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  1. K

    3DP material for RC methanol fuel

    I printed a fuel tank for a Norvel 061 powered 3D printed airboat project and it didn't care. No fuelproofing done, standard Monoprice PLA+ on a Monoprice MP-10 Mini printer at standard PLA print settings. That print was aaaagggesss ago...nearly a yaer ago in fact...that fuel tank is fine. No...
  2. K

    Engine sucks but will not blow

    There was a day I would have agreed, but then I got my hands on that Magnum 52. It's seriously one of the best running engines I own of any kind. It runs better than the engine in my '14 Challenger! I could spend hours of time with it all strewn about across my desk trying to find the half a...
  3. K

    Engine sucks but will not blow

    Eh, rotating them by hand and not feeling compression isn't the biggest of deals with small engines like this. I've got a couple of Magnum 52 4-stroke RC airplane engines in active flight rotation(IE on aircraft I fly regularly). One, an engine I'm the only one to ever put fuel and fire to, has...
  4. K

    suitable Al-Si alloys for pistons.

    hypereutectic pistons have been getting my half-ton truck down the road for 37 years now. If they're good enough for a 4.9L I6 with 350,000+ on the clock they're good enough for anything we're likely to build as a model.
  5. K

    Ford 300 Inline Six

    yeah I imagine getting it to idle at 500-600RPM would require an insanely oversized and out-of-scale flywheel that would never fit inside that bellhousing. Either that or it would have to be made out of something like tungsten or depleted uranium. I can also see that in my commercially made RC...
  6. K

    Ford 300 Inline Six

    That thing sounds pretty damn good! Though the idle is definitely up; real thing ticks over at just 500rpm or so. Makes me wonder if it's just scaling of physics laws that makes it so excruciatingly hard to get these small engines to idle as slow as their namesakes in full scale. Thermal camera...
  7. K

    Ford 300 Inline Six

    Eh, as the owner of two 300's in full scale....they really just don't look right unless they're soaked stem to stern in oil. They're notorious for valve cover and sideplate leaks in particular. One of mine leaks so much oil it doesn't even get oil changes anymore because the oil doesn't stay in...
  8. K

    Anyone else playing around with the Microcosm engines?

    I've got the M-17b on order to play around with, make it actually do something....thinking powering a small N-scale portable layout as well as its own CDI unit which should be <20 watts total...wondering if anyone else has dabbled with them. They seem to run reasonably well from what I can find...
  9. K

    is it the best scale v8 model engine?

    It's a deeply flawed $1,700 desktop toy noisemaker. Warped Perception got his hands on one too and did his video; his unit overheated on the table spinning nothing but its own flywheel and couldn't rev anywhere close to the claims in the pre-release marketing. His also had a nasty habit of...
  10. K

    in your opinon, what is the youngest age for someone to use a mamod or similar steam toy?

    Oh definitely. It's affecting the quality of what we have to buy, too. Everything we touch today is a disposable 'non-user-serviceable' consumer good. Even our cars have fallen into this trap; the megacorps make more money if shadetrees can't work on these things and if their expected useful...
  11. K

    in your opinon, what is the youngest age for someone to use a mamod or similar steam toy?

    Likewise, I grew up with a wrench in one hand and a hammer in the other. One of my baby pictures from when I was barely old enough to walk and I was already climbing around on the front end of a 70's era barge while h was working on it. And he very much taught me how to turn wrenches, even...
  12. K

    in your opinon, what is the youngest age for someone to use a mamod or similar steam toy?

    There's adults I wouldn't trust with one of these things. Age limits are stupid. Different people mature at different rates and you can't really do a catch-all thing like that. Nah. That won't accomplish anything. We tried that with cigs and booze only to find out that the people banned from...
  13. K

    270 Offy

    Oh, they're fine thread? Huh. Well, either way, they're all standardized to a common thread. 5/16 hex.
  14. K

    270 Offy

    Model aircraft engines have a lot of oil coming in with the fuel. 15-20 percent of the total fuel volume, depending on blend. Mine suck down an 18% lube package, of that, half is castor oil and half is synthetic. Rest of the fuel is, for the most part, methanol with a whiff of nitromethane for...
  15. K

    270 Offy

    commercial model aviation 4-cycles are lubricated solely by blowby and they last for decades working far far far harder than any of the models posted on this site ever do. It isn't that critical on this scale. It's quite impressive when someone goes to the trouble of giving one full pressure...
  16. K

    Feasibility of small 4-cycles in practical usage?

    Electrics are not superior to engines when half the point of flying the model in the first place is having an engine on it. And that's the case for me. I'm well aware that I could have unlimited vertical at half throttle in every plane I own if I went brushless, yet I go the other way. I put...
  17. K

    Feasibility of small 4-cycles in practical usage?

    Are you trying to be pedantic for a reason? Lessee, why one might use a 4-cycle in an RC aircraft over a 2-cycle. * Better fuel economy. Glow fuel costs $30 a gallon and planes tend to fly roughly twice as long on a given fuel load if a comparable 4-cycle is used in place of the 2-cycle. My...
  18. K

    Feasibility of small 4-cycles in practical usage?

    This is why I'm looking into a 1.3-1.5cc 4-cycle to replace a 0.8cc two cycle. The piston, crank, conrod, not hard to do. Commercially available two cycles as small as just 0.1cc are on the market in both glow and compression ignition varieties. The hard part's induction and ignition; these...
  19. K

    Feasibility of small 4-cycles in practical usage?

    It'd need to make enough power to swing a 6x4x2 or 6x5x2 prop at something like 8-10 thousand RPM to be useable where a Cox 049 2-cycle can be used(This would give a thrust/weight ratio of about 0.5:1, flyable but not exactly ripping holes in the skies). And it'd have to be feather light; spark...
  20. K

    Feasibility of small 4-cycles in practical usage?

    The smallest commercially available 4-cycle for RC aircraft use was an OS FS-20, and in current production a Saito FA-30. They're OHV and use standard glow plugs, and they're approaching the smallest limit to combustion chamber size where you can fit practically large valves and a glow plug in...
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