Thumper--a new 1 3/8" bore i.c. engine

[Brian Rupnow]

So what do you do when it's the middle of winter and you don't want to go and play outside?--Well of course, you make parts!!! I've rootled thru all of my scraps and came up with enough material to make the main rocker, the two cross pins for the ends of it, and the two spacers that keep the rocker centered in the frame. I have to buy a bunch of aluminum plate, but I've got enough odds and ends of material here to keep me busy over the weekend.

[crueby]

 

[Brian Rupnow]

Today was connecting rod day at my house. My, but there is a lot of work in one lousy connecting rod---and it isn't finished yet. I still have to turn 0.031" off each side and leave a boss at both ends. Also, I've added a shot of the biggest icicle in the world. It's hanging off the eves over my back deck. I don't think I have ever seen an icicle this big. It's over six foot long!!!

[Art K]

Brian,
Couldn't sleep and am browsing. I do remember 30 some years ago. I drove to work, parked and when I left there was a mountain of snow shoveled on top of my 1965 Chevy Bel Air. Opened the door got in backed out then spent the next 15 minutes clearing the snow off it, was nice and toasty warm when I got back in. They must have spent their whole lunch shoveling it on.
Art

[Brian Rupnow]

And what's better than having one connecting rod?---Well of course, it's having two connecting rods. Now I have to go and chase down bearings and plates.

[Brian Rupnow]

Just got back from running around town. In one picture you see all of the material and bearings for Thumper ($98.00) in the other you see my new TIG welder, so new I haven't got it out of the box yet.

[Brian Rupnow]

In keeping with my "Make at least one part a day" policy, here is todays part. It is the cylinder mounting plate. Nothing really fancy here, but quite a few holes in different places. Thank God for DRO's.

[Brian Rupnow]

This mornings work yielded up a finished baseplate and a muffler. Neither were difficult parts to make. I have to head downtown to the nut and bolt shop now, and do a bunch of searching for the correct receptacle box to plug my new tig welder into.

[Brian Rupnow]

Tomorrow I will designate as "Side plate day". The side-plates are pretty well identical, except that the counterbored holes make them right and left hand. It is much less work if I can do all of the profile work on both plates at the same time. I will bolt the plates together , putting the connecting holes somewhere in the center area that gets milled away as a "last step". One plate will be drilled and tapped, the other will have countersunk or counterbored holes in it so it will lay flat. even the counterbored holes can be put in---When I separate the plates the bottom plate can be flipped over and counterbored.

[Art K]

Brian,
Looks like you're making good progress. I must admit though that from the perspective of someone working 50 hour weeks, a part a day sounds ambitious.
Art

[Brian Rupnow]

Art---Everybody seems to be amazed at the speed I build my engines. I'm retired!!! I can work all day, every day on my stuff. I find it infinitely entertaining. All I really have to be concerned with is that I spend enough of each day with my good wife.

[Brian Rupnow]

I came downstairs this morning with my cup of coffee and began laying out my side-plates. At this point I will join two pieces of material  together, so all of the drilling and cutting applications ca be done at once on both plates. I trust my DRO's completely, but still lay everything out beforehand, just to be sure my layout makes sense and to give me assurance that I have the DRO in the places I really want to be.

[Admiral_dk]

I trust my DRO's completely, but still lay everything out beforehand, just to be sure my layout makes sense and to give me assurance that I have the DRO in the places I really want to be.

Amen to that - makes very good sense 

[Brian Rupnow]

Here we are with all of the major holes drilled. Eventually, all the center has to be cut out/machined away, and the outer profile machined. You can see the heads of the two 1/4" bolts which are holding the plates together.

[Brian Rupnow]

This pretty much covers the work that can be done with the two plates still bolted together. The exterior profile is completely machined, and a good portion of the inner profile. And it comes close to my own limits for the day. Tomorrow I will separate the plates and mill away what is left of the inner profile, and add some counterbores and some tapped holes.