Ok, forgive me if this is in the wrong forum…. but for the past couple of years, I've been casually researching the 14mm pump head swap in that ever present quest for greater hp, without having to resort to an expensive P-pump swap. I've read numerous times about the potential for failure of the 14mm, but as of yet, I'm not sure why they could fail or if that problem has ever been fully resolved. As far as I understand it, am I correct to say that the rotor on these has been known to seize resulting in catastrophic failure. Is this correct?
The reason I bring this up is, it kinda dawned on me one day when I had to give my dog about 15 ml of medicine that I had to "inject" into her mouth with a large 35 ml syringe. While I was cleaning it, I noticed that if I filled the syringe with a little water, say 10 ml, I could forcefully squeeze it out very quickly, but when I filled the syringe to 35 ml and tried to squeeze it out just as quickly, I noticed two things. First, it took longer to squeeze out the water, and second, it took much more pressure to squeeze out the water quickly…Thats when it dawned on me that, maybe this is what is causing the 14mm head to fail. When you have a much larger rotor/plunger, the pressure it takes (provided by the cam plate) to push the larger volume of fuel, in the same period of time is causing the equivalent of hydrolock. If I had the strength to squeeze out a full 35 ml in the same time it takes to squeeze out that same 10 ml, I would have either exploded the plastic tube or bend the plunger. The only way to squeeze out a greater volume of water, in a shorter time with less pressure was to enlarge the hole. Am I on to something here? Or am I way off base and have no stinkin' clue as to what I'm talk about?
Ed
The reason I bring this up is, it kinda dawned on me one day when I had to give my dog about 15 ml of medicine that I had to "inject" into her mouth with a large 35 ml syringe. While I was cleaning it, I noticed that if I filled the syringe with a little water, say 10 ml, I could forcefully squeeze it out very quickly, but when I filled the syringe to 35 ml and tried to squeeze it out just as quickly, I noticed two things. First, it took longer to squeeze out the water, and second, it took much more pressure to squeeze out the water quickly…Thats when it dawned on me that, maybe this is what is causing the 14mm head to fail. When you have a much larger rotor/plunger, the pressure it takes (provided by the cam plate) to push the larger volume of fuel, in the same period of time is causing the equivalent of hydrolock. If I had the strength to squeeze out a full 35 ml in the same time it takes to squeeze out that same 10 ml, I would have either exploded the plastic tube or bend the plunger. The only way to squeeze out a greater volume of water, in a shorter time with less pressure was to enlarge the hole. Am I on to something here? Or am I way off base and have no stinkin' clue as to what I'm talk about?
Ed
Last edited: