X-Mozilla-Keys:
Paul Yaw wrote:
The emissions ARE painfully off scale. They come from the factory with
three catalytic converters! Hydrocarbons are through the roof.
PY
We shall see if the new side exhaust ports change this situation.
I hope they do.
Paul Lamar
I have been thinking about this, and digging through some old dyno
runs. So far I am seeing an interesting trend. The engines that make
best power with the leanest air fuel ratios are the stock 12A's (13.5:1
to 13.8:1) which have a little tiny exhaust port. I am starting to
wonder if this is due to a greater amount of unburned gas being swept
around into the next cycle.
That turbo aircraft engine had a set of the most efficient (Flow vs.
Area) exhaust ports I have ever built, and required an extremely rich
air fuel ratio for best power. (High 11's) This has been driving me
nuts. The BSFC was pretty bad at approximately .58 to .60, but
considering the air/fuel ratios I would expect it to be worse. I don't
know if the fuel flow meter is freaking out, or if there is something
else going on.
Has anyone out there had any experience with injector atomization? The
fuel injector drivers had resistors in series with the coils, and I
wonder if a lazy opening and closing rate could have caused poor
atomization. Any input would be appreciated as I am baffled. I am
happy with the power/manifold pressure, but pretty disgusted with the
fuel burn. Heeelllppp!
PY
There is some recent evidense that higher injection pressures and
shorter
pulses give better atomization and better BSFC's. What injection
pressure
are you running?
PL
PRINT # 187 A1417.WC 13BT.CFG No Fric. Fact Jul 1 '99 8:16 PM Pg 1
Yaw Power Products 520-670-0110
DEPAC # 99 Thu Apr 29 '99 6:10 PM F1200 Flow Tst# 1417 2200 to 6600 RPM
ROTARY13.CFG IF: 10 29.23" Dry Air @ 25C FUEL SG .755 Time 35.9
Disp.:70 Disp:80
RPM HP STP TQ STP Fuel F A/F BSFC CFM V Eff BSAC TIME
BAND #/Hr RATIO #/HrHP % LBS/HP SEC
2205 54.0 128.4 24 15.05 0.475 84 82.6 7.142 3.0
2300 56.6 129.3 27 14.08 0.503 88 82.4 7.087 2.6
2400 59.5 130.2 31 12.92 0.547 92 82.8 7.066 1.3
2500 61.8 129.8 34 12.30 0.581 96 83.4 7.147 1.2
2600 64.6 130.5 37 12.01 0.599 101 84.4 7.192 1.4
2700 68.3 132.9 39 11.53 0.611 105 84.2 7.044 0.7
2800 71.9 134.9 41 11.70 0.599 110 85.1 7.012 0.9
2900 75.3 136.4 41 12.04 0.580 115 85.7 6.985 0.8
3000 79.0 138.3 43 11.89 0.578 119 85.6 6.880 0.6
3100 80.5 136.4 45 11.72 0.593 122 85.2 6.946 1.2
3200 83.1 136.4 46 11.68 0.591 125 84.7 6.904 0.9
3300 86.1 137.1 47 11.78 0.583 129 84.6 6.861 0.9
3400 89.3 137.9 49 11.75 0.584 134 85.2 6.864 0.9
3500 93.3 140.1 51 11.73 0.581 139 85.8 6.811 0.9
3600 97.2 141.9 53 11.73 0.582 145 87.1 6.828 0.7
3700 102.3 145.2 57 11.72 0.585 153 89.6 6.858 1.6
3800 108.6 150.1 60 11.65 0.583 161 91.7 6.791 0.9
3900 113.6 153.1 64 11.53 0.594 170 94.3 6.847 0.6
4000 120.2 157.9 68 11.40 0.600 179 97.1 6.839 0.6
4100 133.2 170.6 75 11.52 0.599 200 105.9 6.900 3.1
4200 141.4 176.8 80 11.40 0.60 211 108.5 6.823 0.4
4300 147.4 180.0 83 11.43 0.59 219 110.1 6.797 0.4
4400 155.1 185.1 85 11.59 0.58 228 112.0 6.727 0.3
4500 160.7 187.6 88 11.57 0.58 235 113.3 6.711 0.4
4600 166.6 190.2 91 11.68 0.58 245 115.3 6.740 0.3
4700 172.2 192.5 94 11.72 0.58 254 117.1 6.762 0.4
4800 177.9 194.6 98 11.65 0.58 264 118.9 6.790 0.4
4900 184.0 197.2 100 11.80 0.576 273 120.5 6.790 0.6
5000 187.8 197.2 102 11.89 0.577 281 121.7 6.859 0.7
5100 193.2 198.9 105 11.95 0.576 290 123.1 6.878 0.6
5200 197.2 199.2 109 11.77 0.584 296 123.1 6.871 0.6
5300 201.2 199.4 111 11.82 0.585 303 123.9 6.908 0.7
5400 204.7 199.2 113 11.90 0.585 311 124.8 6.965 0.9
5500 210.2 200.7 116 11.85 0.583 317 124.8 6.909 0.5
5600 215.4 202.0 118 11.82 0.58 323 125.0 6.880 0.4
5700 219.3 202.1 123 11.65 0.595 331 125.9 6.926 0.5
5800 224.1 203.0 127 11.60 0.60 340 127.1 6.961 0.3
5900 230.6 205.3 130 11.69 0.60 350 128.5 6.957 0.4
6000 235.9 206.4 132 11.73 0.59 358 129.3 6.962 0.3
6100 240.0 206.6 137 11.68 0.60 369 131.0 7.047 0.2
6200 247.9 210.0 140 11.74 0.60 380 132.6 7.022 0.3
6300 252.0 210.1 144 11.73 0.60 389 133.7 7.072 0.3
6400 256.4 210.4 146 11.78 0.603 398 134.5 7.105 0.5
6500 262.2 211.9 151 11.66 0.61 405 135.0 7.084 0.4
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