Hello all, been a while since I have posted. Long explanation why. Another time. So I added two Stromberg 81’s, high rise manifold, Red’s 2 into 1 header, dual’s exiting by passenger rear tire, two Smithy’s. Sounds awesome! Runs great! Problem? Backfiring at speeds over 23 because starving fuel. How are the Pegasus facet pumps? They are small and compact. Also does the pump need to be mounted below the carbs? You can see from my setup that the fuel line does not drop much lower than the gravity feed. The 81’s can’t take more than about 3.5 psi. Input appreciated!
Are you sure the backfire is fuel related? I would think that gravity feed would be able to keep enough fuel in the bowls to keep it from going too lean. I'd be looking at the ignition system first.
Yeah, it certainly looks like it would run out of gas gravity feed like that. I have a similar set up on my Vicky. It looks like you have an alternator so I'm guessing 12V. Holley 12-426 It's a 1.5 - 4lb I run this fuel pump with no regulator or overwhelming of the needle valves. It is a digital fuel pump and doesn't keep building pressure after the valves close. Don't know about the Facet may be the same pump. That style air filter doesn't flow enough air either, FYI. Looking good and good luck.
I went to the Pegasus web site, they list many different pressure ranges for the Facet electric fuel pumps. https://www.pegasusautoracing.com/group.asp?GroupID=FACET12CUBE They show a 1.5 - 2.5 psi model and a 2 - 3.5 psi model. The decision is yours, I don't know enough about your carbs. I have used the Faucet pumps to feed Edelbrock 4 barrel carbs in 392 CID International Harvester V-8 engines. They worked OK on multi-state trips. Like all electro-mechanical devices that wear out and leave you dead on the side of the road. The last couple of electric fuel pump installations, I ran dual electric fuel pumps with one way check valves on the output of each pump. A simple flip of a toggle switch and I was running again. My current off topic truck (Cummins 4 cylinder conversion) uses this switched setup, the electric pumps are Edelbrock diesel (green). The Facet pumps do not prime well, the instructions tell you to mount them as low as possible, preferably lower than the fuel pickup in the fuel tank. I usually mount my electric pumps on the frame rail, away from any heat source. And living in Southern Arizona, lots of insulation on all the fuel lines. Russ
Gravity should be fine as long as your over half a tank. I would bet it's your fuel filter you added. I think its restricting flow. Try taking it off and see if that changes it. I had a similar problem. Sent from my SM-G950U using The H.A.M.B. mobile app
This is the fuel pump I use from Vintage Speed. I like it. Sent from my SM-G950U using The H.A.M.B. mobile app
I ran a Facet pump on a twin cylinder Briggs and Stratton, it did fine, never overloaded the carb float. It was the 2.5 gph model. They will pull fuel uphill a short distance, but work better if they are below the fuel level. I have a 5 gph Facet on my car, it fed a 350 Chevy with no problem.
Thank’s all, So I went with the Facet. Max 2.5psi model. Didn’t want regulator and gauge. A little noisy. I removed the old tea pot from the firewall and mounted the Facet inside. Same hole. Fit perfect. So took for ride, better, but sputtering-missing, by 3rd gear somewhat smooth but what the ! Then it hit me. Don’t you love it when that happens! I noticed the chokes on the 81’s after a rev would not fully open. How could I miss that! So I took the old throttle linkage, cut it, bent it. And welded it to a thick coat hanger that ran thru dash, that’s how. Works like a freakin charm! ‘Snowing / Raining big time here in Jersey. Set my timing and point gap. Starts up perfect. I think I nailed it! I will post after test run... Be safe all...
I have a little square Facet on the Minor, installed low on the inner rear wing near the tank. It was installed when I finally grew tired of trying to get the SU electric pump to work properly. It was reliable enough over the time I used the Minor regularly.
Those air cleaners are restrictive, Take a test run with them off. pretty sure youll feel a slight change.
Both you and winduptoy both commented on air filter restriction. I greatly appreciate any input but we are talking about a 40hp motor at best. These are open at the bottom also. Don’t really see how they can be restrictive. I’m willing to learn...but, as I said, I believe it was a choke issue which I resolved, but not able to test ride yet...
Im in the same camp as winduptoy on those air cleaners.They are very restrictive.I run a frogs mouth with the screen and foam insert works really good.Being such low horsepower no sense in restricting it.I dont run a choke cable either rarely need to use it and i live in Minnesota where its cold 9 months out of the year
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