Discussion in 'Engines From Castings' started by Jack3M, Jan 13, 2019.
Already cast them, just need to cut off sprue. They came out really nice. Will try to photo later
Just learned that Gary Martin has a set of water pump castings, no drawings, but some photos. He sent a photo of that awesome purple machine with one.
As promised the casting for the nipples, and in the background a bit of the floor before it was done.
Well, the engine is completed. Still need to make up the oilers, fuel system, ignition system, water pump and cooling system, but these are all over and above the engine itself. There are a lot of little fiddly things to do still. Made up the holder for the hall sensor. Need to get black PLA to print out the final version.
The chalk mark in the last photo is where a magnet is on the backside of the gear.
Also finished out the exhaust. Doing the elbows was pretty rewarding in that I did do the inside threading on them. Used the 4 Jaw to do that.
Cant really say final photos, but first completed photos.
Beautiful job Jack. Can’t wait to hear/see it running. Thanks for helping me along the path on this engine.
Karl, As I mentioned in email, there is still a long way to go, but step one is complete
VERY VERY nice job Jack!!!
That purple engine is killer isn't it? I spoke with him. He almost ruined it. He left plain water in the jacket and plugged it up with rust. That was where I realized I will always use machine coolant. I think I would cry if I rusted mine.
That is good to know, never considered that aspect.
On to other items of need and interest in this project. Got to have elbows and T fttgs. Broke down and bought the tap and dies for 1/16-27 npt. Work well on the brass and bronze. Anyhow, the process.
Drew up some elbows and T fittings in groups of 3 contiguous fittings in Fusion360. It has a nice feature of splitting something into parts on any given plane you choose. For molding at home in sand there is nothing less expensive nor as simple as my process. Years of trial and error and still improving. Mind you these are for 5/16 brass pipe, not large stuff.
Printed out the halves on 3d printer using PLA. A touch too small to effectively use drawn in locators and time consuming to get the different sizes, so just drilled some holes for 1/16 pins to hold each half during the casting. Did two groups of castings this morning and used brass with a touch of zinc added as it has been melted several times. That was very nice to work with, not as sticky as brass can be. Had previously cast the T's in bronze.
Not sure how many I will need in total for fuel and cooling at this point. It took all day to cast, clean, drill and tap them all. (and clean the mess from it all)
And you only did enough for one engine? Lol. Nice job.
That probably is't enough
I don't get it. I use the correct size tap and die and it doesn't start. NPT thread. What might I be going wrong? Finally had to go to 5/16-27 to be successful
tWell tried to make her pop, but no pop. Did valve timing according to Newsletter data. I am getting spark at the plug. Got one pop, just one. Nothing but issues with mixing chamber so I think this may be the issue. Sure seems to me like not even close to enough air. As I remember a #60 hole for the gas needle and a #54 for air as I recall. Those that have had success, was it with the shown mixer?
Spark timing is either slightly before or right on TDC. Holding intake valve open to get fuel in has no effect.
Been getting some help and feedback. Trying to run on LP and use the mixer in the plans. Apparently just getting too much fuel and I need a demand regulator. Awaiting plans and more info, my assist person has personal stuff to attend to first and get me a file. Found a mixer plan/diaphgram/needle that I may just get. Not sure yet. Meanwhile I have the grease cups and, unfortunately, I am going to have to disassemble and strip the whole thing and redo the finish and see if I can reassemble without chipping the powder coat. It chips very easily. Am also going to contact the coat people and see if they have suggestions. Forward ho.
I used propane with a hand-made demand regulator and the diaphragm/needle valve from a Briggs-Stratton carb. Not difficult to make and it works well.
Were you shocked at the “Tiny” restriction in the exhaust system? It seems counter intuitive to force the cylinders to exhale/inhale through such a small opening, but it would not work with a larger opening.
Well I find out today that the issue was resolved. You see, on the exhaust chambers, someone, cannot say who this might have been, someone, drilled the holes bass ackwards. LOL. So got to fix them up and give it another shot. No wonder it wouldn't run/fire/do anything. What a stupid mistake
That was it, still need to improve valve sealing but got popping now.
During all this, have been putting a little time in on the water pump. Much of it was to make gears 8t, 16 dp. I had a set of cutters for 16 dp, but the 'count' of eight was not listed for any of the cutters. Took a chance and used the one closest....12-13t and got a good set. I had bought a set on Ebay, but they were only .375 thick and therfore would not work well with the ports. So made a set that were .5". Made one long gear on a shaft and cut them off. Will get photos down the road.
Damn gremlins!! I'm glad I'm not the only one with those little rodents!!
Success. Need work on fuel system as it starves out. Need cooling system first.
Very well done Jack!!!
Isn't it a great feeling when it comes alive!
Well done. You’ll get the bugs out soon enough. Great community to help us along.
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