RacinNdrummin
Member
Whoa Whoa Whoa... You guys all need to cool it down a bit... We are all here for the same reason... lets work it out in the numbers...
I will state upfront, without the intention of offending you GM guys, that these numbers are impossible out of a .29 or .31 DB2... The stroke is just too long, and the pump will hydrolock with ANY sort of timing adjustment... Not to mention that the duration of the injection event is just too damn long to produce any useable power with... I understand you guys feel TP pressure is the answer to filling the chamber, I disagree, the key to filling the chamber is Volume, not pressure... Thats why added fill ports are better than cranking the TP... You guys cant have correct timing with jacked TP pressure, and do it all without having it on a stand... Until you guys get a pump on the stand, you have no dog in the fight... You can claim all you want out of equations, and the math involved, but until you have a dynamic reading from a stand, your just spouting.... According to the "math" my .400" DB2 will put out 144cc at stock max stroke with a "2" leaf spring... And guess what, with added fill ports, it will probably do it to 3400RPM... You CANNOT do that with ANY sort of stock ported pump, it wont happen... Now I do believe that added stroke can deliver fuel, but the thing is, you have to take into account port over port duration when figuring it.... The Ports are spaced equally between the 8 cylinders with a bias towards the pumping side, they occupy every bit of surface area on the face of the rotor and head, as far as timing is concerned... The variable is cam ring advance... if your at max stroke on the cam ring, it leaves 0 degrees of cam ring movement to achieve full delivery at that stroke... You would have to totally lock the cam ring advance out at the perfect spot, to achieve full filling and pumping at RPM... Thats nearly impossible and have ANY sort of drivability to go with it... Think a gas engine with locked timing, but even worse... All that is assuming that your TP pressures can even fill the chambers at 2000 RPM (pump speed)... even at 250psi (which NONE of you are hitting with the TP) you cant fill the chamber at 2k with 2 fill ports on the stock rotor, its just impossible...
Get some papers with the pump on the stand, post them, and If you can prove what I just said wrong, I will admit it, and fully admit you guys are superior pump builders... until then, your nothing but a bunch of rednecks that like to tear into these things and make assumptions about what they are putting out...
BTW... I actually admire what 6.2 has done with the pumps, I like to read his results... However, there still isnt anything to prove what you guys are stating...
I will state upfront, without the intention of offending you GM guys, that these numbers are impossible out of a .29 or .31 DB2... The stroke is just too long, and the pump will hydrolock with ANY sort of timing adjustment... Not to mention that the duration of the injection event is just too damn long to produce any useable power with... I understand you guys feel TP pressure is the answer to filling the chamber, I disagree, the key to filling the chamber is Volume, not pressure... Thats why added fill ports are better than cranking the TP... You guys cant have correct timing with jacked TP pressure, and do it all without having it on a stand... Until you guys get a pump on the stand, you have no dog in the fight... You can claim all you want out of equations, and the math involved, but until you have a dynamic reading from a stand, your just spouting.... According to the "math" my .400" DB2 will put out 144cc at stock max stroke with a "2" leaf spring... And guess what, with added fill ports, it will probably do it to 3400RPM... You CANNOT do that with ANY sort of stock ported pump, it wont happen... Now I do believe that added stroke can deliver fuel, but the thing is, you have to take into account port over port duration when figuring it.... The Ports are spaced equally between the 8 cylinders with a bias towards the pumping side, they occupy every bit of surface area on the face of the rotor and head, as far as timing is concerned... The variable is cam ring advance... if your at max stroke on the cam ring, it leaves 0 degrees of cam ring movement to achieve full delivery at that stroke... You would have to totally lock the cam ring advance out at the perfect spot, to achieve full filling and pumping at RPM... Thats nearly impossible and have ANY sort of drivability to go with it... Think a gas engine with locked timing, but even worse... All that is assuming that your TP pressures can even fill the chambers at 2000 RPM (pump speed)... even at 250psi (which NONE of you are hitting with the TP) you cant fill the chamber at 2k with 2 fill ports on the stock rotor, its just impossible...
Get some papers with the pump on the stand, post them, and If you can prove what I just said wrong, I will admit it, and fully admit you guys are superior pump builders... until then, your nothing but a bunch of rednecks that like to tear into these things and make assumptions about what they are putting out...
BTW... I actually admire what 6.2 has done with the pumps, I like to read his results... However, there still isnt anything to prove what you guys are stating...