SSP:  £117.50
                                    
                                    
                                        
                                        Part No: X-OS72001000
                                    
                                 
                                
                                    
                                    
                                        
                                            OS Engine Hyper Head 91SX-H
                                        
                                    
                                 
                             
                            
                            
                            
                            
                                
                                
                                
                                Improved cooling and
a significant weight
saving are the
hallmarks of this
precision machined
cylinder head. Modern
helicopters with
cooling fans designed
for higher revving 61s are often insufficient for
the slower revving Max 91SX-H, so here's a little
help from O.S!