Daves1940Buick56S Posted November 5, 2018 Share Posted November 5, 2018 (edited) It appears my mechanical pump is on the way out (no surprise after the car sat for years). It also has an old Facet electric pump mounted that sorta works, but frankly I don't trust that much either. I am planning on swapping in a new Facet pump and running totally with that while I get the mechanical pump overhauled, and then leave it in as a priming pump. The new ones are all 12V so I will run with a small step up converter for the pump, which draws 1 to 2 amps. My question is on the pressure. For the lower pressure pumps, I can get either 2.75 - 4 lbs, or 4 - 5.5 lbs. Both are about 35 gph. I am leaning towards the lower pressure. Any suggestions? Cheers, Dave Edited November 5, 2018 by Daves1940Buick56S (see edit history) Link to comment Share on other sites More sharing options...
Gary W Posted November 5, 2018 Share Posted November 5, 2018 Here's a 6V one from a Model "A" Supplier: Maybe it'll make the install a little easier? 1 Link to comment Share on other sites More sharing options...
Spinneyhill Posted November 6, 2018 Share Posted November 6, 2018 (edited) I have seen pressures expected by carburettors, or was it put out by fuel pumps, somewhere. Definitely in the lower range. I might find them... Found them. 3 to 4.5 psi. Edited November 6, 2018 by Spinneyhill (see edit history) Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted November 6, 2018 Author Share Posted November 6, 2018 Roger that, as I suspected. Will order the lower pressure. Cheers, Dave Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted November 6, 2018 Author Share Posted November 6, 2018 Gary: I already have an installation of the old Facet pump (I am assuming it's 6V). By getting another Facet of the same size etc I can just drop it in. The only change will be the 6V to 12V converter. I will take before and after pix when I do the swap. Thanks, Dave 1 Link to comment Share on other sites More sharing options...
Matt Harwood Posted November 6, 2018 Share Posted November 6, 2018 Don't over-think the plug-and-play convenience of finding the exact same pump. It's really not a big deal, they all have an input and an output, a power wire and a ground, and the brackets are simple. Changing to a slightly different pump is a lot easier and cheaper (just buy the pump rather than the pump AND an electrical converter of some kind) than figuring out how to run a 12V pump on 6V. I've done the electric fuel pump twice on this Lincoln in the last three months. Not a big deal. Here are details on how to do it right: Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted November 6, 2018 Author Share Posted November 6, 2018 Matt: No worries, I don't have much time for overthinking right now! I have been doing post-retirement consulting work for my old company this year and they just told me the current project I am working on must be done by year-end. That means I gotta probably work more than 200 hrs in the next few weeks. With the other obligations I have it looks like I will have a busy Nov and Dec! Giddy up! Yeah, so I just ordered the pump. This way I don't have to refab any brackets or other HW. And then I can hopefully get the mech pump pulled and off to repair by mid December. Cheers Dave Link to comment Share on other sites More sharing options...
Guest Posted November 6, 2018 Share Posted November 6, 2018 If your electric pump is going to be running all the time (ie wired through the ignition switch) you should have a safety switch (inertia perhaps) to protect you in case of an accident. Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted November 6, 2018 Share Posted November 6, 2018 Man, Dave, in the time you have spent on this post, the pump could have been pulled! Terrell Machine in DeLeon , TX does a great rebuild. Ben Link to comment Share on other sites More sharing options...
Stooge Posted November 6, 2018 Share Posted November 6, 2018 (edited) Carter makes a readily available 6V pump,(maybe $70ish?), that works well and I have used several times before in both 6 and 12v, (same pump style, just 12v) applications, and I very much agree on using a safety switch on it incase something were to happen. i like using an oil pressure switch in line of them, so in case the engine stalls and dies, the lack of oil pressure stops the fuel pump. Edited November 6, 2018 by Stooge (see edit history) 1 Link to comment Share on other sites More sharing options...
Matt Harwood Posted November 6, 2018 Share Posted November 6, 2018 And please DO NOT wire it directly through the ignition switch. Pulling power for an electric fuel pump from the ignition switch may seem like a good idea because it shuts off when you turn off the car, but the power that it steals from the ignition system can cause all kinds of driveability problems that are very difficult to trace. That link above includes a wiring diagram for how to do it with a relay so that it shuts off with the ignition but doesn't affect the ignition system. Only one extra wire. Even though there was already an electric pump and wiring in there, that doesn't mean the guy who installed it did it properly. In fact, I'd bet money against him, given the number of cars that I've had in my shop with hack workmanship causing all kinds of problems. Doing it right is not particularly difficult and you'll be happy that you never have to think about it again. I've learned the hard way that trusting that the last guy did it right is a BIG mistake and I have more than $1000 in flatbed tow bills just on that Lincoln to prove it. Link to comment Share on other sites More sharing options...
MCHinson Posted November 6, 2018 Share Posted November 6, 2018 The main purpose for an electric fuel pump on these cars is to refill the carburetor prior to starting the car after the fuel has evaporated out of the carburetor while the car is parked. While an oil presssure switch might sound like a good idea for safety, it defeats the primary use of the electric pump. If you want to be safe, use a relay activated by the ignition switch. I use my electric fuel pump routinely for a few seconds before a cold start after the car has been parked for a few days. Other than that, I have only used the electric fuel pump to prevent vapor lock in 90+ degree temperature driving on tours when I have had to use ethanol containing fuel. With non-ethanol fuel, the electric fuel pump is typically not needed except for refilling the carburetor after fuel evaporation while parked for multiple days. 2 Link to comment Share on other sites More sharing options...
BuicksBuicks Posted November 6, 2018 Share Posted November 6, 2018 For my 37-48 I just bought the higher of the flow ratings as described in an Amazon listing. It was something like $15 and there was a large selection to choose from in that price range. It works just fine; don't think that you need to spend a lot more from an auto parts supplier. My $15 pump sells for around $70 from one of the big Buick parts suppliers; its the identical pump, and the same photo in the listings. Link to comment Share on other sites More sharing options...
DonMicheletti Posted November 6, 2018 Share Posted November 6, 2018 I have had vintage cars for nearly 60 years. I put electric fuel priming pumps on all of them. They were all wired through the ignition switch and I never had a problem ....until this latest '38 Special. This one had a problem. Solved by adding a relay as Matt suggested. The switch contacts had pitted and oxidized and went south. I ended up running all the other switched acessories like the heater, defroster, instrument lights and radio through the relay too. I also cleaned the contacts. Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted November 6, 2018 Author Share Posted November 6, 2018 At this point the wiring in the '38 is a bit of an unknown, although it appears a new harness was put in a few years back. On my 1940 I had to go behind the dash and do a whole lot of wiring and gauge repairs. I also put in several relays to keep current thru the ignition switch to a minimum, and overlaid in 8 gauge wire for all heavy current paths, as well as 2/0 for the starter circuit. The '38 appears to have had wiring mods done behind the dash and my plan is to pull the windshield garnish and dash this winter to see what has been done. I will normalize/repair and then put in whatever relays are required for the added equipment such as the Super Ray lights, fuel pump, etc. On this car I am going to go to more effort to hide the changes and will use authentic-looking cloth covered wire. Since "someone" drilled a few holes in the original dash, I managed to get a nice replacement dash and plan on using that to restore the proper look of the car. I am also removing the spotlight that "someone" added after 1979 so I will be looking for either another windshield garnish molding or find someone to fill the hole. Don't yet know how I am going to deal with the hole in the A pillar. Cheers, Dave Link to comment Share on other sites More sharing options...
Steves Buick Posted November 11, 2018 Share Posted November 11, 2018 In the for what's its worth category, I used a 12 volt 4-6 psi electric pump from NAPA ran it on 6 volts reducing the pressure to 2-3 psi for my Marvel carb. Better than using a pressure regulator on an 4-6 psi 6 volt pump. Only used for starting as previous stated, no relay but an on and off switch along with a main line fuel shut off valve in case of fire. 1 Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted November 13, 2018 Author Share Posted November 13, 2018 Swapped it out today. All good. No more air sucking. Now to pull off the old pump and send it off... The original pump, a bit hard to see The new pump in the same location as the old. 6V to 12V 10A converter in bottom pic. Cheers, Dave 1 Link to comment Share on other sites More sharing options...
Larry Schramm Posted November 14, 2018 Share Posted November 14, 2018 Do you have some information on the 6v to 12v converter? Brand, part #, where to buy? Link to comment Share on other sites More sharing options...
Daves1940Buick56S Posted November 14, 2018 Author Share Posted November 14, 2018 Amazon or Ebay. The unit I used is a DROK. This one looks equivalent: https://www.amazon.com/DIGITEN-Converter-Regulator-Waterproof-Module/dp/B019GY2FLW/ref=pd_bxgy_23_img_2?_encoding=UTF8&pd_rd_i=B019GY2FLW&pd_rd_r=c1d02f8c-e864-11e8-8581-ff357aa136b3&pd_rd_w=KIcEG&pd_rd_wg=hQ4Nf&pf_rd_i=desktop-dp-sims&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=6725dbd6-9917-451d-beba-16af7874e407&pf_rd_r=GZTJKB68GKJHYK9KH5MQ&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&psc=1&refRID=GZTJKB68GKJHYK9KH5MQ Or if you only need 3A https://www.ebay.com/itm/DROK-DC-12V-Step-Up-Voltage-Conveter-DC-5-11V-to-12V-Boost-Voltage-Regulator/323328748433?hash=item4b47e52b91:g:7JEAAOSwBARbOzvF:rk:9:pf:0 Cheers, Dave Link to comment Share on other sites More sharing options...
Larry Schramm Posted November 15, 2018 Share Posted November 15, 2018 Dave, Thanks Link to comment Share on other sites More sharing options...
Jim Nelson Posted January 18, 2019 Share Posted January 18, 2019 I use Airtex model E 8011 pump that comes with a pre-filter around ? 30- microns. It is a 6 volt unit. If you have a 12 volt system, they have a 12 volt version. I bought it thru Walmart. Yes, they sell things like this. Then off to the auto parts house and got one of those big filters. Some you can see thru and some are all metal. Get some new fuel hose and some screw clamps (Lowes or other big box store). Less expensive than the model A club supplier. Link to comment Share on other sites More sharing options...
Matt Harwood Posted January 18, 2019 Share Posted January 18, 2019 Here are details on how I built an all-new fuel system from tank to carburetor on my 1935 Lincoln. I incorporated a Carter rotary-vane electric fuel pump and used 100% hard lines, no rubber, so it should last the life of the car. I also included a wiring diagram and details on how to wire it properly using a relay so you're not pulling power from the ignition system, which can cause all kinds of drivability bugaboos. Hope this helps. 1 Link to comment Share on other sites More sharing options...
Jim Nelson Posted January 18, 2019 Share Posted January 18, 2019 Hi Matt, Your write up on your Lincoln is a very good write up. I've heard of the copper based lines. The cost is a bit high but you get what you pay for. I have a 35 Buick that had a poor fuel system. The tank was perforated on the bottom side from water. That was not so bad that it could not be "ReNu" 'd. The fuel line system was ugly. The pickup line was separate from the level unit. The pickup line ran from the far right side of the fuel tank and down the right side of the frame but there were lots of factory bends (5) with in the first 12" from the tank. The previous owners used copper and rubber hose to make it work. It was a spaghetti from the tank to after the axel. So I had to go to rubber just to get it away from the tank. I guess I could have removed the body to get to the fuel lines. It was interesting to use wood screws to attach things like the fuel line. Its my first car with wood framing. I was able to use some of the original fuel line clips along the frame once I was clear of the weirdness at the tank. Buick used a fuel level unit that used the ? modern 5 screw mounting flange. So I replaced the original pickup line with a modern ? twin unit. Level float with fuel pickup tube. This eliminated one fuel tank penetration. I needed to re-orientate the direction of the discharge line. Of course the newer level pick up system was 180 deg from my needs. I was able to redirect the fuel out put line to get it to my Airtex E 8011 6v boost pump and on to the regular fuel line. More fun than I'm supposed to have when I retired. Link to comment Share on other sites More sharing options...
Jack Welch Posted January 18, 2019 Share Posted January 18, 2019 A lot has been posted on this subject. , if it were me using an electric pump , I would wire it to a momentary switch and only use it as Matt Hinson has said to prime the carb on start up or to compensate for a momentary vapor lock problem. I had a friend lose a very nice 41 Caddy to fire a couple of years ago. He had a toggle under the dash to do both of those things. He thought he was having a vapor lock problem on the highway , flicked on the pump switch. He really had a carb with a stuck float that was dumping raw gas on to the engine. By the time he realized what was happening , the car was on fire and he barely had time to get out. Our cars all ran fine when they were new. The problem with re engineering them is that most of us are not engineers and as they say "stuff happens". Link to comment Share on other sites More sharing options...
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