Roger B
Well-Known Member
Are you planning to make a compression tester? There is quite a difference between what feels like a lot of compression and enough to reach ignition temperature ~30 bar plus.
Model Diesel: 32mm bore, 38mm stroke, indirect injection
- Thread starter Nerd1000
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I have a small engine compression tester, but I would need to make some kind of funky adaptor to allow it to connect up to the injector hole.
I think my next mission is the rockers and pushrods. I've been a bit indecisive on this matter, and actually designed two options
Which option do people like more? I see pros and cons to each. The second option might also be altered to omit the side supports and just use the pillar in the middle.
Roger B
Well-Known Member
I would remove the centre pillar from the second option and just support from the sides. This would give you more space if you have to modify the injector design (which my experience suggests will be the case).
I favour the former... as the rockers area straight line of thrust.
K2
K2
EDM I'm looking into this myself
I don't often have time to do machine work during the week, but the 3d printer is at my apartment so I can sometimes print a part. I just did the rear gear cover, from carbon fiber filled nylon 6.
I think this is the best part I've ever printed from this material, must have finally got the settings just right. The cover is also the housing for the centrifugal governor which accounts for the funky shape.
I think this is the best part I've ever printed from this material, must have finally got the settings just right. The cover is also the housing for the centrifugal governor which accounts for the funky shape.
After some trials, tribulations and a redesign, here are the rockers fitted along with the pushrods.
I like this system of rocker pedestals and trunnions, it turned out very nicely and I'd certainly use it again. I would however beef up the middle of the rocker a bit, I managed to squash one in the vise and had to remake it.
It's not so obvious in the photo, but I also made the copper head gasket. It seals well, and at present the only obvious leak is the valves. I'll have to re-lap them. Even with a substantial leak from the valves the compression pressure is considerable, the engine is very difficult to turn past TDC by hand. This of course raises the question of how I'm going to start it, as it is also a struggle for my electric drill.
In terms of major assemblies I only have the injection pump and governor left to go. Plus a few odds and ends. Very exciting and I can't wait for the next time I've got some free time for machining
I like this system of rocker pedestals and trunnions, it turned out very nicely and I'd certainly use it again. I would however beef up the middle of the rocker a bit, I managed to squash one in the vise and had to remake it.
It's not so obvious in the photo, but I also made the copper head gasket. It seals well, and at present the only obvious leak is the valves. I'll have to re-lap them. Even with a substantial leak from the valves the compression pressure is considerable, the engine is very difficult to turn past TDC by hand. This of course raises the question of how I'm going to start it, as it is also a struggle for my electric drill.
In terms of major assemblies I only have the injection pump and governor left to go. Plus a few odds and ends. Very exciting and I can't wait for the next time I've got some free time for machining
Buy a bigger drill?After some trials, tribulations and a redesign, here are the rockers fitted along with the pushrods.View attachment 156112
I like this system of rocker pedestals and trunnions, it turned out very nicely and I'd certainly use it again. I would however beef up the middle of the rocker a bit, I managed to squash one in the vise and had to remake it.
It's not so obvious in the photo, but I also made the copper head gasket. It seals well, and at present the only obvious leak is the valves. I'll have to re-lap them. Even with a substantial leak from the valves the compression pressure is considerable, the engine is very difficult to turn past TDC by hand. This of course raises the question of how I'm going to start it, as it is also a struggle for my electric drill.
In terms of major assemblies I only have the injection pump and governor left to go. Plus a few odds and ends. Very exciting and I can't wait for the next time I've got some free time for machining
But seriously:
Can you set up a movable shim on your exaust valve to be a decompression set up. Then once the flywheel has some speed you could drop the valve?
Buy a bigger drill?After some trials, tribulations and a redesign, here are the rockers fitted along with the pushrods.View attachment 156112
I like this system of rocker pedestals and trunnions, it turned out very nicely and I'd certainly use it again. I would however beef up the middle of the rocker a bit, I managed to squash one in the vise and had to remake it.
It's not so obvious in the photo, but I also made the copper head gasket. It seals well, and at present the only obvious leak is the valves. I'll have to re-lap them. Even with a substantial leak from the valves the compression pressure is considerable, the engine is very difficult to turn past TDC by hand. This of course raises the question of how I'm going to start it, as it is also a struggle for my electric drill.
In terms of major assemblies I only have the injection pump and governor left to go. Plus a few odds and ends. Very exciting and I can't wait for the next time I've got some free time for machining
Can you set up a movable shim on your exaust valve to be a decompression valve to let you spool it up freely?
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