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I've got the L48 in my 74 convertible that many hands have touched and "repaired" before me so I'm having to deal with a lot of non-stock parts and bubba work. The previous owner threw away the Quadrajet and replaced it with an Edelbrock intake and 1406 carburetor. In doing so, obviously the routing of the steel fuel line from the pump to the carb is different and there is no fuel filter between the two. Also, the fuel pump appears to not be factory correct as the inlet and outlets face the front of the car and not towards the passenger side. I easily replaced these two 3/8" and 5/16" rubber hoses with local auto parts store fuel line without having to use the correct S molded hoses since there was plenty of room to make a long 180 degree loop. The previous owner had installed a 20 micron fuel filter before the mechanical pump and called it good. It shouldn't have been on the suction side from what I've read and did not really fit well so I removed it and now I'm looking at options of how to properly get a fuel filter between the pump and carb. Below are some photos of my current setup. I do not have a pipe bender or flaring tool but am willing to learn if necessary. Any thoughts or suggestions would be great.
P.S. I will be replacing those tinny looking valve covers in the future.
Passenger side of the car showing how the steel fuel line connects to the pump and is routed up the front of the engine. Note the 3/8" rubber line next to the lower radiator hose is the fuel supply to the pump from the metal lines running along the frame.
After coming up past the intake, the fuel line runs against the valve cover and makes a 90 degree bend up towards the Edelbrock fuel supply fitting.
Fuel filters have commonly been plumbed between the pump and carb, on that vertical run you show in your picture. Your line is a little close to the engine, so it will have to be a small diameter filter, and you may have to tweak the lower bends to get some clearance. Earls (sold by Holley) makes a good filter that is about an inch in diameter that may work for you. I am using it in the same location, but I bent the metal line to move the line forward, provided some better room between filter and engine.
Last edited by Shovels and Vettes; Mar 23, 2021 at 05:16 AM.
Why do you need a fuel filter? If the fuel system currently installed in the car is clean than I wouldn't worry about it. If this was my car I would direct my efforts into gathering up the required parts to put the car back to it's original configuration vice adding more mods. But I'm funny like that. Nothing wrong with mods if done correctly but most are done for the bling factor vice performance.
I’ve never been a fan of using rubber hoses in any fashion other than what was originally installed. Risk of fire is not worth it.
Fuel filters were a necessity back in the day when the chance of getting contaminated fuel was far higher than it is today. I had an 89 Toyota truck that I changed fuel filters per the factory recommended intervals for years. After my curiosity had me dissect one and I found it to be pristine, I never changed it again. I sold it with close to 300k miles and running like a top (er, Toyota).
Buy your gas from known suppliers and enjoy your car. Don’t worry about having to have a filter.
You NEED a fuel filter because of the cr@p you get from the fuel in some of these gas stations!! You never know how old the tanks/pumps might be nor their condition. Water, sediment, particulates, etc, etc.
You NEED a fuel filter....
Last edited by 7T1vette; Mar 23, 2021 at 01:22 PM.
Interesting responses so far. I hadn't thought of going without a filter, probably because I'm simply used to having one. I get my fuel here in Arizona at Costco and Chevron which is supposed to be 'top tier' fuel but who knows what their tanks look like or what could possible come out of them. If I do go this route, I'd prefer not to use rubber line from the filter to the carb. I'll do some more digging and in the meantime, I'm all ears to all suggestions and pictures. Thank you Sig for forwarding that onto me! I'll send Lars an email soon.
You NEED a fuel filter because of the cr@p you get from the fuel in some of these gas stations!! You never know how old the tanks/pumps might be nor their condition. Water, sediment, particulates, etc, etc.
You NEED a fuel filter....
running without a fuel filter is a bit like using all rubber hose from the pump to the carb. It's going to bite, you just don't know when, One little piece of trash gets into the needle and seat in the carb and it will flood like crazy.
Both of those are nice, original, unmolested, rebuildable carbs that will run very well on your application once correctly rebuilt and set up. The one with the manifold is a really sweet setup that's priced right.
Deleting the fuel filter is asking for trouble. Never delete the filter.
Please correct me if I am wrong but it is my understanding that the 427-435 and L-88s did not have a filter between the pump and carb. I presume the “sock” in the gas tank and the sintered porous bronze filters in the carb(s) were adequate?
From: At my Bar drinking and wrenching in Lafayette Colorado
The L88 cars had 2 filters in the carb - one in each float bowl. The filter was not deleted - the filters were in the carb inlets just like a Q-Jet filter. So, yes, they had a filter between the pump and the carb. All manufacturers used fuel filters on all and any carbs they used, either in the carb's fuel inlet, or in-line in the fuel line between the pump and the carb. Other than the strainer "sock" in the tank, filters were not used on the suction side of the mechanical pump.
Dual-inlet (4150-series) Holleys used by Chevy had the pump-to-carb fuel filter in the float bowl inlet:
4160 single-inlet Holleys used by Chevrolet usually had an in-line filter, rather than using a single filter in the primary bowl inlet:
Ford took a different approach to the Hi Performance Holley carbs used on the 428 CJ engines, and had a screw-in filter at the driver's side primary bowl inlet, allowing the filtered fuel to cross-flow across the top of the primary bowl, out the passenger side, and then back to the secondary bowl:
Bottom line: Filters are always used between the pump and the carb.
Lars, thanks for the clarification. When I said “between” the pump and the carb I meant the “in-line” (what I will term) canister filter.
Reason for my interest in this thread is my car was delivered new (Dec ‘69) with a 350/350 that had the canister and the return line back to the tank. I am putting in a clone L-88 and have been debating the pros and cons of whether I should retain the return line (and canister filter) or just build it like the factory without said return line (and without the canister filter).
I have a date code correct 4296 that was restored by Holley about 7 years ago but the only run time on it was when I dyno’ed the engine after build.
i would leave and use the return line since its a clone ,you will have less problems,
i restored LT-1s and tri power BBs with one fuel line because that's how they came stock
but with clones I would do a return
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by 69L88
Lars, thanks for the clarification. When I said “between” the pump and the carb I meant the “in-line” (what I will term) canister filter.
Reason for my interest in this thread is my car was delivered new (Dec ‘69) with a 350/350 that had the canister and the return line back to the tank. I am putting in a clone L-88 and have been debating the pros and cons of whether I should retain the return line (and canister filter) or just build it like the factory without said return line (and without the canister filter).
The gasoline formulations of pump gas are today completely different from the gasoline formulations in 1969. The current pump gas is much more prone to vapor lock due to high vapor pressure of the fuel formulation. Just because a fuel system design worked well in 1969 does not mean that a perfectly restored 1969 fuel system will work well in a car being operated in 2021 on available pump gas. So you need to take proper design considerations if you intend to operate your 50 year old antique vehicle on available fuels, unless you just intend to display the car in a museum. Part of that "roadworthy reliability" using modern fuels is to use a return-line fuel system to prevent the vaporization of the fuel on the suction side of the pump. If you dead-head the fuel system with no return using modern pump gas, you will see fuel system problems on hot days in stop-n-go situations. It's particularly bad up here at higher altitudes, where atmospheric pressure is lower, and it will cause severe and consistent problems for cars going uphill in the mountains on hot days (going uphill puts the fuel tank lower than the engine, aggravating the low-pressure suction on the fuel line from the tank, causing the fuel to vaporize in the line if there is not constant circulation in the line).
Lars
74 Fuel Filter Location
running without a fuel filter is a bit like using all rubber hose from the pump to the carb. It's going to bite, you just don't know when, One little piece of trash gets into the needle and seat in the carb and it will flood like crazy.
