NonMember Posted December 11, 2021 Report Share Posted December 11, 2021 12 minutes ago, johny said: the solution is to pack out the pump from the mounting on the block so reducing the travel of the operating lever I know this has been found to work but I can't figure out why. Reducing the travel of the operating arm will reduce the flow capacity but shouldn't affect the pressure. The operating arm works on the "draw" half of the cycle, filling the pump from the tank. The pressure on the outlet is dependent only on the force on the diaphragm, which is governed purely by the spring strength. Unless, of course, the spring is actually too short so that a smaller stroke means it's not being compressed significantly. That strongly suggests the wrong spring - it should be weak but long so that it's pre-compressed by more than the operating stroke, leaving the force moderately constant. Link to comment Share on other sites More sharing options...
johny Posted December 11, 2021 Report Share Posted December 11, 2021 well I think its because as you progressively compress a spring it needs more pressure (springs are quite often rated force/mm travel) so if the operating arm of the pump only compresses its spring a little the force on the diaphragm will be less when as you say it comes to the fuel expulsion stage. This is key when the carb float valve closes and has to hold back the pressure being exerted by the diaphragm. Obviously the volume pumped per stroke will be less but as long as the flow rate matches the maximum demand of the carb(s) all will be well.... Link to comment Share on other sites More sharing options...
Jeffds1360 Posted December 11, 2021 Author Report Share Posted December 11, 2021 Get your drift, yes, shorter movement definitely reduces pressure build up but of course reduces volume passing through. Pleased my old one is OK! (Well I hope so)....must test that too. I know it sucks at about 2psi but not tested push yet as I was exhausted. Link to comment Share on other sites More sharing options...
Jeffds1360 Posted December 11, 2021 Author Report Share Posted December 11, 2021 All sorted. Old pump fine. Embarrassed to say it was all caused by a split pie, tank to hard PIE?? ummm must be xmas pie Link to comment Share on other sites More sharing options...
johny Posted December 11, 2021 Report Share Posted December 11, 2021 well good to have a spare(s) although thats a dangerous road to start down🤣 It shows that just quite a small increase in pressure can overcome float valves... One things thats noticeable on most replacement pumps is that their operating arms are thinner that the originals and I recall a previous post that showed this, along with possibly more spring resistance, had lead to significant wear on the cam... Link to comment Share on other sites More sharing options...
Paul Amey Posted December 12, 2021 Report Share Posted December 12, 2021 Are there any specialist company's that can clean out and repair fuel tanks? I think my Vitesse tank is the original fitment from 1967 judging by the state of it. It is the larger tank and has the screwed in sender unit . Link to comment Share on other sites More sharing options...
Colin Lindsay Posted December 12, 2021 Report Share Posted December 12, 2021 9 minutes ago, Paul Amey said: Are there any specialist company's that can clean out and repair fuel tanks? I think my Vitesse tank is the original fitment from 1967 judging by the state of it. It is the larger tank and has the screwed in sender unit . https://www.fueltanks.co.uk We have a local branch of these guys, excellent service that splits the seams, blasts the entire tank inside and out then rewelds and seals. Link to comment Share on other sites More sharing options...
PeteH Posted December 12, 2021 Report Share Posted December 12, 2021 300 quid plus (new) from Rimmer. Probably cheaper elsewhere?. So how much cheaper to refurbish a used one?. Will it last as long?. Ahhhh! the questions we have to ask ourselves?👍 Pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 12, 2021 Report Share Posted December 12, 2021 they are made by t d fithetts as they have the tooling its always worth a call to a local radiator repair specialist to ask about fuel tank refurbs Pete Link to comment Share on other sites More sharing options...
PeteH Posted December 13, 2021 Report Share Posted December 13, 2021 I suppose, to take the further step. With a refurbishment. You are then in a position to ask about coating the inside as protection against the reported potential ravages of E5/10?. I know Tanks can be refurbished, but from experience of Motorcycle ones, many, many moons ago, They are a dangerous proposition. Just getting dents out of a bike tank was difficult enough, resealing split seams involved a tank full of HOT water, and Brazing. Pete Link to comment Share on other sites More sharing options...
Paul Amey Posted December 13, 2021 Report Share Posted December 13, 2021 ok thanks. So are we saying just buy a new one and be done with it? Link to comment Share on other sites More sharing options...
Colin Lindsay Posted December 13, 2021 Report Share Posted December 13, 2021 58 minutes ago, Paul Amey said: ok thanks. So are we saying just buy a new one and be done with it? No, they can be repaired, but leave it to the professionals. My Estate tank is unobtainable anyway so was really the only way to go. Cost me £180 for the work, three year guarantee, and should be ethanol resistant. Link to comment Share on other sites More sharing options...
PeteH Posted December 14, 2021 Report Share Posted December 14, 2021 10 hours ago, Colin Lindsay said: No, they can be repaired, but leave it to the professionals. My Estate tank is unobtainable anyway so was really the only way to go. Cost me £180 for the work, three year guarantee, and should be ethanol resistant. That sounds quite reasonable to me, considering the potential hazards of dealing with a contaminated vessel. Before I could do an internal examination Calor had to steam the tankers, sometimes for days, and then certify "gas free", even then I had a respirator, and a back up man with B-A. My the boiler suit stank for days!!. Wasn't allowed back in the house until I stripped and put the gear in the Washing Machine either!. Pete Link to comment Share on other sites More sharing options...
Paul Amey Posted December 14, 2021 Report Share Posted December 14, 2021 Right thank you. I will get the tank out and start looking in to it! Link to comment Share on other sites More sharing options...
Jeffds1360 Posted December 14, 2021 Author Report Share Posted December 14, 2021 Don't breath the fumes when your looking in Link to comment Share on other sites More sharing options...
Chris A Posted December 14, 2021 Report Share Posted December 14, 2021 41 minutes ago, Jeffds1360 said: Don't breath the fumes when your looking in Well, I guess if you hadn't said it someone would have. 🙄 Link to comment Share on other sites More sharing options...
ahebron Posted December 24, 2021 Report Share Posted December 24, 2021 Twin tanks in the back of my Vitesse 6 was an idea I had when I was a lot younger, I would have used the smaller Herald ones. Link to comment Share on other sites More sharing options...
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