Headbang said: I hope you have the spings for starting them! 049's are finicky beasts until broken in. Click to expand...

I do have spring starters, but I don't have any way of getting them installed. I have to pull the cranks to get the drive washers off and then get the plastic part of the spring starter in. GG. Might try to get it primed up nice, then bounce each engine backwards against compression while glow heat's applied in the hope itt'l kick itself around in the correct direction. I'll have a shop rag on hand if they want to start backwards, chuck that in the prop to stall it and try again.

At some point I'll get the spring starters installed. Whole reason I bought them was to make it easy as can be to start these things. But I'm not gonna go trying to pull the drive washer off the crank without the proper tools, done some reasearch, real easy to destroy the crankcase, crankshaft, and/or washer if you try other methods. Not like a larger engine where the drive washer tends to just flop off, or if it's stuck, just needs a whap or two.

Get at least a few tanks of fuel through them before trying to dial them in. Same as any glow motor, run it rich on break in. Click to expand...

With a twin you want to always be a bit rich, less chance of engine failure in flight. Click to expand...

The real trick is how touchy the needles are, to sync them is going to take a bit of patience! Make sure you have good way of accurately measuring rpm, dialing in twins by sound is difficult to say the least. Click to expand...

Looks awesome so far! Click to expand...

Edit: Ran some numbers. Quick and dirty napkin math tells me that, if I'm getting ~15,000RPM out of these engines(which is what I should be getting per Cox Intl) I'll have a top speed of somewhere around 40MPH and it should have a cruise speed somewhere between 25 and 30 with the engines turning a happy 10k or so.I don't expect to be able to balance it on the props, but those numbers are lookin' quite good for my goal of having a relaxing, fun to fly 1/2a powered wing that can take off and land from a paved strip!Will run them in one at a time, won't worry too much about synchronizing them until I have them attached to the radio system. Gonna use a couple of linear 1.9g servos hotglued right to the sides of the fuel tank for throttle, and I'll connect them on a Y-harness for now. Later on if I do want to experiment with differential thrust I can just omit the Y-harness.I'm an idiot. The plastic bits that mate with the drive washers install from the prop side and I just didn't realize that earlier. I have now, props off, spring starters on, props back in, confirmed that the RH starter is on the RH turning prop and vice versa. Also, they spin these things with some authority, I can actually feel a breeze off the prop just from the spring starter!I hear tell these things also take a fair bit longer to wear in than a typical ABC or Ringed engine, too. Given the tank is 4oz/118cc, each engine running through the entire thing...mm, 5 tanks maybe? 6? It's a LOT more fuel than they usually had available back in the day, that's for sure. I won't be running both engines at the same time until run-in is complete, what I'll do is heat-cycle them in alternation. Port engine runs through a tank, then while it cools down I'll refill the tank and run the starboard engine, then repeat until they're suitably ready.You don't have to tell me twice about runnin' 'em fat! My glow cars, my NexSTAR's engine, all smoke like crazy. In fact, I actually managed to smoke myself outrunning the SC10GT one day. The wind was dead still and the smoke just wasn't going anywhere, after about 30 minutes it had gotten so thick I couldn't really see the truck anymore.Way I see it, if it ain't smokin' blue under load, it ain't rich enough. I don't expect to see any smoke out of these things, though...they're so small and the exhaust is so diffuse relative to the size that itt'l be nigh impossible to spot...but I do expect to see a lot of castor schmoo accumulating near the exhaust ports if the mix is on the right side of peak.Difficult, but so is getting a cantankerous 33 year old Ford I6 to pass emissions, but I manage. I'm a gearhead right down to the core, I'm sure I'll be able to get these little guys to play nice with each other. I don't expect OS dependability out of a mixer that small but it should still prove reasonably easy for me to wrap my head around.I'm also not overly concerned about it going into a flat spin if one engine fails mid-air. Between the relatively low output and how close to the centerline/CG the engines are the yaw moment created should be fairly minimal and countered well enough by the winglet stabilizers FT put on the Spear. I can't imagine it's gonna be climbing if it loses an engine, but I do expect to be able to semi-glide it back to the runway if that happens. Will certainly be an emergency landing situation but I don't expect it to be a crash situation.Thanks!