V-TWIN--MAYBE V4

[Brian Rupnow]

And that's it for today!! The support feet are attached to the crank-case. I have to trim the length of the bolts, but that can be tomorrows job.

[Brian Rupnow]

At this point in the game, just as I am about to machine the cylinders, I have changed the design of the cylinders and cylinder heads. My original cylinders and cylinder heads were exact copies of the cylinder and heads that I used on the 7/8" bore horizontal. These cylinders were tapered at the top, and the heads were 1.6" diameter.  I have decided that due to the mass of the crank-case, the cylinders and heads had to appear larger. This didn't change anything internally---it's just that with the taper removed, the cylinders and heads "grow" to 1.9" diameter. I think this gives a much better overall "balance" to the engine.

[Brian Rupnow]

Here we have the new cylinder which doesn't have tapered fins on it and the old style cylinder which does have tapered fins. Both cylinders are the same bore and same length, but the new style with untapered fins looks much more robust in comparison to the crankcase. I was going to make a second cylinder this afternoon, but I feel a fit of lazy coming on, so will make the second cylinder tomorrow. They are made from cast iron.

[Brian Rupnow]

So, now we have two cylinders the same. Second cylinder went considerably faster than the first one. I started this one at 10:00 this morning and finished it at 12:30. I like making all of these large parts first.  Tomorrow I will get the tapped holes and clearance holes and the o-ring groove finished in the cylinders. I had some thoughts this morning about a cooling fan, and will probably spend some design time this afternoon to rig a cooling fan that is driven by an o-ring belt off the flywheel.

[Brian Rupnow]

When you end up with the cooling fan and the carburetor both wanting to be in the same place, this is what you do. Looks wild and crazy, but I can't see any reason that it wouldn't work. I've got lots of things to do before I get to the point where I need to make this intake-carburetor-fan mash-up, so I've got a while to think about it.

[Brian Rupnow]

Spent the first half of today drilling and tapping 18 holes in the crankcase and sideplates to get everything bolted together. Probably the next thing will be putting threaded holes and clearance holes in the cylinders.

[Brian Rupnow]

So, here we are with both cylinders drilled, tapped, grooved for o-ring head gasket seal, and bolted into place on the crankcase. Oh my, what nasty little buggers those socket head capscrews are that hold the cylinders in place. It would have been a lot simpler if I had cut the bottom cooling fin off each cylinder to give myself some more clearance. I didn't want to give up that cooling fin, so I shortened up one end of an Allen wrench and tightened them up, about 1/4 of a turn at a time. Ah well, it's progress.

[Brian Rupnow]

I'm running out of "quick and easy" parts to build. Today I will attempt the swoopy looking gas tank mount and the tank itself, and then I get into the more technically challenging things like con rods and crankshafts. I'm building this engine in reverse---most times I recommend that people build the difficult engine parts first. If they can build the crankshaft, con rods, and valve train, then they can go on to do the easier large parts. Thank you to all who are following this build thread.---Brian

[Brian Rupnow]

Holy Gas Tank Batmen!!!--There's a full days work in that gas tank and bracket, but I like it a lot.

[crueby]

Really coming along nicely. This looks like a large engine, think it will be used to drive one of your machines?

[Brian Rupnow]

I don't really know Chris. The cylinders are 7/8" bore so it will have some power. I don't have anything in mind for it to run ----right now.

[Art K]

Brian,
Good to see the progress you are making. We've been on vacation and this is the first time in half a week I've been on the forum. I have to say that I like the straight cylinders better.
Art

[Brian Rupnow]

Not a lot of new fabricating today, as I had some automation design to do for an old customer. However, I did get my new points and condensers and had to try them to make sure they fit, and I managed to pick up some oilite bronze bushings for my camshafts and the two idler gears.

[Brian Rupnow]

Today was gear making day. Not terribly difficult but time consuming. Tomorrow I will add a bunch of set screws and get all of the gears meshing with one and other.

[gunna]

Hi Brian, I don't know if it is just me or if others find your pictures a bit large? This last one looks like 20Megapixels and comes out about 6 feet square on my pc. Can you reduce them in size if possible? Love the build.
Ian.