[Wade Congdon]

I personally subscribe to the school of check EVERYTHING yourself or you have only yourself to blame for any problems. The flaw in this theory is that not everyone is capable of checking things themselves. In this case they rely on the experts or builders to do it for them. I'm sure PDude does an excellent job of checking things, he obviously has disassembled these pumps or he wouldn't have found the problems in the first place. I think there is a fine line between what Tom V is saying and what PDude is saying. New parts often need to be checked and adjusted for application or geography, but one would not expect to find defects, dirt/rust, etc in new parts. Being a mechanical engineer, I agree with what Tim says about volume capacity being a function of the gear diameter and length. If replacing a 5/8 tube with a 3/4 tube increased volume, then the 5/8 tube was undersized in the first place. The pump that Butler was/is selling had taller gears and thus increased volume. I believe Marty had designed this at one point. Unsubstantiated Rumors said there were problems with this design. I have no experience with this pump. The Titan pump uses a gerotor, which is more efficient than gears. Unfortunately the Titan pump is expensive ($600 plus last time I checked) and does require modifications to the oil pan because they used pieces from other makes. We (BOP) have been working on a gerotor pump that would require no mods and cost maybe in the $200 range. Does anyone think there would be a market for something like this? IF so let us know via email or in this post. [img]smile.gif[/img]

As I composed this I just read HI Stud’s response, very thorough and informative as usual. Agree with his comments on “Hydro loc”, may be an issue for the tall gear pump. I also like his assessment of the distributor drive location. “The oil pump load at the cam's end allows for torsional damping for almost decent distributor operation” That’s just another reason many high end racers use a front belt drive distributor.