====== OS SPEED 21VZ-B Spec II ======
This is the 2008-2009 Worlds Edition.
{{http://nitroenginewiki.com/images/osspeed13911/banner.gif}}


===== OS Speed 21VZ-B Spec II =====
==== Specifications ====

^Variant ^ Notes 
| Manufacturer | OS Engines |  
| Re-branded Engine | No |
| Brand | OS Speed |
| Model | 21VZ-B Spec II |
| Evolution of | OS Speed 21VZ-B V-Spec |
| Part # | 13911 | 
| MSRP | $399.99 | 
| Bore | 16.6mm / 0.654in |
| Stroke | 16.0mm / 0.630in |
| Displacement | 3.46cc/0.211cu in |  
| Weight | 349g/12.32oz |
| Instruction Manual | [[http://nitroenginewiki.com/images/osspeed13911/13911_OSSP21VZ_VSPEC2_MANUAL.pdf|Click]] |
| Exploded View | [[http://nitroenginewiki.com/images/osspeed13911/13911_OSSP21VZ_VSPEC2_EXPLODED.pdf|Click]] |

==== Crank Specifications ====
{{ http://nitroenginewiki.com/images/osspeed13911/crank.gif}}
^Variant ^ Notes 
| Crankshaft  | Double Tungsten Slugged/DLC Coated/Silicone Fill |
| Crank Type | 14mm SG Style |


==== Crankcase Specifications ====
{{ http://nitroenginewiki.com/images/osspeed13893/bearing.gif}}
^Variant ^ Notes 
| Rear Bearing | Ceramic 14.00 x 25.40 x 6.00 |
| Front Bearing | Steel 7.00 x 19.00 x 6.00 |
| Case | Cast Aluminum Black Oxide Coated |
| Backplate | Bump Start |


==== Rod Specifications ====
^Variant ^ Notes 
| Rod | Knife edged Aluminum with brass bushing |
| Rod Length | 30mm |

==== Piston/Sleeve Specifications ====
^Variant ^ Notes 
| Piston/Sleeve Type | ABC(Aluminum Piston, Brass sleeve, Chrome Liner) |
| Intake Ports | 3 |
| Exhaust Ports | 1 |


==== Carburetor Specifications ====
Carb Needle settings are default after breakin.
{{ http://nitroenginewiki.com/images/osspeed13911/carb.gif}}
^Variant ^ Notes 
| Carburetor | OS 21J |
| Carburetor Size | 7mm |
| Carburetor Style | Slide |
| Carburetor Material |Aluminum Body with Nylon insulator |
| Carburetor Adjustment | 3 Needle |
| Carburetor Restrictors | 6mm, 6.5mm, 7mm |
| Carb LSN | - | 
| Carb MSN | - | 
| Carb HSN | - | 


==== Head Button/Cooling Head Specifications ====
{{ http://nitroenginewiki.com/images/osspeed13911/coolinghead.jpg?330x337}}
^Variant ^ Notes 
| Head Button | Turbo |
| Supplied Glow Plug | OS P3 |
| Cooling Head | Black Anodized Drilled Aluminium |




 





==== Timing Specs ====
^ ^  
| Intake Rotor Timing Opening | 15.5° ABDC |
| Intake Rotor Timing Closing | 74.5° ATDC |
| Intake Rotor Timing Duration | 239° |
| Transfer Timing Height | 3.5mm from BDC |
| Transfer Timing Duration | 114° |
| Exhaust Timing Height | 6.4mm from BDC |
| Exhaust Timing Duration | 114° |

TIMING DIAGRAM HERE

==== Performance ====
^ ^  
| Manufacturer Claimed Peak | 2.5ps @ 34,000 |
| X-Dyno Peak Power(HP) | 1.5 @ 26,000 |
| X-Dyno Peak Torque(oz-in) | 59.82 @ 25,000 |
| X-Dyno Peak RPM Measured | 42,750 |

{{ http://nitroenginewiki.com/images/ptk2500/xdyno.jpg }}

==== Variants ====
^Variant ^ Notes 
| [[osspeed21vzbv-spec|OS Speed 21VZ-B V-Spec]] | Original, Magnesium cooling head, 21H Carb 320.5g/11.3oz, Part#13893 |  
| [[osspeed21vzbv-spec|OS Speed 21VZ-B V-Spec AL]] | Same as original, Aluminum cooling head, 361.8g/12.46oz, Part#13894 |  
| [[osspeed21vzbspecii|OS Speed 21VZ-B SpecII]] | Same as original, Drilled Aluminum cooling head, 21J Carb 349g/12.32oz, Part#13811 |
| [[protek321bsamurai|Protek 321B Samurai V2]] | Same as Speed, Drilled Aluminum cooling head, 355g/12.52oz, Part#PTK-2500 |  
| [[ninjajx21bo1|Ninja JX21 B01]] | 5 port version of speed, OS 28XZ Case, no slugs in crank, Aluminum cooling head, 361.8g/12.46oz, Part#JX21B01 |
| [[ninjajx21bo1a|Ninja JX21 B01A]] | Same as original JX, Drilled Aluminum cooling head, 374g/13.19oz, Part#JX21B01A |