J79 - Turbine Engines: A Closer Look

A guided tour of the J79 turbojet engine, from intake to afterburner. This is the cutaway display we have in front of our shop at S&S Turbine Services, where we overhaul and repair industrial gas turbine engines for customers all over the world.
If you liked this video, check out my channel page and type J79 into the search bar to see test run videos featuring afterburners.
To help support the channel, check out Patreon for AgentJayZ.
Thanks!

[@luarbiasawaras8700]

This is a 9 years old video, still teaching us valuable leasons, thank you Sir

[@AgentJayZ]

Thanks for that... I'll keep makin' 'em as long as you keep watchin' 'em!

[@wingsofmind]

In which aircraft model it was equipped with????

[@4rct1c9Ic3m4n]

Hot Musician: What kind of instrument do you play? Cool Musician: a J79

[@Marauder1981]

That´s Einstürzende Neubauten. They actually play on turbine parts

[@RayRay-wn5vh]

The first stage turbine is probably the hardest working part of this amazing machine. Your explanation is on point for anyone. Thanks forgot doing this video. This incredible machine made this world a small place. Now let's live in peace.

[@MiguelMartinez-il9vs]

Hello Ray. Can you explain why the First stage is the hardest working part? I work for an MRO for the J85 and see many 1st and 2nd stage that we work on.

[@jshanker2005]

He got distracted a little and started playing music in the middle.

[@doctorTF_2]

who wouldn't?

[@AgentJayZ]

Thanks. you have a lot more experience with this engine than I do! I have not tested a modern fighter engine, so I can't really compare, but I just love these old beasts ! Your approval means a lot.

[@69adrummer]

I have the utmost respect for people that make this their art and their life and their career! While it's pretty easy to understand, I know there is so much going on here! This video helped a lot!

[@黃冠瑋-h1o]

It's hard to understand why that shape and its material,I still don't know why this J79 engine will blow out much black smoke when it's working?It's pretty bad when flying and fighting.

[@stanleyallan6997]

This is a terrific video. I have, for a long time, understood the basic operation of a jet turbine engine. To see it up close and explained was informative and very enjoyable. Thanks!

[@AgentJayZ]

@justforever96 The turbine nozzles are located upstream of their respective turbine stage, while a compressor stator is located downstream of its respective stage, otherwise the two components are similar. Stators decelerate air coming off a compresor stage, raising its pressure, and direct it at the next. Turbine nozzles accelerate exhaust gases, lowering their pressure, and direct them towards turbine.

[@Slikibastic]

The engineering that goes into something like this is just amazing... Great video fella

[@larrycrawford7240]

At the Ontario, California Engine Shop, we overhauled J-79 engines for the Air Force in the early 60's to the late 70's man there were alot of engines we overhauled. A great place to work.

[@Blaze0357]

Fantastic Video, Thank you. I'm 45yrs. old and have had the jet turbine engine explained to me in many ways. Now finally (Thanks to your video) I 'fully' understand how they work. Very cool!

[@mccc4559]

OMG THIS WAS SO COOL TO WATCH!!!! I CAN'T THANK YOU ENOUGH. I REALLY APPRECIATE YOUR KINDENSS IN SHARING.

[@SuperStevegrant]

Sitting in The Cotswolds in England.. I am addicted to these videos. Don't know why, but I am.........

[@THEBASIL1946]

I work on F 4B & J for 9 years in the Marines

[@sarahyarwood4612]

Very informative, music to the ears even when it doesn't run.

[@corymcdonald3703]

FYI, I subscribed because of your short to the point explanation and telling me you had other videos to show what you were explaining. Great job!!!

[@AgentJayZ]

Thanks, and thanks.

[@AgentJayZ]

Those are shielded electrical lines that carry the low voltage signal generated by the thermocouples just aft of the last stage of the turbine. They indicate EGT or exhaust gas temperature. The circular arrangement of thermocouples is divided electrically into two halves, so there are two lines.

[@alexy1085]

Thanks so much for sharing and this vid and ur explanation are so helpful for students who want to see the actual jet engine in detail.

[@marcemarce9821]

You were playing music with it, while I am very amazed, so awesome to, & thank you very much for showing

[@tonyv8925]

Wow, I remember these when I was in the Air Force, along with J-69's and J-85's 42350--F4E's, C-141's, T-38's and T-37's

[@javacup912]

Somehow the comments went from a J79 (GE) to the R&R RB211, but to make even clearer to Mr. Bradley below, the RB211 is what's called three-spool engine, and as AgentJayZ stated, each spool has it own compressor as well as their own turbine, but no "three piece shaft" as you stated and corrected by AgentJayZ. Great video, guys. I'm well up to speed on this technology, but still amazed how well you explain things in just plain English, and not just this video but others. Thanks.

[@nestea322]

Simply amazing... Believe it or not, the IGV's are very similar to many IGV assemblies on centrifugal refrigeration compressors. The old Westinghouse/Mcquay centrifugals had IGVs and rear diffusers (variable outlet) that worked in sync with the IGV assemblies. to assist in the variable capacity capability of the 'pump', if you may. Tolerances were critical. Thanks for the video.. I always loved the J79's in my favorite plane, the F104.

[@AgentJayZ]

Yes, like this, but a few details might help. "Air" does not turn "the shaft". The turbine takes energy from the expanding exhaust gases and converts it to torque on a shaft connected to the compressor. The compressor, turned by torque supplied by the turbine , compresses air and feeds it to the combustors, which mix fuel with the air and burn it, supplying the hot expanding exhaust gases to the inlet of the turbine. Your last sentence is true but unexplained, therefore confusing.

[@AgentJayZ]

r1cw is 100% correct, and I endorse his answer completely.

[@Waschi111]

A very good tour! Nice and understandable explained even for a German like me :-)

[@doctim111]

What a great overview, glad I watched again after a few years

[@danielvazquez8966]

This must be one of the sexiest vids out there, thanks man it's just a beautiful piece of engineering.

[@Ihavetruth22]

This is one of the best videos on turbines i have ever seen. Great job!

[@zapfanzapfan]

What a beautiful piece of musical instrument, a very big music box :-)

[@c.y.1458]

+zapfanzapfan, What instrument do you play? "The J-79"

[@davidfriesen7748]

Nice , I now know a lot more about them dam things now . Always wondered about that.

[@AgentJayZ]

@discofishing There is a dividing line between engine and airframe that aims to simplify as much as possible the whole arrangement. The aircraft hydraulics are powerd by an engine-driven pump, but the engine hydraulics are not part of that system. The engine oil pump may be used to power the engine hydraulics, or they may be powered by yet another external hydraulic pump.

[@Nyck461]

Very detailed and instructive video. This guy really knows what he is talking about. Congrats for your video.

[@AgentJayZ]

@IWMYB61 This is a complicated question, which I will partially answer with a simplified explanation. Think of a compressor blade as a small wing flying through the airstream. The angle of attack of this wing depends on its own speed ( engine rpm ), and on any velocity the air it is flying through might have. The VIGVs and the VSVs work to make sure this resultant angle of attack is kept within a range of values at which the wing will not stall.

[@mulyadirekso8428]

You give the amazing information video, thanks.

[@ibrahimabdullah7793]

THANKS A LOT FOR DETAILS, ITS HELP TO UNDERSTAND HOW JET ENGINE WORKS, ITS SIMPLE BUT DEEP TECHNEC,

[@donaldvincent]

Thanks, Always loved ANYTHING about aircraft but I never dreamed that internal parts of a jet engine could be musical.

[@AgentJayZ]

@anoncritic The liner of the afterburner duct is ceramic coated, and it is usually white or light grey. Sometimes the coating is green.. I don't know the reason.

[@AgentJayZ]

Well, thanks. It seems you enjoy these machins almost as much as I do. I make these videos for fun, and for people who are interested.

[@Artiscrafty]

Always the best. Thank you

[@AgentJayZ]

The compressor stators convert the velocity of the air created through mechanical work done by the compressor rotor blades, into increased pressure. Saying the stators provide the compression ignores the contribution of the rotor in supplying the energy to the process. It takes both the rotor blades and the stator vanes to compress the incoming air.

[@lmechb3305]

Without entering a pissing contest, don’t both the stator and rotor blade sections within a compressor increase pressure as they form a divergent duct between each aerofoil? As you say, the rotor blades provide an increase in velocity as well, but pressure gradually increases through each stator and rotor.

[@thcoura]

What a work of art!

[@raymonddupuis9041]

I do NDT fpi inspection recognize a lot of the parts. Interesting to see where they go. I did learn a lot from your videoes, thanks. Front frames mid frames rear frames compressor cases etc. etc.

[@tyymclarenfan]

Absolutely amazing details, as i love anything technical 👍🔧🔩

[@AgentJayZ]

A scrap engine is cheap. But it's a lot of work to make a cutaway. Some of the disassembly needed to make a clean job of it takes special tools. And the alloys it's made of are very durable and difficult to cut. If you want to make a cutaway... call the shop. We can help you out.

[@AgentJayZ]

Maybe I should add, before you decide to correct me on how the three shaft engine really works... I have in fact taken a couple RB211s apart, and I've helped rebuild them. I'm not an expert on this engine, but I am quite familiar with the general arrangement of the internal workings. Not trying to start a pissing match, but you need to be right if you're going to correct someone. Cheers!

[@michaelrichter8973]

Very informative thank you good video no goofy music just instructive !

[@TechMan-sl5gf]

Well, I worked AGS in the Air Force for a few years on F4E/G. Yeah, I've seen it and it was a royal pain to put in and take out.

[@bilalsayed5381]

Thank you for sharing this valuable information. .

[@williamyamm8803]

Thanks a lot ! Excellent video, as usual.

[@AgentJayZ]

@svenp Sounds good! As far as exactly where the force/thrust is generated and exactly how much pushes on which part... that's a mixture of engineering and black magic.

[@AgentJayZ]

That's an idea for the future...

[@cprashanthreddy]

The best video I have ever seen. Best Channel... Good Job...

[@capitanvonchickenpants8492]

I worked for General Electric for 11 years as a welder, we always referred to the power "blades" as buckets

[@buckrogers5331]

Thanks, man. I was just looking for such a video!

[@gjpetryk]

Enjoyed watching this and getting a description of all the major components. Thanks, but not sure I would now consider myself an "Expert"... Hey, but if you insist! :)

[@syedmuzamil2044]

awesome i like it very much its a cutaway model for gas turbine basics.thanks

[@gpolaski]

There is a Facebook group called USAF Engine Mechanics. There are bout 2500 of us on there; active duty, reserve, guard, and retired. You might get a kick out of it. A number of us "old dudes" have F-4s in our past. We are assuming your engines are mainly J79-GE-19s (from later F-104 aircraft), whereas most of us worked -15s and -17s from F-4s.

[@MattH-wg7ou]

Great video!

[@AgentJayZ]

Jet City is in Fort St John, BC. An easy-going 12 hour drive from Mission !

[@AgentJayZ]

@svenp Hey, you're looking at a video, and I can't capture all of it. If you worked with the stuff, you'd see everything is made like the finest workmanship possible. What looks like sheet metal is mostly thin machined parts from super-tough metal alloy. Also, turbine engines don't have pressures and shock loads like piston engines trying to contain explosions. If car engines were made like this, they'd last for millions of Km.

[@TheArfdog]

I think the correct description is the stator vanes direct the airflow to optimize the flow for the next stage. I don't think they play much of a role in increasing pressure or changing velocity/energy of the air. The rotors and decreasing case volume is what really compresses the air.

[@AgentJayZ]

Kind of for the same reason the engine e block in your car doesn't rotate in the opposite direction of the crankshaft. A great introduction into how these things are designed and how they work can be found in "the Jet Engine" by Rolls Royce publishing... in your library now, I'll bet.

[@MuhammadTayyab-iv4rd]

Very nicely explained....thank you sir....🙏👏🏽👍

[@newcoyote]

Holy lordy, this is the coolest channel ever. I have had a life long love of aircraft (I'm an amateur aviation photographer) but only a basic understanding of jet engines. These walk through & breakdowns are fascinating. I jumped when I saw you mention Mission BC because this is where I am. I don't get where you are. Do you say?

[@NOPEnameMC]

I love your videos! Now I finally understood how such an engine works :D

[@riche4you1975]

Great vid and knowledge even if I am 9 years late

[@Beemerboy324]

VERY well done, lad. Very informative.

[@umarshahbazahmadumarshahba3612]

Very good explanation

[@dhrupadsaha4171]

Thank you so much sir for this content..

[@timtravasos2742]

Amazing! Great video.

[@bts845]

Well done, you are a good teacher. Keep it up!

[@democracyforall]

Thanks for the explanation.I am an ELectrical Engineer and want to build a small mock engine but there are a couple of things unknown to me.

[@Musti087]

Once again, a very interesting video (not only for aviation students ;) ) , tnx m8!

[@tejay511]

AWESOME Video!! Thanks!

[@mii3000]

@AgentJayZ don't worry I'm am way ahead of you on that one. I get excited to see ":A Closer Look" in the titles. I hope to build my own turbine for a college project soon by using a old car turbo. Now I'm thinking of the best flame holder or flame tube design that I could make with out major tools.

[@sampintilie9]

Hey thank's for showing in details this video !

[@jumpmaster15k]

Also, if you counter rotate the stator vanes, you lose all compression. The compressor stator vanes slow down the accelerated air and are what actually cause the compression.

[@AgentJayZ]

Just noticed this comment. You do not understand what you are saying. Three piece shafts is incorrect. Three shafts are contained in the RB211. Each shaft has a turbine and a compressor, and the relative speed of the compressor to the turbine on each shaft is of course zero. Each of the three shafts, or systems, rotates as a unit. In order which the air encounters the compressors, they are called the LP, IP, and HP systems. Nobody made anything up; you just misunderstood.

[@MikheilGhvinianidze]

they sound amazing

[@lincolnengland5005]

Another excellent video; I'm an engine designer and it's always really interesting for me to see how somebody else approaches the same design challenges as we do....the cans and transition duct is very different to the annular systems that are commonplace now this side of the pond. Given the uncooled turbine blade 1 the firing temperature must be quite low? I didn't grasp the length of the engine; obviously the afterburner makes up a lot of that but that's going to take a lot of aircraft to hide that!...again, thank you for your video and kindly sharing your experience.

[@AgentJayZ]

It's important to remember that this is a design from the early 1950's.

[@lincolnengland5005]

​@@AgentJayZ Absolutely.....

[@xBIGMUSCLEx]

Which company do you design engines for?

[@lincolnengland5005]

@@xBIGMUSCLEx I've freelanced to Rolls-Royce, Siemens, GE-Alliance, GE-Honda, MTU and maybe some more!

[@xBIGMUSCLEx]

@@lincolnengland5005 Do you have an email address I can reach you at? I am working on a project involving a unqiue gas turbine design and looking for freelance designers. Please let me know.

[@AgentJayZ]

As radioactivity sensors become more sensitive and more common, expect this problem to worsen.

[@AgentJayZ]

@COD5252 Well, you're getting into design philosophy of engines, which determines the engineering solutions, which then determines the way the things are actually built... which is where my experience is, to be honest.

[@pancudowny]

I take it that despite believe of "The hotter discharge from the combusters, the better/more-efficient the operation.", there does come a point where too-high of discharge temperature over-stresses the metals found in the aft-section & cooling the charge aids said pieces longevity.

[@AgentJayZ]

You are totally correct up to the point where you say cooling the charge. To me that would mean cooling the inlet air. That has no effect. The discharge of the combustor is a combination of combustion gases mixed with what is called cooling air. So If you mean that, then you are also correct. You just said it in an unfamiliar way. The gases that make the turbine turn are only a few degrees below melting temp of the parts at full power. In some engines with air cooled blades, it is higher than blade melting temp.

[@pancudowny]

AgentJayZ Sorry if my phrasing caused confusion... I guess in my urgency to comment I didn't think to double-check my phrasing. But yes, I did mean it as you said in the latter part. And having an understanding of heat-regenerative turbine design--Chrysler"s legendary turbine-car developments--I certainly understand the importance of keeping post-compressor air temperatures high for the sake of more complete burning of the fuel introduced & overall fuel-efficiency. Also, I'd like to mention that I've seen a similar such design used in exhaust-tip design by Banks Engineering on their after-treatment exhaust systems to cool diesel exhaust gases--Most successfully!--with just ambient/surrounding air.

[@LargeWave]

Nice walk through and compressor blade music. Thanks!

[@AgentJayZ]

Your tongue must be firmly in your cheek, because you have described exactly one of the aircraft this engine was installed in. Most of the J79 tests I have posted are of engines from and returning to F104 Starfighters.

[@svenp6504]

@AgentJayZ I get what you're saying regarding pressures. But still, something has to transmit the 18,000lbs of thrust to the airframe. That outside skin doesn't seem like it's made for that. I'm guessing that the rotor is designed to carry the axial load to the bearing housings which transmit it to the airframe?

[@tm502010]

Very nice video!

[@volsanslimit]

Hello I love your videos. Instructiv and interessting. thanks

[@zero00tolerance]

Thankyou for sharing it with us !! This video was very informative, i learned a lot

[@AgentJayZ]

@51zelao If you mean where are the fuel nozzles, at 1:30 you are looking right at one. If you mean what are fuel nozzles, well they are fuel nozzles.

[@tiagohnf]

this video is priceless! thank you!

[@jesusdacoast872]

Thanks

[@mytmousemalibu]

Fantastic Jay! Thanks for the tour! Hows the torch ignited and stay lit jay? I presume its burning liquid fuel? Somthing i saw on another video, but what would cause some random sparks to come from the jetpipe?

[@RAHULKUMAR-wm9wk]

Thnks brother ❤👍❤️

[@discofishing]

@AgentJayZ Thanks. Out of curiosity, why is engine oil used? Is there a reason it was kept separate from the aircraft hydraulic system? The only thing I ever worked on was T700 engines on Apache helicopters. It's really cool to know about other engines and their operating principles, especially something as historic as the J79.

[@mytmousemalibu]

@AgentJayZ Ah ok! kinda neat! I saw in comments of another video of F-104's at night so i could see the torch igniter in action, real neat how it illuminates the jet pipe at night! That same video, one of the Starfighters spit a few sparks out the back. But it was just off idle so prolly some blade contact then. Unless the torch caused it because it was on? Thanks Jay!

[@sanjeevalasantha4502]

Good explanation.thanks .

[@princejaa]

thanks for the vid. im going for my o&p soon. i found this vid helpfull. thumbs up.

[@jamesbradley1695]

Hi AgentJayZ, it would be interesting to know why there are such huge axial clearances between the compressor vanes and the stator vanes (yes I know they pivot). If the gaps were a fraction of the size, you could knock nearly two feet off the length of the engine and seemingly make it more efficient?

[@danafield4696]

Well I wouldn't say I was an expert on this after ur great video , but I did learn a few things , I know more about this j79 then I do women !! Lol thanks