A few tidbits I have heard or read about this engine. I had the honor of speaking with Bite Livingston in the 1970's. I asked if he had flown behind an OX-5. He said he had, and that when you did you always had two landing sites in view: the one you just passed and the one you are headed for. Time between overhaul (TBO) was something like 50 hours. You had to oil the exposed valve mechanism before each flying session. For about $20 you could add an automatic oiler (so said the magazine ad). All gasoline at the time was of poor quality and had to be filtered through a chamois. The chamois would not let water contamination pass along with the fuel. There were some rpm figures to avoid because of harmonic vibrations. The original engines were nickel (?) plated, giving it an elegant silver patina and corrosion resistance. Great video to show us the inner bits!
Thank you so much for covering the (especially intake) valve operation. I could not figure out how this worked while examining an OX-5 at the USAF Museum in Dayton, Ohio last week. I have overhauled aircraft engines but only those with conventional pushrod actions---this was new to me and I've been around a while. Excellent video---thank you so much!
Great video. Was the camshaft hollow (drilled through) for weight savings? Were the valve seats ground and/or hardened? Finally, what sort of valve guides were used on the top of the piston? Many thanks in advance!
The cam shaft is hollow for oil circulation to the bushings. We did grind the valve seats by hand to match the valves. This engine's valve guides were just fine so we did not have to replace them. On other engines, we have made new valve guides.
@@BlueSwallowAircraft Thanks for the quick response. With the tappets, pushrods and springs non-pressure lubricated it would appear that valve train wear would reduce MTBO on this engine-assuming no adjustment for mechanical tappet. If there is an adjustment my old eyes missed, how often does lash need to be adjusted?
@@pimpompoom93726 You can adjust the rocker arm mechanism very easily to accommodate any wear of the rocker arm roller. Later engine mods had different roller assemblies as well that might have been a bit better design. OX5 engines were rebuilt during the War on a regular basis (50 hours?) as part of service maintenance. I do not think any of my customers are putting that kind of hours on their engines per year.
@@BlueSwallowAircraft Ahhh, so the engine has roller lifters? That's pretty novel for 1917. In the auto industry where I work we didn't get into hi-volume roller lifters/rocker arms until the mid 1980's. It's really amazing how much research and development went into these old engines, they were particularly innovative in materials technology. I've been doing a lot of reading on the Liberty Engine lately-making the best of the Pandemic slowdown-and there are some really great articles online regarding how we developed that engine. I love this stuff. Thanks for the information!
What defines a Hemi engine? A HEMI® engine is composed of a hemispherical combustion chamber with dome shaped cylinders and matching piston tops. This creates less surface area than traditional engine which means that less heat and energy lost, and more power is produced.
A few tidbits I have heard or read about this engine. I had the honor of speaking with Bite Livingston in the 1970's. I asked if he had flown behind an OX-5. He said he had, and that when you did you always had two landing sites in view: the one you just passed and the one you are headed for. Time between overhaul (TBO) was something like 50 hours. You had to oil the exposed valve mechanism before each flying session. For about $20 you could add an automatic oiler (so said the magazine ad). All gasoline at the time was of poor quality and had to be filtered through a chamois. The chamois would not let water contamination pass along with the fuel. There were some rpm figures to avoid because of harmonic vibrations. The original engines were nickel (?) plated, giving it an elegant silver patina and corrosion resistance. Great video to show us the inner bits!
Thank you so much for covering the (especially intake) valve operation. I could not figure out how this worked while examining an OX-5 at the USAF Museum in Dayton, Ohio last week. I have overhauled aircraft engines but only those with conventional pushrod actions---this was new to me and I've been around a while. Excellent video---thank you so much!
Great stuff. (watched all three of course...)
The OX5 crank shafts are steel. The have been ground to tolerance. Thanks, John Gaertner BSA, LLC
excellent videos 1,2,3 plus all the rest
Great video. Was the camshaft hollow (drilled through) for weight savings? Were the valve seats ground and/or hardened? Finally, what sort of valve guides were used on the top of the piston? Many thanks in advance!
The cam shaft is hollow for oil circulation to the bushings. We did grind the valve seats by hand to match the valves. This engine's valve guides were just fine so we did not have to replace them. On other engines, we have made new valve guides.
@@BlueSwallowAircraft Thanks for the quick response. With the tappets, pushrods and springs non-pressure lubricated it would appear that valve train wear would reduce MTBO on this engine-assuming no adjustment for mechanical tappet. If there is an adjustment my old eyes missed, how often does lash need to be adjusted?
@@pimpompoom93726 You can adjust the rocker arm mechanism very easily to accommodate any wear of the rocker arm roller. Later engine mods had different roller assemblies as well that might have been a bit better design. OX5 engines were rebuilt during the War on a regular basis (50 hours?) as part of service maintenance. I do not think any of my customers are putting that kind of hours on their engines per year.
@@BlueSwallowAircraft Ahhh, so the engine has roller lifters? That's pretty novel for 1917. In the auto industry where I work we didn't get into hi-volume roller lifters/rocker arms until the mid 1980's. It's really amazing how much research and development went into these old engines, they were particularly innovative in materials technology. I've been doing a lot of reading on the Liberty Engine lately-making the best of the Pandemic slowdown-and there are some really great articles online regarding how we developed that engine. I love this stuff. Thanks for the information!
The crankshaft looks surprisingly smooth. Is it a form of cast iron or is it steel of some kind?
"Hemi" actually refers to the shape of the combustion chamber rather than the shape of the pistons.
What defines a Hemi engine?
A HEMI® engine is composed of a hemispherical combustion chamber with dome shaped cylinders and matching piston tops. This creates less surface area than traditional engine which means that less heat and energy lost, and more power is produced.
Where is OX-5 Engine Rebuild Chapters 4 ?
We never made one. Not enough time.