Thanks for the video.. You mention the "recycling" of the exhaust gases by the supercharger (roots blower). Instead the exhaust gases are force out of the cylinder by fresh air supplied by the supercharger. Thanks once again.
I heard that too, 2 stroke diesels require forced induction to scavenge the cylinder (force exhaust out of the cylinder) because they lack an intake valve, they only have exhaust valves. As the piston moves down on the power stroke at BDC (bottom dead center) the intake ports are uncovered and the exhaust valve is open. This is where forced air will force all the exhaust out.
Union Pacific was the force behind the EMD turbocharging, there’s a good story on the whole Omaha GP9 project in the late 50s. UP did a lot of the R&D for EMD teaming up with Garrett and Air Research on turbo development and testing of turbocharged GP9s. Of course in the end the EMD design is what lives as you shown here.
wonder if the GP20 sold so "few" units because there were so many super successful GP7-9's in service that roads didn't really need to add anything to their rosters like they had during the initual buy-in for the switchover to diesel motive power. Great video as always, Peter!
I don’t think EMD ever referred to it as super charged. That called them roots blowers and that’s what they did, they provided scavenging air. I don’t think they ever provided boost above atmospheric pressure, therefore they were of no power gain. They were required for the engine to operate. And the 567 was released in 1938.
So, at 1:27 I see the same photograph of a used up prime mover 567 and I’m curious I did a quick Google search and I found lots of better pictures of that engine. Did you use that image because of copyright issue or lack of? Anyway you do great videos Bro keep doing what you’re doing
The function of the geared turbo was explained well, except for the part which you say the recirculation of exhaust gasses. Which is incorrect, the turbo, and the roots blower on the older engines, have the function to provide positive air flow trough the cylinders to propel exhaust gasses out and replace them with fresh air. As the EMD engine is two stroke the exhaust and intake strokes are not there as individual strokes. The engine has 2 exhaust valves in the cylinder head and intake ports in the lower part of the cylinder bore. The piston itself acts as valve for these ports. After the combustion stroke the piston nearing BDC, the exhaust valves open just before the point the intake ports are uncovered, initially residual combustion pressure will force gasses out of the exhaust so that pressure is low enough when the ports open and no exhaust gets pushed back in the intake. When both valves and ports are open the piston is around BDC and has little movement, so there isn't much encouragement for the exhaust gasses to move out. Here the roots blower or turbo comes in, it forces air in to expel exhaust gasses from the cylinder, this is called forced induction. The roots blower had enough capacity for this proces but not enough to boost the pressure, that would require a larger blower and as you said that eats to much power from the engine and the turbo is the better option. Timing of the exhaust has to be a bit different too, it closes earlier than on the non turbo versions.
@@FixAndForget I have to correct this, there are indeed more exhaust valves, 4 to be precise, but there are 2 rocker arms each actuating a pair of valves, the third rocker in between is for the injection I suppose?
@@Tom-Lahaye you are absolutely correct. 4 exhaust valves actuated by two rockers acting on valve bridges. Middle rocker is for the injector. Excellent explanation you wrote above, thank you for that sir.
Okay, the 567 was first introduced by late 1938 into 1939, not 1950(s) as you stated. The first EMD with a turbo was the SD24, which came out around 1958, predating the GP20. As for the low sales, as you stated the railroads had pretty much dieselized by 1960, (Norfolk and Western still had a few pockets of steam in service). Plus a recession was underway. That economic climate also affected Alco, and GE was releasing its U25 series. BTW all EMDs were roots blown until they came out with the turbo option, (the GP18 is the non-turbo version). EMD would continue to use roots blowers in the 645 series of prime movers, the SW1000/1001/1500, GP/SD38 series.
Weren't Buchi turbochargers good ones?....i live in india and old alcos here have Alco branded and napier turbochargers 2600 hp.....newer alcos have bharat heavy electricals (BHEL) turbochargers and are rated from 3100 to 3400 hp...
I tell ya Joe- yeah a single part paint is easy and cheaper. But a 2 part does hold up better. And it does look better longer. I work at a boatyard and we've never had a customer request a single part paint. I'll have about 5 years into my Hatteras when I get done- and the only thing I'm laying down is Alexseal, and then I'm gonna drop another $2000 on ceramic coating. I want my boat looking good for as long as possible
Wrong video? But since we're here non catalyzed paint has many drawbacks for almost every situation. 2k is almost always better except for very cost driven applications and some niche powder coatings. Yes there is 1k and 2k powder coatings.
I work on ships and volunteer on museum ships. It has become a side hobby trying to get the museum ships to switch from 1 to 2 part paint. I won't even use single part paint on a refrigerator.
Thanks for the video.. You mention the "recycling" of the exhaust gases by the supercharger (roots blower). Instead the exhaust gases are force out of the cylinder by fresh air supplied by the supercharger.
Thanks once again.
I heard that too, 2 stroke diesels require forced induction to scavenge the cylinder (force exhaust out of the cylinder) because they lack an intake valve, they only have exhaust valves. As the piston moves down on the power stroke at BDC (bottom dead center) the intake ports are uncovered and the exhaust valve is open. This is where forced air will force all the exhaust out.
Union Pacific was the force behind the EMD turbocharging, there’s a good story on the whole Omaha GP9 project in the late 50s. UP did a lot of the R&D for EMD teaming up with Garrett and Air Research on turbo development and testing of turbocharged GP9s. Of course in the end the EMD design is what lives as you shown here.
Nice video man, thanks for the credit. Keep up the nice work.
Glad you liked it! Thanks
wonder if the GP20 sold so "few" units because there were so many super successful GP7-9's in service that roads didn't really need to add anything to their rosters like they had during the initual buy-in for the switchover to diesel motive power. Great video as always, Peter!
I don’t think EMD ever referred to it as super charged. That called them roots blowers and that’s what they did, they provided scavenging air. I don’t think they ever provided boost above atmospheric pressure, therefore they were of no power gain. They were required for the engine to operate. And the 567 was released in 1938.
So, at 1:27 I see the same photograph of a used up prime mover 567 and I’m curious I did a quick Google search and I found lots of better pictures of that engine. Did you use that image because of copyright issue or lack of? Anyway you do great videos Bro keep doing what you’re doing
The function of the geared turbo was explained well, except for the part which you say the recirculation of exhaust gasses.
Which is incorrect, the turbo, and the roots blower on the older engines, have the function to provide positive air flow trough the cylinders to propel exhaust gasses out and replace them with fresh air. As the EMD engine is two stroke the exhaust and intake strokes are not there as individual strokes.
The engine has 2 exhaust valves in the cylinder head and intake ports in the lower part of the cylinder bore. The piston itself acts as valve for these ports. After the combustion stroke the piston nearing BDC, the exhaust valves open just before the point the intake ports are uncovered, initially residual combustion pressure will force gasses out of the exhaust so that pressure is low enough when the ports open and no exhaust gets pushed back in the intake. When both valves and ports are open the piston is around BDC and has little movement, so there isn't much encouragement for the exhaust gasses to move out. Here the roots blower or turbo comes in, it forces air in to expel exhaust gasses from the cylinder, this is called forced induction.
The roots blower had enough capacity for this proces but not enough to boost the pressure, that would require a larger blower and as you said that eats to much power from the engine and the turbo is the better option. Timing of the exhaust has to be a bit different too, it closes earlier than on the non turbo versions.
This is exactly correct. And explained better than I could have put it into words
Never seen an EMD or Cleveland/Winton with 2 vales per cylinder. Are there any examples of this? Thanks
@@FixAndForget I have to correct this, there are indeed more exhaust valves, 4 to be precise, but there are 2 rocker arms each actuating a pair of valves, the third rocker in between is for the injection I suppose?
@@Tom-Lahaye you are absolutely correct. 4 exhaust valves actuated by two rockers acting on valve bridges. Middle rocker is for the injector. Excellent explanation you wrote above, thank you for that sir.
Thanks for catching my error! I have posted a note in the description to correct my mistake.
Great again .mr alco man .your the alco man in the business butt i still love those old smoking and cussing engines
Okay, the 567 was first introduced by late 1938 into 1939, not 1950(s) as you stated. The first EMD with a turbo was the SD24, which came out around 1958, predating the GP20. As for the low sales, as you stated the railroads had pretty much dieselized by 1960, (Norfolk and Western still had a few pockets of steam in service). Plus a recession was underway. That economic climate also affected Alco, and GE was releasing its U25 series. BTW all EMDs were roots blown until they came out with the turbo option, (the GP18 is the non-turbo version). EMD would continue to use roots blowers in the 645 series of prime movers, the SW1000/1001/1500, GP/SD38 series.
3:43 the rare SDP35.
I saw both the L&N and SCL versions many years ago.
I am thinking that because most railroads have just finished dieselizing and were happy with their GP-7'S, GP-9's and RS-11's.
0:12 I have a m3 from one of those guys!!!! (Same railroad and everything I believe)
Weren't Buchi turbochargers good ones?....i live in india and old alcos here have Alco branded and napier turbochargers 2600 hp.....newer alcos have bharat heavy electricals (BHEL) turbochargers and are rated from 3100 to 3400 hp...
Are they still building Alco powered locomotives in India?
@@RichardKroboth They are being phased out.....replaced by emd 4000hp 710 engined diesel locomotives....
@@RichardKroboth Alcos will be gone by 2025-2026..
I tell ya Joe- yeah a single part paint is easy and cheaper. But a 2 part does hold up better. And it does look better longer. I work at a boatyard and we've never had a customer request a single part paint. I'll have about 5 years into my Hatteras when I get done- and the only thing I'm laying down is Alexseal, and then I'm gonna drop another $2000 on ceramic coating. I want my boat looking good for as long as possible
Wrong video? But since we're here non catalyzed paint has many drawbacks for almost every situation. 2k is almost always better except for very cost driven applications and some niche powder coatings. Yes there is 1k and 2k powder coatings.
I work on ships and volunteer on museum ships. It has become a side hobby trying to get the museum ships to switch from 1 to 2 part paint. I won't even use single part paint on a refrigerator.