Chevyboy_0
Mr.SunnyDisposition
I am quite curious as to why diesels don't have throttle plates. I understand they have little to no vacuum in the intake manifold but why is it that they don't have throttle plates?
why don't diesels have throttle plates?
- Thread starter Chevyboy_0
- Start date
sootman73
Registered User
because diesels dont regulate rpm with air. they do it with fuel and because they are injected straight into the cylinder there is no mixing of air and fuel before the cylinder. gassers control the amount of air and fuel to regulate engine rpm and power.
Chevyboy_0
Mr.SunnyDisposition
Ohhhh that makes sense
jperecko
Diesel Ape
^to add to what he said... your throttle pedal is saying how much fuel to give the engine. Diesels can run with a mix broader range of air to fuel ratios when compared to gassers.
On a gasser, you are controlling how much air you let in... and the carb or fuel injection puts in enough fuel to let the engine run.
On a diesel, the engine will still run with minimal fuel but lots of air... and give you better eceonomy. More air, better economy and such... no need to turn off how much air you let in.
On a gasser, you are controlling how much air you let in... and the carb or fuel injection puts in enough fuel to let the engine run.
On a diesel, the engine will still run with minimal fuel but lots of air... and give you better eceonomy. More air, better economy and such... no need to turn off how much air you let in.
And the reason that they have little vacuum is because they have no throttle body. A gas engine builds vacuum against the throttle plate, a diesel engine has nothing to build vacuum up against because you are not limiting how much air is getting in like you do on a gasoline engine. One of the reasons that diesel is more efficient than a gas engine is because they don't have a throttle plate.
Knuckledragger
blowing chunks and grabbing porcelain
Diesel magic.
seawalkersee
It needs a turbo...
you can save yourself some trouble and not try to "think" gasoline while you are thinking of the principals of diesel. Gasoline will melt stuff with more air or a lean condition. Therefore, they have a throttle plate to keep the cyls. from leaning out. Diesels use fule to do this, hence the way they add fuel to speed up. No need to add extra crap that is not necessary.
SWS
SWS
h2odrx
Anti-O
could a single injection point be used? like a T.P.? 
Wait it could be Like LPG or Nitros?
Wait it could be Like LPG or Nitros?
I don't think diesel would do well with being injected prior to the cylinder and then having to travel through the intake and over a valve. Diesel needs to be injected at High pressure and then "swirled" to atomize properly (or a precombustion chamber in the case of IDI), if it had to travel very far it would probably end up back in liquid form and not atomized very well.
I have a somewhat related example, back when me and several friends used to pull tractors almost every weekend all summer, we were always looking for ways to get more power. Well one of my buddies had the idea to injector diesel intake the intake at the same place he was injecting water (because more diesel is always better no matter how it gets in there in his mind). I told him it didn't sounds like a great idea but he said he was going to try it anyway. He went up to the local pulling track one evening, hooked to the sled when no one else was around and then took off with it down the track, about 1/4 the way out he turned on the valve for the fuel to go in the intake, Black smoke rolled and then the tractor shut down, dead in it's tracks. After lots of cranking it got it started back and finally made it back home. The tractor was making some awful noises and had a lot of blowby. We pull the head and 3 of the pistons looked like candles with melted lines all the way down past the rings. Needless to say he has never tried that good idea again. This was all mainly due to way too much fuel but still I don't think it helped that it wasn't atomized properly.
I have a somewhat related example, back when me and several friends used to pull tractors almost every weekend all summer, we were always looking for ways to get more power. Well one of my buddies had the idea to injector diesel intake the intake at the same place he was injecting water (because more diesel is always better no matter how it gets in there in his mind). I told him it didn't sounds like a great idea but he said he was going to try it anyway. He went up to the local pulling track one evening, hooked to the sled when no one else was around and then took off with it down the track, about 1/4 the way out he turned on the valve for the fuel to go in the intake, Black smoke rolled and then the tractor shut down, dead in it's tracks. After lots of cranking it got it started back and finally made it back home. The tractor was making some awful noises and had a lot of blowby. We pull the head and 3 of the pistons looked like candles with melted lines all the way down past the rings. Needless to say he has never tried that good idea again. This was all mainly due to way too much fuel but still I don't think it helped that it wasn't atomized properly.
BigRigTech
Diesel junky
A diesel get's a full lung of air every stroke, it's up to you how much fuel you put in there to burn.
icanfixall
Official GMM hand model
Add this to te above post..... 12 to 15 lbs of added atmoshere (pressure) and just think what the running pressure is plus the added volume in the cylinders. A while back I was talking to an engineer at ARP. He told me a customer wanted an intake stud kit for a psd because his kept breaking the bolts.....
So he asked the guy what kind of boost pressure are you running. The guy told him around 250 psi..... Then he told him there studs wouldn't hold the pressure.... Shop elsewhere.....
So he asked the guy what kind of boost pressure are you running. The guy told him around 250 psi..... Then he told him there studs wouldn't hold the pressure.... Shop elsewhere.....
freebird01
Post Turtle!
i think at that point you should be making the engine a limited life engine and try welding the cylinder head to the block hahahahaha
CDX825
filtration nut
Atomization is not so much of a problem with pre injection as the fuel would be igniting way before it needed to. Remember the heat of the compression is what causes it to burn.
Alex S
Jeoff
dont forget the timing of the fuel shot is very very important so the intake port injection idea is out the window ....
