Hot Fuel Lines

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rod7515 said:
A few more answers to some of the questions that have come up. Yes the tank is vented with a 1/2" aluminum line. The dark marks around the trans mount is not the paint being cooked but that was fom when I first started the engine and did not have any exhaust behind the headers. I will be repainting that area in the next few weeks but I dont think that will return unless I run no pipes again. As for running a plate under the carb I have added a kool keepers insulator a few weeks ago when I first found this issue. Next would be the fuel percolating and yes I believe that could be possible. I did hit the bowls with the infra red thermometer and the front bowl was at 151* while hte back was at 145* and that was with the insulator on. The carb is a Sean Murphy built carb, 750 reworked to flow at 830* cfm if I rememeber correctly.
So tonight I plan on installing the wrap around the lines and I will start looking for someone that sells a guarding to cover the lines as well. I may have to try to make a guard cover!
I will keep you updated on what I find.
Thanks Rod
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Do you have room under the carburetor for something like this?

Holley Carburetor Heat Shields 108-70
 
I would regulate the pressure as close to the carburetor as possible with a bypass regulator. That way a lot of gas get recirculated, only what's needed goes to to carb, the rest goes back to the tank. There is absolutely no way the fuel can get hot if you route the gas lines as shown in the below diagram. I had basically the same problem you are having and this solved the problem.
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Rusty, I stopped this morning to take a pic of the plate under my carb now. I put this on about 6 weeks ago while I was fighting the cooling issue I had.
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69_340_GTS, how did you mount your regulator? What brand of regulator is it? I'm hosed the same way just mounted on the inner fender.
Rod
 
Just curious as to what ignition you are running and where its located. I had a friend that fought vapor lock for a long time before we found the coil was breaking down when warm. New coil and good to go.
 
rod7515 said:
Rusty, I stopped this morning to take a pic of the plate under my carb now. I put this on about 6 weeks ago while I was fighting the cooling issue I had.
View attachment 1715354603 View attachment 1715354604 View attachment 1715354606
69_340_GTS, how did you mount your regulator? What brand of regulator is it? I'm hosed the same way just mounted on the inner fender.
Rod
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I put the regulator on the inner fender, sort of beside the heater motor. Fuel lines enter/exit inside frame rail between the header. The fuel has no chance to pick up much, if any, heat... it is going in and out of the regulator so fast. I did use -6 AN S/S hose everywhere, that could act as insulation I suppose. The regulator is an Aeromotive #13351. I picked it because you can use it for EFI (20-60 PSI) or carburetor (3-20 PSI). I am running a 780 "3310" Holley with no heat shields at all, just a 1/4" phenolic gasket. Also using an in-tank 60 psi Walbro pump with a Tanks Inc. gas tank. This solved all my "runing out of gas when hot" problems. Going on several Summers now, and it was well worth the investment.

Do check the coil and/or igntion box for reduced spark when hot. I've had that issue too! But not with new MSD parts.
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69_340_GTS said:
I would regulate the pressure as close to the carburetor as possible with a bypass regulator. That way a lot of gas get recirculated, only what's needed goes to to carb, the rest goes back to the tank. There is absolutely no way the fuel can get hot if you route the gas lines as shown in the below diagram. I had basically the same problem you are having and this solved the problem.
View attachment 1715354497
Click to expand...

I've preached that for years right here on this forum and been argued into oblivion, so I've given up. All the naysayers said it doesn't matter where the regulator is. I like mine as you say, as close to the carburetor as possible, but on the return side. That way you're using the regulator as the return restrictor. Of course you must use a return style regulator, but there are plenty out there to choose from. It does make a difference, IMO, where the regulator is. At least it always has for me.
 
rod7515 said:
Rusty, I stopped this morning to take a pic of the plate under my carb now. I put this on about 6 weeks ago while I was fighting the cooling issue I had.
View attachment 1715354603 View attachment 1715354604 View attachment 1715354606
69_340_GTS, how did you mount your regulator? What brand of regulator is it? I'm hosed the same way just mounted on the inner fender.
Rod
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Ok, cool. You're trying everything that I would. I'm beginning to think the lines close to the header might be the issue. As for the regulator, I like the regulator NEXT TO the carburetor. That's why a lot of those carburetor shields and spacers have a spot to mount the regulator right on it. That way the fuel transition area is as close to the carburetor as possible. Again, I could be crazy, but it makes sense if you think about it. It's always worked for me.
 
RustyRatRod said:
I've preached that for years right here on this forum and been argued into oblivion, so I've given up. All the naysayers said it doesn't matter where the regulator is. I like mine as you say, as close to the carburetor as possible, but on the return side. That way you're using the regulator as the return restrictor. Of course you must use a return style regulator, but there are plenty out there to choose from. It does make a difference, IMO, where the regulator is. At least it always has for me.
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Can you post up a couple of the return style regulator you like.

TIA
 
yellow rose said:
Is that a return style fuel log? I switched to some bottom feed needle and seats and want to lower my fuel pressure a bit.
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It says it is. But it doesn't say what the pressure range is. Might have to check with Moroso. I've never pulled the trigger on buying one.
 
rod7515 said:
Some answers to your questions, Yes it is a mallory electric pump and regulator. The mounting position is below the tank as instructions say it must be.
View attachment 1715354017
Jadaharabi, heres the outside of the car and also you can see how the pump sits,
View attachment 1715354019 View attachment 1715354020 View attachment 1715354021
A408cuda, Fuel pressure starts at 6.5-7 when its first started up, but once it starts to do its what I think is a vapor lock its drop to about 5 psi. You will feel the car start to hesitate when pulling out or feeding throttle. Then if you shut the car down and it sits for 10 minutes or more it wont start unless I drop accel to floor and crank for about 10 seconds.
Blindsquirrel, Im not sure what rules you are concerned with but yes the car I hope will see track time at some point. There is no rubber line in the system at all, its all braided or solid and it does not go up the firewall at all. It does get close to the header collectors but I dont have any pics of that. That will get some of the shielding.
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I was able to find this pic of the engine compartment fuel line routing.
I will be traveling home today so wont get to check my email or reply back until later tonight. Thanks for all the responses and I hope to resolve this issue soon with your help.
Rod
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That car has some real kool attitude!!:thumbsup: Love the intake!:steering: How does intake run on street? I just installed one but car not running yet.
 
QuickDart360, Thanks for the compliment, i appreciate it. As for the intake im just now starting to run the car on the street as I have battled over heating issues and now the fuel issue. Finally tonight I was able to drive the car the the most and it seemed to really run good. I put about 20 mile on it tonight.
 
Just a quick update on the fuel lines and issues I have been having. Last night I put the heat shield on all the fuel lines from the tank up to the inner fender. Such a shame to have to cover all that hard work I did on the piping and hosing but I guess it had to be done.
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It took 22' of the shielding to cover it all. I ran out of the velcrow shielded cover with about 2' left too do and lucky I had some other shielding left over.
Tonight I took the car for a drive but before I did I changed the thermostat from the 180* to a 160* . The car temps were down some and the shielding seem to help. The outside temp was about 82* which is higher then when I drove the car last week. So far it seems to better. I will keep driving and let you know if anything changes.
Thanks Rod
 
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Hey hows it going? how is the car running? Nice work. Can you try again, only putting the 180 stat back in?
 
Just a quick update on the fuel issue. Im still having issues with what I still believe to be the fuel getting to hot and vapor locking. Its not as often as when i first started but its still there. I have covered probably 80% of the fuel line with the heat temp wrap. There is one section of where the line turns to go up into the engine compartment/inner fender that the fuel line is almost directly above the header collector area. I would guess it to be less then 3" inches. I will be building a metal steel guard and also using some temp wrap around the guard in that spot. It doesnt make the car hesitate while driving like it originally had but if it sits idling or when shut off after its been driven for a few miles and up to operating temps if you try to restart it it will start but stall right away then wont restart and will act as tho its flooded. Then when it restarts it will shut off again and act as tho it just ran out of gas. I am sure it is vapor locked at that point. Then I will crank and crank before it restarts. Then once it finally restarts i can drive it again without issue until the next time.
One last thing, it seems as tho it has to sit a while after running which seems to be time for the header heat to soak in.
I still only have about 140- 150 miles since its been running/driving on the street. I have the winter now to get some guards built.
Rod
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Someone here recommended covering/shielding the front bowl to help prevent boiling from the upper radiator hose/thermostat neck heat on my setup. Might that work for you?
 
Can ya move the line? Thru the sub frame rail or sub frame connectors if you have them to get it out side away from them headers?
 
I dont think I'm pulling any heat from the radiator hose that would cause these issues. I also am running a carb cool plate to keep heat from coming up from underneath. As for the lines into the frame. I am sure that would be possible but would take lots of work as it would require more bands which will cause more pressure in lines and also the inside of the frame is not completely open as I tried to run some electrical there but couldnt get all the way thru. I guess my best bet is to make some guards and insulate them but in order to do that I will probably have to take the headers off to drill and fasten a guard down.
Thanks, Rod
 
Wait a second. My post said "thru the sub frame or sub frame connectors, to get the FUEL LINE "OUTSIDE" AWAY FROM THE HEADERS". Not all the way up thru the frame. Your saying "that would be lots of work and "more bends in the line which would cause "more pressure in the lines".
A clean bend does NOT cause "more pressure"
Now you think building some guards and removing the headers would be less work, NO WAY !
 
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