New to the forum and new to the forum society

[SkyNet_Blue]

Hey everyone. My name is Robert, i'm 21 and I live in the small city of Toowoomba in Australia and a huge fan of physics and astronomy and the human brain. I really only have basic knowledge in these areas so i'll have more questions than answers. I enjoy reading theories and I have a few idea's of theories of my own, (I just don't fully understand the maths that a theory requires). I'm currently studying Engineering part time, majoring in Mechatronic and expect to finish this in about 6 years. I work full time as a Diesel Mechanic for a dealership of Caterpillar equipment (Not directly for Caterpillar, which would be cool.) I frequently browse youtube, mainly chilling at one of the Vsauce channels or minutephysics who post links to other intriguing channels. I don't have my own channel... yet... until I actually have something to offer to the youtube community. Outside of the realm of all things science, I enjoy the Japanese culture, read manga, watch anime and play in one of their sports, Kendo. I can go on but i'd bore you to tears.

Thanks for taking the time to read this introduction. I look forward to discussing the sciences with everyone.

[RedPanda]

Hello and welcome!

[jocular]

Hey everyone. My name is Robert, i'm 21 and I live in the small city of Toowoomba in Australia and a huge fan of physics and astronomy and the human brain. I really only have basic knowledge in these areas so i'll have more questions than answers. I enjoy reading theories and I have a few idea's of theories of my own, (I just don't fully understand the maths that a theory requires). I'm currently studying Engineering part time, majoring in Mechatronic and expect to finish this in about 6 years. I work full time as a Diesel Mechanic for a dealership of Caterpillar equipment (Not directly for Caterpillar, which would be cool.) I frequently browse youtube, mainly chilling at one of the Vsauce channels or minutephysics who post links to other intriguing channels. I don't have my own channel... yet... until I actually have something to offer to the youtube community. Outside of the realm of all things science, I enjoy the Japanese culture, read manga, watch anime and play in one of their sports, Kendo. I can go on but i'd bore you to tears.

Thanks for taking the time to read this introduction. I look forward to discussing the sciences with everyone.

Greetings! I am instantly interested in several things you introduced. Good for you, regarding studying Engineering; what is "Mechatronics"?

My question for you is specific: Are the newest Caterpillar engines using Electronic Fuel Injection systems, and have you been trained in working with them? My interest here centers around the difficulties posed by the need to control very high diesel fuel injection pressures, at very high rates on operation, by means of teeny devices (solenoids?) controllable by computer.

One system I am somewhat familiar with uses engine lubricating oil, circulated out of the oil sump, and pumped to the fuel injection system, to be used as a hydraulic medium to bring about mechanical movement needed in the injectors themselves. EFI was a fairly straightforward proposition in gasoline engines, using roughly 50 psi injection pressure. Given diesel operation, the necessary injection pressure is much higher, perhaps 2,000 psi or more, since cylinder compression pressure may be 3 to 4 times as high as gasoline engines, and the fact that diesel fuel must be injected directly into the cylinder while it is under pressure, rather than into the airstream just above the intake valve, in gasoline usage.

Sorry I have strayed away from the main theme here, but perhaps someone will be interested! jocular

Edit: Please do go on; you will never bore this reader to tears!

[SkyNet_Blue]

Hi, Mechatronics is a major that consists of both mechanical and electrical engineering, so more like robotics and robots are cool.

Yes, Caterpillar do use EFI systems and all of them use solenoids and are controlled by a computer. (I usually refer to them as an ECM (Electronic Control Module)) That area isn't my specialty, but I do know the ECM's are pre-programmed with fuel maps and cannot be altered unless you use a custom built ECM.

I know the system you're familiar with (Cat calls them HEUI (Hydraulic, Electronic Unit Injector)) Using engine oil from an oil gallery which is at about 50 psi and then ramps it up to a range of about 800 to 4000 psi depending on oil viscosity and temperature. The solenoid controls the oil going on top of a plunger within the injector and this action ramps fuel pressure to about 25000 psi. During the injection phase the solenoid will activate twice, creating a pilot injection and a main injection (the pilot injection is just to start the fire for the main injection).

In diesel engines compression pressure averages around 600 psi, but it is the combustion pressure that the injector has to overcome. The mechanical fuel pumps i've dealt with have cracking pressures of 10000 to 20000 psi!

Cat also have MEUI systems, which instead of using oil pressure to actuate the plunger, uses a "roller rocker" that rolls along the cam shaft and acts just like any other inlet or exhaust valve mechanism. However this system only has one injection phase but compensates for it by the shape of the cam lobe and also achieves similar pressures to HEUI systems.

And Cat has also gone into common rail fuel systems which have even greater fuel pressures, averaging about 30000 psi. In this system the fuel pump ramps the fuel to these pressures and stores it in a tube (what they call the rail, acting kinda like an accumulator), each injector has access to this fuel and a solenoid controls when and how much fuel to inject. I'm not exactly sure, but i do think this system has 4 injection phases. Pretty intense job being a solenoid.

There are gasoline engines that use a direct injector, Holden use it in some of their cars, called spark ignited direct injection (SIDI) however it still injects during the intake stroke. The advantage is improved air flow since the injector doesn't hinder it (not that i thought it did in the first place) and high pressures causing better atomisation and cooling of the cylinder.

I'm hugely interested in how things work. I hope I answered your question and incited more questions.

[overthelight]

Hello. I was studying French. The French culture is intersting and exciting for me.

[shlunka]

I'm shlunka, studier of cheesy one liners and hold a PhD in stupidity. Welcome to the scienceforum mate, hope you can contribute. Cheers.

[jocular]

I'm hugely interested in how things work. I hope I answered your question and incited more questions.

Well, thank you for taking the time to write so thorough a description! Your time is likely more valuable than that of an old man! Your mention of Caterpillar alerted my memory to a few significant things about Cat. As a young man, your age, I began work in a Development Test Lab, where diesel engines were run on dynamometers, the objective being mainly head gasket development. The engines were placed by the manufacturer; a Mack END-864 V-8 broke a connecting rod one night, and threw a piece of it out of a hole cracked through the crankcase! Happened around midnight, scared the lone night man there so badly, he quit two weeks later.

At any rate, Cat brought in an experimental V-8 having overhead camshafts, unheard of in diesels (at least then, about 1965). I believe I still have a pic of it, will try to find it. That engine was supposedly destined for use in over the road trucks, but I have no idea if it made it there. It pulled 350HP 24 hours a day, cycling up and down between no load and full load every 15 minutes or so, week after week! It's heads were very wide, with a "box" of aluminum alloy atop each containing valve mechanism, cams being driven from front and rear by large gears.

My employer, Victor Manufacturing & Gasket Co., supplied many of Cat's OEM use crankshaft seals; rear crank seals were huge, about 8" diameter, silicone rubber, difficult to make in huge quantity. Lagging in production, Cat warned Victor if they could not step up production to meet their demand, they (Cat) would build a plant to produce their own oil seals! Such was the power of Caterpillar Tractor Co!

I suspect reminiscing this way is not the typical stuff moderators expect here, thus, perhaps my meandering belong in Private Message territory. On the other hand, there may be skilled-trade afficionados, mechanics, who might enjoy it. jocular

[Neverfly]

Yeah, for being 21 years old, you're rockin.' I was still learning how to be sober, back then.

[SkyNet_Blue]

Well, thank you for taking the time to write so thorough a description! Your time is likely more valuable than that of an old man! Your mention of Caterpillar alerted my memory to a few significant things about Cat. As a young man, your age, I began work in a Development Test Lab, where diesel engines were run on dynamometers, the objective being mainly head gasket development.

=D It was my pleasure, Engines, Transmissions, Machine Hydraulics and Machine Electronics are my strong point, but still not as involved as the science behind it which i want to learn more about. A development test lab sounds like an awesome place to work!! The dealership i work for, Hastings Deering, do test engines (also transmissions) on dynameters but nothing experimental and only to check for correct pressures, speed and torque against a specifications sheet.

The engines were placed by the manufacturer; a Mack END-864 V-8 broke a connecting rod one night, and threw a piece of it out of a hole cracked through the crankcase! Happened around midnight, scared the lone night man there so badly, he quit two weeks later.

Haha, i've never actually seen it happen but i do hear of it happening a fair bit, we call them ventilated engines (or an engine that has thrown a leg out of bed). Actually in the workshop now is an engine that has thrown a chunk of the cam shaft out the side of the block!

I'd like to see that engine, I haven't seen that size engine in an on highway truck in Australia, mainly just straight 6 cylinder. They use overhead cam shafts in most of their engines now a days (except for the engine in the workshop), but the cam doesn't ride on the valve more to the side of the valve with a rocker arm connecting the two. Their engines are very impressive and in recent years they have brought out 3600G series engines, which run on LP gas, the connecting rod is nearly 800mm long! The rods require a special tool that checks the stretch of the bolts for correct bolt torque! (Just a torque wrench isn't enough).

That's pretty amazing, I would like to see the cat factory in America one day. Yeah i found it is pretty easy to go off on tangents on this forum, but i have seen threads where conversation has gone from one topic to a nearly completely unrelated topic (still interesting non the less).

Yeah, for being 21 years old, you're rockin.' I was still learning how to be sober, back then.

Haha thanks! Though I do like a few brews after work every now and then.

Thanks everyone for welcoming me to the forum, much appreciated!