JICA Piston Port Specs

2010

Intercontinental A Junior Piston Port Engines, 1995 Homologation

                                     Intake                Exhaust
                              -------------------  -------------------------
 Engine       Bore    Stroke  Degs   Inches  Width  Degs   Inches Width  Web
 -----------  ------  ------  -----  ------  -----  -----  ------ ------ ----
 Comer P50    1.9685  1.9882  160.43  .949   1.379  172.4  1.297  1.537  .157
 Comer B52    1.9385  2.0472  159.13  .969   1.358  171.2  1.347  1.516  .157
 CRG S30-T1   1.9685  1.9882  160.4   .949   1.378  172.4  1.297  1.528  .150
 Dino M3      1.9685  1.9685  160.8   .942   1.378  172.8  1.281  1.536  .157
 Fox MC 30P   1.9645  1.9921  160.4   .951   1.376  172.4  1.300  1.490  .114
 Italsis MA21 1.9685  1.9882  160.3   .948   1.379  172.3  1.298  1.537  .157
 Parilla PV95 1.9685  1.9685  160.8   .942   1.379  172.8  1.281  1.541  .161
 PCR PV95 *   1.9685  1.9882  160.5   .952   1.379  172.6  1.298  1.537  .157
 Rotax PP95   1.9685  1.9882  160.5   .950   1.379  172.6  1.295  1.537  .157
 Solo PP98    1.9685  1.9685  160.8   .942   1.378  172.8  1.281  1.536  .157
 Titan PP95   1.9685  1.9882  160.5   .950   1.378  172.6  1.295  1.535  .157
 TKM BT95     1.9685  1.9882  160.4   .949   1.385  172.4  1.297  1.542  .157
 Vortex VA95  1.9685  1.9882  160.3   .948   1.385  172.3  1.298  1.542  .157

* 98mm rod, all others 100mm

-> Degrees are total from opening to closing.
-> Inches are from TDC.
-> Intake opening inches are NOT with IKF/WKA port tech tool. From TDC to port opening, counting bevel on skirt.
-> Exhaust Inches are from TDC with .110″ IKF/WKA port tech tool.
-> Widths are chord dimensions.
-> The formulas for calculating maximum port widths are:
Exhaust port(s) chord width = Standard Bore x pi x .223 + any web
Inlet port(s) chord width = Standard Bore x pi x .223 + any web
-> Inlet port tract length is 3.5827″ (91mm) minimum from the bore center line to the carburator mounting surface, including any spacer blocks.
-> Number of transfers are free.
-> 100cc max. displacement. (6.1024 cubic inches)
-> CIK homologated butterfly carburators only.
Air horn = 1.1811″ max. diameter.
Venturi = .9449″ max. diameter, .0787″ long min.
Throttle bore = 1.0629″ diameter max.
-> Crank case pulse hole, .128″ max.
-> CIK homologated side pods, drivers fairing, and nose piece.
-> CIK homologated intake silencer.
-> 286lbs (130kg)
-> The official method of measuring port heights is in degrees using a minimum 200mm (7.875″) diameter degree wheel.


1995 Engine Homologation book page numbers:

 Comer P50        112           Comer B52        123
 CRG S30-T1       141           Dino M3          209
 Fox MC 30P       489           Italsistem MA21  399
 Parilla PV95     289           PCR PV95         560
 Rotax PP95        75           Solo             183
 Titan PP95       243           TKM BT95         577
 Vortex VA95      612



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