Lobo Pup Twin 1.6 cc diesel
- Thread starter GailInNM
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Thanks for the comments everyone.
A new contra piston was made. The old one was borderline on my rule of thumb test. If I can push it in with my thumb then it is too loose. I just put washers on each end of the spring to stabilize the needle valve. It could use a heavier spring with properly ground ends, but it works OK with the washers.
Video is attached. The Lobo is running about 6900 RPM at the beginning of the video and climbs to about 71oo RPM with a Master Airscrew 8-4 propeller. It is still running rich while I break it in, but these are acceptable numbers for a long stroke engine of this displacement.
I will have the final updates on the drawings in a few days. All the changes have been made to the files but I want to make one final check before converting to PDF and re-posting them in the early posts for this thread. I will also post the final photos as the engine gets ready to disappear into the dark recesses of my display cabinet so I can start on something new.
Gail in NM
[ame]http://www.youtube.com/watch?v=PtPvTr94_7w[/ame]
A new contra piston was made. The old one was borderline on my rule of thumb test. If I can push it in with my thumb then it is too loose. I just put washers on each end of the spring to stabilize the needle valve. It could use a heavier spring with properly ground ends, but it works OK with the washers.
Video is attached. The Lobo is running about 6900 RPM at the beginning of the video and climbs to about 71oo RPM with a Master Airscrew 8-4 propeller. It is still running rich while I break it in, but these are acceptable numbers for a long stroke engine of this displacement.
I will have the final updates on the drawings in a few days. All the changes have been made to the files but I want to make one final check before converting to PDF and re-posting them in the early posts for this thread. I will also post the final photos as the engine gets ready to disappear into the dark recesses of my display cabinet so I can start on something new.
Gail in NM
[ame]http://www.youtube.com/watch?v=PtPvTr94_7w[/ame]
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FINAL REPORT
First off I want thank everyone who followed along on the Lobo Pup Twin from concept to the final run video. It has been a fun trip and having others follow the progress along has just made it more fun. I think we all welcome positive comments. I know it helped keep me going.
Arv, I measured the RPM using a contact tachometer. The 6900 RPM number came from the last part of the previous run before the video and the 7100 RPM came from the start of the run following the video. At the last run I was measuring about 7300 RPM and I do not expect it to improve from that. The tachometer loads the engine about 100 RPM, but I did not correct for that. I have an optical tach also, but did not use it on this engine.
All the drawings are contained in the first three posts of this thread. They have been updated to reflect the "as built" status of the Mk2 version. They all carry a REV E notation and a date of Feb 9,2010. Any one using these drawing for reference or building should make sure they have the REV E drawings.
Thank you everyone.
Gail in NM
Photos show both the Mk1 and Mk2 versions and the Mk2 version alone. The Mk 1 has the Lobo head on it.
First off I want thank everyone who followed along on the Lobo Pup Twin from concept to the final run video. It has been a fun trip and having others follow the progress along has just made it more fun. I think we all welcome positive comments. I know it helped keep me going.
Arv, I measured the RPM using a contact tachometer. The 6900 RPM number came from the last part of the previous run before the video and the 7100 RPM came from the start of the run following the video. At the last run I was measuring about 7300 RPM and I do not expect it to improve from that. The tachometer loads the engine about 100 RPM, but I did not correct for that. I have an optical tach also, but did not use it on this engine.
All the drawings are contained in the first three posts of this thread. They have been updated to reflect the "as built" status of the Mk2 version. They all carry a REV E notation and a date of Feb 9,2010. Any one using these drawing for reference or building should make sure they have the REV E drawings.
Thank you everyone.
Gail in NM
Photos show both the Mk1 and Mk2 versions and the Mk2 version alone. The Mk 1 has the Lobo head on it.
- Joined
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Welcome to HMEM Metalmad.
I invite you to put a little introduction to yourself in the welcome section.
Thank you for your comment about the Lobo Pup. The engine you build should be based somewhat on the level of engine building experience you have. The Whittle V8 is a wonderful engine, but I feel that anyone who builds it should have at least one or two successful 4 stroke engines under their belt before attempting it. Tony (Cobra428) has a very nice thread going on about his Whittle V8 build.
Whatever you decide to build, keep us informed and if possible do a build thread on it.
Gail in NM
I invite you to put a little introduction to yourself in the welcome section.
Thank you for your comment about the Lobo Pup. The engine you build should be based somewhat on the level of engine building experience you have. The Whittle V8 is a wonderful engine, but I feel that anyone who builds it should have at least one or two successful 4 stroke engines under their belt before attempting it. Tony (Cobra428) has a very nice thread going on about his Whittle V8 build.
Whatever you decide to build, keep us informed and if possible do a build thread on it.
Gail in NM
GAILinNM,
I just can't get over the talent that is on this website, I have only been coming here for a few days thanks to gbritnell and all I can say is that I am delightfully impressed with everyone and everything I have seen so far. Major congratulations on a great build and having the tenacity to see it through, thank for the time you took to photograph and explain everything you did.
Are you far from the town of Reserve, NM? I have a sister that lives there. Thanks Again; Tad
I just can't get over the talent that is on this website, I have only been coming here for a few days thanks to gbritnell and all I can say is that I am delightfully impressed with everyone and everything I have seen so far. Major congratulations on a great build and having the tenacity to see it through, thank for the time you took to photograph and explain everything you did.
Are you far from the town of Reserve, NM? I have a sister that lives there. Thanks Again; Tad
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Thank your for the kind comments Tad.
There is a lot of talent on HMEM, but most important is that the members are willing to share their talents no matter what level they are at. Everyone has something to contribute at some level and no one has to be afraid of putting forward any build of any level.
Welcome to HMEM. Please share your talents with us.
I live about 200 miles NE of Reserve. I have never been there, but have passed within a dozen miles of there a number of times when I lived in the SW part of New Mexico years ago. It is a little off the beaten path.
Gail in NM
There is a lot of talent on HMEM, but most important is that the members are willing to share their talents no matter what level they are at. Everyone has something to contribute at some level and no one has to be afraid of putting forward any build of any level.
Welcome to HMEM. Please share your talents with us.
I live about 200 miles NE of Reserve. I have never been there, but have passed within a dozen miles of there a number of times when I lived in the SW part of New Mexico years ago. It is a little off the beaten path.
Gail in NM
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A few updates on the Lobo Pup Twin.
The complete drawing package has been placed in the Downloads section on page 17. The drawing are in three different formats. PDF, DWG, and DXF. The CAD versions are in the lowest ACAD format that I can generate so should be able to load in most CAD programs that can read either DWG or DXF formats.
Someone in one of the countries that is metric based is converting the drawings to metric standards and building an engine to those specifications. He has contacted the editor of "Model Engine Builder Magazine" about having the plans and an article published after he completes building and running an engine. The editor contacted me for permission to do the spin off article, which I gave. I also sent the editor, at his request, my electronic drawing files. IF the article comes to be, then the editor plans to publish both the Imperial and Metric drawings. He would redraw my drawings to the MEB standards as he does with most submissions. I am not holding my breath on all of this happening as I know how easy it is for most of us to get side tracked on projects and the metric engine may be a long time coming.
For those not familiar with MEB, their website is:
www.modelenginebuilder.com
It is a great magazine. In the beginning it was devoted almost entirely to internal combustion engines, but it is now branching out into other types.
Ron gave the Lobo Pup a nice plug on his long running website in the March 2010 issue. By his own admission, Ron is a sucker for twins.
http://modelenginenews.org/ed.2010.03.html#t1
The rest of his website is at
http://modelenginenews.org/index.html
and contains the last 8 years of his monthly editorials along with an astounding amount of information about model engines, mostly model aircraft engines.
Gail in NM
The complete drawing package has been placed in the Downloads section on page 17. The drawing are in three different formats. PDF, DWG, and DXF. The CAD versions are in the lowest ACAD format that I can generate so should be able to load in most CAD programs that can read either DWG or DXF formats.
Someone in one of the countries that is metric based is converting the drawings to metric standards and building an engine to those specifications. He has contacted the editor of "Model Engine Builder Magazine" about having the plans and an article published after he completes building and running an engine. The editor contacted me for permission to do the spin off article, which I gave. I also sent the editor, at his request, my electronic drawing files. IF the article comes to be, then the editor plans to publish both the Imperial and Metric drawings. He would redraw my drawings to the MEB standards as he does with most submissions. I am not holding my breath on all of this happening as I know how easy it is for most of us to get side tracked on projects and the metric engine may be a long time coming.
For those not familiar with MEB, their website is:
www.modelenginebuilder.com
It is a great magazine. In the beginning it was devoted almost entirely to internal combustion engines, but it is now branching out into other types.
Ron gave the Lobo Pup a nice plug on his long running website in the March 2010 issue. By his own admission, Ron is a sucker for twins.
http://modelenginenews.org/ed.2010.03.html#t1
The rest of his website is at
http://modelenginenews.org/index.html
and contains the last 8 years of his monthly editorials along with an astounding amount of information about model engines, mostly model aircraft engines.
Gail in NM
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