Wonderful engine. We are having some valve sticking issues with our OX-5. It could be several things, we are suspecting fuel issues. We are running 100 avgas. Also do you have any techniques for lubing the valves? Would love to see a video of you lubricating the rocker arms and/or valves....I am not sure if we are getting it done right.
Here`s some tech talk guys….Curtiss OX5 1918. 8 cylinder water cooled.90HP @ 1200rpm.Max 1400rpm for a short time.Bore and stroke 4 x 5 inch Total 500 cubic inch (8 liters).Pressure feed lubrication by oilpump via camshaft and crankshaft.Oil 4 Gallons (15 liters).Oil consumption (1.2 liters) per hour at full speed.Fuel consumption 9 Gallons per hour at full speed.
On the valvetrain there was no provision for lubrication other than oil applied by hand. 50 hours was the typical total life limit of the valvetrain…..!...
Lubrication by hand was done every time at take off.The factory adviced to take the complete motor apart after 50 hours of service and replace all worn part, especially the valvetrain parts.This engine could certainly benefit from the mass and drag of a big wooden prop. With that installed, the engine will tick over and run at high speed nicely.
.Valves have springs holding down the valves on their seats.The exhaust valves have conventional pushrods, situated inside the hollow inlet push (pull ) rod.The inlet valve has also another stronger spring that holds the pushrod ( in fact a hollow pullrod) in constant contact with the camshaft.The camshaft has a flat point , the pullrod will follow and pull open the inlet valve while passing this flat point.
its running a little weird because it has no flywheel, what with the prop not on it. i am sure they used a flywheel on it for a car or boat, to get rid of the lurching from no balancing and momentum-weighting.
This engine could certainly benefit from the mass of a big wooden prop. With that installed, they tick over quite nicely.
And yes, parts of the valvetrain wore out in 50 to 75 hours.
I'm fortunate enough to have been able to talk to oldtimers who worked on these.
By the way, and nothing to do with this, most American and Canadian Air Force mechanics I've talked to hated working on Merlins. "Awful (or maybe another adjective) Limey shit" was the phrase they used the most.
@BikerRussell I think you might be right...pretty strange. I wonder if the valves are driven by a mini-crank like a sleeve-valve engine, rather than a cam? Because a cam can't "pull" on a pushrod. It does have two intake valves on the "inside" of the cylinder bank, one exhaust on the "outside". In that, it is a pretty advanced engine for it's time...cross-flow OHV heads when most cars were still running on flathead designs. I'm curious to find out more about this engine now!
@916fanatic1 This was very high tech for the time it was made. Sure, compared to to a P-51 (or an F-15), the JN4 was a "shitty" plane ("what, no canopy?"). But it was more important historically than a lot of "better" planes are. Yeah, a modern Lycoming is a "better" engine, but it ain't one of the pioneers. And there's no reason to cover the valves other than to keep all the oil inside...if you don't mind filling it periodically. It's called "total loss lubrication", and it was standard in 1918
@saffronwales The engine oils them itself with a oil pump, like a modern engine, but the oil doesn't drain back into the sump, it just goes "by-by". I'm not exactly sure WHERE it goes...I just asked some friends, and hopefully I'll get an answer soon. It may just spray all over the place and run down the engine. In any case, you had to keep the oil tank full, just like the gas tank...it was considered a "consumable" back then (although even WWII-era engines used a lot of oil).
@saffronwales Actually, never mind that...I was giving mis-information. I haven't gotten an answer yet, but I just read that "there was no provision for lubrication other than grease on oil applied by hand." It also says that "50 hours was the typical limit of the valvetrain"! I'm not sure if that means between lubrications, or if that's the TOTAL LIFE of the valve train.,.although since I'm sure they lubed it every time they took off, I guess it must be the life expectancy!
yeah! i was depressed until i saw and heard this! g.h.curtiss has been a hero of mine for 50yrs. against all reason, he was very successful. mecganic, inventor, pilot, motorcycle manufacturer and racer. THANK YOU!
dankjewel voor de mooie video!
ijzerable 2 months ago
Wonderful engine. We are having some valve sticking issues with our OX-5. It could be several things, we are suspecting fuel issues. We are running 100 avgas. Also do you have any techniques for lubing the valves? Would love to see a video of you lubricating the rocker arms and/or valves....I am not sure if we are getting it done right.
hoodoo2001 3 months ago
Curtiss was one cool man. Are you guys now deaf ?
VMATT500C 4 months ago
Jesus. 500 cubic inches for 90 hp? Sounds like it puts out 500.
beeroosterm 4 months ago
I'm into high tech high hp/ci japanese engines but I have to say, THIS IS DAMN COOL!!!!
RIPSNZ 5 months ago
dat is eenprachtige motor man egt waar!!!
djlau1 6 months ago
You could literally throw a wrench at it and completely destroy it O.o
peepeevagi 7 months ago
Very cool !!!!!
kevintheblacksmith 7 months ago
SACRAFICE A PRIUS TO IT!
iexploderacoons 9 months ago
Here`s some tech talk guys….Curtiss OX5 1918. 8 cylinder water cooled.90HP @ 1200rpm.Max 1400rpm for a short time.Bore and stroke 4 x 5 inch Total 500 cubic inch (8 liters).Pressure feed lubrication by oilpump via camshaft and crankshaft.Oil 4 Gallons (15 liters).Oil consumption (1.2 liters) per hour at full speed.Fuel consumption 9 Gallons per hour at full speed.
yesterdaysnl 1 year ago
On the valvetrain there was no provision for lubrication other than oil applied by hand. 50 hours was the typical total life limit of the valvetrain…..!...
yesterdaysnl 1 year ago
Lubrication by hand was done every time at take off.The factory adviced to take the complete motor apart after 50 hours of service and replace all worn part, especially the valvetrain parts.This engine could certainly benefit from the mass and drag of a big wooden prop. With that installed, the engine will tick over and run at high speed nicely.
yesterdaysnl 1 year ago
.Valves have springs holding down the valves on their seats.The exhaust valves have conventional pushrods, situated inside the hollow inlet push (pull ) rod.The inlet valve has also another stronger spring that holds the pushrod ( in fact a hollow pullrod) in constant contact with the camshaft.The camshaft has a flat point , the pullrod will follow and pull open the inlet valve while passing this flat point.
yesterdaysnl 1 year ago
For practical reasons we`ve put on an electric 2HP Volkswagen starter and a Porche flywheel.
By the way: Gnome Monosoupape Rotary Aero engines had a total lifespan of 25 hours !.....
yesterdaysnl 1 year ago
its running a little weird because it has no flywheel, what with the prop not on it. i am sure they used a flywheel on it for a car or boat, to get rid of the lurching from no balancing and momentum-weighting.
bulletman100 1 year ago
niceeeee......
cfb36 1 year ago
Curtis OX5's were also adapted into racecars and boats quite successfully in the 1930's and into the 1940's.
JGMagoo 1 year ago
This engine could certainly benefit from the mass of a big wooden prop. With that installed, they tick over quite nicely.
And yes, parts of the valvetrain wore out in 50 to 75 hours.
I'm fortunate enough to have been able to talk to oldtimers who worked on these.
By the way, and nothing to do with this, most American and Canadian Air Force mechanics I've talked to hated working on Merlins. "Awful (or maybe another adjective) Limey shit" was the phrase they used the most.
schlusselmensch 1 year ago
That engine is a work of art .
Ratridez 1 year ago
V8 :p
over2seeyer 1 year ago
This is indeed a very interesting engine. Looks like the intake valve is being controlled by a pull rod?
BikerRussell 1 year ago
@BikerRussell I think you might be right...pretty strange. I wonder if the valves are driven by a mini-crank like a sleeve-valve engine, rather than a cam? Because a cam can't "pull" on a pushrod. It does have two intake valves on the "inside" of the cylinder bank, one exhaust on the "outside". In that, it is a pretty advanced engine for it's time...cross-flow OHV heads when most cars were still running on flathead designs. I'm curious to find out more about this engine now!
justforever96 1 year ago
How does the cooling work on this machine?
prootuning 1 year ago
How does the cooling work on this machine?
prootuning 1 year ago
What a shitty engine,totally exposes valve gear?
916fanatic1 1 year ago
@916fanatic1 It's a 1918 engine, you dumb. You know nothing about engines...
whisperdancer 1 year ago
@916fanatic1 This was very high tech for the time it was made. Sure, compared to to a P-51 (or an F-15), the JN4 was a "shitty" plane ("what, no canopy?"). But it was more important historically than a lot of "better" planes are. Yeah, a modern Lycoming is a "better" engine, but it ain't one of the pioneers. And there's no reason to cover the valves other than to keep all the oil inside...if you don't mind filling it periodically. It's called "total loss lubrication", and it was standard in 1918
justforever96 1 year ago
@ saffronwales:This is only like a 90HP motor, wouldn't do any good in a car. Keep it in the Jenny.
bicyclemonkey 1 year ago
flywheel anyone?
30GB 2 years ago
nice long pistons :D put it in a car and watch the wheels rip up with too much torque :P
nice engine by the way, i like it how you can see everything moving, not like now, do you have to oil the tappet like things?
saffronwales 2 years ago
@saffronwales The engine oils them itself with a oil pump, like a modern engine, but the oil doesn't drain back into the sump, it just goes "by-by". I'm not exactly sure WHERE it goes...I just asked some friends, and hopefully I'll get an answer soon. It may just spray all over the place and run down the engine. In any case, you had to keep the oil tank full, just like the gas tank...it was considered a "consumable" back then (although even WWII-era engines used a lot of oil).
justforever96 1 year ago
@saffronwales Actually, never mind that...I was giving mis-information. I haven't gotten an answer yet, but I just read that "there was no provision for lubrication other than grease on oil applied by hand." It also says that "50 hours was the typical limit of the valvetrain"! I'm not sure if that means between lubrications, or if that's the TOTAL LIFE of the valve train.,.although since I'm sure they lubed it every time they took off, I guess it must be the life expectancy!
justforever96 1 year ago
cool good song! muy buen y grande mounstro colombia ;)
drkggjh 2 years ago
it looks a bit like an Antoinette....
nilsameyer 2 years ago
I've got My Grandfathers prop from his, hanging in my basement!!!!!!
indianchief741 3 years ago
What a lovely piece of mechanical sculpture. From the days when you could see everything moving.
AndreiTupolev 3 years ago
Nice old engine and sounds good...
nocrap62 3 years ago
Hermoso !!!..
YO tengo uno igual a este motor, en Buenos Aires. por aqui en Las Pampas Argentinas los usaban para "Racing Cars".
erzclassicars 3 years ago
Hermoso !!!..
YO tengo uno igual a este motor, en Buenos Aires. por aqui en Las Pampas Argentinas los usaban para "Racing Cars".
erzclassicars 3 years ago
Hermoso!!! Yo tengo un motor igual a este, en Buenos Aires. Por aqui en las Pamapas los usaban para "Racing Cars".
erzclassicars 3 years ago
yeah! i was depressed until i saw and heard this! g.h.curtiss has been a hero of mine for 50yrs. against all reason, he was very successful. mecganic, inventor, pilot, motorcycle manufacturer and racer. THANK YOU!
ur124q 3 years ago
Wow , that engine is beautiful , would make an awesome hot rod engine .
Ratridez 3 years ago
Electric start?
windpowergood 3 years ago
Gentleman, a real work of art, nice sounding engine. My complements to the chef!
pepsiman63 3 years ago
that thing is beautiful!! did you burn your hands getting it started though? :P
whotookmeethed 3 years ago