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Searched but can't find a good answer to my filter/regulator question. I'm going to convert my 2003 LM4 engine to returnless fuel delivery. I see on line the 2002 Corvette filter/regulator runs anywhere from about $30 to $165. That's a big spread! What is everyone using? I saw that the low end Wix were unreliable in one thread. How do you block off the 5/16" return line at the fuel rail? Anything else I should know to make this conversion?
My rail utilizes an fittings, so a simple cap there. The corvette style regulator/ filter does use a return. But it is only as long as your supply line from the pump, so depending on where you mount it is how long or short those lines are instead of returning all the way from the fuel rail.
Last I got mine from Speedway as a part of a kit they sell that also comes with an adapters, it cost me about $65.
Parts store brand filters suck, the cheapest one I would use is a Wix. As for the fuel rail, get a returnless rail if thats what you want. Blocking the return on a returnless rail isnt a good idea because you dont want that plug coming off and spraying 58psi of fuel all over a hot engine. Not to mention youll have another fuel regulator, and they are known to leak, but with a vacuum hose on it it gets sucked into the engine, without it, it will just leak on the intake. Returnless rails are cheap, and cheap insurance. Just my opinion though....
Just the kind of info I need. Like to take it one more step. I have a truck intake coming and will smooth it out and paint it the same as the valve covers (trying to put lipstick on a pig!). Rather than buy an OEM set of rails would it be a good idea to buy an aftermarket set of billet rails? I see them on line for just under $60 and the OEM rails are about the same. Trying to avoid doing this twice!
I'm not saying they don't exist, but I've never seen aftermarket rails made for truck intakes. The rails I've seen for sale typically have car brackets with them.
I prefer stock rails because the price is right - free with the engine or pretty cheap from someone doing an upgrade.
searching on line for billet fuel rails there are some for the LS1/LS6 but not much for the 5.3. Is this just because of the mounting brackets or is the injector spacing different? In other words can the LS1 billet brackets be made to fit the 5.3 with just a little mounting bracket modifying?
searching on line for billet fuel rails there are some for the LS1/LS6 but not much for the 5.3. Is this just because of the mounting brackets or is the injector spacing different? In other words can the LS1 billet brackets be made to fit the 5.3 with just a little mounting bracket modifying?
If I remember right, the 5.3 injectors are longer, but the Flex Fuel 5.3s have injectors that are the same length as LS1 and LS6. Don't quote me for sure on that though. I switched over to an LS2 right after I was fiddling around with my 5.3 (sold it) so I am not an expert.
You can cap the returnless rails, its not going to hurt anything. The odds that the capped return connector blowing off under fuel pressure isn't a single bit higher than any other fuel connector in the entire fuel system blowing off from the same pressure, so saying it will blow off is an absolute ABSURD assumption. All connectors after the pump will see the same 58 PSI.
You can buy the 5/16 blockoff connectors fairly cheap.
You can cap the returnless rails, its not going to hurt anything. The odds that the capped return connector blowing off under fuel pressure isn't a single bit higher than any other fuel connector in the entire fuel system blowing off from the same pressure, so saying it will blow off is an absolute ABSURD assumption. All connectors after the pump will see the same 58 PSI.
You can buy the 5/16 blockoff connectors fairly cheap.
You can offer all the advise you want, and when someone puts a vacuum cap on it with a worm clamp and it blows off and all hell breaks loose, that's on you. There is more than one way to do things, but there seem to be a lot more ways to do things wrong. Returnless rails are cheap, readily available in salvage yards, and in my opinion, the correct way to do it, but then I'm not one to half *** things especially when it could have bad consequences. If that's ABSURD, then so be it.
Thanks guys. I respect the opinion of you guys (Nova's? CamAro's) and welcome your inputs. I also understand that any input is meant to solve a problem I have posed. Each solution introduces a "tree" with positive and negative aspects. Several different inputs require ME to make a decision and I take responsibility for the final outcome. If the car burns down, the rear end falls out or the engine quits is it your fault? Nope, it's my fault for doing something half-assed, stupid or not considering inputs. I didn't ask for inputs to see who is stupid, I asked for inputs because I'M stupid and need options. Now, have a nice Memorial Day, remember those who gave it all and enjoy the BBQ.
You can offer all the advise you want, and when someone puts a vacuum cap on it with a worm clamp and it blows off and all hell breaks loose, that's on you. There is more than one way to do things, but there seem to be a lot more ways to do things wrong. Returnless rails are cheap, readily available in salvage yards, and in my opinion, the correct way to do it, but then I'm not one to half *** things especially when it could have bad consequences. If that's ABSURD, then so be it.
Vacuum cap and hose clamp? Who would half *** it that bad? You can buy block off connectors that snap on to the rail with the exact same clip the OEM uses. That is what I was recommending. This way is no less safe that a factory feed or return fitting.
You'd be amazed at what I've seen people do. When you say "cap off the return" some peoplewill think vacuum cap, hose with a bolt in it, etc. We could go further, into wiring where ive seen wire nuts, butt connectors, and even just twisted wires with cheap electrical tape on them, they all conduct electricity, but i think most will agree some of them are just wrong. I'm not going to get into a pissing match with anybody, just trying to make sure that people know there are better ways to do things.
Still very confused about the filter/regulator. Nova said he would use a Wix and I researched and found a Wix 33737 which is billed as a FILTER but has all the attachments and external fittings of a filter/regulator. Has anyone used this Wix part and does it actually regulate the pressure to 58 pounds?
Yes, the corvette filter/regulator is one piece. It is this way on a LOT of vehicles from the factory. I just put a Wix corvette filter/regulator into a 69 Chevelle 5.3 swap.
OK, got the filter/regulator. I'm using the factory style nylon fuel lines. No problem hooking up the pump supply to the regulator (3/8") or the return to the tank (5/16") BUT the outlet to the fuel rail is a standard GM female fuel line fitting. It's the type that requires the tool that slides up in to move the fingers away from the rib. I can't find any such male fitting with a single rib on one side and barbed on the other to accept the nylon line. What is everyone using?
Really can't use the Russell fitting because I'm using factory style nylon fuel lines would still have a problem going from -AN to the barbed fitting for the nylon line. I have the Dorman tool to put the fuel line on the fittings and did look at the Dorman site but did not see that double barbed hard line. That would work.
What I ended up doing is going old skool, fire up the lathe and making a fitting. One line is made up from the pump to the filter/regulator and the other fitting with a short piece of hose is a test. I'll pull the supply line out and push the home built piece on and then connect it to the filter out side.
Got things back together and running. Long term fuel trips are 6 percent and fuel pressure is 58 lbs. Here is what I've learned so far. The fuel pressure regulator on a (my) 5.3 is set at 50 lbs. and the program seems to be set to that also. What I mean is the program is set to respond to 50 pounds of fuel pressure with a pulse width that matches the EXPECTED operating pressure of 50 PSI. That's OEM for my engine. Aftermarket tunes seem to be for a 5.7 that require 58 lbs. Just about the only way to get 58 lbs is with a Corvette filter/regulator or, in some cases, an adjustable regulator.
In my case I just installed a Corvette regulator/filter (Wix 33737), blocked off the return on the rail and piped the regulator back to the tank. Sounds easy but there are a few problems. first, the fuel rail block off. I used a Russell fitting with a cap which works just as designed. Next was the fittings to go to the "Vette filter/regulator. No room for the OEM fittings so I went with the Dorman plastic ones that do not have a separate positive lock so I lock wired them on.
05-28-2016, 09:11 AM
Filter/regulator 
