The pramates for her motor will be New stock bore as listed, a new milled head and recut, mild porting, stock exhaust with sting mod( she does not like it loud) intake mod with new carb. Her present motor has a (BYH)woods port with a CW racing head milled and cut running 165. reshaped the CW head when I rebuilt last Changing the CR and I improved intake flow and made an exhaust port height and width adjustment. This is why I reshaoed it to keep CR in check with stock pipe. When done we chased quads at dunes. Now she is chasing Drakes. That a hole new animal. I had done some testing with mine Dialing the motor in for the chase. Since she does like it loud( aka power pipe) the port and head work I use will not work. I now have to apply data to her pipe,suspension and driving style. She tend to brake in hard and power out. So the bottom has to remaine. If she changed her approch angle and rolled though powering out I could give her a little more top end port. This is why I must map the cylinder first do math than start Hacking. The base math is wanting a 38 mm carb with intake angle increase. Sorry tend to babble. The polish part I do not do much of. I tend to like a satin type finish on intake tract to bottom end and piston port. I use my finger to final taper so I can find every uneven surface I can as not impeed the flow by creating a low pressure point upsetting the tract strenght. One way to look at is a set of woops. The bump and ridges on the air streamallows the strenght of the mix to be altered before reaching the intake port. Darn molacules anyway This also effects the blow back resonant pressures.The bump and ridges effect both than it compounds at max prm when the intake in time closes the reeds, altering strenght properties. Babbling again. I will try to post in a pdf format or adobe. Not real good with computors.
STOCK, USED DAYCO,USED
ALT W 29.700 MM W 29.580 MM
D 13.350 MM D 11.280 MM
CD 4.860 MM CD 4.550 MM
F 0 15 DEG F 0 15 DEG
M 0 16 DEG M 0 18 DEG
RO 1.380 MM RO 0.280 MM
HRD W 30.600 MM W 28.860 MM
D 13.230 MM D 12.540 MM
CD 4.570 MM CD 4.550 MM
F 0 14 DEG F 0 12 DEG
M 0 13 DEG M 0 12 DEG
RO 0.100 MM RO 0.430 MM
STOCK, NEW
HRD W 30.770 MM W =WIDTH
D 13.080 MM D = DEPTH
CD 4.480 MM CD = COGG DEPTH
F 0 15 DEG F = FIXED SIDE OF DRIVE CLUTCH FACE BELT DEGREES IN TAPER
M 0 15 DEG M = MOVABLE SIDE OF DRIVE CLUTCH FACE BELT DEGREES IN TAPER
RO 0.004 MM RO = ROLL OVER (belt squeeze)
Limits limits Min bore max bore Stock bmep target bemp Safe Cm CR stock 6.2:1
Tobey piston 3-08 measured at OD min max 150 168 6800
Piston OD 10 mm up from skirt 79.925 0.080 0.092 80.005 80.017
Piston crown 17 mm down fron crown 79.516 79.596 79.608
Swell factor tolerence 0.409 19.56% 22.49%
Bores A Avalible 80.013 80.018
B Avalible 80.007 80.012
C Not Avalible 80.000 80.006
Comp increase level% 12.00%
Bhp 56.7927936 69.76353485
mechianl effency 70% 70% based on average dyno run rear wheel HP
engine output HP 39.75495552 48.83447439
FOOT POUND PER MINUTE
Bores A Avalible 80.013 80.018
B Avalible 80.007 80.012
C Not Avalible 80.000 80.006
Stock Woods Dune DCP Race
PSI p x 150 165 168 171 185 psi
n x 6200 6500 6800 7300 7700 rpm
BHP 56.7927936 65.4949152 69.76353485 76.23058522 86.99068224 bhp
Engine BHP 39.75495552 45.84644064 48.83447439 53.36140965 60.89347757 m-bhp
Bemp 150 165 168 171 185
stock Woods Dune DCP Race Cm piston speed
0.166 0.166 0.166 0.166 0.166 0.166
3.11 3.11 3.11 3.11 3.11 L stoke In inches
6200 6500 6800 7300 7700 N Crank speed in rpm
power range 3200.812 3355.69 3510.568 3768.698 3975.202 Cm
bearing stress good safe borderline max
Note: increase bemp 12% leave Cm alone Larger bore for piston increase thermal load reduse thermal expansion area and reduce mechinal resistance