March 20, 201213 yr Author comment_384759 Well just ordered my 40mm DCOE's from MSA. Got the holley regulator, but still need to find a good quiet low pressure pump. Looking at several right now. Mr. Gasket, Mallory, Aeromotive, etc.I also plan to use the return line back to the tank as well. Does anybody sell a custom three carb fuel line for Datsuns. Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384759 Share on other sites More sharing options...
March 20, 201213 yr comment_384771 I'm a big fan of the OEM RX7 electric fuel pump. I run it on my L30 track car and on my bone stock L24 and never had an issue with fuel supply. It is very quiet inexpensive solution. I can't hear the pump when the car is running. Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384771 Share on other sites More sharing options...
March 21, 201213 yr Author comment_384792 I found a carter pump I liked with bushings for vibration and sound insulation. It looks very much like the OEM electric pumps in the 260 or 280 Zs. It puts out 4-7 psi. Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384792 Share on other sites More sharing options...
March 21, 201213 yr comment_384794 I also run triple Webers (40DCOE's), but had to fabricate the fuel line that I wanted from individual components. I could not find anything that was off the shelf that met the design goals that I had, including the use of all stainless steel braided lines. I have the whole design documented as well as a bill of material if you are interested. This includes not just the fuel lines, but also the pump setup and regulator that I used. I am not familiar with the Holley regulatr that you selected, but I do know that when I was researching my system there were distinct differences between regulators that required a return line and those that did not. If you plan to use a return you might need to check on the capability of the regulator that you selected to ensure that it supports a return line. I've attached a few pictures of my setup for your reference. I also agree on the sidedraft central forum. I've only posted there a few times but the folks were very responsive and ultimately solved one the problems I was struggling with. Some very informed folks over there. Mike. Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384794 Share on other sites More sharing options...
March 21, 201213 yr comment_384795 Be sure to review the thread below - you can find a single non-return/deadhead fuel line with three fuel inlets and heat shield in Japan with ease of ordering and shipping (contact info included in link with pics). I have had absolutely no issues without having a return line no matter what RPM. I was very concerned with this when I was doing my install but now......not a second thought about it. I have not had to drill any holes in my Mikuni's (per the above message about the Webers) - they have been dead on fantastic since day 1.Be sure to think about a primary fuel filter back at your tank, it's even more important to make sure there is no trash going into your needle valves since you will soon to have 3 of them at one time. My install is well documented in "my garage" if needed for reference.http://www.classiczcars.com/forums/showthread.php?42045-Wolf-Creek-Racing-Mikuni-40-s Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384795 Share on other sites More sharing options...
March 21, 201213 yr Author comment_384846 Mike WWhat are your choke cables going to? It looks like you fabricated some sort of improvised choke. Can you enlighten me on that. Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384846 Share on other sites More sharing options...
March 21, 201213 yr comment_384863 The Webers do not have a choke circuit per se, but they do have an enrichment circuit that will help during cold starts. The choke cables are the original OEM cables that I cut so that I could use them to engage the enrichment circuit on a dead cold start. That is what you are seeing. I will say however that for the most part, I never really have to use them especially given the weather here in Texas. I find that typically on a cold start, all I have to do is pump the carbs a few times and the accel pumps provide sufficient fuel to start the engine and so the effect of the chokes is not really necessary Since I have taken this picture, I have actually removed those cables and cleaned up the engine compartment a bit. I also replaced my center console recently and wanted to avoid the console cracking issue where the choke assembly attaches to the console so at least for the time being I have taken them off. When you do go to the Webers I would strongly recommend removing the stock throttle linkage and replace with a throttle cable. This is probably the single biggest improvement that I have made to the Weber setup as it makes the drivability of the car so much better. I used a cable setup from Lokar and would be happy to provide more details on what I did if you decide to go that route. Hope that helps. Mike. Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384863 Share on other sites More sharing options...
March 21, 201213 yr Author comment_384864 I was hoping to keep the stock throttle rods in use. But I have noticed many go with the cables. Can you provide some information on what makes the stock linkage so hard to drive? Thanks again Mike. I am planning out my fuel system. This is almost as much fun as carb tuning. I really love building custom stuff! Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384864 Share on other sites More sharing options...
March 21, 201213 yr comment_384865 Mike, I really like the way you set up your throttle return springs, I may have to copy that! I've been considering a throttle cable as well so I wouldn't mind seeing some more details. Nice job! Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-384865 Share on other sites More sharing options...
March 22, 201213 yr Author comment_385028 UPDATE:I have been ordering things feverishly. MSA is out of stock on the Webers, it will take 2-5 days for them to get them. Oh well. IN the mean time, I may have found something that may shed some light into the weaker spark theory. I will hold off my thoughts until I test it when I get home tonight though. But if I fixed it last night, this could be the biggest waste of 18 pages in the history of Z car club. Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-385028 Share on other sites More sharing options...
March 22, 201213 yr comment_385029 Oh great-leave us hanging Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-385029 Share on other sites More sharing options...
March 22, 201213 yr Author comment_385032 It is so dumb, that I would be ashamed to admit it unless it is the actual problem. Yes, suspense thrillers keep the audience enthralled Link to comment https://www.classiczcars.com/forums/topic/41429-popping-through-the-exhaust-at-4500-rpm-or-so-help/?&page=37#findComment-385032 Share on other sites More sharing options...
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