Swifty's build of Rupnow engine.

[manop]

This engine is going to be beautiful,

 

[Brian Rupnow]

That looks really sweet. You can make the valves from two pieces, but you really don't have to. If you have a look at the post in my forum thread about turning the valves there is an excellent tip there on how to keep the valve stem from deflecting when it is being machined.----I am really thrilled that you are proceeding with this build.-Brian

 

[Swifty]

Brian, I recall the posting about turning the valve stems down in steps, but decided that if I used 1/8" drill rod with larger pieces soldered on it might work out better. I have a nice fit between the reamed hole and the drill rod, so off to a good start already. Hopefully my ignition and spark plug will arrive next week, as I want to get it running before starting on the governor.

Paul.

 

[Brian Rupnow]

Brian, I recall the posting about turning the valve stems down in steps, but decided that if I used 1/8" drill rod with larger pieces soldered on it might work out better. I have a nice fit between the reamed hole and the drill rod, so off to a good start already. Hopefully my ignition and spark plug will arrive next week, as I want to get it running before starting on the governor.

Paul.

Swifty--Just be aware that drill rod generally comes in at .0005 over nominal and won't fit thru a nominal reamed hole. Cold rolled comes in .0005 undersize, and is consequently a "perfect" sliding fit in a nominal reamed hole. (Sorry about that!!--I didn't have enough zero's.

 

[Swifty]

Brian, drill rod, or what we call silver steel over here, is spot on on size. I measured the valve stems as best I could and they are 0.12525". I used a new 1/8" reamer in the holes and the rod slides in nicely.

Paul.

 

[Brian Rupnow]

Okay Paul---I'm not sure why the difference. It may just be a North American thing.

 

[gus]

Brian, drill rod, or what we call silver steel over here, is spot on on size. I measured the valve stems as best I could and they are 0.12525". I used a new 1/8" reamer in the holes and the rod slides in nicely.

Paul.

Hi Paul,
Hard to buy Silver Steel here in Singapore. Next trip to HongKong,will buy a two of each from 3 mm------------10mm to stock up and store in dry location to minmise rust. Balcony m/shop is a rusty place.

The Grade 5 bolts I picked up from fastener store is good to make tappet valves. Used same for Webbie.

Still following your threads to prep up making this engine. Alas. There are so many other engines distracting me.

Just bought WinZip---Mac to d/l Brian's engine prints.


Just wondering the possibility of getting Tin Falcon to organise a get together
at a model engine trade show next year. It's Time we meet up with Tin,Brian & Paul & others to talk engines.

Take Care.

 

[Brian Rupnow]

Gus--I like that idea!!----Paul--Are you going to make the small bore carburetor I posted the design for?---And Oh yes--I goofed with the sizing on drill rod and cold rolled rod. I didn't have enough zero's. I have corrected my original post----Brian

 

[Swifty]

Brian, yes I will make your latest carburettor, the small bore one. Seeing that it works for you, that's good enough for me.

Picked up some 1/8" "E" rings this morning, I plan to use them on the valve stems instead of a pin.

Paul.

 

[gus]

Swifty--Great Progress!!! I am pleased to see another build of this neat engine. I hope you have fun, and come up with a good runner. ---Brian

Hi Brian and Paul,
Drawings for base,side plates,o/head,etc printed and now diligently studied to make a B.O.M. to buy material. Decided to jump in,sink,drown or swim & survive.There are some skills I lacked and some to refine.Press fit will be tough on Gus. Can try. Gung Ho.:hDe::hDe:
In about a month or two ,should have some progress to show. Alas!!! My poor Sakai Lathe and mill will be required to perform beyond it's limits.
Plenty of jigs and fixtures to make. I have no DROs.Will be fun.

Would prefer to buy the conical gears to save all the hassle.

Gus will need expert advice and help from all my Gurus.Material should come in by latest next week. Plan to use cast iron for the F/wheels.

 

[Swifty]

Glad that you have decided to jump in Gus, everyone needs challenges to make life interesting. In order to gain skills you need to get out of your comfort zone and try something a bit more advanced. You have already built an IC engine, so you are ahead of me there.

Just take things slowly and don't rush, this is how mistakes are made. However if you do make a mistake, learn something from it and move on. Before you machine something, go through the steps in your mind before starting, and then go for it. If you are going to use metric size silver steel, just make sure that you change the drawings where necessary, I used 10mm instead of 3/8" for the main axle and therefor had to change hole sizes.

Good luck with your build.

Paul.

 

[Swifty]

Made my valves this morning, I used 1/8" silver steel with a larger piece soldered on for the head. Before I soldered the parts together I machined a groove to take the "E" clips that I am using to hold the assemblies together, the groove is only 0.020" wide. I only need 2 E clips, but purchased 12 to allow for those that disappear into no man's land.

Here is a photo of the parts after soldering.


Machined the valves without any problems, it certainly helped leaving some shaft protruding from the head end as it enabled me to clean up the longer part of the valve.

Here are the valves with the E rings attached.


And some spring retainers.


Paul.

 

[gus]

Glad that you have decided to jump in Gus, everyone needs challenges to make life interesting. In order to gain skills you need to get out of your comfort zone and try something a bit more advanced. You have already built an IC engine, so you are ahead of me there.

Just take things slowly and don't rush, this is how mistakes are made. However if you do make a mistake, learn something from it and move on. Before you machine something, go through the steps in your mind before starting, and then go for it. If you are going to use metric size silver steel, just make sure that you change the drawings where necessary, I used 10mm instead of 3/8" for the main axle and therefor had to change hole sizes.

Good luck with your build.

Paul.

Hi Paul,

Thanks for the kind advice. I normally would make up a W.I .(work instructions,step by step. When reducing OD I would go for a hit list to log every cut depth and OD to give me a fair idea of how much I have gone and how more to trim off.Been hitting the required diameter spot on. A cutter sharpening and hone for the last cut. Since 2010 my turning/drilling/reaming/honing/milling skills have improved vastly. As you said its true,to make further skill improvement,we must take up challenges. Been studying the prints carefully before jumping in . Went into the FireFly IC Engine w/o total grasp of requirement. Made a big mess. There after this, Gus got smart. Do it right the first time and every time.
Only now , did I realised my "meisters" were seen as very fussy when they were very meticulous in prepping and finishing the job.
Friend of mine did his apprenticeship in Tool & Die" at GM,South Africa. He nearly gave up after three months with the strict ,no nonsense Dutch/German/British Meisters.

 

[Swifty]

I was fortunate Gus, that we had a lot of German toolmakers when I was doing my apprenticeship. I was taught well, made my first press tool, to blank a component, 6 months into my apprenticeship.

Paul.

 

[Brian Rupnow]

Swifty--Great progress. You are now far out ahead of the pack. I think my one Englishman has stalled out due to lack of equipment, and the other one is still finishing another engine which he is posting on this forum. Luc the Canadian has been pulled off his build with some other "real" work. I've lost track of my other two Australians at the moment, and the chap in California doesn't appear to have started his build. Gus, we are watching for you to start your build.----Brian

 

[gus]

Swifty--Great progress. You are now far out ahead of the pack. I think my one Englishman has stalled out due to lack of equipment, and the other one is still finishing another engine which he is posting on this forum. Luc the Canadian has been pulled off his build with some other "real" work. I've lost track of my other two Australians at the moment, and the chap in California doesn't appear to have started his build. Gus, we are watching for you to start your build.----Brian

Hi Brian,

OK .Guru. Now that the water is warmer, I am jumping in. Incidently,I bought 1/2" and 3/8" Silver Steel while holidaying in HongKong. Shall I say,unknowingly,I was already prepped in March. Will bid temporary farewell to Webbie after cleanup. Will buy bearings today.
After slowly and carefully studying your prints,I have better grasp.
Also been viewing your thread.

No worries. Will maintain my good record as per machining Webbie-----not a single scrapped piece to the scrap bin.

 

[Swifty]

Back again with the next piece, I have now made the small bore carburettor, with a few mods. I made the throttle screw 3mm and I also extended the tail that screws into the head by another 5mm, this was to get a bit more clearance between the fuel inlet and the frame side. The needle seats nicely into the fuel inlet hole, and when I blow into the fuel inlet all air is cut off with slight pressure from the screw.

Once soldered together, I held the carburettor by the fuel inlet and drilled the 0.80mm hole through into the inlet tube, then without removing it, drilled and tapped M3 to suit the screw, by doing it this way it gave me the best chance of the holes being in line.



Will make the one way valve for the fuel next.

Paul.

 

[Swifty]

And here we have the fuel check valve.



And assembled onto the carburettor.



Will now probably lap the valves in and play around with the springs.

Paul.

 

[Swifty]

Hi Guy's, I played around with the video function on my small compact camera, the resolution isn't great, but this is a test to see if I can post it here. I will probably borrow my son's video camera for future posts.



Paul.

 

[Cogsy]

That's a beautiful looking piece of work Paul. Looking forward to hearing it run.