Jerry Howell Powerhouse 4 Cycle

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ErikBolyard

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Joined
Jan 19, 2024
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Location
Canton, Michigan
17, near 18 year old engine enthusiast here. I’m working on my second engine build (first internal combustion) — a horizontal, open crankshaft, 4 stroke ICE. The plans are Jerry Howell’s “Powerhouse” 4 cycle engine.

I’m a relatively slow worker when it comes to this sort of project, so it could take me up to a year or two to get the engine up and running.

Most of my time so far has been spent remodeling the engine in Fusion 360, in order to understand operation and the scope of the project. That includes making my own component drawings, even though the original plans come with relatively clear drawings. It’s a great opportunity for me to get more experience in CAD and preparing drawings with manufacturability in mind.

I’m just getting started with the actual machining of the parts, and I decided to start by first tackling the throttle / carburetor assembly. So far I’ve finished the “throttle body” (which is also where the Venturi effect takes place, creating the fuel-air mixture).

IMG_3361.jpg

Next are some various knobs for speed / mixture adjustment, the "fuel spray bar", and the air cleaner.
After the throttle assembly is complete, I plan to tackle the cylinder and cylinder head next. These two components are far from simple (at least for someone with my level of experience), so I want to get them out of the way before moving on to something a little less complicated. That way, I won't have a plethora of frustrating parts to greet me at the end of the build.

I'm hoping to get as much done this summer before I head off to study Mechanical Engineering this fall. I felt as though I would share my process with the members of HMEM, most of whom are much more experienced than me. I will likely be asking questions and requesting advice every step of the way. I'm hoping to learn a lot and have quite a bit of fun with this build!
 
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Looking for some help here —

One part of the throttle assembly for this engine is a small conical compression spring. I have successfully wound my own compression springs before — but the taper adds some frustration.
A simple tapered winding arbor, unsurprisingly, results in the wire sliding down instead of coiling. I suppose this could be remedied with a groove along the taper of the arbor, but I have neither a taper attachment nor access to cnc capabilities for tapered threading.

Has anyone wound their own conical springs in the past? Are there any methods, besides what I described above, that have been successful for folks?
I am not opposed to purchasing a spring — but nothing offered online is exact. And besides, that would defeat much of the fun . . . ;)
 
I have a spring winding tool that has a big knob on it that when tightened squeezes a delrin block against the wire to produce tension so it will wind tight agaist the mandrel you are winding on. I have in the past started with a mandrel sized for the small end of the spring and started with the tension knob tight enough to make the spring the correct size at the start and then released pressure while winding. This will result in the spring unwindinding more when the tension is released. The big end final diameter is pretty hit or miss but it will get bigger. If it is not a very long spring it may work.
YMMV
If that does not work for you, I have a Perkins spring winding tool and would be happy to make it for you. I am in Ohio so getting it to you would not be any problem. But as you say it is far more satisfying to make it yourself. If you just can't get it to behave or nobody comes up with a better idea, let me know.

Scott
 
I have a spring winding tool that has a big knob on it that when tightened squeezes a delrin block against the wire to produce tension so it will wind tight agaist the mandrel you are winding on. I have in the past started with a mandrel sized for the small end of the spring and started with the tension knob tight enough to make the spring the correct size at the start and then released pressure while winding. This will result in the spring unwindinding more when the tension is released. The big end final diameter is pretty hit or miss but it will get bigger. If it is not a very long spring it may work.
YMMV
If that does not work for you, I have a Perkins spring winding tool and would be happy to make it for you. I am in Ohio so getting it to you would not be any problem. But as you say it is far more satisfying to make it yourself. If you just can't get it to behave or nobody comes up with a better idea, let me know.

Scott
Thank you very much for the suggestion and the offer.
Seems like I’ve been able to make a suitable spring — though I’m not 100% confident I could do it again!
Like you said, the spring unwound more when tension was released, resulting in the proper helix angle. The big end is somewhat undersized, but that should be irrelevant for what it’s being used for.
Here are some photos of the setup:
IMG_3935.jpeg
IMG_3936.jpeg
And some photos of the spring:
IMG_3937.jpeg
IMG_3938.jpeg
Thank you again for the suggestion — onwards and upwards!
 
17, near 18 year old engine enthusiast here. I’m working on my second engine build (first internal combustion) — a horizontal, open crankshaft, 4 stroke ICE. The plans are Jerry Howell’s “Powerhouse” 4 cycle engine.
👍👍👍...
A young man's project
It's very Interesting and Great...Please update....
 
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