Rockerblock I.C.--Something a little different-

[sbwhart]

Well that defiantly looks different Brian

I'll be quietly watching the build unfold.

 

Stew

[zeeprogrammer]

Looks to be a very compact design.
Nice.

 

[Brian Rupnow]

Has anybody used this type of con-rod connection at the crankshaft? I'm pressed for room where my rod attaches to the one piece crankshaft, and this would get me out of trouble. I think the actual hole for the rod journal would be the last step in the fabricating operation so everything would run true. I haven't used this before, but there's a first time for everything.--Brian

[Brian Rupnow]

Dang, this thing is like a big chocolate cake!! All the pieces look so good, I don't know where to start. The beauty is in the simplicity. I shouldn't get so excited about my own work. Every time I do this I swear to myself that I'm going to take it easy, there's no rush, I'll just work on it in my spare time. Then it takes over my life and making another part is all I can think about. Good wife is away at her job in the local library, and won't be home until 3:00, so I think I'll make gears today. Gears are always fun. A bit intimidating, but fun, nonetheless.

[b.lindsey]

Very interesting design Brian!  Very compact as someone already said, but I like that about it. Should make for a most intriguing motion too once it's up and running. Standing by 

Bill

[Brian Rupnow]

What good is a build thread without "in process" shots? This is my 50 tooth gear, emerging from another "chucking stub" left over  from making a cast iron cylinder. It was barely, barely long enough. I hate doing really short stubs, because if you get to close to those hardened chuck jaws with the gear cutter you can kiss $80 goodbye. The 25 tooth gear which I will do next is on a comfortably longer piece of 1045 steel that was left over from a customer job.

[Jasonb]

Has anybody used this type of con-rod connection at the crankshaft? I'm pressed for room where my rod attaches to the one piece crankshaft, and this would get me out of trouble. I think the actual hole for the rod journal would be the last step in the fabricating operation so everything would run true. I haven't used this before, but there's a first time for everything.--

You would probably be better off with a split bronze bearing that is retained by the strap. Also as drawn you will have a job getting the strap to pull the bearing up nice and tight, usual way is to have some form of wedge and cotter. Strap can also be cut from rectangular material rather then being rounded as though it was bent.

[Art K]

Brian,
I see you didn't go for the sleeve valve. But maybe the next one can be a little more traditional, like a one cylinder, two piston & crank 2 stroke.
To throw a wrench in the works.

Well Hot-Dog!! I even managed to sneak an ignition cam and my old stand by Chrysler ignition points in behind the offside flywheel.

As it happens I rebuild old British shocks. Seems there was such a heated debate over which side was nearside & offside they solved it only by resorting to left & right.
I am enjoying you starting a new engine project. It's always interesting and informative.
Art

[Brian Rupnow]

So--Today we made a start. I like cutting gears. I especially like making gears from left over bits and pieces that I have laying about. I always drill a pair of holes the calculated distance apart in a piece of scrap and fit the gears to shafts which set in the reamed holes. It is much better to do it this way and correct any "tightness" in the mesh, rather than trying to do it in a partially assembled engine. These gears seem to be "just right", although that is never a certain thing.

[gerritv]

You would probably be better off with a split bronze bearing that is retained by the strap. Also as drawn you will have a job getting the strap to pull the bearing up nice and tight, usual way is to have some form of wedge and cotter. Strap can also be cut from rectangular material rather then being rounded as though it was bent.

Would offsetting the screw holes (like done on insert tooling to force the insert against the holder) pull the strap up and tight? The countersink would do this job.

Gerrit

[Brian Rupnow]

Jason--Thank you for all the great pictures.---Brian

[cfellows]

Nice compact design, Brian.  Very innovative.

Chuck

[Brian Rupnow]

I think that to make the con rod a two piece like I'm thinking of, two separate pieces would have to be machined and bolted (and possibly dowelled) together as shown in the first picture. Then after they are firmly bolted and possibly dowelled together, the hole gets put in as shown in the second picture. The sides would have to be match marked to make sure they went back together the same way they came apart. Then they could be separated and put back together around the rod journal.

[Brian Rupnow]

[b.lindsey]

Brian, Dr. Senft used a similar arrangement in the Poppin flame licker. See the attached image. I realize that there may be more forces in an IC engine but the concept does work.

Bill