An 83 crossing example (from Freedman, Gompf, Morrison, Walker: 
"Man and machine thinking about the smooth
4-dimensional Poincare conjecture".)
 PD[X[22, 2, 23, 1], X[155, 3, 156, 2], X[88, 4, 89, 3], X[79, 4, 80, 5], 
 X[146, 5, 147, 6], X[13, 6, 14, 7], X[7, 93, 8, 92], X[8, 160, 9, 159], 
 X[26, 9, 27, 10], X[10, 25, 11, 26], X[11, 158, 12, 159], X[12, 91, 13, 92], 
 X[67, 15, 68, 14], X[15, 63, 16, 62], X[109, 17, 110, 16], 
 X[17, 105, 18, 104], X[39, 18, 40, 19], X[130, 20, 131, 19], 
 X[20, 126, 21, 125], X[21, 44, 22, 45], X[76, 23, 77, 24], 
 X[143, 24, 144, 25], X[114, 28, 115, 27], X[161, 29, 162, 28], 
 X[94, 30, 95, 29], X[30, 69, 31, 70], X[31, 121, 32, 120], 
 X[32, 49, 33, 50], X[48, 33, 49, 34], X[121, 35, 122, 34], 
 X[35, 134, 36, 135], X[133, 36, 134, 37], X[37, 103, 38, 102], 
 X[38, 60, 39, 59], X[40, 151, 41, 152], X[41, 84, 42, 85], 
 X[87, 42, 88, 43], X[154, 43, 155, 44], X[56, 46, 57, 45], 
 X[99, 47, 100, 46], X[47, 137, 48, 136], X[137, 51, 138, 50], 
 X[51, 73, 52, 72], X[73, 53, 74, 52], X[98, 53, 99, 54], 
 X[165, 54, 166, 55], X[55, 166, 56, 1], X[57, 124, 58, 125], 
 X[131, 58, 132, 59], X[60, 103, 61, 104], X[110, 61, 111, 62], 
 X[148, 64, 149, 63], X[81, 65, 82, 64], X[65, 81, 66, 80], 
 X[66, 148, 67, 147], X[68, 111, 69, 112], X[139, 71, 140, 70], 
 X[118, 71, 119, 72], X[97, 74, 98, 75], X[164, 75, 165, 76], 
 X[77, 156, 78, 157], X[78, 89, 79, 90], X[107, 83, 108, 82], 
 X[83, 107, 84, 106], X[128, 86, 129, 85], X[86, 128, 87, 127], 
 X[145, 90, 146, 91], X[112, 94, 113, 93], X[95, 140, 96, 141], 
 X[96, 118, 97, 117], X[100, 123, 101, 124], X[132, 101, 133, 102], 
 X[150, 106, 151, 105], X[108, 150, 109, 149], X[113, 161, 114, 160], 
 X[115, 142, 116, 143], X[163, 117, 164, 116], X[138, 119, 139, 120], 
 X[122, 135, 123, 136], X[153, 127, 154, 126], X[129, 153, 130, 152], 
 X[162, 141, 163, 142], X[144, 157, 145, 158]]