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Author Topic: GT380 ground up build  (Read 1866 times)

Offline farmer92

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Re: GT380 ground up build
« Reply #30 on: Jun 27, 2018, 07:59:57 »

200cc inline 4 2t made from 4x50cc scooter engines, stuffed into a ysr50 frame.


Honda 800 v8
Made from 2 400f engines.


Anything is possible hahaha

Online irk miller

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Re: GT380 ground up build
« Reply #31 on: Jun 27, 2018, 08:19:54 »
Honda 800 v8
Made from 2 400f engines.


Anything is possible hahaha

I'll take your Honda 800 and raise you a supercharged 1500 made from CB750 motors...



23tbucket was building this over on Hondachopper.  Unfortunately, he passed away this June right when the trike was ready for reassembly.

https://www.tapatalk.com/groups/hondachopper/reverse-trike-with-supercharged-1500cc-engine-t57239.html

Offline farmer92

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Re: GT380 ground up build
« Reply #32 on: Jun 27, 2018, 09:08:20 »
I'll take your Honda 800 and raise you a supercharged 1500 made from CB750 motors...



23tbucket was building this over on Hondachopper.  Unfortunately, he passed away this June right when the trike was ready for reassembly.

https://www.tapatalk.com/groups/hondachopper/reverse-trike-with-supercharged-1500cc-engine-t57239.html

Thatís nuts!
The amount of time that must have gone into the conception of it must be staggering

Offline themotoworks

  • Posts: 65
    • the motoworks
Re: GT380 ground up build
« Reply #33 on: Jun 27, 2018, 11:42:08 »
I remembered what the point of this build was and stopped playing too much, I optimized some pipes and found cutting the piston skirt 10mm seems to bump power and not have much in the way of flat spots, the intake tract is designed around some carbs I had saved for this bike, power shows 60 with a pretty smooth curve, I can live with that, the whole idea of this project was to learn about the process of designing a bike wholly, manufacturing the parts, and then assembling as efficiently as possible, going full radical on the engine isn't in the cards for this one, but it will be cool to keep playing with 2 strokes, I think I could build some stupid stuff with them. 





      * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
      *                                                                     *
      *                       ENGINE PERFORMANCE FILE                       *
      *                                                                     *
      *  FILE NAME: C:\USERS\PUBLIC\MOTA\SAMPLES-6\GT1D.PER                 *
      *                                                                     *
      *  DATE (D/M/Y): 27/6/2018                                            *
      *                                                                     *
      *  TIME: 10:33 a.m.                                                   *
      *                                                                     *
      *  COMMENT: "Optimisation output file"                                *
      *                                                                     *
      * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *



      ENGINE SPECIFICATION
      --------------------
 
      BASIC ENGINE CONFIGURATION:
        Piston controlled induction.
        Single piece expansion chamber.
 
 
      PIPE STEP FACTOR:
      Lower Limit:  4.1   Upper Limit: 16.0   Value: 10.0
 
 
      SCAVENGING PARAMETERS:
 
        Maximum Short Circuit Ratio: 0.20
        Maximum Displacement Scavenging Fraction: 0.80
        Scavenge Ratio for Zero Short Circuit: 1.00
        Scavenge Ratio for No Displacement Scavenging: 0.50



       BORE      STROKE     CONNECTING ROD   GUDGEON PIN
       (mm)       (mm)        LENGTH (mm)    OFFSET (mm)
 
      54.00      54.00          110.00           0.00



      BORE/STROKE   CONNECTING ROD LENGTH
         RATIO          /STROKE RATIO
 
        1.0000             2.0370



      BOX NAME                  CLEARANCE       SWEPT       COMPRESSION
                               VOLUME (cc)   VOLUME (cc)       RATIO
 
      CRANKCASE                  225.00        123.67           1.55
      CYLINDER                    10.00        123.67           8.49



      CALORIFIC VALUE OF    AIR FUEL   THROTTLE AREA
         FUEL (BTU/lb)        RATIO        RATIO
 
           18536.3            13.00        1.000



      COMBUSTION PARAMETERS:
 
      COMBUSTION      BURN PERIOD
      EFFICIENCY       (degrees)
 
         0.800            55.0



      IGNITION TIMING:
 
      IGNITION TIMING
       (degrees BTDC)
          24.5



      AMBIENT CONDITIONS:
 
      TEMPERATURE (F)   PRESSURE (psi)
 
            68.0            14.70



      PISTON PORT DIMENSIONS:
 
      PORT     NUMBER  BRIDGED     MAXIMUM PORT WIDTH    HEIGHT  CORNER RADII
      NAME    OF PORTS  (Y/N)   ANGULAR   ARC    CHORD    (mm)    TOP  BOTTOM
                                 (deg)    (mm)    (mm)            (mm)  (mm)
 
      INLET       2       Y      38.20   18.00   17.67    19.17   3.00   3.00
      TRANSFER    2       N      65.78   31.00   29.33    10.99   3.00   6.00
      EXHAUST     1       -      78.52   37.00   34.17    21.31   5.00   5.00
 
 
      PORT           BRIDGE     RADII AT BRIDGE
      NAME            WIDTH       TOP   BOTTOM
                      (mm)       (mm)    (mm)
 
      INLET           5.00       3.00    3.00
 
 
      PORT            TOTAL      ATTITUDE ANGLES
      NAME             AREA      AXIAL    RADIAL
                     (sq.cm)     (deg)     (deg)
 
      INLET           6.6213       5.0      0.0
      TRANSFER        6.0571       0.0     20.0
      EXHAUST         7.0667      15.0      0.0
 
 
      PISTON PORT TIMINGS:
 
      PORT NAME     START OPEN   FULL OPEN   START OPEN    FULL OPEN
                    (deg ATDC)  (deg ATDC) (mm from TDC) (mm from TDC)
 
      INLET           270.0        311.0        30.37        11.19
      TRANSFER        120.0        180.0        43.01        54.00
      EXHAUST          95.0        180.0        32.69        54.00



      INLET DUCT
 
        A bellmouth is present at the inlet of section 1.
        Section 4 is the inlet duct portion inside the barrel.
 
      SECTION  LENGTH  DIAMETER IN  DIAMETER OUT   AREA IN  AREA OUT
                (mm)      ( mm)         (mm)       (sq.cm)   (sq.cm)



         1      75.0      60.0         35.0         28.27      9.62
         2      95.0      35.0         29.0          9.62      6.61
         3      25.0      29.0         29.0          6.61      6.61
         4      56.0      29.0         29.0          6.61      6.60
 
 
      TRANSFER DUCTS
 
        Smooth entry to each transfer duct 2 is NOT assumed.
        Diameters and areas are those of each individual duct in a group.
 
 
      TRANSFER    (2 separate ducts)
 
      SECTION  LENGTH  DIAMETER IN   DIAMETER OUT   AREA IN  AREA OUT
                (mm)       (mm)         (mm)        (sq.cm)   (sq.cm)
 
         1      50.0      24.0         19.0          4.52      2.85
 
 
 
      EXHAUST DUCT (single air cooled system)
 
      SECTION    LENGTH      DIAMETER          AREA          CONE     VOLUME
                  (mm)      IN     OUT      IN      OUT      ANGLE     (cc)
                           (mm)   (mm)    (sq.cm) (sq.cm)    (deg)
 
       BARREL     60.0     29.5   33.2      6.83    8.66
         1       157.8     33.2   39.3      8.66   12.13      2.2      163.2
         2       171.5     39.3   87.2     12.13   59.72     15.9      564.6
         3       240.4     87.2  122.2     59.72  117.28      8.3     2089.0
         4        39.2    122.2  110.8    117.28   96.42     16.5      418.2
         5        63.2    110.8   79.5     96.42   49.64     27.8      453.4
         6        51.5     79.5   33.5     49.64    8.81     48.1      136.3
        TAIL      86.7     32.5   32.5      8.30    8.30
 
 
      ENGINE PERFORMANCE INDICATORS
      -----------------------------
 
      SPEED     POWER    TORQUE       POWER    TORQUE
      (rpm)      (kW)     (Nm)         (hp)   (ft lbf)
 
       1000     0.370     3.535       0.496     2.607
       2000     0.599     2.860       0.803     2.109
       3000     1.051     3.344       1.409     2.467
       4000     2.197     5.244       2.946     3.868
       5000     5.033     9.612       6.749     7.090
       6000     7.270    11.570       9.749     8.534
       7000     9.548    13.026      12.805     9.607
       8000    13.193    15.748      17.692    11.615
       9000    15.052    15.970      20.184    11.779
      10000    11.601    11.078      15.557     8.171
 
      SPEED      IGNITION TIMING       AIR FUEL
      (rpm)       (degrees BTDC)         RATIO
 
       1000            24.5              13.00
       2000            24.5              13.00
       3000            24.5              13.00
       4000            24.5              13.00
       5000            24.5              13.00
       6000            24.5              13.00
       7000            24.5              13.00
       8000            24.5              13.00
       9000            24.5              13.00
      10000            24.5              13.00
 
      SPEED     MEAN EFFECTIVE PRESSURES  (atm)
      (rpm)     BMEP     PMEP     FMEP     IMEP
 
       1000     1.772    0.082    0.029    1.884
       2000     1.434    0.092    0.059    1.585
       3000     1.677    0.100    0.088    1.865
       4000     2.629    0.233    0.117    2.979
       5000     4.820    0.408    0.147    5.374
       6000     5.801    0.501    0.176    6.478
       7000     6.531    0.539    0.205    7.275
       8000     7.896    0.579    0.234    8.710
       9000     8.008    0.549    0.264    8.820
      10000     5.554    0.418    0.293    6.266
 
      SPEED   FUEL CONSUMPTION        FLOW RATIOS           SCAVENGE  RATIOS
      (rpm)    (BSFC: lb/hph)     DELIVERY    EXHAUST       MASS      VOLUME
 
       1000         1.032         0.337934   0.337727       0.337      0.340
       2000         1.032         0.273492   0.273015       0.273      0.274
       3000         0.943         0.292168   0.294875       0.300      0.301
       4000         0.899         0.436934   0.442361       0.443      0.444
       5000         0.941         0.838447   0.838550       0.839      0.867
       6000         0.872         0.935362   0.935491       0.935      0.982
       7000         0.929         1.121026   1.120974       1.121      1.200
       8000         0.831         1.213048   1.213049       1.213      1.308
       9000         0.774         1.145004   1.145011       1.145      1.257
      10000         0.913         0.936711   0.936364       0.937      0.941
 
      SPEED              EFFICIENCIES             PERCENTAGE ENERGY LOSS
      (rpm)     SCAVENGE   TRAPPING   CHARGING      IN EXHAUST SYSTEM
 
       1000       0.488      0.668      0.226             32.98
       2000       0.424      0.684      0.187             53.57
       3000       0.477      0.712      0.213             41.77
       4000       0.574      0.671      0.297             26.86
       5000       0.774      0.577      0.483             11.45
       6000       0.840      0.591      0.553              9.84
       7000       0.875      0.532      0.597              8.10
       8000       0.879      0.585      0.710              7.02
       9000       0.864      0.636      0.728              7.46
      10000       0.834      0.548      0.513              7.17
 
                   PEAK CYLINDER         TEMPERATURE LIMITS AT CENTRE
      SPEED   PRESSURE    TEMPERATURE    OF THE EXPANSION CHAMBER (F)
      (rpm)     (atm)         (F)           MEAN      LOW      HIGH
 
       1000     27.85       2276.12        449.4    446.9     456.7
       2000     25.45       2150.92        446.0    441.7     455.2
       3000     27.04       2296.55        494.1    484.4     509.9
       4000     36.22       2792.18        552.4    536.4     577.5
       5000     48.61       3263.44        613.9    589.7     654.1
       6000     55.03       3588.20        671.9    644.6     730.1
       7000     58.13       3719.44        648.4    611.5     719.2
       8000     69.42       3783.74        711.5    663.9     780.1
       9000     71.32       3737.32        741.3    686.8     816.5
      10000     48.03       3449.45        633.3    597.4     686.3
 
      The Specific Time Area of a port is the sum of all port areas
      over time divided by the cylinder swept volume.
      The units sec/metre and sec.sq mm/cc are equivalent.
 
              SPECIFIC PORT TIME AREA
                (sec/metre x 10000)
      SPEED    INLET   TRANSFER   EXHAUST                                                                               
      (rpm)                                                                                                             
 
      1000    1245.2     623.9    1031.8
      2000     622.6     311.9     515.9
      3000     415.1     208.0     343.9
      4000     311.3     156.0     258.0
      5000     249.0     124.8     206.4
      6000     207.5     104.0     172.0
      7000     177.9      89.1     147.4
      8000     155.7      78.0     129.0
      9000     138.4      69.3     114.6
     10000     124.5      62.4     103.2
 
  Elapsed time: 24.00 seconds

Offline teazer

  • DTT SUPPORTER
  • *
  • DTT BOTM WINNER
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  • Posts: 8563
Re: GT380 ground up build
« Reply #34 on: Jun 27, 2018, 18:59:07 »
That's starting to look more normal.  How did you measure the two volumes?  They both look a little low.  And be careful with that ignition timing. 24.5 is rather high for 9,000 rpms.

And you are correct, all bike projects are a compromise between different competing constraints. Just out of interest, you might want to go to Jennings or Bimotion to see if all three ducts are correctly optimized in terms of time-area.

Offline 1fasgsxr

  • Posts: 1411
Re: GT380 ground up build
« Reply #35 on: Jun 27, 2018, 19:30:01 »
Thatís nuts!
The amount of time that must have gone into the conception of it must be staggering
   and it don't sound like it's going to fly apart....
http://www.dotheton.com/forum/index.php?topic=41083.0

Life is a journey from the maternity ward to the crematorium....

Offline themotoworks

  • Posts: 65
    • the motoworks
Re: GT380 ground up build
« Reply #36 on: Jun 28, 2018, 07:30:48 »
to get the combustion chamber volume I put the cylinder on the crankcase and sealed the area between the piston and cylinder with some plasticine, then added the head gasket and used a burette to fill the chamber to the edge of the plug hole, I know that'll change a bit with a plug installed but it was the way I know to approximate it.  for the crankcase I drilled a hole in an old piston, installed everything, blocked off the oil injection port, clayed up the transfer sections and the intake port, filled the crankcase to the hole in the piston at bdc, then drained the oil out the crankcase drain and measured that.  the timing was determined by the manual, which has it set to 3mm btdc, which translates to 24.5 degrees, I don't know if it advances or not, didn't have a chance yet to look at the timing plate, my assumption from working on a few mopeds is that it does not, it's going on the dyno when finished, so it'll give us a chance to play with the timing if it starts pinging.  I'd assume that timing indicates a very slow burn due to the nature of the design, if this were a longer term project I'd probably dive right in and copy something like a tm125, probably start breaking rods at that point though
« Last Edit: Jun 28, 2018, 08:00:53 by themotoworks »

Offline themotoworks

  • Posts: 65
    • the motoworks
Re: GT380 ground up build
« Reply #37 on: Jun 30, 2018, 12:34:52 »



made more progress into the design, the rear linkage is basically set, it took me a while to figure out how best to make a light and compact link, fabricating it from a tube with arms welded on seems to be the best way.  I also had a lot of trouble getting a shock configured the way I initially designed it, so I redesigned based on a stock ducati 821 shock, it's still tuned well for anticipated weight, but not quite as progressive, was still able to use up all shock travel for 130mm rear wheel travel.  also figured out how to mount the rearsets as efficiently as possible, this was tough because of how wildly off center the rear engine mounts are, this engine was a pain in the ass platform to start with, but I think it'll work out well. 

Offline themotoworks

  • Posts: 65
    • the motoworks
Re: GT380 ground up build
« Reply #38 on: Jul 03, 2018, 10:14:43 »
finished the design work, minus maybe some little spacers and stuff, going to start machining this week since no one expects much with the 4th falling right in the middle of the week
 ;D



Offline themotoworks

  • Posts: 65
    • the motoworks
Re: GT380 ground up build
« Reply #39 on: Jul 05, 2018, 08:13:31 »
got some sketches back from Jeremy, I am really liking the concept, can't wait to finish the mechanical part of the build and start fabricating the pretty stuff.