Part 2: Allison V-1710 Dynamometer Demonstration

Bud Wheeler from Ace Allisons demonstrates testing an Allison V-1710-99A engine on their exclusive aircraft engine dynamometer. Bud takes you from engine start up through various engine power settings to power down. For more information, visit AceAllisons.com. Be sure to watch Part 1 for an in-depth explanation of our dynamometer.

[@garyplewa9277]

Designed with slide rules and paper. Machined well before CNC was invented.. An absolute work of art.

[@edwardpate6128]

In combat in WW2 pilots pretty regularly pulled 70 inches of manifold pressure which works out to about 1750 hp

[@watsisbuttndo829]

My grandfather was in Darwin Australia during ww2 and recounted that when push came to shove the P40 pilots ignored the operating parameters and the Allison seemed to accept it.

[@capthawkeye8010]

@@watsisbuttndo829 The operating parameters were for prolonging engine lifespan more than they were hard points where failure could occur. Failure is more likely beyond the safe-operating limitations. But at no point in any aircraft does a manufacturer red line 2500rpm with the knowledge that at 2501rpm or even 2600rpm failure *will* occur. By 1941 anyway these engines were being produced like crazy and unhealthy or even destructive use of equipment meant absolutely nothing to the men using them for good reason.

[@EstorilEm]

The fuel and superchargers wouldn't allow for 70" on all but a VERY few variants. This one (-99) was rated just above 50" and 1360hp for war emergency power. Very few US engines were running anywhere near 70" even during late war, I think the P-47 N/Ms were around 72" but also generated around *2,800hp* at that pressure, which was similar for the F4U-5 but that didn't see combat.

[@shaneconrad7816]

The fuel octane was much higher for the high performance fighters in WW2. Believe it was 130 with up to 150 octane available. Wonder if this test was with todays 100LL?

[@edwardpate6128]

I love the sound of an Allison!

[@clivelee4279]

Most interesting , thank you. My father was a engine fitter in the RAF during the war, he said that when the engines had used emergency power in action, which broke a tell tail seal on the throttle , the engine oil/filter had to be drained checked for white metal debris, if it passed this , it was then run up for a specific time/ revs , then drained and checked again , lots of fasteners on the engine Cowlings , filters plus locking wire , many gallons of oil , not a popular job particularly winter in the open. Because he was older/ conscientious, than the rest of the ground crew he often got the job ( he was in his late 30s, the rest were teens early 20s) he was given the nick name “ the cowling king “thank for the video.

[@andyharman3022]

Very nice-running Allison. And with data, too. I'm a total nerd on this stuff. Test setup is very well-engineered.

[@fsj197811]

Oh gawd, can you just leave it at that lopey idle at the end for about 20 minutes and record that??? I could put it on a loop and listen to it all day. Thanks for sharing!

[@glennjames7107]

It does sound blissful, but it's hard to beat the "lopey" sound of an old radial idling, especially right after startup, before its cleaned up and warm. They make the hair on the back of my neck stand up, don't know why, but they sound just lovely ! Next best thing is a nitro motor on startup, when its transitioning from alcohol, and the nitro starts randomly hammering in. That really dampens my drawers ! 🤣

[@HotRodPackard]

Absolutely incredible set up! Very impressive.

[@davidhuff5632]

Excellent presentation and content. Fascinating stuff, thank you.

[@BudWheeler]

I have read about the early engines/pilots using higher than recommended power settings. This required Alliosn to start installing manifold pressure regulators. I have also heard about crew chiefs tampering with these. The facts are that the fuel (100 octane) was the limiting factor. 2" manifold pressure above the recomended begain detonation and that changing depending on outside air temp.

[@pauldietrich6790]

Great vids...I came here right after I viewed pt. 1TY for posting!

[@ericlakota1847]

Great video thanks for sharing it I love all your videos I know alot about thease air craft motors from your channel love how it's hooked to turbine instead of a prop on a stand

[@onemantwohands5224]

Ahhhh this was soooo fun to see !!!! Thanks a million ❤

[@TheAnonymous1one]

Another great video. Love the sound of the engine

[@edwardcarberry1095]

God Yes,! Love the sound of engines. The little bit which I did , many years ago I was able to tell which aircraft was above by the sound of the /that engine although being the same engines. Loved it, the Gent which I worked for was "GREAT"! HE WAS WONDERFUL.!

[@K-Effect]

If you notice nothing on that test stand was vibrating or shaking, not even the pyrometer wires. The only time I saw a slight bit of movement is when he was shutting the engine down. Very impressive work

[@hootersnoocher8467]

I bet they could balance a quarter on the frame. I too was watching for flex upon start up and like you any imbalance on shut down. 👍

[@JoeC88]

Heck yeah, That engine is beautifully balanced. That's perfect engine work 👍

[@BoostedSpeedDemon]

The Allison is actually a very well balanced engine

[@markthompson8656]

Good run . that answered a few questions I had. And I learned something I did not know too. ( I am an war bird buff and A & P)

[@av8bvma513]

Excellent setup! Have you considered preheating for the oil and water circuits?

[@CS_247]

Beautiful!

[@nigelbutler9488]

Great video, thank you

[@mysock351C]

5:45 I bet as a pilot in WWII that was probably your favorite sound in the world.

[@remkojerphanion4686]

That sound - o man! I'd love to hear that thing go from startup to idle, to full power, and back down to idle again - just the engine sound without narration please! 😉

[@paulloveless4122]

Just fascinating

[@edwardcarberry1095]

Love It!! Subed

[@scottpeters9911]

Good on ya! Surprised that it didn’t make more hp. Which grade of Avgas was used? As an A&P I find it very interesting that a J-79 comp section is cleverly used to provide cooling airflow. Good to know & a great show! Subbed!

[@birdboy48]

I think the torque figures are important here.

[@howardsimpson489]

Love the variable turbine vanes, have you tried a Merlin on the same rig? There were quite a few Allison engines in New Zealand after the war, they ended up powering some interesting boats..

[@aceallisons2639]

We specialize in the overhaul and repair of Allison's only. The dynamometer is designed solely around an Allison.

[@dyer2cycle]

When I think of Latrobe, PA, I think of Rolling Rock Beer! It was one of my favorites before AB gobbled them up....

[@aerotech1bob]

Nice what dash number was it?

[@pauldavidson6321]

What sort of decibels are you getting at full power and is the test engine vibration isolated from the test rig ?

[@aceallisons2639]

Decibels recorded are around 120@ take-off power. The engine on the stand is hard mounted but being a V-12 is very smooth and we invite our customer to walk up to engine and put their hand on it to experience it.

[@user-kw7zb8qw1u]

Ace i have question between Harry A Miller and Glen H Curtis who was better engineer and faster in the early 1900s ?

[@lcskibird8883]

How does your calibrated run stand check gear reduction unit oiling with out a F series nosecase?

[@BudWheeler]

Good question. Removing the F-nose or propeller gearbox and installing the E-nose adapter changes oil demand on the system. We installed a calibrated orfice on the main oil gallery to simulate the installing of the F-nose

[@jkdwayne]

I would like to know more about your test stand Data Aq System, I have an Engine Dyno that needs a retrofit and upgrade

[@aceallisons2639]

Please feel free to contact me at 724-875-3120 to discuss your questions and I will try to be of help.

[@user-kw7zb8qw1u]

What are the chts in one of those

[@bmasontv]

What airfuel ratio is this engine running at 100% throttle and war emergency power is emergency power? Also curious as to what timing is commanded at those power settings.

[@aceallisons2639]

10.00 F/A and twin ignition 28 and 34 BTC

[@aceallisons2639]

Allison considered 100% power what the aircraft systems (coolant/Oil continuously)could cool for continuous flight or METO power. This is not full throttle. War Emergency is practically full throttle or 60" MAP or the maximum before detonation. The fuel is 100 LL (the engine is supercharged)

[@bmasontv]

@@aceallisons2639 Very cool! Thank you very much.

[@bmasontv]

@@aceallisons2639 Thank you. I understood 100% throttle to mean maximum throttle for continuous power output. With war emergency meaning maximum maximum manifold pressure. As Someone who has quite a bit of experience with the gen 3 Hemi Hellcat platform, these World War II engines fascinate me. Years ago I was a docent at the Hiller aviation museum. I spent all of my time in the engines section.

[@grafspeem9402]

@@aceallisons2639 I think you had air fuel ratio AFR in mind, because with F/A at 10 no engine could possibly work. F/A at 1/10 then yes.

[@InNeedOfSpeed]

How does the dyno work? The mid section sort of looks like the compressor stage from a gas turbine.

[@InNeedOfSpeed]

Ah, found the first part. Interesting!

[@aceallisons2639]

The J-79 compressor has movable guide vanes that provide the load that we require for all of our test points (manifold pressure, RPM's) The gearbox provides the correct increase in shaft speed to match the engine RPM range with the compressor Range. The dyno is capable of holding any power range for an indefinite period of time. Limiting factor running out of fuel.

[@EnglertRacing96]

Could this dyno hold strega or voodoos merlin @ 3900ish hp? Or the cooper unlimited hydro twin turbo allison?

[@aceallisons2639]

A couple of thoughts. Our test stand is only for an Allison engine. A merlin would require a very different set up. Our torque transducer is rated for around 2400 Hp. Lots of numbers regarding horsepower bantered about( Example. 3900). I have been around and tested on a dyno these engines in many configurations and I can assure you they don't reach those numbers. Our stand is for testing Allison's for aviation use so I hope that helps you.

[@klrmoto]

How is the oil viscosity changed from cold start to operating temperature in an allison aircraft engine?

[@aceallisons2639]

The oil is 25-60W and with all engines becomes thinner or less viscosity as the temperatures rise. We have a controlled oil temperature target of 82-83Deg. C inlet temperature and 62-63 Lb oil pressure @ 2200-2300 RPM to insure proper oil pressures through out all operational ranges. Minimum oil pressure is 55Lbs.

[@BudWheeler]

We are not concerned about viscosity but more over the oil pressure as a result of oil temperature. We run the highest recommended oil temp. in order to make sure the oiling system is capable of suppling enough pressure for the aircraft operation

[@Warhawknm]

ww2 combat records show some pilots admit running their P-40 Allisons up to 70 inches! wow!

[@BoostedSpeedDemon]

Yeah I think there were reports of some engines exceeding 1700 horsepower in emergency situations based on airspeed of the aircraft.

[@sebclot9478]

That wouldn't have been much of a problem if they used the late war 150 octane fuel

[@sandrawheeler3331]

Hi Bud, I see you are an expert on Allison Engines. I have two! My grandfather Ellis White was part of the design team when he was in the military. He purchased two engines for my dad who recently entered a skilled nursing home. In short, I wanted to know if you know anyone that would like to purchase the engine(s). The other one is in a formula boat. All are in fair condition, but only an expert would understand what I have and know how to operate them. I don't unfortunately.

[@BudWheeler]

Hi Sandra. I am sorry but I have retired as of June 2023 and am no longer a player in the Allison field. Their are other parties that may be interested so try reaching out to them. Bud

[@sandrawheeler3331]

Hi Bud, Glad to hear you are retiring, and thank you for your response. Glad to know there are others out there that have an interest in the big beautiful engines!@@BudWheeler

[@ncktbs]

ive always assumed with these big bore and stroke ww2 engines that the torque would be similar to a diesels about double the hp rating

[@deeremeyer1749]

AvGas has half the "energy density" of diesel fuel.

[@JoelHouser-pv6iu]

Why no Alisons in PT BOATS?

[@wilburfinnigan2142]

joelHouser Because the M2500 Packard Marine was more powerful and more readily available, and designed as a PT Boat engine

[@williambikash6645]

Do you know the amount of hp the super charger draws from the engine at max boost? I add that figure to the engine hp output to cal fuel consumption

[@edwardcarberry1095]

I had read years ago, If my memory severs me?? if and if?? A turbo charger produces about 480 Hp and the super charger uses about 400 hp. So there was a slight dual increase in HP? Any knows this is not accurate do, Please correct this. As no offence taken.

[@wilburfinnigan2142]

@@edwardcarberry1095 The superchargers main job was not to increase HP but to MAINTAIN the HP as the plane went up in altitude where the air is thinner and needs more air pumped into the engine !! !

[@edwardcarberry1095]

@@wilburfinnigan2142 Yes, I learnt that some 50 years ago.

[@demonic477]

someone tell me if I got it wrong but didn't the American emergency power setting also include methanol water injection to help protect the engine under an emergency power situation. I know it was standard on a lot of planes in the armed forces and would increase the power output on the engine while keeping it cooler . like I said someone tell me if I got it wrong

[@aceallisons2639]

The answer to your question is somewhat involved. The limiting factor is always the fuel and how much manifold pressure or boost you can apply to a given engine design that is a limit before detonation. The engine in the video is typically limited to 60 inches Manifold pressure @ sea-level on on the ground because that is it's safe level before detonation without any form of intercooling or water/ alcohol injection. This engine is only capable of producing 62 inches MAP @ 3000 Rpm on a cool day on the ground. Every WW 2 engine is rated for maximum MAP for a given RPM and fuel grade. Forms of suppressing detonation and applying more MAP if available are intercooling and water-alcohol injection.

[@sebclot9478]

Some late war aircraft did have water injection. I don't think this particular engine did.

[@CreeperOnYourHouse]

Doing the math, that's around 0.67lb/hph consistently during testing. Is there any reason why it seems to be so inefficient? Aircraft engines during ww2 were getting around 0.5lb/hph from my researxg.

[@aceallisons2639]

The engine is being demonstrated in auto-rich. In the aircraft during cruise it would have been in auto lean and 0.5Lb/Hph

[@z31drifterlf]

How long could it run in WEP?

[@aceallisons2639]

Good question. We run in WEP for 1min. duration for 6 different cycles. The test stand is able to support the engine for an indefinite period of time. Allison required the engine to run for 150 hours @ WEP to qualify for certification. Take off power for 6 cycles of 5 minutes in duration

[@sebclot9478]

Luke, I looked up the engine flight chart for this engine in a P-40N. It doesn't list a limit for WEP. It just says "EMERGENCY ONLY" in upper case letters. "Take Off Power" has a 5 minute limit and "Military Power" has a 15 minute limit. The other settings were all unlimited. They were "Maximum Continuous", "Maximum Cruise", and "Minimum Specific Consumption".

[@u.e.u.e.]

Is this a straight 12 or a V24? 😃

[@aceallisons2639]

The engine is an Allison V-12. It has 2 exhaust pipes per cylinder or 2 exhaust valves per cylinder as well as 2 intake valves per cylinder. Please look it up on wikpedia

[@u.e.u.e.]

@@aceallisons2639 Thank you very much - even just the appearance is impressive! 😃👍 I also like the sound of engines with many cylinders. 😉

[@sebclot9478]

@@u.e.u.e. Two intake and exhaust valves per cylinder is common on WW2 era V12 engines. This is not unique to the Allison. I mention it in the event you see the extra exhaust on other era engines.

[@u.e.u.e.]

@@sebclot9478 Thank you! 😃👍

[@hoost3056]

Oooooof.......I'm just looking at the fuel consumption.......at cruise.......I can think of some turbodiesels that can equal the power but with better fuel economy

[@wilburfinnigan2142]

hoost3056 Not in an aircraft they won't !!!!!

[@311Bob]

I'd love to have a packerd,Allison,Pratt and Whitney and a merlin in my front room instead of a 70" tv

[@jp-um2fr]

Not quite the grunt of a Merlin but a lovely sounding engine.

[@wilburfinnigan2142]

jp-um2fr These Allison V1710 engines out grunted the 20 series and earlier Merlins as they were in case you did not know all also SINGLE stage supercharged, it was only the 60 series Merlin early 1943 that had the LATER, get that LATER newer 2 stage supercharger, they added a second compressor wheel to the supercharger and added a 2 speed gear box to turn the compressor FASTER at altitude. there were over 40 different models of Merlins produced throughout the war and most all dummies want to compare the LATE model 60 series as if ALL merlins were as such. and to compare the later merlins to the Allisons. That why the Allison Mustangs Mk I & II or P51A's would out run the later P51B/C'&D/K below 20,000 ft. the Allisons supercharger was tuned to the low med altitude the Merlin to High altitude. Those same early Allison Mustangs were also faster than the then current production $hitfire Mk V's with their single stage superchargers also and by 30 MPH !!!! The Allison did NOT get a later 2 stage supercharger because some dumb @$$ army brass thought the turbocharger was the answer but except for the P38 no room for the large turbo. It would have been nice IF the Allison would have gotten a 2 stage supercharger like so many other engines got. The Merlin the PW R1820's & the R2800's

[@basiltaylor8910]

Nicely engineered bit of kit, a trailer mounted dyno you can tow behind a Ford F 250 Pick-Up or Jeep Gladiator, can the trailer test a 60 Series Rolls Royce Griffon ?. , The '1710 'was a gift squandered ,originally designed by GM to power the US Navy,s second generation airship hence the lower rpm. In 1935 after the ZR-3 Macon,s tragic loss, in their illogical wisdom the US Navy cancelled the ZR- 4 and 5 Airship Programme. This Left GM with an engine they could not sell on the open market, but be suitable for the latest all metal monoplane fighters then under development. GM went about its re birth as an aeroplane engine in a cack handed manner, bolting on a blower bought from a Wallmart store . Anyone at GM with a functioning brain cell would have sent a technical commission to Rolls Royce at Derby, to study how they go about fitting decent performing blowers to their Kestrel and embryonic Merlin Engine, to pick the brains of Ernest Hives and Stanley Hooker , regarding blower design. Think of a '1710' fitted with a blower designed by Rolls Royce!!!!. Early ,1710,s were short on ponies, wheezy above sixteen seventeen thousand feet, and lacking an automatic boost control, standard on a Merlin or Kestrel. In short 1710,s were good 'hound dog' engines, ideal for rooting through the woods and weeds searching for an escaped prisoner,( ably demonstrated in low level ground attack missions by A-36 Apaches). To turn a hound dog into a race bred greyhound, like those on the sides of greyhound coaches(buses), simple, bolt on a General Electric Turbocharger, just like Clarence 'Kelly Johnson' the Medici of US Aero engineering to design develop and produce the USAAF,s coolest fighter, the P-38 Lightning.

[@andyharman3022]

None of those developments you're talking about on RR superchargers were available at the time the V1710 was originally designed. When Allison passed the 100-hour type test for the USAAF at 1000 hp, they were ahead of Rolls-Royce.

[@basiltaylor8910]

@@andyharman3022 That is maybe so as the 1710 like the Merlin was designed between 1932 and 1933, regarding blowers Rollers caught up damn fast, you forget, Rollers cut their teeth developing blowers for the 'R' Series Sprint Drag Race Engine used in Reggie Mitchells S6-B . By 1931-32 Roller Kestrels were entering RAF service, using blowers developed from the 'R' Series, all down to Cecil Rowledge and Stanley Hooker. Look at the back of a Kestrel 'V' designed around 1934,as its blower casing hid a bigger rotor impeller than the 1710. As early as 1925 Roy Fedden of the Bristol Aeroplane Company with help from the Royal Aircraft Establishment built a turbo charger for a Bristol Jupiter Radial, flying this combination in a Bristol Seeley Tourer, a civvied F2B Fighter. by 1934-35 Curtiss Wright and General Electric had a workable turbo for the V-1650 Conquerer, that powered the PB2 two seat fighter by Consolidated Vultee. When the 1710 passed its 100 hour test in 1937,Rollers ,from their test centre at Hucknall flew a Merlin with cats&kittens, a two speed blower in a Hawker Horsley Light Bomber April of that year

[@wilburfinnigan2142]

@@basiltaylor8910 Shut the F up you have NOT a clue !!!! RR did not get a decent supercharger until early 1943 with the 60 series 2 stage supercharger!!! The 2 stage supercharger was invented and patented in 1938 in AMERICA and the first plane to fly with a 2 stage supercharger was the F4F Grumman with the PW R1820 !!!! Followed by the F4U Corsairs R2800!! Notice they were both NAVY planes and both flew long before RR came up with their 2 stage supercharger. The USAAF did NOT want a 2 stage supercharger, believing in if needed they would add the TURBOcharger as a second stage, BUT Only the P38 with its twin booms and the fat Pig P47 had room for the turbochargers, the B17 and B24 also got the turbos as a second stage because there was room for them !!! Remember too the USAAF was the customer and you provide what the customer wants. BUT the Dummies at the USAAF got a rude wake up call when they found the bombers could NOT get through by them selves, they needed fighter escort and nothing had the range that could get up to 20,to30,000 ft the solution was the latest long range fighter the P51 had the range but not the altitude and RR had just installed a 2 stage supercharger on the Merlin BUT nothing was AVAILABLE in the USA,PACKARD was building the Merlin in the USA FOR THE BRITS, and Vincent of Packard had developed on paper an aircraft version of the M2500 PT boat engine they were dekivering to the US Navy and the Brits, and he had a 2 stage supercharger designed for that ans as RR had a 2 speed supercharger Vincent adapted his 2 stage supercharger to the Packard built Merlin and the V1650/3 Packard Merlin went into the XP51B which flew late nov 1942 and the Merlin Mustang was born. It took a real wake up call to awaken and over come the huge EGO's of the people in charge at the USAAF, What happens when non engineers set up requirements for aircraft !!!

[@nyftn]

wtf 100 gallons per hour cruising lol .

[@sebclot9478]

That is consumption at Maximum continuous power. Not cruise.

[@davidbell7091]

now put a merlin on there.

[@sebclot9478]

You would get similar numbers.

[@jamesaucutt8284]

Now how high can you rev the engine before it floats the valves and causes total destruction I’ve always been curious on the engine like that maybe you guys can get a junk engine that runs but would cost more than it’s worth to fix it and make a video on it where the engine is completely over rev’d

[@aceallisons2639]

It is well documented thru boat racing ,tractor pulling that an Allison upper limits of RPM's is 4500. With overhead cam's the valves don't float. that is the limit of the engine without damage occurring. Hope this helps

[@tomhighway1952]

@@aceallisons2639 Camshaft position does not determine whether or not an engine can experience valve "float". Any engine that has valve springs for closing the valves can float the valves if the RPM exceeds the ability of the valve spring to fully close the valve between openings. Basically, it's the strength of the valve spring that allows or prevents valve float. The only engine I have personally owned that could not experience valve float was a Ducati motorcycle with Desmodromic valve operation. There were no valve springs in the engine. Each valve had a lobe on the cam for opening the valve, and a separate lobe for closing the valve.

[@andrewsmart2949]

big cont HP LOL

[@dennisyoung4631]

Yup, that’s what *three spins* sounds like!