Saito 170 3 cylinder radial
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Saito 170 3 cylinder radial
With a 16 x 8 APC, using 20% oil, 20% nitro I got 7100 rpm, with a idle of 1680rpm. The top cyl was reading about 200*, the port about 150*, the starboard was 100*. Looking at the exhaust the starboard cylinderseemed much wetter than the other two. It was about 45* during the test.
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RE: Saito 170 3 cylinder radial
I ran my engine today, after adjusting the intake valve on the starboard cylinder I got 7400 rpm for a gain of 300 rpm. The temps on the cylinders, right between the rocker boxes was 219* top, 219* port, 109* starboard, the starboard is defiantly running rich. While trying to get the idle lower I ran out of trim, so on the radio I went to the EPA and adjusted the idle down by over driving the servo, I now have a 1350 rpm idle, I could probably got it lower, but that's so slow I didn't see the point. The really good new is that the EPA for high throttle was set at 91%[:@], moving the EPA up to 100% got me 8200 rpm. As my mentor said, 'Life is like a box of chocolates.' I was so happy with that reading I didn't even try for more, my backyard sounded like a Harley convention, the only thing missing was toppless tattooed girls.
I forgot to take temp readings after getting the 8200 rpm, but I suspect that the starboard cylinder is still rich, and that's the nature of the beast.
I forgot to take temp readings after getting the 8200 rpm, but I suspect that the starboard cylinder is still rich, and that's the nature of the beast.
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RE: Saito 170 3 cylinder radial
I have a Saito 170. You should be getting around 9000 peak with the APC 16/8. Sounds like the starboard cylinder isn't lighting up. Make sure the glow plug there is heating up enough.
Put your hand under the exhaust for this cylinder. If it's blowing cold fuel, you know it isn't firing.
My 170 has been pretty reliable since switching to 15% Cool Power and a a Cline regulator. I don't use onboard glow.
Put your hand under the exhaust for this cylinder. If it's blowing cold fuel, you know it isn't firing.
My 170 has been pretty reliable since switching to 15% Cool Power and a a Cline regulator. I don't use onboard glow.
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RE: Saito 170 3 cylinder radial
I hadn't thought of feeling the exhaust, I'll give that a try.
I swapped the glow plugs and I have a on board glow-driver, I tested all three leads and they all light a glow plug. I'll have to check that the starboard cylinder isn't isolated electrically, during my tests I always touched the plug to the top cylinder's intake pipe.
I'm using Coolpower YS/Saito 20/20 mix for fuel.
I swapped the glow plugs and I have a on board glow-driver, I tested all three leads and they all light a glow plug. I'll have to check that the starboard cylinder isn't isolated electrically, during my tests I always touched the plug to the top cylinder's intake pipe.
I'm using Coolpower YS/Saito 20/20 mix for fuel.
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RE: Saito 170 3 cylinder radial
I strongly suspect the starboard cyl isn't lighting. That one seems to be the toughest one to get going. My 170 does exactly 7100 RPM with the 16/8 when the starboard cylinder is missing.
Please post the outcome of this.
Please post the outcome of this.
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RE: Saito 170 3 cylinder radial
I flew the engine in my bipe today, the first flight, very short due to radio glitches, was OK. The second flight the engine didn't seem to be putting out. This is the first time I ran it with the cowl on, I may have to put baffles in the cowl for better cooling.
I'm sick as a dog right now, in a couple of days I'll get compression readings from each cylinder, and temps at full throttle. If I have to I'll take the engine apart to see why the starboard cylinder runs so rich.
I'm sick as a dog right now, in a couple of days I'll get compression readings from each cylinder, and temps at full throttle. If I have to I'll take the engine apart to see why the starboard cylinder runs so rich.
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RE: Saito 170 3 cylinder radial
I flew the engine in my bipe today, the first flight, very short due to radio glitches, was OK. The second flight the engine didn't seem to be putting out. This is the first time I ran it with the cowl on, I may have to put baffles in the cowl for better cooling.
I'm sick as a dog right now, in a couple of days I'll get compression readings from each cylinder, and temps at full throttle. If I have to I'll take the engine apart to see why the starboard cylinder runs so rich.
I'm sick as a dog right now, in a couple of days I'll get compression readings from each cylinder, and temps at full throttle. If I have to I'll take the engine apart to see why the starboard cylinder runs so rich.
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RE: Saito 170 3 cylinder radial
I found out where Forrest Gump works! After $400 of work on this radial at Horizon Hobbies the engine was timed wrong. The timing on the engine was 123, it should be 132! When I was hand flipping it it didn't feel the way I thought it would, I've got 3 radials but this is the first one I've run, it now feels the way I thought it would. Tomorrow I'll take it out and see how it runs now.
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RE: Saito 170 3 cylinder radial
I ran the engine, it sounds very different, last time it sounded like a lot of little Harleys ( V twins?), this time it sounds much smoother. I was able to get 9000 RPM at first, then the top RPM keep getting lower, and I wasn't able to over richen it, so I assume I have dirt in the needle valve. I ran two tanks out at 4000 rpm, and had it idling at 1100 RPM. I was getting 230* on #1 & #2, 265* on #3.
I've posted the invoice. The way he describes it is the way it was when I got it, by changing the timing 360* on the #2 cylinder, it's now a nice compression bump every 240* like it should be. If you read the invoice it seems like he's guessing, and he never said he fixed it or that it had proper power levels. I'd be pissed if it had cost me $400!
I figure my neighbors heard it enough for today, so I'm going out for some large fuel tubing, I have medium on it now, and it's quite long so that may be a problem.
I've posted the invoice. The way he describes it is the way it was when I got it, by changing the timing 360* on the #2 cylinder, it's now a nice compression bump every 240* like it should be. If you read the invoice it seems like he's guessing, and he never said he fixed it or that it had proper power levels. I'd be pissed if it had cost me $400!
I figure my neighbors heard it enough for today, so I'm going out for some large fuel tubing, I have medium on it now, and it's quite long so that may be a problem.
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RE: Saito 170 3 cylinder radial
Ran my 170 today for the first time. Right cylinder (looking tail to nose) was really rich (compared to the others) and dropped out a lot. Will this get better as the engine is broken in?
Thanks,
Teryn
Thanks,
Teryn
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RE: Saito 170 3 cylinder radial
It should, but run it and feel the heads, they should be close to the same temp. Also check to see that it's timed correctly, you should feel compression then a softer bump then compression then another bump then compression again followed by another bump for every two turns of the prop. You should not feel compression three times then three bumps.