I have a new bent steel (stainless) pipe from the fuel pump to the carburetor, I'm going to install it in the car instead of the fuel rubber hose and I need your advice:

- should I use the white teflon tape only on the 90° fitting on the thread to the fuel pump?
- will it be enough to use small original (new) sintered bronze fuel filter on the inlet of the Rochester 2JET carburetor?
- I've used an additional plastic fuel filter between the pump and the carburetor for 500 miles now and it's still beautifully clean
- if I wanted to reinstall the additional filter, can I place it in the fuel rubber hose at the back at the outlet from the fuel tank? I don't seem to have enough space in the engine compartment (I have AC and a return fuel line to the tank)
- I would appreciate your photo of the filter placement
Thanks

 

 

Teflon tape is not used on any connection involving the carburetor fuel line. The seal is made by compressing the flared end of the tube against mouth of the receiving end of the fitting by tightening the nut. No teflon tape or similar seal was used by the factory.

 

NPT threads are supposed to seal just by wedging but I always use a sealer. Frankly, I've used teflon tape with zero issues. Don't go crazy with the tape and I try to start the tape down a little from the small end of the threads so that it doesn't go into the fuel passage. Never had a problem.Inverted flare nuts NEVER use sealer. The threads are not where the seal is made, it's the flare. If you are getting fuel past the flare, you have a problem that sealer won't fix. And use a little common sense. Even if you put sealer on the threads, what seals between the ID of the flare nut and the OD of the tube?

 

I use Teflon tape at times to make dis-assembly easier in the future. I DON'T allow tape to be closer than 1/8" from the beginning end of threads. Teflon tape between two threaded parts is not thick enough to seal anything. Call it a corrosion inhibitor between two threaded parts. Anti-seize would work, but it seems to get smeared on everything.
Tapered Pipe threads do seal because of the interference fit, as Joe P said. If you think you need sealing, use the appropriate sealant and stay at least 1/8" from the small end of the male threads. A continuous ring of sealant about 3/16" wide is sufficient.

 

I use anti-seize, and I make it a point to apply it between the flare nut and the tube in addition to on the threads. I can't tell you how many times I've twisted a hard line because it was seized to the ID of the nut.

 

Yes to all comments about anti seizing.

 

Joe P, I have to agree with you on that location. I have used motor oil and grease instead of Ant-seize. If I was to sparingly apply any Anti-seize it would be with a Q-tip that was immediately discarded.

 

 

HAHAHAHAHA Joe P, thats obviously a freshly opened container. Nothing smeared around the outside or around the cap.

 

As other's said, teflon on the NPT part of the 90 degree adapter is common. I never get a good NPT seal without something - tape or paste - on the threads.
No need on the tube nuts due to the flare. Siezing may or may not be a problem. Depends on how long you think this will stay together and if it will be parked outside. I keep worrying about things like that but it seems like nothing on my car stays together for more than 2 years anyway.

Joe, that drawing is mostly helpful but the way the labels are phrased on the lower part makes it sound like tape is **supposed** to be used.

Yes, you can put a fuel filter anywhere. You "shouldn't" put a filter before a mechanical pump but in reality it's usually fine. Just know that it makes the pump work a little harder and it might have problems priming if it runs dry. I would use a pre-filter like a 100 micron, and rely on the filter inside the carb for the real filtering.

Being a 66...... it's a quadrajet with the filter in the fuel inlet, right? I never remember which year they switched over and I never remember what the filter setup was for the 4gc cars other than the glass filters. Just make certain to use a good filter and check it once a year or so. The ones with a little stopper inside of them are nice because they stop fuel draining back out of the bowl, just in case the pump's anti-drainback isn't working, but it does cut down flow. But if you're not racing then it almost certainly doesn't matter.

 

Here's how my 455's are outfitted. This is the Starfire with A/C, the 98 with no A/C is sleeping as we've had early rain and I finally bit the bullet on offsite storage.

I never knew it was a bad idea to put filters before the fuel pump, so I've done it this way for 20 or 30 years, maybe more. As I recall, I did have to gently bend the end of the hardline on my Starfire to get the right clearance well behind the A/C belt.

When I do my filter changes I'm fairly consistent on a few points. Get good quality low micron number metal filter. The glass and plastic ones make me nervous. I generally use new hose clamps at each change.

I've gotten careful to use stronger, but harder to work with fuel injection hose on the idea that strength is good and the rubber just might be formulated to resist the alcohol gasoline I get here in CA. This may not be a problem in Czech Republic.

Here's a look from the middle of the engine:

I use metal filters, fuel injection hose, and fresh clamps on filter changes which I do every 3-4 years.

Here's a look from the passenger side fender

Hose length are very short. They must be long enough to allow for engine movement, but short enough not to kink.

Hope that helps.

Chris

 

Thanks, I will also go with the same solution, a 40 micron metal filter right before the fuel pump. I use in Europe 100 octane gasoline (equivalent to Premium 93-94 gasoline) without mineral biocomponent - it contains 5% ETBE, but the price here is 6.5 dollars per gallon :Ó