ÿþ <html> <center><a href="http://www.greatlakesxj.com/tech.html"><img src="http://www.greatlakesxj.com/tech/techheader.jpg" border="0"></a><p> <b>Great Lakes XJ Tech Article</b></center><p> <b>INJECTORS</b><p> The following is a list of the injectors used on the 4.0L since 1987 along with their rated static flow:<p> <table x:str border=0 cellpadding=0 cellspacing=0 width=387 style='border-collapse: collapse;table-layout:fixed;width:292pt'> <col class=xl25 width=78 style='mso-width-source:userset;mso-width-alt:2852; width:59pt'> <col class=xl25 width=82 style='mso-width-source:userset;mso-width-alt:2998; width:62pt'> <col class=xl25 width=65 style='mso-width-source:userset;mso-width-alt:2377; width:49pt'> <col class=xl25 width=90 style='mso-width-source:userset;mso-width-alt:3291; width:68pt'> <col class=xl25 width=72 style='mso-width-source:userset;mso-width-alt:2633; width:54pt'> <tr height=17 style='height:12.75pt'> <td height=17 class=xl25 width=78 style='height:12.75pt;width:59pt'>Model Year</td> <td class=xl25 width=82 style='width:62pt'>Part Number</td> <td class=xl25 width=65 style='width:49pt'>Color</td> <td class=xl25 width=90 style='width:68pt'>Fuel Pressure</td> <td class=xl25 width=72 style='width:54pt'>Static Flow</td> </tr> <tr height=17 style='height:12.75pt'> <td height=17 class=xl25 style='height:12.75pt'>1987-1990</td> <td class=xl25 x:num>53003956</td> <td class=xl27>Black</td> <td class=xl25>39psi</td> <td class=xl25>18.6lb/hr</td> </tr> <tr height=17 style='height:12.75pt'> <td height=17 class=xl25 style='height:12.75pt'>1991-1993</td> <td class=xl25 x:num>33007127</td> <td class=xl25>Brown</td> <td class=xl25>39psi</td> <td class=xl25>21.0lb/hr</td> </tr> <tr height=17 style='height:12.75pt'> <td height=17 class=xl25 style='height:12.75pt'>1994-1995</td> <td class=xl25 x:num>53030343</td> <td class=xl25>Tan</td> <td class=xl25>39psi</td> <td class=xl25>21.0lb/hr</td> </tr> <tr height=17 style='height:12.75pt'> <td height=17 class=xl25 style='height:12.75pt'>1996-1999</td> <td class=xl25 x:num>53030778</td> <td class=xl25>Grey</td> <td class=xl25>49psi</td> <td class=xl25>23.2lb/hr</td> </tr> <tr class=xl24 height=17 style='height:12.75pt'> <td height=17 class=xl26 style='height:12.75pt'>1999-2006</td> <td class=xl26>04854181</td> <td class=xl26>Blue Tip</td> <td class=xl26>49psi</td> <td class=xl26>22.5lb/hr</td> </tr> <![if supportMisalignedColumns]> <tr height=0 style='display:none'> <td width=78 style='width:59pt'></td> <td width=82 style='width:62pt'></td> <td width=65 style='width:49pt'></td> <td width=90 style='width:68pt'></td> <td width=72 style='width:54pt'></td> </tr> <![endif]> </table> <p>The injector flow rate varies as the square root of the pressure drop across the injector. The stock '91-'95 4.0 injectors are rated at 22lb/hr @ 43psi fuel pressure, so at 39psi they flow ( sq. rt.(39/43) x 22.0 = 21.0 ).<p> For stock/modified 4.0 engines or stroker build-ups the following injectors can be installed. The flow rates are:<p> Ford Motorsport 19.0lb/hr @ 39psi (Part no. FMS-M9593-C302)<br> Ford Motorsport 24.0lb/hr @ 39psi (Part no. FMS-M9593-A302)<br> Ford Motorsport 30.0lb/hr @ 39psi (Part no. FMS-M9593-B302)<br> Chevy LT1 24.0lb/hr @ 43.5psi (Part no. 17124248)<br> Chevy LT4 28.0lb/hr @ 43.5psi (Part no. 17124251)<br> Accel 19.2lb/hr @ 44.1psi (ACC-150119)<br> Accel 21.1lb/hr @ 44.1psi (ACC-150121)<br> Accel 24.4lb/hr @ 44.1psi (ACC-150124)<br> Accel 25.6lb/hr @ 44.1psi (ACC-150126)<br> Accel 29.4lb/hr @ 44.1psi (ACC-150130)<p> The '95 Jeep 5.2 ZJ/Dodge 5.9 injectors (Part no. 53030262) are rated to flow 24.6lb/hr at 39psi.<p> The selection of injector size will depend on the estimated horsepower output, brake specific fuel consumption BSFC (assume 0.5), no. of cylinders, and the injector duty cycle (assume 80% or 0.8). The formula is: Injector size (lb/hr) = (horsepower x 0.5)/(no.of cylinders x 0.8) </body><p><center> Original info courtesy of Dino Savva<br> Copyright © Great Lakes XJ </html>