L84 fuel system

[Michael G.]

As we go into the hotter months, I thought it might be a good idea to post this before FI owners start to see the typical problems. About a year ago, I altered my 63 L84 engine plumbing to try to cool the fuel. After making the changes and driving the car several thousand miles, using any old fuel that was available, I've found that fuel percolation is no longer a problem. The car runs fine, even when its hot outside (90+), even with 10% ethanol pump gas. No more $8 a gallon racing fuel.

The changes were easy, cheap and 100% quickly reversible. Here's what I did. 1) I disconnected the fuel line from the fuel meter inlet and slipped a 3/4 ID tube made of fiberglass insulation over the whole length of the tube. 2) I removed the filter bracket and wrapped the filter with fiberglass cloth with foil backing 3) I disconnect the fuel filter from the front fuel line and slipped a wrap of fold backed fiberglass over the whole length, down to the pump, 4) I wrapped the lower fuel line from under the battery tray to the fuel pump with foil backed tape. 5) I slipped a 6" x 8" foil backed fiberglass cloth under the plenum.

The whole thing took maybe an hour and now my idle sits steady, right about 800 RPM at idle, even after prolonged driving. Here are some pics:

lower.JPGfilter1.JPGinlet1.JPG

[Rob M.]

Re: L84 fuel system

As we go into the hotter months, I thought it might be a good idea to post this before FI owners start to see the typical problems. About a year ago, I altered my 63 L84 engine plumbing to try to cool the fuel. After making the changes and driving the car several thousand miles, using any old fuel that was available, I've found that fuel percolation is no longer a problem. The car runs fine, even when its hot outside (90+), even with 10% ethanol pump gas. No more $8 a gallon racing fuel.

The changes were easy, cheap and 100% quickly reversible. Here's what I did. 1) I disconnected the fuel line from the fuel meter inlet and slipped a 3/4 ID tube made of fiberglass insulation over the whole length of the tube. 2) I removed the filter bracket and wrapped the filter with fiberglass cloth with foil backing 3) I disconnect the fuel filter from the from fuel line and slipped a wrap of fold backed fiberglass over the whole length of the fuel line, 4) I wrapped the lower fuel line from under the battery tray to the fuel pump with foil backed tape. 5) I slipped a 6" x 8" foil backed fiberglass cloth under the plenum.

The whole thing took maybe an hour and now my idle sits steady, right about 800 RPM at idle, even after prolonged driving. Here are some pics:

[ATTACH=CONFIG]46378[/ATTACH][ATTACH=CONFIG]46380[/ATTACH][ATTACH=CONFIG]46381[/ATTACH]

good tips, I'll keep them handy for when I'm going to start my car for the first time later this year...

[Michael G.]

Re: L84 fuel system

Rob, are you talking about the unrestored L84 engine you posted pics of here a couple of years ago?

[Rob M.]

Re: L84 fuel system

Rob, are you talking about the unrestored L84 engine you posted pics of here a couple of years ago?

yes indeed!

IMG_0392.jpg

[John D.]

Re: L84 fuel system

Good job Mike. Now let me report on the 58 to 61 also the 62 FI units. Seems that the fuel line that goes from the engine fuel pump to the fuel filter is hugging the valve cover and in some cases hitting the valve cover. Seems that most of the repro fuel lines are incorrectly bent. What happens is the fuel is boiling or very hot before it even reaches the FI unit!!!
The original fuel lines are at least an 1" or more up off the valve cover. Those lines are typical parallel to the valve cover. And the originals are not hitting the valve cover on the radiator side or at the firewall side like a typical repro.
Your job is to alter those lines or have a new one fabricated. Then insulate it well and you should notice an improvement.
How about someone here posting some pics of a known original fuel line for a 58 to 62 FI car. JD

[Michael G.]

Re: L84 fuel system

Rob, it looks a bit better than it did:

DSC03712.jpg

Nice job.

John thanks for the comments, I can't help you much with pre c2 fuelies.

[John S.]

Re: L84 fuel system

Mike,

nice job! Looked a little rough originally huh? Saving this post for if and when I have problems with the 65 this summer in So. Cal. Next test is a local car show this Saturday. Temps supposed to be around 90 degrees. Place is less then 10 minutes away, so I may be driving out of the way to get there.

[Michael G.]

Re: L84 fuel system

John, sorry I didn't explain, the pic of the rusty engine that I posted is not my engine, its a pic of Rob's engine two years ago, before restoration (the after is shown in post #4)

[Charles M.]

Re: L84 fuel system

Mike, where did you get the fiberglass pipe insulation you used on the lines from the pump to fuel meter? My 61 FI has always had vapor lock issues unless I use av gas.
Thanks Chuck M.

[Michael G.]

Re: L84 fuel system

Chuck, most auto parts stores carry similar shielding. One web site that carries most of the available heat shielding materials is:

http://www.heatshieldproducts.com

Next time I take the fuel system apart, I'm going to use the foil backed reflective tubing (that I used on the front fuel line) on all of the lines, as it reflects about 90% of the radiant heat. IMO the most important line to insulate well is the lower one, since it is very close to the exhaust manifold and normally gets very hot (160 F+). I think this line heats the fuel and it never gets cool again.

[Charles M.]

Re: L84 fuel system

Thanks for the info Mike, will give it a try. Av gas is expensive here in Fla., $6.00+ a gallon!
Chuck