event during the proper crank angle injection window. They said they would custom extrude hone some nozzles for me to experiment with, they would require me to send them one of my current nozzles to examine using an electron microscope to record the nozzles exact orifice diameter as well as their geometric orientation in the combustion chamber.

 

[SkyPup]

A couple of folks have contacted me about upgrading their injector nozzles on their Grand L Series tractors so I'll let you know when I hear back from the engineers about when to expect the test design models.

Don't forget, a diesel engine has the same air supply all the time due to a total lack of any throttle valve, the only way to increase power is to inject more fuel into the combustion chamber after the valves are all closed inside the limited crank angle window taking into account the ignition delay of approx 1ms.

 

[SkyPup]

Some progress has been made! /forums/images/graemlins/wink.gif

The injector nozzle part number for my Kubota Grand L-3130 D-1503 engine model is #16082-53610 and it is a super simple low pressure (40 Mpa or about 6,000 psi, one MegaPascal = 150 psi) IDI pintle nozzle design with only one hole of yet to be determined diameter.

This makes it much less of a hassle since it does not have multiple holes (making the precise spatial geometric orientation a mute point) and NipponDenso makes an entire series of screw-on single hole pintle injector nozzles in 5 micron increments, i.e. a 150 micron, 155 micron, 160 micron, 165 micron, etc. each nozzle producing more hp and torque as the opening is enlarged.

Apparently the Yanmar engines on the John Deere's also use a similar FIE.

 

[SkyPup]

Attached is a closeup of the primitive low pressure IDI Nippon Denso (Diesel-Kiki) nozzle design.

 

[JimMorrissey]

I was thinking that JD just boosted the pressure on the turbo a bit for the HP differences....along with increase in fuel.

 

[v8dave]

I love TBN. There are no limits to the good stuff here. We'll have to get Muhammed to open another topic area for us speed freaks--TBN Tractor Tuners.

More Power! Tim the tool man would love it.

 

[sparrowhawk]

Commonly, diesels have approximately 5 degress retarded timing to account for a decrease in NOx emissions these days.

However, all you have to do is increase the injection nozzles orifices diameter a couple of microns to add mucho horsepower and gobs of torque, either that or increase the crank injection window a couple of degrees to prolong the injection event.

Installing a new injection nozzle onto the injector with larger nozzle orifices is a super simple ten minute job and works excellent. There is no need to tweak the fuel injection pump or add more injection pressure with either of these methods.

Problem is they both increase the EGT under load, smoke alot more, and violate emissions laws, but the power output increase is spectacular. /forums/images/graemlins/wink.gif

just remember that if you just add a new nozzle tip to the injector body, you really should have this done by someone that can pop test the injector afterwards, else they may not pop at the same pressures and this could cause a bit of lumpiness..

 

[TracTrac]

It is really quite simple, there are only a couple of standard diesel fuel injector sizes (not sure if Kubtoa uses DENSO FIE system or their own design (I kind of doubt Kubota designs their own FIE though so most likely it is DENSO FIE but probably it is a Variable Closed Orifice P type pintle multi sac hole nozzle design of standard dimensions).

All you have to do is remove the entire OEM injector, screw off the OEM nozzle and replace with a standard nozzle having the same number of nozzle holes but larger nozzle orifices for more fueling per each injection event. These replacement nozzles could be sourced from other similar 'Bota engines with larger displacement and similar piston bowl design to keep the injection orifice geometry similar i.e. same number of holes in the same geometrical orientation to avoid hot spots in the combustion chamber). The IDI design of the current smaller 'Bota engines below 50hp only utilizes about a 3,000+ psi injection pump, whilst the newer larger Kubota diesels use direct injection at much higher pressures >10,000psi, although this technique will easily work with either design. There is no need to get entirely new injectors or mess with anything else, just change out the nozzle to new larger ones, it is extremely simple and only takes a few minutes.

On my two Volkswagen 1.9 liter TDIs with the Bosch VE37 rotary distributor injection pump (20,000 psi direct injection) and the Bosch VCO P type sac hole 17mm injectors, I just changed out the four injector nozzles in about 15 minutes. The OEM Bosch nozzle orifices were 0.158 microns which I replaced with new 0.205 micron nozzles. This increased the fueling event considerably with no increase in fuel pump pressure. Result was the OEM 90HP and 155 pounds of torque was increased to 140HP and 240 pounds of torque, this kind of power boost is very easy to detect with the butt dyno as well. Did this about four years ago after ordering the new larger injection nozzles from Italy and both TDIs are still running extremely strong with little decrease in fuel mileage (from 48mpg down to 42).

Here is where I purchased the larger replacement nozzles for less than $100:

http://www.bosio-estfb.it/pag3eng.htm

As you can see, you can get new nozzles for virtually any diesel engine if you know the engine design details well enough. I'll have to pull an injector on my L-3130 and take some measurements to see about ordering a replacement larger nozzle to boost the horsepower and torque sometime. /forums/images/graemlins/wink.gif

.
It's been 6 years since this thread was started. Did anybody burn a piston from increasing their fuel?
At what temperature does aluminum melt?

 

[sparrowhawk]

.
It's been 6 years since this thread was started. Did anybody burn a piston from increasing their fuel?
At what temperature does aluminum melt?

aluminum melts around 1200 or so. with more fuel, you don't melt things. its when you lean things out that you have an issue!

I had a VW TDI that made 90hp stock that I tuned out over 170hp/337 lb/ft with computer, turbo, nozzles and larger fuel pump... nothing melted other than my wallet when I started snapping cv joints and cooking clutches...

 

[TracTrac]

aluminum melts around 1200 or so. with more fuel, you don't melt things. its when you lean things out that you have an issue!

I had a VW TDI that made 90hp stock that I tuned out over 170hp/337 lb/ft with computer, turbo, nozzles and larger fuel pump... nothing melted other than my wallet when I started snapping cv joints and cooking clutches...

Sparrowhawk, The 14.7 stoichiometric air/fuel ratio for gas engines does not apply to diesels. When a diesel idles it is running so lean that it actually runs cool. In fact so cool that it can leave unburned fuel inside the combustion chamber. Under load a turbo not only adds more air for power but it keeps things lean enough to prevent pistons from burning. A diesel runs on the lean side of the air/fuel curve when tuned properly.