KiwiTR5 Posted April 20, 2016 Report Share Posted April 20, 2016 The TR5 and earlier TR6's had a fuel tank with no baffle around the outlet port. As a result of this these cars tend to lose fuel delivery when going around a left hand turn with less than 20-30% fuel level. With the original Lucas pump and plumbing this was overcome to some extent by the return fuel from the PRV feeding directly back into the fuel filter and thence back to the pump. However, when any of these cars are modified with a Bosch / Sytec pump system the original inlet filter is usually discarded as it restricts fuel flow through the pump to an unacceptable extent. Unfortunately this makes the loss of fuel delivery much more apparent. The later TR6s had a redesigned fuel tank with a baffle around the fuel outlet port. I need to add this "feature" to my TR5. Yes, I could buy a new tank which is expensive enough to begin with but, by the time I get it to New Zealand, the freight and other costs adds about another £100 to the cost and it has been suggested that maybe I could modify the existing tank to resolve the problem. Has anyone done this? Any major problems? Does anyone have any sketches, drawings, photographs, suggestions etc about how best to do this? Thanks Robert Johnston Auckland, New Zealand Quote Link to post Share on other sites
jerrytr5 Posted April 20, 2016 Report Share Posted April 20, 2016 Add a fuel swirl pot either below the tank and gravity feed or alongside the tank with a low pressure pump to fill. Jerry Quote Link to post Share on other sites
openroad Posted April 21, 2016 Report Share Posted April 21, 2016 Morning Robert, I have the same problem on my car....but is it such a hardship ? It just reminds me that I need to fill up and do a load more enjoyable TR miles. Have fun, Conrad. Quote Link to post Share on other sites
TriumphV8 Posted April 21, 2016 Report Share Posted April 21, 2016 The problems may move although the idea with the catchtank is a good way to start next problem will occure when car takes not excessive fuel and a longer trip is invisaged. The fuel gets warm from pumping around because the whole electrical energy from the pump is transferred into heat into the fuel and it will boil. If half of tanks fuel can accept that heat there is less trouble, with empty tank the fuel tends to boil. On my trips to Italy it was essential to add a fuel cooler from BMW or VW diesel cars. So a bulletproof fuel supply for our TR PIs is quite a long trip of try and error where Norwegian drivers that prefer short trips and full tank will have significantly less problems than Italian drivers that like to drive topless all day long during a hot day in the Toscana. Quote Link to post Share on other sites
Andy Moltu Posted April 21, 2016 Report Share Posted April 21, 2016 As Jerry says - the option is to fit a swirl pot or a tank with adequate baffles. The problem is probably worse with the Bosch pumps because they do pump more fuel and consequently draw air in sooner. Again they don't have the Lucas CAV filter to function as a crude swirl pot. Unfortunately the pump effectively draws fuel from the top of the Lucas CAV filter so it doesn't function too well in this respect. I have seen the filter housing modified to draw from the lower in the filter but this only gives a very small additional reserve and in my experience wasn't a functionally worthwhile mod. Only the very early cars had the return from the PRV feeding back into the CAV filter, the rest have the return feeding back to the top of the tank, some of these cars lack the baffling so have the worst problems. Quote Link to post Share on other sites
Alec Pringle Posted April 21, 2016 Report Share Posted April 21, 2016 In the early days of PI I found that simply adding an extra filter canister, without filter, between tank and standard filter cured most of the occasional splutter problem. For a sprint/hillclimb car we simply added a second outlet to the opposite side of the tank, each outlet feeding an empty filter can, and both little reservoirs feeding the filter. A cheap exercise all Lucas/CAV kit sourced from scrapyards . . . . . . which worked adequately. A proper larger swirl pot has to better, and easier than trying to baffle the original tank. Cheers Alec Quote Link to post Share on other sites
TR NIALL Posted April 21, 2016 Report Share Posted April 21, 2016 Time to reintroduce this maybe. Quote Link to post Share on other sites
TriumphV8 Posted April 21, 2016 Report Share Posted April 21, 2016 Very nice and clean work. This my take off from the bottom of the CAV: Also in combination with my above remedys perfect. Quote Link to post Share on other sites
jerrytr5 Posted April 21, 2016 Report Share Posted April 21, 2016 (edited) Nice work Niall. Mine's a bit cruder. Jerry Edited March 9, 2020 by jerrytr5 Quote Link to post Share on other sites
TR NIALL Posted April 21, 2016 Report Share Posted April 21, 2016 Sorry for the Confusion but it's not my work,one of our Forum Members was making these, Kevart I think was our Man. Quote Link to post Share on other sites
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