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Post by rowdy235 on Feb 7, 2021 19:11:51 GMT -5
Thanks for the offer, I’ll keep it in mind but think I’ve already got one lined up hopefully!
I’m not sure how forced induction would work on a reed valve two stroke, since the pressure of the induction would essentially be fighting the engine pressure sealing the reeds. The Detroit I know has an exhaust valve and piston ported intake. I suppose a rotary valve would be an option as well.
The speeduino does have a built in rev limiter, so I’ll have to make good use of that. I know the c series is a pretty stout saw, but high rpms could be an issue.
I also think it’s a good idea to get the fi working before worrying about a charging system. I may not even be able to have the factory magnet in the flywheel with my homebrew crank position sensor.
This may be a long term project but I’m hoping it’ll be a cool outcome!
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Post by sweepleader on Feb 8, 2021 11:52:08 GMT -5
I don't think the reed would be a factor in a forced induction situation. The inlet pressure would fill the crankcase and the piston would compress it more on the down stroke. That would make the crankcase pressure higher than the inlet pressure and things would work "normally". With a positive pressure blower on the inlet, it might be possible for the inlet pressure to rise above the crankcase pressure toward the end of the flow of the crankcase charge into the cylinder. I still don't see that as a problem, just more mix into the engine. The reed would still prevent backflow as it is intended to.
A centrifugal blower would only make pressure up to its rating/speed, I suspect a positive displacement blower would make pressure up to the engine's ability to flow air. Both normally would have blow off or backfire valves to prevent overpressure. If they are designed for low pressure, there would likely be no need for pressure controls (60's Corvairs for example).
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Post by rowdy235 on Feb 8, 2021 19:39:03 GMT -5
Well, I never claimed to know a lot about forced induction lol.
I have a C-5 on the way, so once it arrives I can get started. This pry won’t be a quick project, as I’ll be learning on the fly!
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Post by rowdy235 on Feb 11, 2021 18:06:31 GMT -5
And the project has begun! Big thanks to Ron (ronaldt) for hooking me up with the saw, and auger attachment to go with it! Although I will probably end up putting the auger attachment on my C-91. As far as this project goes, I'm going to sort it into systems and complete them from hardest to easiest. First will be mounting magnets to the flywheel to create my homebrew crank position sensor. Stay tuned!
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Post by sweepleader on Feb 11, 2021 22:35:21 GMT -5
As long as you are going to have crank magnets and a battery, maybe you should also make it electric start...
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Post by rowdy235 on Feb 11, 2021 23:03:39 GMT -5
Haha, good idea. I'll keep it in mind! Made a little progress tonight. Got the flywheel off and started planning for my pickup. As of right now the only place I think I'll be able to put a sensor under the flywheel is on the rear bottom of the saw, right where the factory coil wire runs through. That is the only place there is enough room under the flywheel other than in the middle where the factory coil is-- that will be my backup plan but not as much real estate on the flywheel to put magnets there (more "teeth" = more accuracy). If I can get the sensor to fit under the edge, that should work out to put 12 evenly spaced 1/4" magnets around the edge (-1 for the "missing tooth"). However, I'm a bit worried the factory magnets will interfere. Has anybody ever removed them? Saw had intermittent spark and looking at the coil I can see why. Somebody had tried to glue the wire on but still fell off immediately when I moved it. Won't be needing the assembly anyway. Also popped the muffler off and had a look at the piston/cylinder, there's some light scoring but nothing awful. Should be fine for this project. If it works out well may consider doing new piston/cylinder. I also realized fitting an O2 sensor in a stack muffler is unlikely. Were there other mufflers that will bolt up? I'm thinking my C-91 doesn't have a stack, but can't recall right now.
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Post by rowdy235 on Feb 11, 2021 23:22:39 GMT -5
Also came up with this in my spare time tongight. Maybe a little early to think about decals, but gotta look the part if its going to be one of a kind! My girlfriend has a vinyl cutter which should handle the job fine!
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Post by rarefish383 on Feb 12, 2021 10:17:58 GMT -5
I think one of my C’s has a cam muffler, like a1050. I know I held a 1050 muffler up to one with a stack, that had a third hole tapped in it that looked like it lined up with the 1050 muffler.
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Post by rarefish383 on Feb 12, 2021 17:19:17 GMT -5
I think one of my C’s has a can muffler, like a1050. I know I held a 1050 muffler up to one with a stack, that had a third hole tapped in it that looked like it lined up with the 1050 muffler.
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Post by rarefish383 on Feb 12, 2021 17:20:51 GMT -5
Tried to edit our "cam" muffler for "can" muffler and goofed.
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Post by ronaldt on Feb 13, 2021 7:57:29 GMT -5
From what I've seen, the c-5,51,and 52 tended to have the stack exhaust. Mufflers are more common on the bigger cube C series (71-91 etc) and should bolt right on to that C-5.
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Post by edju1958 on Feb 13, 2021 11:10:45 GMT -5
Good luck on trying to find a "normal" muffler for the C5.I bought about 3 of them over the past yr.& the muffler body is the toughest part to find.Leon is out of them & so is Feebay & Bob J.I also tried CM Small Engine.Also,the prices on the muffler body can be quite pricey.Even the muffler caps are getting tough to find.I did manage to grab 3 baffles at a good price & a few muffler studs & air deflectors.If you can find an entire muffler you might be paying upwards of $60 or more.
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Post by rarefish383 on Feb 13, 2021 20:41:28 GMT -5
Wow, back when I ran my Dad's 1050 lean and cooked it, I joined here and on AS, around 2009 and 2010. I found an NOS cylinder and an NOS full muffler, base, spark arrestor, top and bolts and I think it was under $15. Unfortunately for me, I let Steve have all that stuff when I gave him the 1050. I could use that Muffler now.
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Post by rowdy235 on Feb 14, 2021 22:08:35 GMT -5
Well I put the first round of parts on order (magnets and Hall effect sensors), so should be making progress this week!
Here is my tentative to-do-list, mostly listing here so I don’t forget lol
Phase I: 1. Crank Position Sensor 2. Fuel System (Fuel Pump, Press Regulator, Line, Injector) 3. Ignition / Air / Exhaust (Coil, Idle Air Valve, O2 sensor) 4. Misc Sensors (Engine Temp / IAT / TPS) 5. Control Module Mounting and Battery
Phase II: 1. Get Engine Running! 2. Tuning
Phase III: 1. Tear down, paint saw 2. Rebuild (maybe) 3. Nice wiring harness
Future Hopes: 1. Charging System / Smaller Battery 2. Forced Induction?
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Post by edju1958 on Feb 14, 2021 22:17:40 GMT -5
You know Rowdy,Hollywood just might be interested in this for a SciFi flick,Lol.
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Post by rowdy235 on Feb 16, 2021 16:35:47 GMT -5
Still waiting on my magnets and hall-effect sensor to be delivered, but did take some time and mark out the flywheel. The tooth pattern I will be using is a 12-1, meaning there are twelve teeth with one missing (actually 11), this allows the computer to know exactly where the crankshaft is by programming how many degrees before/after TDC the missing tooth is. 360° / 12 = 30°. So I broke out my protractor and marked the flywheel at 30° increments. The one with the X will be the skipped tooth. I am holding off on drilling the holes to make sure the sensor/magnet arrangement I have in mind will work.
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Post by blythkd on Feb 16, 2021 19:47:58 GMT -5
I think I can come up with a full size muffler body. Not sure about a cap. Let me know if you still need one.
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Post by rowdy235 on Feb 22, 2021 13:00:23 GMT -5
Spent a lot of the weekend doing brush cleanup from an ice storm we had here last week, and also trying to get a permiter drain installed around my shop... all while working 50 hours a week but did find some time to make some progress on the saw! Got the flywheel done Really wanted to do something more elaborate for the sensor but with the size/location had limited options. Ended up just dremeling a small area and installing in a bed of epoxy (didn't use my usual JB weld as was worried it would interfere with magnet as its steel reinforced). And here's the assembly together Waiting on my resistors to get here so can finish up the sensor wiring and hook to the scope and test. Miss when radio shack was around and could go grab those. They're not expensive online but waiting for shipping is a bummer! After that's wrapped up its onto the fuel system. A buddy gave me a brand new fuel pump assembly for a vehicle he sold, hoping I can make that work.
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Post by rowdy235 on Feb 22, 2021 18:06:51 GMT -5
And we have a crank position sensor (I think, lol) Got my resistors today and soldered one in. Hooked up to my oscilloscope and turned over engine by hand. Each drop represents one of the magnets, and you can see the gap from the missing one. I'm obviously flying by the seat of my pants here, but I think this should work!
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Post by ronaldt on Feb 22, 2021 20:05:40 GMT -5
Looks like a hospital monitor...
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