Vertical I.C. Rupnow Engine

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Hi All,
Thanks Brian, a copper tee fitting and a couple of welsh plugs and one gas tank. Had all of this in my junk bin.
Now for the cam cutout.

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Bruce, Set up on the mill and done the outside first, then used the lugs on either side to set up on the mill, and with a long 12 end mill, opened up the slot to the width and 4mm short of the depth, then used a 4mm R long ball nose bit to the final depth, sorry only pic of it on the mill when I was test fitting the crank and cam. Hope this helps.
EDIT, If you have not already done, do all the vertical holes first, there is a clearance hole for the exhaust push rod that would be hard to do after. Also work the 0.719" side first(crank web side) as the exhaust pushrod is set that side, and then I made the slot to fit the cam I had made up.

Andrew

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I got sidetracked Brian. Had to clear the block of long grass etc to keep the snakes at bay this summer. Will be back into it this weekend with a bit of luck. And have a runner with a lot of luck :D
 
Congratulations Andrew--That is the third Rupnow Vertical engine up and running across the face of the world. Hopefully Herbie will be next up.---Brian
 
Been playing with my engine but it doesn't even look like starting. Ive got spark, good compression and remade the valves and cages to get a good seal. Not sure what to try next.
 
Been playing with my engine but it doesn't even look like starting. Ive got spark, good compression and remade the valves and cages to get a good seal. Not sure what to try next.
Set your ignition points so that they are open about .025" unless the rubbing block is on the flat part of the cam. When the piston is coming up to top dead center, the points will close, and just before the piston reaches top dead center the points should open. When the points open, that is when you will get the spark. Take the sparkplug out of the engine, and lay it on top of the cylinder with the high tension lead attached. Make sure you don't have any fuel laying around the engine. (don't ask me how I know this.) Turn the flywheel by hand in the direction the engine would normally turn, with power on. If your timing is set correctly you will hear a "snap" and see a big fat blue spark jump across the gap in the sparkplug. If you don't see a spark, tell me. If the spark occurs at the wrong time, loosen off the set screw in the cam and adjust the timing to the way I have just told you by rotating the cam on the shaft. Since the ignition points are running off the crankshaft on that engine, it is going to be a "waste spark" system, which means you will get a spark on the compression stroke which fires the charge, and also on the exhaust stroke. Since there is no charge in the cylinder to ignite on the exhaust stroke, that spark is "wasted". Let me know what happenes. You may be on the other side of the world Herbie, but I'm right there looking over your shoulder.---Brian
 
Herbie

I have just found something on my metric version that might be causing an issue on yours.

My counterbores on the cylinder head bolt holes are too deep and the 8mm thread (5/16" - 18 ) of both inlet and exhaust ports have broken through (JB Weld to the rescue) :wall: (Didn't read my drawings properly)

If the same has happened on yours then you may have a vacuum leak on the inlet side.

Cheers

Bruce
 
Many thanks for the encouragement Brian. I have now adjusted everything to your specifications. The points gap i had was about 1/8". I am now getting a spark exactly as you described at the correct time. One major issue i had was fuel leaking everywhere. On closer inspection i noticed the bit of air hose i used had longitudinal ridges running along the inside of the hose preventing a good seal on the barbs from the fuel tank and carby. I shall get some proper tubing on Thursday and try the engine out again. Will keep you posted.
 
Installed the new fuel line confident I would have a runner by now but alas, not even trying to run .. very frustrating :confused:
 
Next stage--check valve timing. The intake is automatic. You can't do anything there except make sure you are using the lightest spring that will still close the valve after you push it open with your finger. The stem of the valve should slide very freely with no binding in the guide. The exhaust valve--well, first turn the flywheel clockwise until you know the piston has reached top dead center on the compression stroke. Then keep on turning it slowly and watch as the piston approaches bottom dead center. When the piston skirt has reached a point about 1/8" before the very bottom of it's stroke, stop. Loosen off the set screw that holds the crankshaft timing gear in place, and without letting the crankshaft turn, rotate the crankshaft gear slowly clockwise until you see the cam just start to have some influence on the rocker arm. This is hard to see, so you might want to have a dial indicator positioned so that if the rocker begins to move you will see the dial move. As soon as the dial indicates that the cam is influencing the rocker arm, lock the set-screws in the crankshaft gear. That sets your valve timing.--report back to me what happened. Before you set the exhaust valve timing, make sure that the cam is not exerting any influence on the long lifter, use a feeler gauge and make sure you have about .005 to .008" clearance between the lifter rod and the rocker arm--that is called "valve lash". If you don't have that set correctly, your exhaust valve will never close properly and you will lose compression during the compression stroke.
 
Herbie, i would try and run it with a vapour carb for trouble shooting purposes. Doesnt need to be anything fancy, just a glass jar and some tubing. Just to see if you get a different result.
 

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