turbocharged bx2200

[Anonymous Poster]

Rex says ...
>On some of the subjects I have to agree, for example when someone braught up the subject of increasing the output on their hydraulic pump, you simply can't pull higher numbers out of a pump if their is not an ample supply of power to run it.

Obviously true, but let's face it - the same engine HP spec at lower RPM and torque rating as the BX2200 (5gpm pump) operates a 7.0gmp pump in a larger B series. No one was suggestion a perpetual motion machine.

>Now when it comes to you question of turbocharging a small engine, I have to agree there is some merit.

Whoa there - using a larger capacity pump is dangerous and silly because of the forces involved and somehow turbocharging an engine doesn't place greater forces on the mechanics and "has merit". Go back and look at failure modes on turbo engines - Nissan had a spate of them on a small 4cyl engine circa 1985. The 1700cc non-turbo-engine was underbored to 1550cc or similar on the turbo vesion and it still blew the heads apart with enough regularity to cause a major recall. Nissan folks aren't exactly amateurs at engine design either.

You can certainly turbocharge your tractor, but you are creating greater stresses in the combustion chamber and all through the drive train. Maybe less lethal than a blown hydraulic line, but certainly more costly.

-Stephen

 

[JATO_RaT]

Todd, the fuel is the only way you control RPM on a diesel, short of increasing/decreasing the load. When you increase the oxygen or more accurately, air, you are increasing the combustion effieciency. The air delivery is inherent in the design and is not something you can change in a conventional diesel without modifying it. A normally aspirated diesel can receive a more free flowing intake air via a larger air cleaner and larger exhaust. An intercooler can provide more dense air since cooler air is more dense. To further improve on that, a pressurized air system such as a turbocharger can be added which helps by putting a "head pressure" on the air at the intake valve. A turbo will restrict the free flow of exhaust, but it also is used in conjunction with larger exhausting manifolds and exhaust systems. While it may be impractical to put a turbo on a tractor engine such as the one in this thread, that may have more to do with the lack of folks who would even want to and therefore not practical for any manufactuerer to even consider it. There are turbocharged small diesels out there though. It would however cost me about $2500 to add a Banks turbo system to my 7.3L diesel, but the cost to increase displacement, probably far greater then that as I would probably be buying a new engine (I have yet to see big bore kits for the Navistar 7.3) and would probably mean a new drive train. Turbos have been around for decades, the engineering, tolerances, oils, bearings we build today keep those toasty high reving turbos going for hundreds of thousands of miles. I still conted that the first diesel was designed to be turbo charged. I made the comment about the diesel and the fuel/air mixture ratio which can be as high as 100:1 but more commonly 80:1 at idle all the way down to about 33:1 at full throttle. The air which is being delivered in high volumes at high RPMs is actually less because it is the fuel that is being increased. A turbocharged diesel aids in the high RPMs in particular not only because it is spinning faster which understandably moves more air, but by putting pressure on the air intake you greatly add to the cylinders ability to fill more completely with the oxidizer, which at high RPM's has very little time. Add to much fuel for a load and check your pyrometer (exhaust gas temp meter), anything over approx. 1200 degrees and its time to consider backing off. Now theres a new thread to liven up TBN, "Exhaust temp. meters, should we have them on our compact tractors" Rat...

 

[RobS]

Rat and Todd, interesting thread /w3tcompact/icons/smile.gif I'm trying to remember something useful to add from my various IC engine studies in school, but it's been too long.

Another factor to consider is the business/market situation. Yes, a larger engine is no doubt a cheaper way to increase output but it's also an enormous investment for the manufacturer (castings/machining centers/forge dies/etc.). Although the turbo is relatively expensive in piece cost, they are already tooled (assuming an off the shelf turbo) and the investment to add one is relatively low. Thus the overall cost is within the bounds of "what the market will bear" and it provides a good selling feature in the brochures and advertising.

Keep this going, it's very interesting /w3tcompact/icons/smile.gif

 

[toddler]

Rob,
That's an excellent point that I didn't factor in, and probably explains why my B2710 has the same bore and stroke as the B2100, just one extra cylinder! This one would come down to numbers. If you sell a lower number of tractors, then maybe buying x number of turbos would be less than retooling. Does MF sell less compacts than Kubota? Or does their engine manufacturer sell less baby diesels? It might explain why they have a compact turbodiesel.

Rat, I'm still not convinced about fuel being the only way to increase RPMs. Take an engine that is only on or off, with a fixed fuel volume injected into the cylinders. If you run it on top of Mt Everest with poor combustion efficiency, then in my back yard (~sea level) with good efficiency, then add an intercooler or turbo, are you saying it will always turn at the same speed if resistance doesn't change? That makes absolutely no sense to me. Turbos have better fuel economy because you get more energy from a given amount of fuel. More air, more energy, more oomph, more rpm, no??

(Where are all you guys who knew what a cetane level is, and about fractional distilation of oil when I need you?)

Todd

 

[Anonymous Poster]

OK now, I still don't see a problem with running a few pounds boost(like up to 5) If we were talking about heavy boost(7+) pounds then I have to agree you are looking at heavy engine modifications having to do with lowering the compression ratio just to deal with the added boost, and you stillwon't get any substantial power increase without larger injectors, but like I said with little boost i see no problems,your judging one companys failure(who if I recal, were new at the time, in the field of turbocharging strret vehicles) against the many companys that have had great sucess with turbochargers, take the Volvo 240 turbo coupe from the mid eightys was commonly known for going easily to 150k miles with no problems.

in adition ,I have a 84 diesel blazer which has a factory installed BANKS turbo kit. It now has 130k miles on it with no problems, and acording to the mechanic works on it; it is one of the tightest diesels he has ever seen in a vehicle like mine,(he has also told me of other diesel engines with aftermarket turbo kits that come in in excelent mechanical shape) he goes on to say, "it has by far the least amount of problems compared to its normally aspirated counterpart." I had asked him why for the sake of conversation,and he said it is because it can run cooler under load.....

I tow a horse trailer over one of the most difficult grades in my state it so it has seen a lot of load, for along peroid of time. I have a small guage set with it that shows both boost and exaust gas temp. And when Iv'e tried to pass 1000 degrees it simply won't do it. So in conclusion, I see little problem with The idea of turbocharging one of these little guys, If your willing to front the money

 

[JerryG]

Todd,
Does MF sell less compacts than Kubota? Or does their engine manufacturer sell less baby diesels? It might explain why they have a compact turbodiesel.

The reason that the MF-1260 is turbocharged is to get more horsepower from that chassis size. Iseki is the supplier and they have several more models with more horse up to 125 hp. If you only had room to use a Kubota L series for what ever reason and you need the power of an M series; a turbo would be what you needed

 

[toddler]

Rex,
We weren't talking about a multi-liter car/truck diesel early in the thread, we all agree on the turbo benefit there. We were talking about a 22hp 3cylinder diesel on a tractor that weighs under 1500#.
Todd

 

[JATO_RaT]

Todd, of course it changes the efficiency of the combustion, which in turn will be altered by the load, but your figuring a factor that is always a variable, depending on altitude. My point is, find a diesel that uses air restriction to govern diesel engine RPM. Is there a butterfly valve like carbs have, no. Of course you can always add a turbo charger, intercooler, or even clean the air filter etc., but try doing it at 70 mph or while loading with a tractor. Your refering to a modifiction and it only goes to reason that those modifications will have an effect on power and ultimately on RPM. If you currently use 140W oil in your rear end and change to a synthetic 80W you could say it is a way of governing a diesel engines RPM. Add propane injection and that can change things, pure oxygen injection, vary the cetane level in the fuel, increase compression, install a higher boost turbo, all these will change engine RPM. Is the accelerator attached to any one of these? In the end, our fuel amount is how to change engine RPM on a diesel, everything else is designed to increase combustion efficiency, power or fuel btu content/efficiency. Rat...

 

[toddler]

Rat,
You are clearly talking about curent diesel tractor engines. I didn't realize that, and was asking a theoretical question. There must be an optimum air-fuel mix at a given RPM, for a given engine. Auto makers use multi-valve engines, variable valve timing, turbocharging, etc to increase efficency and power. Clearly there are other ways to alter RPM. Maybe diesel tractor engines will someday be as sophisticated as our auto engines. Wouldn't that be nice? And maybe they'll vary more than just fuel flow. Guess we'll have to wait and see.
Take care,
Todd

 

[JATO_RaT]

Todd, its my understanding that gasoline engines, always run at exactly the same air/fuel ratio (16:1) regardless of RPM. I would think if the ratio was different then 16:1 we might expect to see it in specialty applications like auto racing. Rat...