leakdown tester

[rex.burkheimer@chrysalis.org]

Jack Ryan wrote:
>I took apart a friend's leakdown teaster, and the orifice was .055", and the
>calibrate pressure was 35PSI.  it very rarely turned an engine over, and it
>looked like the % was close to straight percent (ie 35PSI=0%, 17.5=50%).  it
>was marked at good being between 40-30% to 10% leakage (the green area).

                                                                               
   So, with your report and several previous ones, it looks like:              
                                                                               
     @ 100 psi, orifice size is .060                                        
                                                                               
     @  60 psi, orifice size is .057                                        
                                                                               
     @  35 psi, orifice size is .055                                        
                                                                               
                                                                               
  That looks pretty consistent to me. Could all these be right? Any formulas
to verify this pressure/orifice curve?   Any more data points?                 
                                                                               
                                                                               
                                                                              
Rex Burkheimer    Ft. Worth TX                                                
Texas Region SCCA                                                             
FC Reynard #19  ITB Pinto #49