Rupnow i.c. Engine with governor

[Brian Rupnow]

Alright--I have finished the water cooled cylinder, the water reservoir, and the the water reservoir retaining ring. They were a little more involved than I had first thought they were going to be, but not bad.--Just a lot of hours. --So--Herewith are the associated drawings.---Brian





View attachment CYLINDER-RUPNOW.PDF

View attachment WATER JACKET RETAINER-RUPNOW.PDF

View attachment WATER JACKET-RUPNOW.PDF

View attachment RESERVOIR COVER.PDF

 

[Brian Rupnow]

I spent this afternoon pressing out the old 3/8" cold rolled shafts from the flywheels and pressing in the new 3/8" drill rod which will form the end pieces of the crankshaft. I miss-spoke in the video--the drill rod is actually .3755" outer diameter, not .375 as I say. That's why I had to polish it down to .375" everywhere but the area which fits into the brass flywheels. I have assembled everything to check for clearance issues, and there don't appear to be any. I did use some Loctite 648 retaining compound which claims to be for "press fits" on the part of the shaft that engages the flywheel. This is the first time I have had all of the parts together. Its always a bit of a thrill for me when I see everything together for the first time.

 

[Brian Rupnow]

What to do next??? That's a good question. The really critical things that simply MUST work in concert with one and other are all done.--And they do work, seemingly very well. I have tightened all of the bolts and Hooray!! Everything still turns freely. I know that I have built everything on the side with the gears on it at least 3 times now. (I was actually "gifted" my first set of gears on my first i.c. engine build, the Webster). I do know that right now, while everything is tightened up and there are no "binds" anywhere in the system would be a good time to finish all of the drilling and dowelling, so that this current assembly is "repeatable". I will probably have everything apart and back together again another two dozen times before the engine is ready to run. This engine was designed to have a spacer washer between the outsides of the flywheels and the inside of the sideframes. They were designed to be equal on both sides, but, invariably they always end up different, due to stack up of tolerances and "a few thou here/a few thou there" machining. Perhaps tomorrow would be a good time to slide some feeler gauges in on each side and determine what thicknesses my two spacer washers must be.

 

[Brian Rupnow]

Either I'm getting better or else I'm getting luckier!!! I was able to keep both spacers that fit between the flywheels and the outer frames the same at 0.050" wide. If I go strictly by the calculated figures, they should have each been .064" wide, but I knew that my center piece which joins the two flywheels was a tad too long after I pulled it out of the lathe and measured it.

 

[Brian Rupnow]

I feel like doing something outrageous today!!! I have been machining like a madman, wanting to work my way through all of the major engine parts before any of the other people building this engine might discover (God forbid) an error in one of my drawings. It seems that the drawings were all okay, and the main portion of the body, crankshaft, con-rod and cylinder all fit together and work well together. I feel that a lot of the "pressure" is off, and today I'm going to machine something for fun. I have this really nasty, crusty, piece of aluminum that I picked up somewhere that has been kicking around in my shop forever. Today this ugly duckling is going to transform itself into a swan---A governor body style swan, as it happens to have all the dimensions required. I may have to stop at some point and take my grand daughters for a swim, but hey, that's okay too!!!

 

[Brian Rupnow]

The water was COLD!!!Brrrrrr. Its been a very backward spring here, with a lot of rain, but enough high temperatures that the lakes are warm enough for swimming---barely!!! 9 year old grand daughter swims like a fish. 5 Year old granddaughter lies like a rug--Tells everybody she can swim--but she can't. I thought grandpa better get in the lake with her and see where the truth is before some trusting adult buys her line and lets her jump off the end of the dock!! Looks like another winter of swimming lessons for the younger one.--Oh yes---The engine---I got my "one part per day" obligation fulfilled. Turned that ugly block of aluminum from the previous post into a very nice governor body. Damn, I like it when I follow my drawings and everything bolts together the way I intended. Of course, now there will be no rest for me until I get a bushing and shaft made up so I can see how those bevel gears mesh.

 

[Brian Rupnow]

I have made a somewhat arbitrary decision to make the governor stempost in two pieces. For any of you guys who have larger machines, the drawing posted is fine. For people with small machines like mine, that's just too much steel to be cutting in the scalloped areas. I am going to make the large diameter part with all the fancy work from aluminum, and the actual center that the gear fits on from cold rolled steel, then Loctite them together. I will put up new drawings of the two-piece stempost tomorrow.

 

[Brian Rupnow]

Check this out!!! This is so neat----

 

[Brian Rupnow]

As promised yesterday, here is the governor stempost designed as a two part assembly for those of us with snaller machines. When assembled, dimensionally it is identical to the one piece stempost drawing which is already posted.




View attachment ASSEMBLY OF 2 PIECE GOVERNOR STEMPOST.PDF

View attachment GOVERNOR STEMPOST-TOP SECTION.PDF

View attachment GOVERNOR STEMPOST--TWO PIECE--STEEL PART.PDF

 

[canadianhorsepower]

Brian, man your flying at it good work
can you supply info were to get the gears from

 

[Brian Rupnow]

And now we get to the two parts that most often confuse and confound the builders of small i.c. engines--the timing gears!!!



View attachment CRANKSHAFT TIMING GEAR-RUPNOW.PDF

View attachment CAMSHAFT GEAR WITH CAM-RUPNOW ENGINE.PDF

 

[Brian Rupnow]

Brian, man your flying at it good work
can you supply info were to get the gears from

See post #15 for part number. The gears were purchased from McMaster Carr.

 

[Brian Rupnow]

This is my first step in cutting the steel 15 tooth cam gear. The piece of cold rolled steel is .875" o.d. which fortunately will fit into the body of the chuck which is attached to my rotary table. The end is machined down to .708" diameter which is the finished outer diameter of the gear, x 1/4" wide which is the finished thickness of the gear. The next turn down is to slightly less than 0.521" diameter which is the root diameter of the finished gear. The 1/2" or so of reduced diameter is to allow for "run out" of the gear cutter when I cut each gear tooth. I have drilled and reamed the finish bore of 3/8" to approximately 3/8" depth. The next step is to set it up in the rotary table and start cutting teeth.

 

[Brian Rupnow]

The gears I am going to make are the same as the gears used on the Philip Duclos Odds and Ends engine. I went back in time (Neat how I have my own personal time machine) and copied the sheet of instructions out of my "gear book" for cutting the gears. This is a picture of the calculations I made to set up my mill and rotary table, and to turn the blanks in preperation for cutting the gears. The bits of brass are irrelevant as they are for a different engine. If anyone has questions, go ahead and ask.

 

[starnovice]

Brian,
In the plans for the cylinder head in msg 13, you refer to a 1.25 counter bore in the notes for the slot and the valve holes. I assume this is the counter bore for the cyl but the plans show that as 1.125 +/- .001. Am I miss reading your plans?

Pat W

 

[starnovice]

Brian,
I am looking at making the complete base assembly one Al casting. The two concerns I have are if I will be able to machine the cyl counterbore and the bores for the crank bearings. Doing the cyl counter bore will just depend on whether I can fit the casting under the mill spindle, I can figure that out.

My question is, you left a lip on the outside of the bearings bore, could this be put on the inside so I can bore the casting from the outside?

 

[Brian Rupnow]

Brian,
In the plans for the cylinder head in msg 13, you refer to a 1.25 counter bore in the notes for the slot and the valve holes. I assume this is the counter bore for the cyl but the plans show that as 1.125 +/- .001. Am I miss reading your plans?

Pat W

My mistake Pat---And the first one brought to my attention so far. The bore is 1.125". The note was wrong. I will go back and repost the drawing with that note corrected.

 

[Brian Rupnow]

Starnovice--The lip at the bearing counterbore could be put on the opposite side to what I have shown without effecting anything. You MIGHT get into an interference issue with the hub of the bevel gear, but then again, you might not. My solid model shows the back side of the bevel gear hub being perfectly in line with the outside of the sideplate.--Of course, you could always shave .010" off the back side of the bevel gear hub if you had to.---Brian

 

[starnovice]

Thanks Brian, I will draw it up in SW and let you know how it comes out.

Pat W

 

[Brian Rupnow]

I am reposting this drawing, as the notes which refers to a 1.25" counterbore were incorrect. The counterbore is, in fact, 1.125" as dimensioned. I have deleted the earlier post. The attached .jpg shows only the first sheet. The link to the pdf file will bring up both sheets, although only the notes were changed on the first sheet, nothing else.---Brian

View attachment CYLINDER HEAD-RUPNOW.PDF