BLKMGK Posted July 3, 2007 Share Posted July 3, 2007 one of the issues with doiong this that has caused me to drag my feet has been the fuel system - running dual lines, the return into the tank, blah blah - it's a PITA! Well tonight flipping through the July Hot Rod I foound something that looks like it would make life MUCH easier! Can you say mechanical (as in pushrod) drivenEFI pump that mounts in place of the original style mechanical pump?! It uses a single line fromthe back and deadheads the fuel rail - pressure in the line modifys the amount of fuel pumped. Good for over 2K HP supposedly using the big lines. (lol) They listed some issues that occured on cold starts and ways to fix it related to pressure leak down, the valve mentioned might even be nice to use on convential electric pumped EFI systems actually. To my surprise they claim that there's no massive strain on the cam eccentric either which is nice. It's billet construction with O-ring seals and only a single moving part - they claim it's durable too. Check out racepumps.com for info on this thing, if it can be fit between the rail and the motor it might be just the ticket for an easier EFI install! $300 so not cheap but hey IMO it might be worth it! P.S. I see they list SBC, BBC, and SBF as apps - nice! Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted July 3, 2007 Administrators Share Posted July 3, 2007 Hmm.. Sounds like the old school Mechanical injection, ala Kinsler, Hilborn etc.. Do you have any more info on this? Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted July 4, 2007 Author Share Posted July 4, 2007 Hmm.. Sounds like the old school Mechanical injection, ala Kinsler, Hilborn etc.. Do you have any more info on this? No, not as bad as that. The old stuff used barrel valves blah blah and a belt driven pump as I recall. This is for normal EFI systems and isn't belt driven. It's a plunger driven thing, most of the info was from the Hot Rod article including some back to back dyno tests with an electric pump and this one - not much power diff on same maps. Pressure fluctuates some at idle but not much and not so much that it's a problem apparently. Has a ceramic lightweight disk of some sort inside rather than a diaphragm. -8 fittings standard, -10 for more flow if you want. The WEBsite has some info, check it out Quote Link to comment Share on other sites More sharing options...
strotter Posted July 4, 2007 Share Posted July 4, 2007 I was thinking about a non-return efi fuel delivery system. Here's a sketch of a conventional efi fuel circuit: Now my idea is this: The idea being that the pump and remote regulator (one of which I already have, and aren't that expensive) goes in back by the tank, and only the one line goes forward to the engine compartment. Everything between the pump and the regulator is at high pressure, including the "T" and the delivery line. Heck, you could probably use the stock line if the engine isn't a real fire-breather. Thoughts? Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted July 4, 2007 Administrators Share Posted July 4, 2007 Within this mechanical pump, there has to be some sort of a built in pressure regulator. Do you have a link to the manufacture, or article regarding this mechanical EFI fuel pump? With so many questions, it would just be easier to read it first hand. Something that sounds out of sorts is why they would tout back to back dyno pulls with the same fuel maps. With EFI, the engine doesn’t care how the fuel is being pumped, so long as the required fuel quantity is being delivered at the right pressure. Outside of that there should be NO power difference and really no need to prove that on the dyno if “only†the pumps were changed. Now if they changed something else as well as the pumps, that would make sense. Here is another hand drawn diagram, (just like Strotters above), of a “returnless†or “dead head†fuel system. Just place the pump and fuel pressure regulator back at the tank. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted July 4, 2007 Author Share Posted July 4, 2007 Check out racepumps.com for info on this thing, if it can be fit between the rail and the motor it might be just the ticket for an easier EFI install! $300 so not cheap but hey IMO it might be worth it! My first post had the WEB site for the manufacturer, I also mentioned the magazine issue that has the article - it's on newstands NOW. RACEPUMPS.COM The reason for the testing has to do with how concentric (eccentric?) driven pumps normally deliver fuel - in spurts or surges. This pump doesn't have a regulator inside but it does have a way to figure out if it's greatly overrunning the regulator somehow. The reason for this is so that at idle where fuel demands are low it moves less fuel and then at higher RPMs moves more fuel. Anyway, the test was to demonstrate that the pressure is steady and doesn't surge up and down as a normal cam driven pump does. It is a variable displacement constant pressure pump - per their WEB site - sums it up well IMO. Honestly, if you'd get the magazine and read the multi-page article it would save much typing on my part. The WEB site has some info as well, apparently they make hi-po carb pumps too and the EFI pump is a bit more than the $299 I saw on their front page. Quote Link to comment Share on other sites More sharing options...
jasonZ Posted July 4, 2007 Share Posted July 4, 2007 Here's a link to their homepage http://www.racepumps.com/index.html I have been looking at these pumps for quite a while and they seem to be a good product. It definatly would simplify the fuel system on an EFI engine. Not sure about any clearance issues as I don't have an engine in my car yet. I'm sure there would be some issues with the set back plate in a JTR configuration but I don't think it would be a deal breaker. Jason Quote Link to comment Share on other sites More sharing options...
getZ Posted July 4, 2007 Share Posted July 4, 2007 I'm not so sure about simpler. First you have to deal with making it fit with the JTR mounts. I have enough trouble just getting the bottom bolts to go on the block off plate. Then you have cold start no pressure problem? My biggest hangup with electric fuel pumps is just that they're noisy. I like Cliftons internal tank pump idea and may go to that one of these days. The return line isn't that big a deal if you plan ahead when you build a car. The last two cars I built, I purposely installed two fuel lines in the car when everything was taken apart. Installing an extra solid aluminum line cost about an extra $30. If you don't use it you can just cap it off. It also makes life a little easier if you label them as well. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted July 4, 2007 Author Share Posted July 4, 2007 Well shoot, just looked under the hood of mycar to see how close the JTR mounts come... no way This thing is smaller than a normal pump but if it sticks out much at all it's not going to fit, that stinks. Sorry, maybe on the Fords? As for electric pumps being noisy - they don't have to be. If you buy the big coffee grinder ones they will be but I've not ever found those to be real reliable anyway. I like the Walbro small ones like OEM's use in-tank. Aeromotive is even advertising their big pumps as in-tank capable (always have been so far as I know) but I doubt even THAT would quiet them much and mounting them in the tank is a puzzle. Walbro has some external ones too but priming and whatnot could be an issue with a fuel cell like mine. I seem to recall one of the Econoline vans was good for these pumps. Guess maybe it's back to the surge tank thing I really thought this thing would be a good option but had forgotten how danged close the mounts come to the front of the motor... P.S. It's not cost I worry about. It's the hassle of running the lines and trying to plumb them so they don't get aerated fuel or any other weirdness going on plus the pump priming etc. Still trying to figure out the best way to (easily) vent my cell too without having all the gas just evap into my garage. Umm and is that solid aluminum line rated for EFI pressures? you using that just for a return or hat? Quote Link to comment Share on other sites More sharing options...
getZ Posted July 4, 2007 Share Posted July 4, 2007 In all honesty, I've never checked to see what aluminum line is rated for. I've never had any problems and I've seen a lot of ricers use them, but that doesn't mean it is right either. I've heard of people using it for pressures over a 100psi, but I can't find a manufacturer stating a burst pressure rating or any rating for that matter. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted July 4, 2007 Administrators Share Posted July 4, 2007 I have never really thought that replacing or adding fuel lines to a z car was ever much of a problem. I think most if not all Z cars have a fuel return line, at least the ’72 and later cars have fuel return lines. Though on the 240, that itty bitty excuse of a return line really is too small for any performance application, even an N/A L-series, and actually, the 280 return and supply lines are a bit on the small side for a real performance V-8. Installing a second line, or even replacing the existing fuel lines really isn’t a huge a project especially compared to a V-8 conversion on the whole, or even a rear disc conversion on the S-30. I ran new Stainless fuel lines, (purchased from Summit), both supply and return, up in the top of the trans tunnel of my race car with the complete drive train in the car and it wasn’t too bad. The 280 cars ran the fuel lines beside the frame rails which would be even easier to swap out than running them in the upper portion of the trans tunnel. Not all electric fuel pumps are noisy. There are quiet “street†versions available, and if you also mount the pump in a fully isolated suspended manner, that will further reduce pump noise in the cabin. I used a simple inexpensive Holley EFI fuel pump, mounted it in the an OE 280-Z EFI fuel pump mount and in the fully gutted race car I could barely hear the fuel pump when I kicked it on without the engine running. As for your aerated fuel concerns, even with a complete dead head system like this mechanical pump set up, if the fuel pickup, picks up an air pocket from extreme maneuvers, that air pocket is trapped in the fuel line and you’ll have aerated fuel, though it wont get to the engine till much later. With a return type fuel system, that same air pocket will quickly move through the fuel system with only a short hiccup, (used to experience that quite often with the OE ’75 EFI with less than ¼ tank of gas). A fix for aerated fuel is a surge can/tank. There are few ways to go about building one, and HybridZ member Strotter posted a wonderful DIY surge tank concept… (worthy of Sticky in my opinion) http://forums.hybridz.org/showthread.php?t=122978 That’s my $.02 on EFI fuel lines, pumps, and aeration. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted July 4, 2007 Share Posted July 4, 2007 On the Chevy Corvette (97-04) they did away with the return line off the fuel rail. At the fuel filter at the rear of the car, there's a return line. The excess fuel returns to the tank from that point, instead of having the fuel run all the way up to the engine compartment... pretty trick if you ask me. Mike Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted July 5, 2007 Author Share Posted July 5, 2007 On the Chevy Corvette (97-04) they did away with the return line off the fuel rail. At the fuel filter at the rear of the car, there's a return line. The excess fuel returns to the tank from that point, instead of having the fuel run all the way up to the engine compartment... pretty trick if you ask me. Mike Until I'd seen it posted here I hadn't thougth much about returning it in the back actually. On the late model Corvettes that do that they are probably adjusting the pressure by changing pump speed, I know the late model Mustangs do that. However doing that with most any programmable EFI isn't going to happen, I've yet to see one employ that. Even putting the regulator in the back is an issue unless you're willing to run one looong vac line back there - doable though I guess, maybe a hard line? On a forced induction motor this is a must as pressure has to increase with boost or you'll run it lean. You could tune around this but you'll end up running out of injector more quickly - it's a headache tuning around stuff like this to say the least. I actually had an issue on the Supra where my two pumps were overrunning the regulator after they had broken in. At idle pressure climbed like 15 PSI when warmed up and couldn't be adjusted lower. Once running it dropped to normal and the tune was fine, only idle was screwed up. I ended up having to stage those pumps as the small pressure momentary bump when the 2nd turned on was easy to ignore - unlike the super rich condition I had to fight down low with teeny tiny injector duties Aeration worries me not because the engine might stumble but because when it does it's LEAN. Return fuel right next to the inlet (like my cell) and you can churn things up pretty good. I once tuned on a guy's Honda - made BIG power on the dyno - like 600++ at the wheels at reasonable boost. Took it to the track and it knocked like mad and had all sorts of issues going down the track no matter how much fuel I put into the tune. Finally it blew a head gasket (copper too) and I could never figure out WTF was going on - it had run flawlessly on the dyno. Come to find out from someone else who finally figured it out that he had mounted the fuel cell sideways and on accel fuel was running away from the pickup - doh! Learned a couple of lessons from that, seems he never noticed the low mounted fuel pressure gauge fluctuating down by the shifter Fun stuff Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted July 5, 2007 Author Share Posted July 5, 2007 In all honesty, I've never checked to see what aluminum line is rated for. I've never had any problems and I've seen a lot of ricers use them, but that doesn't mean it is right either. I've heard of people using it for pressures over a 100psi, but I can't find a manufacturer stating a burst pressure rating or any rating for that matter. Some is apparently rated for EFI. If it's seamless I'd be more tempted but not all of it is I don't think. Aluminum fatigues too so while it might hold fine on day one on day 100 it might not. Even a tiny pinhole is a disaster waiting to happen at 50PSI. I run braided line personally and while it too has issues I'm more comfortable with it than the solid stuff. Certainly some folks get away with it but I've seen what occurs when a fuel line fails catastrophically - it was the Challenger waiting to happen, luckily it was a cold start with the hood up. I've also seen fuel injector O-rings fail suddenly and badly, that too is a complete mess and a disaster waiting to occur. It doesn't take much of a fuel leak at all to ruin your day. To each his own I guess but the solid stuff certainly is cheaper! Quote Link to comment Share on other sites More sharing options...
Administrators RTz Posted July 5, 2007 Administrators Share Posted July 5, 2007 Even putting the regulator in the back is an issue unless you're willing to run one looong vac line back there - doable though I guess, maybe a hard line? I may have missed it, but somehow I was under the assumption you were going to use an aftermarket ECU? A vacuum line to the regulator is not mandatory. There are benefits but, most often, its not a *requirement*... depends on the specific 'build'. On a forced induction motor this is a must as pressure has to increase with boost or you'll run it lean. Not with a standalone (and factored in up front). You could tune around this but you'll end up running out of injector more quickly Yup... if you don't plan in advance, but it sounds like you're the kind of guy to do just that. - it's a headache tuning around stuff like this to say the least. Not really. unlike the super rich condition I had to fight down low with teeny tiny injector duties Resolution helps. I've run monster injectors on small engines. With the right EMS, its realistic. Took it to the track and it knocked like mad and had all sorts of issues going down the track no matter how much fuel I put into the tune. Because thats not the right answer Where are you right now? You're down to physical fuel delivery, correct? This is a small hurdle. Tell us more about your objectives and maybe the collective wisdom of HZ will save the day Quote Link to comment Share on other sites More sharing options...
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