Author Topic: The "2-Bits" V-Twin  (Read 10527 times)

Offline crueby

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Re: The "2-Bits" V-Twin
« Reply #30 on: March 09, 2022, 01:12:39 AM »
Great progress on the bunny... I mean engine block!

 :popcorn: :popcorn: :popcorn:

Offline RReid

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Re: The "2-Bits" V-Twin
« Reply #31 on: March 11, 2022, 01:22:55 AM »
Thanks Chris!

Quote
And you have the core to use in some future project to boot! 
Prophetic words, Kim, but the current project, not a future one. The core from hole sawing the crankcase blank was used to make the first of the two cylinder jackets. Since it already had a 1/4 hole from the pilot drill, it was screwed directly to the 1/4-20 threaded center hole of the faceplate fixture I'd made back in the Radial Five build.


I quickly realized that soon I would need to remove the center screw to allow for boring, plus I wanted more security against the part spinning on the bolt during a heavy cut. So after cleaning up the surface a bit and center marking the bolt, I moved the assembly over to the mill to mark the two holes for the crankcase screws. I drilled these part way on the mill, then went to the drill press to finish them all the way through the faceplate. Then I removed the jacket blank, tapped the faceplate 6-32, clearance drilled the jacket, and reassembled everything back onto the lathe.




With the blank well secured, I finished the OD and started cutting in the fins. The lower five fin grooves go deeper than the outer screws, so I just went in a short way to mark them, then removed the screws. A couple of short 6-32 screws were threaded in from the backside of the faceplate to pin the part against rotation. Then all the grooves were finished. The deep ones were cut by using the 0.0625 cut-off tool, followed by the 0.094 one. This made life a little easier, and a little quieter!




Now the outer screws were reinstalled and the center screw removed, allowing the center to be drilled/bored for a snug fit over the cylinder sleeve.


The part growing out of one side in the drawing is the exhaust valve housing. That will be made as a separate part and attached later.


Not fully seated on the sleeve, but you get the idea.


Since I only had the one hole saw plug to work with, the blank for the second sleeve will have to be cut out from the plate stock on the bandsaw. The outer scribed circle marks the cut line.

Regards,
Ron

Online Kim

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Re: The "2-Bits" V-Twin
« Reply #32 on: March 11, 2022, 05:03:45 AM »
Excellent!  How frugal of you!  And now you have one of the cylinder jackets complete - only one more to go :)  :popcorn: :popcorn:

Kim

Offline RReid

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Re: The "2-Bits" V-Twin
« Reply #33 on: March 13, 2022, 12:33:07 AM »
The second cylinder jacket was pretty much a repeat of the first. As usual, it went faster, as the method was refined and steamlined, and I didn't have to second guess myself as much. What didn't happen was the mistake that sometimes happens on a second go, just when you're feeling like "I got this now...".


Then I started carving away some of those fresh fins to make way for the soon to come exhaust valve housing.
Regards,
Ron

Offline Don1966

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Re: The "2-Bits" V-Twin
« Reply #34 on: March 13, 2022, 01:20:10 AM »
 :Love:



 :cheers:
Don

Offline RReid

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Re: The "2-Bits" V-Twin
« Reply #35 on: March 13, 2022, 11:18:58 PM »
Thanks Don!
And a late Thanks to Kim!

The exhaust valve housings have been cut out and fitted to the cylinder sleeves. Pretty straightforward stuff, so no process pics. One has been finished to size all around, the other not yet. Still to be done besides that is drilling for the valve guides/seats and the exhaust ports and working out the attachment screws (or I might go with pins and loctite). They will also get some rounding off, but I think I'll leave that until the heads are made since they will have a matching shape.


Regards,
Ron

Offline RReid

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Re: The "2-Bits" V-Twin
« Reply #36 on: March 15, 2022, 12:33:14 AM »
Continuing with the exhaust valve housings. Each of the housings was drilled for the exhaust outlets, the exhaust pipe flanges, and the future valve seats and guides.


It occurred to me that the screw holes for attaching the exhaust flanges could do double duty to attach the housings to the cylinder sleeves. This will still probably be supplemented by loctite or JBW, but the fit of the housings to the sleeves is nice and snug even without that.


The holes were match drilled through the sleeves, then the housings were removed and the holes tapped.





Regards,
Ron

Offline gary.a.ayres

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Re: The "2-Bits" V-Twin
« Reply #37 on: March 15, 2022, 09:26:37 AM »
Wow... great machining. Looks amazing.

gary

Offline Hugh Currin

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Re: The "2-Bits" V-Twin
« Reply #38 on: March 15, 2022, 02:51:13 PM »
Ron:

Great progress. I still like this engine and your work is very nice. Thanks.

But I must ask, are you sponsored by Shars? :-)

Thanks.
Hugh

Offline Roger B

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Re: The "2-Bits" V-Twin
« Reply #39 on: March 15, 2022, 05:03:42 PM »

But I must ask, are you sponsored by Shars? :-)


These things happen  ::) Many of my posts include my small Proxxon vice with the name clearly visible  :)
Best regards

Roger

Offline RReid

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Re: The "2-Bits" V-Twin
« Reply #40 on: March 15, 2022, 07:32:55 PM »
Thank you, Gary!

Thank you, Hugh! I can understand your question (and that it was meant in good humor). But no, no sponsorship has been received, offered, nor would be accepted if it were.  :o

Thanks Roger!
Regards,
Ron

Offline Hugh Currin

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Re: The "2-Bits" V-Twin
« Reply #41 on: March 15, 2022, 08:57:09 PM »
...nor would be accepted if it were.

Better man than I! :-)
Hugh

Offline RReid

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Re: The "2-Bits" V-Twin
« Reply #42 on: March 16, 2022, 12:47:34 AM »
Moved on to thinking about how to make the cylinder heads, which means I did a lot more thinkin' than workin'.


Unlike the cylinder sleeves, I'm going to try making these as one piece, even though they also have a wart growing out of one side. The cylindrical feature growing out the top in the drawing is meant to be made as a separate piece and will be, even though it's not drawn that way. That's mostly a cosmetic feature enclosing the intake valve and guide, and is there to approximate the appearance of the Curtiss engines.

Yet another piece of scrap is being sacrificed to the cause.
Regards,
Ron

Offline gary.a.ayres

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Re: The "2-Bits" V-Twin
« Reply #43 on: March 16, 2022, 10:06:36 AM »
The guy who owns a local machine shop here assures me that there's no such thing as scrap.    :)

Offline RReid

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Re: The "2-Bits" V-Twin
« Reply #44 on: March 16, 2022, 02:18:00 PM »
Quote
The guy who owns a local machine shop here assures me that there's no such thing as scrap.
I think that's very true.  :ThumbsUp:

The other side of the coin though is that much of what used to be considered scrap or junk is now often labeled "collectible" and priced accordingly!  :(
Regards,
Ron