I was taught in transmission school that automatics even older style ones also have kindof an engine/trans brake. If youre going downhill and your brakes fade you can slam the trans from OD or D into L2 or L1 and it will actually apply extra bands and clutch packs and the engine will rev up to a certain rpm. But will not go further because the throttle is closed. Thats when the torque converter will compensate and slow the vehicle. The atf is cooled right after it leaves the converter to the trans cooler. You will not damage it. Ive tried that even on the poor 700r4 gm. It grabs the rear end and you slow down quick. So many people have died losing brakes going down a mountain and not knowing this engineered function of an automatic
This is what the Chevy Volt does to recharge the battery. It's a technique by hybrid drivers to shift into Low to recharge the battery and slow the engine, very similar to engine braking in a manual
That's funny. We were taught all this in middle school. That's ages 9 through 12. Four strokes, how a carburettor 4 cylinders engine works. Just as part of the countrywide standard curriculum. So everybody who was there but taught it as well. What did they teach you in America?
@@baerschuman111 Fascinating aren't they? The evolution of prokaryotes into eukaryotes. One of our best hypotheses speculates that a mutant predator prokaryote ate a mutant prokaryote and formed a symbiotic relationship from their predator and prey relationship. The probability scale on which this was built is mind crushing. Billions of years and giga-trillions of interactions and we're decended from a handful of interactions that have a cell an advantage. Along cane photosynthesis, multicellular organisms and sexual reproduction. Primitive evergreens populated the pangean super continent along with the terrestrial animals and giant arthropods. Almost all of the coal we dig up was layed down during this 60 million year period at the end of the Devonian to the start of the Permian. I love me some megahistory. A lot of the history I learnt after I left school, what we see on TV and UA-cam now were bleeding edge when you and I were at school.
Modern diesels DO have throttle bodies, but they are primarily for emissions/ EGR functions. They still don't control throttle. The ECU by means of electrical motor or solenoid controlled vacuum line can control the actuation of the butterfly valve in the throttle body to restrict the amount of fresh air (from turbo charger) into the intake manifold under low engine load situations. This helps create a pressure differential and thus helps the EGR system to feed more exhaust into the intake manifold.
Learn something new every day, interesting. Almost as functioning as a vacuum increasing butterfly, This plus variable geometry turbochargers is changing the game for all engines.
Which in reality the EGR still doesn't work properly. Like in my Freightliner. It has to have the carbon pushed out of the holes every 9-12 months. And let's not get started on the DEF system that drops my trucks mpg from 6.5 to 5.5 as soon as the temperature drops below 35f.
@@karlporath8904 the DEF shouldn't have an effect on fuel economy since it is all taking place downstream in the exhaust. Probably just seeing the effects of an engine running cooler than it's used to
So basically its creating a vacuum that adds friction to the system thus slowing it down? Man what a time we live in, I literally heard the term "jake brake" 30 seconds ago and within 15 seconds I found an explanation on what it is! What a time to be alive, everything every little bit of info in the world is within arms reach.
You can feel it in automatic cars that have a manual setting or paddle shifted. My car is automatic but I use the button shift sometimes especially if it is snowing out so I can control what gear the car is in better and to use engine braking so I can slow down without hitting the brakes and maybe losing control.
Same. My car has a dual clutch transmission, and it helps slow down ther car very well. Heck, sometimes I don't even have to use the brakes. The transmission slows me down enough.
it feel like he is being condescending as if im a baby and he is explaining different animals. I love it, its like a combination of all the coolest english art and history teachers
What an excellent explanation! I never understood why semi trucks made that obnoxious noise to slow down, while my manual car or bike was nice and quiet. Now I do!
Simple depending on how strong your Jake's pull back,weight and gradient of the hill and select the proper gear say 15% grade on my truck at 50T or 110k lbs I'd sit in 8th with Jake's on stage 3. Should hold at 1900rpm
Missed opportunities on discussion: 1. Gear train backlash when shifting from (a) driving the wheels with engine power, to (b) driving the engine with wheel power. 2. Engine oil consumption when the combustion chamber is in a vacuum for prolonged periods. 3. Braking effects by electric vehicles, regenerative braking systems.
little did we know that this was the last time we wd see bart wearing the donut colors. miss u bart, hope ure having a great time at motor trends. u were the one to teach me everything about cars, miss u sensei.
My kids will enjoy the visual. Good job explaining Jake brake. You did forget to mention the displaced heat in the Jake process, though. Maybe in another video, then? Subscribing now.
Lol.. this diagram is sorta correct.. actually the jake works on vacuum. It opens the exhaust valve right before TDC top-dead-center releasing the compressed air then the exhaust valve closes leaving the piston drawing a vacuum while both valves are closed on the piston’s way back down..
Incorrect, the jake does not use vacuum. It uses the compression of the engine to slow it down, it only opens the exhaust valve on the compression stroke so that the combustion stroke does not work like normal. Then closes the valves during the exhaust stroke untill the last second to use the compression a second time before starting the intake and compression cycle again. There is never a vacuum created. Just no power, only absorbed.
Wait wait wait.. 73,000 pounds. Normal standard is 80,000 pounds. Some states may allow you to carry more than 100,000. Whenever you get a chance go on a ride to with some heavy haulers.
First of all, semi-trucks have 12 to 16 liter inline 6 cylinders. And what you hear, is not an engine brake, but straight exhaust, which a lot of classic trucks using;) Engine brakes also work on trucks with automatic transmission. And you don't have to flip the switch to activate engine brake every time unless you drive old school truck with the mechanical engine. You simply flip switch once, and engine brake either works when you release the throttle or turning off cruise control. You may also set ECU, so engine brake will engage only when you touch or press and hold the brake pedal.
Most loads are 79k-80k lbs. total weight ,as most companies want to move the most product per load. (That’s @ 45k lbs. in product and @ 34k lbs. in truck and trailer weight)
South Africa has some of the highest weights a semi can legally be on the road without having any additional special permits which is a combined weight of 54 000kg which is around 118800 lb and the max weight per axle is: front wheels 6000kg, and on the rest is 9000kg in the case of a single axle and 18000kg in case of a tandem axle, it's also common to have two trailers hooked up to each other with an 5th wheel on the first trailer and the weight rules for the second trailer is the same as for the first, in this case its 6000kg for front wheels 18000kg for the driving wheels, 18000kg for the first trailer axle, 18000kg for the rear trailer axle, combined weight not more then 54000kg and total combined length not more then 22 meters...
DFCO is what slows the gasoline engine, not the throttle body, especially in ETC vehicles. You can tune DFCO out of an engine and get the car to coast with zero throttle. DFCO retards the timing and cuts fuel to allow for engine braking. Without DFCO, you would coast to a stop, or accelerate downhill. Also, automatic transmissions can utilize engine braking as well, using DFCO, which keeps the converter locked and downshifts the trans to run the engine at a higher RPM to achieve the desired amount of braking. Most vehicles today, trucks especially, have multiple DFCO modes to use more or less engine braking to either conserve fuel and increase MPG, or increase engine braking. You can actually increase the MPG of most vehicles by enabling DFCO at higher RPMs, but increasing the timing, and reducing the deceleration effect of the engine. There are other factors, like valve timing, throttle position, engine speed, injector minimum pulse width, etc that all need tuned for the maximum benefit. You also completely ignored exhaust brakes, which uses the exhaust to create the pressure on the piston in the same manner, more or less, to the Jake brake. Video was good, just a little too simplified to actually explain what is happening.
🙋🏽♂️gas engine vacuum from intake and compression resistance from compression stroke.. my little diesel doesn't have a jake brake nor a throttle body but down shifting using the engine to brake still occurs.. so u regot the compression stroke resistance
I have the same question, I drive sub-CDL trucks, they still have large diesel engines, but no jake brake. Non the less I engine brake a lot when loaded heavy.
WHAT HAPPENED TO THIS SHOW?!?!?! It was honestly so good! I loved it! It was both informative and fun! You guys are short-sighted for canceling this show!
Trabant driver here, you forgot us 2 stroke folk, it is foot on the gas or out of gear for me from first to third, 4th gear has freewheeling ;) for me engine breaking is breaking my engine ;D
Diesels solved that issue a long time ago a VGT or variable geometry turbo is the reason why they can run big turbos on diesels and not have any turbo lag, it's the same concept of a CVT where the geometry and ratio are always adjusted to have best air flow for instant boost it's just it ain't a cheap system so it's not worth the cost in gasoline engines
@@Shazzkid not if you keep your turbo stock, the series 60's, Volvo D13's we have at work have never had that issue because the turbo nozzle keeps adjusting literally for that purpose of eliminating lag the VGT's work so well they dont even need waste gates because they can control boost very well, Caterpillar fixed their lag issue by making a twin turbo setup but they're turbos always go out, besides that what manufacturer has a turbo lag issue in heavy duty engines
@@alextepozteco3681 my old lexus is220d had turbo lag, my scoda octavia 1.9tdi had lag, and everyone ive spoken to who doesn't have a brand new car has turbo lag in their TDI
@@Shazzkid like I said it's mostly used in heavy duty Diesels like engine brakes because they're way too expensive for automotive use obviously if you're talking about cars they will not have VGT's especially if they're older vehicles
My ford fusion hybrid 2018 has the low gear on the automatic transmission and it does engine braking, kinda nice my parents always think I'm breaking my car when I do it
The valves in the engine animation are moving in the wrong direction, the values open inward toward to piston to eliminate the possibility of the compression blowing the vales open. Oher than that I like the video 👍
The throttle body found on diesel intakes tracks has absolutely nothing to do with acceleration or deceleration it functions as part of the egr system. When the emissions system sees the right conditions to start recirculating exhaust gas into the intake the throttle body or throttle valve closes partially to create vacuum in the intake and help pull the exhaust gasses into the intake and engine properly so that the system actually functions. During all other operation it is fully open
That's really interesting I've always wondered how a jake brake worked. I kinda just thought that it block off the exhaust some how which would kinda work in the same manner but obviously no where close to as effective as this way. Also like to mention that the illustrations are not accurate. It gets the point across just fine but the valves shouldn't open up into the head.
Semi trucks can absolutely engine brake without a Jake brake. It's not that diesels can't do it, it's the amount of weight we're trying to hold back. Without the Jake brake we'd be going down some of these big grades at like 15mph. Also, the max load is typically 80,000lbs and in some states it's up to 110,000 not sure where you got the 73,000 number
Jakes is the old kind of brake. Newer truck engines got more sufisticated systems, lile volvo engine brake VEB+? exhaust flaps of dirrernt desine, air controlled additionl valve in cylinder head.... But principalls are the same as old good jakes. But, this is not only a way to slow down big rig. In Europe hydrolic retarders are popular. This is big heavy box on output shaft of transmisson mixing fluid inside and transgering energy of speed and mass to heat. Of course retarders are water cooled. It is not all/ Telma makes electromagnetic brakes.
I once had no brakes in my VW , e brake barely worked …. I would carefully slow myself down with engine braking until the ebrake could handle the stop for about a week until I got the brakes fixed
Pretty damn accurate except those exhaust valves animation..... also I was hoping your cover exhaust brakes which consequentially do the same thing just farther down stream of the motor itself. But still a great video!
Very informative, I had a guy lie and say the jake brake is actually spinning the motor backwards ( I know it sound dumb as shit) but I believed him because he drive trucks... Smh
The original purpose of a Jake Brake was not to slow down the vehicle but to prevent the diesel engine from doing what is called a runaway which is a horrible event that can happen to a diesel engine which causes them to go out of control and often can lead to damage and destruction of the engine thrown rods though the block is a common effect. Stopping them is all a matter of luck and how fast you can move. First thing is to cut fuel but sometimes they will still run because they then begin to burn the engine's oil because of bad seals most times so in order to stop it you have to get to the air intakes and plug them with whatever you can find to cut off air to the engine. If your quick enough you can do this before any damage is done to the engine.
@@идиотты I dont think you understand the joke so instead of saying r/woosh I will explain it every engine can get to 15000 rpm at least once because it will brake it
Holy hell. This dude can explain things so well. He's better than all of the teachers I've ever had.
I'd say something similar but nobody beats mr. Summa
Check out all of science garage . They’re amazing and funny
@@LTV746 Don't worry I have lol. Gonna be cool when Bart's back
My shop teacher just put science garage on half the time
@@maz5miata269 he didn't 🥲
Science has shown that a Jake Brake is significantly quieter than an out of control truck crashing into your house.
Bruh
@@thespeechboss
Do I be wrong though
True
Depends on your house, dont think you hear much if it is just a standard american house
😂
I was taught in transmission school that automatics even older style ones also have kindof an engine/trans brake. If youre going downhill and your brakes fade you can slam the trans from OD or D into L2 or L1 and it will actually apply extra bands and clutch packs and the engine will rev up to a certain rpm. But will not go further because the throttle is closed. Thats when the torque converter will compensate and slow the vehicle. The atf is cooled right after it leaves the converter to the trans cooler. You will not damage it. Ive tried that even on the poor 700r4 gm. It grabs the rear end and you slow down quick. So many people have died losing brakes going down a mountain and not knowing this engineered function of an automatic
This is what the Chevy Volt does to recharge the battery. It's a technique by hybrid drivers to shift into Low to recharge the battery and slow the engine, very similar to engine braking in a manual
Thanks. I was wondering why I would use engine braking on my little Toyota Yaris.
@@simon-the-bar5657I use that when I'm speeding and see a cop ahead to slow down quicker without applying the brake
i learn more from this than school
thx sensei-donut for teaching me -life- about -cars- semi trucks
I learned about this literally be hearing the truck
That's funny.
We were taught all this in middle school.
That's ages 9 through 12.
Four strokes, how a carburettor 4 cylinders engine works.
Just as part of the countrywide standard curriculum.
So everybody who was there but taught it as well.
What did they teach you in America?
@@MostlyPennyCat mitochondria and shit
@@baerschuman111
Fascinating aren't they?
The evolution of prokaryotes into eukaryotes.
One of our best hypotheses speculates that a mutant predator prokaryote ate a mutant prokaryote and formed a symbiotic relationship from their predator and prey relationship.
The probability scale on which this was built is mind crushing. Billions of years and giga-trillions of interactions and we're decended from a handful of interactions that have a cell an advantage.
Along cane photosynthesis, multicellular organisms and sexual reproduction.
Primitive evergreens populated the pangean super continent along with the terrestrial animals and giant arthropods.
Almost all of the coal we dig up was layed down during this 60 million year period at the end of the Devonian to the start of the Permian.
I love me some megahistory.
A lot of the history I learnt after I left school, what we see on TV and UA-cam now were bleeding edge when you and I were at school.
It’s Donut-sensei not sensei-Donut
Modern diesels DO have throttle bodies, but they are primarily for emissions/ EGR functions. They still don't control throttle. The ECU by means of electrical motor or solenoid controlled vacuum line can control the actuation of the butterfly valve in the throttle body to restrict the amount of fresh air (from turbo charger) into the intake manifold under low engine load situations. This helps create a pressure differential and thus helps the EGR system to feed more exhaust into the intake manifold.
Learn something new every day, interesting. Almost as functioning as a vacuum increasing butterfly, This plus variable geometry turbochargers is changing the game for all engines.
Which in reality the EGR still doesn't work properly. Like in my Freightliner. It has to have the carbon pushed out of the holes every 9-12 months. And let's not get started on the DEF system that drops my trucks mpg from 6.5 to 5.5 as soon as the temperature drops below 35f.
@@karlporath8904 the DEF shouldn't have an effect on fuel economy since it is all taking place downstream in the exhaust. Probably just seeing the effects of an engine running cooler than it's used to
Bart you will be missed, so does science garage :’)
What happened to Bart and is he the one speaking in the vid
@@timeless_2022 he left and joined Motor Trend
really miss this show, we actually watched these videos in my high school auto-shop class to learn the basics of a lot of stuff
So basically its creating a vacuum that adds friction to the system thus slowing it down? Man what a time we live in, I literally heard the term "jake brake" 30 seconds ago and within 15 seconds I found an explanation on what it is! What a time to be alive, everything every little bit of info in the world is within arms reach.
Absolutely great show. I wish you'ed been around when I was a kid with ZERO access to any info like this. Thanks dudes!
You can feel it in automatic cars that have a manual setting or paddle shifted. My car is automatic but I use the button shift sometimes especially if it is snowing out so I can control what gear the car is in better and to use engine braking so I can slow down without hitting the brakes and maybe losing control.
Same. My car has a dual clutch transmission, and it helps slow down ther car very well. Heck, sometimes I don't even have to use the brakes. The transmission slows me down enough.
Bart: intake, compression, combustion, exhaust.
Uncle Jerry: suck, squeeze, bang, blow!
it feel like he is being condescending as if im a baby and he is explaining different animals. I love it, its like a combination of all the coolest english art and history teachers
What an excellent explanation! I never understood why semi trucks made that obnoxious noise to slow down, while my manual car or bike was nice and quiet. Now I do!
Simple depending on how strong your Jake's pull back,weight and gradient of the hill and select the proper gear say 15% grade on my truck at 50T or 110k lbs I'd sit in 8th with Jake's on stage 3. Should hold at 1900rpm
Missed opportunities on discussion:
1. Gear train backlash when shifting from (a) driving the wheels with engine power, to (b) driving the engine with wheel power.
2. Engine oil consumption when the combustion chamber is in a vacuum for prolonged periods.
3. Braking effects by electric vehicles, regenerative braking systems.
I had implemented Diesel engine braking for heavy duty trucks. Gasoline engine braking was new to me :)
Bring this back please 🙏🏻🙏🏻🙏🏻
little did we know that this was the last time we wd see bart wearing the donut colors. miss u bart, hope ure having a great time at motor trends. u were the one to teach me everything about cars, miss u sensei.
My kids will enjoy the visual. Good job explaining Jake brake. You did forget to mention the displaced heat in the Jake process, though. Maybe in another video, then? Subscribing now.
When he said I’ll wait for you to subscribe I was going too but realized I already was, I didn’t know that
I miss this so much we need this back!
BRING BACK SCIENCE GARAGE!!! I miss this show. The best one on the channel
Lol.. this diagram is sorta correct.. actually the jake works on vacuum. It opens the exhaust valve right before TDC top-dead-center releasing the compressed air then the exhaust valve closes leaving the piston drawing a vacuum while both valves are closed on the piston’s way back down..
Incorrect, the jake does not use vacuum. It uses the compression of the engine to slow it down, it only opens the exhaust valve on the compression stroke so that the combustion stroke does not work like normal. Then closes the valves during the exhaust stroke untill the last second to use the compression a second time before starting the intake and compression cycle again. There is never a vacuum created. Just no power, only absorbed.
Wait wait wait.. 73,000 pounds. Normal standard is 80,000 pounds. Some states may allow you to carry more than 100,000. Whenever you get a chance go on a ride to with some heavy haulers.
That would require them fact checking their content
Lol.. it would...
Yeah I'm sitting at 78,000 right now
I miss science garage!!!... Does bug deflector work/affect mpg?, door guard?, 3m protection film on hood,bumper and etc?
do you know why they stopped posting science garage?
First of all, semi-trucks have 12 to 16 liter inline 6 cylinders.
And what you hear, is not an engine brake, but straight exhaust, which a lot of classic trucks using;)
Engine brakes also work on trucks with automatic transmission. And you don't have to flip the switch to activate engine brake every time unless you drive old school truck with the mechanical engine. You simply flip switch once, and engine brake either works when you release the throttle or turning off cruise control. You may also set ECU, so engine brake will engage only when you touch or press and hold the brake pedal.
Other then the valve going in the wrong direction this is the best explanation of engine braking
Went to trucking school, they never mentioned the engine/exhaust brake once. Great video!
Wow thats actually kinda cool. Gas engines use the vaccum to slow down, but the (older?) desal engines use the compression.
Most loads are 79k-80k lbs. total weight ,as most companies want to move the most product per load. (That’s @ 45k lbs. in product and @ 34k lbs. in truck and trailer weight)
I have a diesel pickup with a manual transmission, you can definitely still engine brake with it lol
Most pickups have exhaust brakes. They close off the exhaust and build back pressure to slow it down.
@@EasternExplorer Most modern pickups do, older ones don't
South Africa has some of the highest weights a semi can legally be on the road without having any additional special permits which is a combined weight of 54 000kg which is around 118800 lb and the max weight per axle is: front wheels 6000kg, and on the rest is 9000kg in the case of a single axle and 18000kg in case of a tandem axle, it's also common to have two trailers hooked up to each other with an 5th wheel on the first trailer and the weight rules for the second trailer is the same as for the first, in this case its 6000kg for front wheels 18000kg for the driving wheels, 18000kg for the first trailer axle, 18000kg for the rear trailer axle, combined weight not more then 54000kg and total combined length not more then 22 meters...
DFCO is what slows the gasoline engine, not the throttle body, especially in ETC vehicles. You can tune DFCO out of an engine and get the car to coast with zero throttle. DFCO retards the timing and cuts fuel to allow for engine braking. Without DFCO, you would coast to a stop, or accelerate downhill.
Also, automatic transmissions can utilize engine braking as well, using DFCO, which keeps the converter locked and downshifts the trans to run the engine at a higher RPM to achieve the desired amount of braking.
Most vehicles today, trucks especially, have multiple DFCO modes to use more or less engine braking to either conserve fuel and increase MPG, or increase engine braking.
You can actually increase the MPG of most vehicles by enabling DFCO at higher RPMs, but increasing the timing, and reducing the deceleration effect of the engine. There are other factors, like valve timing, throttle position, engine speed, injector minimum pulse width, etc that all need tuned for the maximum benefit.
You also completely ignored exhaust brakes, which uses the exhaust to create the pressure on the piston in the same manner, more or less, to the Jake brake.
Video was good, just a little too simplified to actually explain what is happening.
RIP Science garage :(
4:34 is what my old kick scooter with light up wheels sounds like
🙋🏽♂️gas engine vacuum from intake and compression resistance from compression stroke.. my little diesel doesn't have a jake brake nor a throttle body but down shifting using the engine to brake still occurs.. so u regot the compression stroke resistance
I have the same question, I drive sub-CDL trucks, they still have large diesel engines, but no jake brake. Non the less I engine brake a lot when loaded heavy.
Im totally putting an old blower, turbo, and intercooler in my kitchen as decoration, this kitchen looks so good lmao but no lie looks cool
WHAT HAPPENED TO THIS SHOW?!?!?! It was honestly so good! I loved it! It was both informative and fun! You guys are short-sighted for canceling this show!
I would love to see a step by step video on how to turbo a car and everything you need including tools
i’m out here missin bart
Semi truck drivers use the weight of the combination to slow down not always but the weight helps slowing down to
Bring this show back it was the best show on Donut
By letting the fuel mix out at the end of the compression stroke the jake brake also causes a vacuum on what should be the power stroke.
Valves go down, not up
Got that reverse lobe cam bro
And don't forget regenerative braking in electric cars!
Your back!!!! Yayyyyyyyyy missed seeing you around my guy
The Cajon Pass pic, thats the old Route 66 at the bottom of the pass right?
Trabant driver here, you forgot us 2 stroke folk, it is foot on the gas or out of gear for me from first to third, 4th gear has freewheeling ;)
for me engine breaking is breaking my engine ;D
I live in San Bernardino and that place of the gravel road i pass through there all the time
Did he say, "That's a lot of Faygo" ?
WHOOP WHOOP !
Jake brake = answer to turbo lag
Diesels solved that issue a long time ago a VGT or variable geometry turbo is the reason why they can run big turbos on diesels and not have any turbo lag, it's the same concept of a CVT where the geometry and ratio are always adjusted to have best air flow for instant boost it's just it ain't a cheap system so it's not worth the cost in gasoline engines
@@alextepozteco3681 most diesels still have turbo lag though
@@Shazzkid not if you keep your turbo stock, the series 60's, Volvo D13's we have at work have never had that issue because the turbo nozzle keeps adjusting literally for that purpose of eliminating lag the VGT's work so well they dont even need waste gates because they can control boost very well, Caterpillar fixed their lag issue by making a twin turbo setup but they're turbos always go out, besides that what manufacturer has a turbo lag issue in heavy duty engines
@@alextepozteco3681 my old lexus is220d had turbo lag, my scoda octavia 1.9tdi had lag, and everyone ive spoken to who doesn't have a brand new car has turbo lag in their TDI
@@Shazzkid like I said it's mostly used in heavy duty Diesels like engine brakes because they're way too expensive for automotive use obviously if you're talking about cars they will not have VGT's especially if they're older vehicles
I really miss this guy
This guy should be a high school shop teacher i think i just learned more from watching his video than i did in 4 years of high school
My ford fusion hybrid 2018 has the low gear on the automatic transmission and it does engine braking, kinda nice my parents always think I'm breaking my car when I do it
The valves in the engine animation are moving in the wrong direction, the values open inward toward to piston to eliminate the possibility of the compression blowing the vales open.
Oher than that I like the video 👍
I'm confused, my diesel Mazda 6 has an e-throttle, so diesels DO have throttle bodies. Is it just big semi truck diesels that don't?
The throttle body is only used for engine braking on a diesel, during normal operation it is wide open.
In a diesel the throttle controls the injectors
Modern diesels can have a throttle body, it's something to do with getting better fuel economy.
The throttle body found on diesel intakes tracks has absolutely nothing to do with acceleration or deceleration it functions as part of the egr system. When the emissions system sees the right conditions to start recirculating exhaust gas into the intake the throttle body or throttle valve closes partially to create vacuum in the intake and help pull the exhaust gasses into the intake and engine properly so that the system actually functions. During all other operation it is fully open
Damn salted rice on tortilla chips are the best y’all should t try it sometime.
1:20
Somebody doesn’t know how intake and exhaust valves work.
Bart buddy where ya been!? Need some content ideas? Maybe hand brakes and conversion kits for newer model cars
Compression ratio please... we need to know what is it so make a video please!
khaled mohamad he’s dead
Any Owner Operators on here besides me? OOIDA
Really miss science garage 🙃
Who else is here just cuz you love this guy
Why was this show shot in his kitchen? Haha does this guy have some secret blend of herbs and spices for HP that we don't know about? 😂
I like how your valves open the wrong direction... :D
Bring back Science Garage
A 15% grade is cringe worthy. The most I have ever been up or down is 13%.
Believe it or not I've been up 50% grades and 100%
That's really interesting I've always wondered how a jake brake worked. I kinda just thought that it block off the exhaust some how which would kinda work in the same manner but obviously no where close to as effective as this way. Also like to mention that the illustrations are not accurate. It gets the point across just fine but the valves shouldn't open up into the head.
What ever happened to science garage? This host was cool
Bring back science garage!
Semi trucks can absolutely engine brake without a Jake brake. It's not that diesels can't do it, it's the amount of weight we're trying to hold back. Without the Jake brake we'd be going down some of these big grades at like 15mph. Also, the max load is typically 80,000lbs and in some states it's up to 110,000 not sure where you got the 73,000 number
Jakes is the old kind of brake. Newer truck engines got more sufisticated systems, lile volvo engine brake VEB+? exhaust flaps of dirrernt desine, air controlled additionl valve in cylinder head.... But principalls are the same as old good jakes.
But, this is not only a way to slow down big rig. In Europe hydrolic retarders are popular. This is big heavy box on output shaft of transmisson mixing fluid inside and transgering energy of speed and mass to heat. Of course retarders are water cooled.
It is not all/ Telma makes electromagnetic brakes.
Miss this show
The first time I was in a truck and the driver Jake Braked, I thought the Porsche Panamera driving next to us had the craziest engine swap lmao...
2019 new engines be crazy bruh
nice videos....i'll watch EVERYTHING AGAIN....
I once had no brakes in my VW , e brake barely worked …. I would carefully slow myself down with engine braking until the ebrake could handle the stop for about a week until I got the brakes fixed
Pretty damn accurate except those exhaust valves animation..... also I was hoping your cover exhaust brakes which consequentially do the same thing just farther down stream of the motor itself. But still a great video!
Bring it back!!!
How does a starter and ignition work?
Very informative, I had a guy lie and say the jake brake is actually spinning the motor backwards ( I know it sound dumb as shit) but I believed him because he drive trucks... Smh
I didn’t get any of this but still love this.
forgot to mention runaway ramps
Bring back Bart!! I wanna learn more :)
Hey can you guys do an episode on two stick transmissions? Thanks
My god that poor poor man! What a name!
The newest truck has now duble brakes on each wheel,each wheel has two disk brakes
you have big triceps work the biceps now
Great explanation!
The caption for Diesel engine said a spark ignited the fuel on the combustion stroke. Whoops on that one.
My biggest question is why specify a manual gas car when from my experience driving an automatic gas car it can engine brake effectively
18 wheeler trucks are 80,000 in all 50 states.
I miss science garage so much
Do air brakes next.
The Steve Brule of cars
The original purpose of a Jake Brake was not to slow down the vehicle but to prevent the diesel engine from doing what is called a runaway which is a horrible event that can happen to a diesel engine which causes them to go out of control and often can lead to damage and destruction of the engine thrown rods though the block is a common effect. Stopping them is all a matter of luck and how fast you can move. First thing is to cut fuel but sometimes they will still run because they then begin to burn the engine's oil because of bad seals most times so in order to stop it you have to get to the air intakes and plug them with whatever you can find to cut off air to the engine. If your quick enough you can do this before any damage is done to the engine.
I miss science garage!!!! Definitely one of my favorites!
What happened? Why do I no longer see those type of videos? Did the actor leave donut?
@@italengro197 I think so, if I recall correctly the host, Bart, had a child and is focusing on that. Don't know if he'll be back however.
I respect his decision, i hope he comes back though!
@@Hakiri27 agreed
@@josephgambino8306 well actually he said if it was up to him he would still be there
UA-cam is broken. My video released same time and also has no views, not visible in videos. Awesome UA-cam!
No u reeeeeeee
Engineering Explained have you taken it down I can’t see your video?
EE, I'm subscribed to you too and your video isn't showing up in my sub feed yet.
ill watch it man. once it shows up of course.
And was cursing my service provider
We miss you Bart and science garage :(
We need science garage
Science Garage! WHERE ARE YOU????
@@waynegrape he took a break because he had a child, he said this in a video about rolling coal, they deleted it though..
he is playing hide and seek
@@thewannabeweeb Why would they delete the video?
Fact: every engine can get up to 15000 rpm at least once
Edit: people are taking this joke to serious calm down
@@идиотты I dont think you understand the joke so instead of saying r/woosh I will explain it every engine can get to 15000 rpm at least once because it will brake it
Sorry for my stupidity, I get you now
Only once...maybe some break before reaching 15000rpm
@@онгпник not if its fast enough
Mmm if the engine gets there before throwing a rod into space
Coming up to a tunnel? It's Jake Brake O'clock.
Dang straight
😂
BRBRBRBRBRBRRBRBRBRBRBRBRBBRbrbrbbrbrbrbbr......
I hate how most of the new trucks have Jake brake noise dampeners so you can barely hear them
A straight-piped Cat C15 has beautiful rumble! I always bring the thunder going through a tunnel.
@@ant0n0vich the C12 as well. The C7 is one of those engines with the noise reduction.