Its been a while since i have posted. I'm running out thoughts on what could be causing the problem. The last pull at the track we are running for points they had the sled a little light and ended up having 4 trucks in the pull off. The first hook was fine, the pull off was a different story. About 50ft off the line it started to choke out like it was loosing fuel. I popped the hood and noticed the fuel filter (the clear mr gasket type with replaceable filters) was 80% air and 20% fuel. So i just assumed it was from being hot from the first back to back pull we had ever had to do. So i replaced the filter cartridge, removed the solid line between the fuel pump and carb, and replaced it with rubber, and rerouted it away from heat as far as i could up over the power steering pump and by the coil and up over the vacuum port on the dist. Along with that i added a phenolic carb spacer and i thought if a pull off happened again we would be good. The thing that has me sure its heat related is its perfect on the first run up the track and has been since that engine has been together. It was just last month that we have ever had a pull off situation and have had to run it back to back runs.


Little info on the fuel system

Mr gasket fuel filter
3/8" line from tank to carb all rubber hose
140gph mech. fuel pump (ebay holley copy)
No pickup screen in tank
running pump 93 gas.

And last night of course there was a pull off, just her and a dodge and this is what happened. Even running the way it did she was only 10ft behind.

Here are the first hook, and pull off vids.

First Hook


Pull off

 

From the tank to the pump, suction side, I would run a metal line except for 3 to 6 inches for the tie in at each end. When things warm up you could easily be colapsing that much rubber hose under suction. You could also mount an electrical pump at the tank to push fuel to the mechanical pump. This would also eliminate the suction.

 

I had actually been suggested that last night by a fellow puller. I will have to check prices for push pumps vs running hard line.

Any suggestions on where to get hard line for a good price?

 

I know people that have run 3/8" copper tubing with no problem. That can be purchased at places like Home Depot and Lowe's. Electic fuel pumps can be purchased from Summit Racing quie reasonably.

 

Alright, I'll have to look around locally to see what price i can get copper or alum. tube for. And decide from there if i want to do the electric pump or change the line out.

 

just an update i found 25' of alum. 3/8's for 23.00 free ship on amazon. I'll probbably be ordering it and using a very minimal amount of rubber line. I also have a moroso super cool can i had got used for a pretty awesome price and hooked it up the day before the pull and it leaked, so i pulled it and never ran it. I did contact moroso and they have gaskets to repair the leak for $1. I just have to call and order it. If its still doing it after this I will have to look into the pump or the filter i guess.

The crappy thing is I doubt it will be in a pulloff anymore this year as last nights pull was the last at the track we had it happen at.

 

i have the 3/8 aluminum on my 68 , just make sure you have no rubbing . i used 3/8 fuel hose and 1/2 conduit clamps to make a cushion mount .

 

thanks for the conduit clamp idea. I will have to try that

 

Just an update. I got the rebuild gaskets from moroso, and the hard line. I will try to run it for the next pull tue night. I doubt i will find out anything though since we probably wont have a pull off or make it.

 

Where is the fuel filter located?
I once had a similar type issue, but on a 300 I6. The filter had been installed by the PO in a location that was close to the carb. This put it right over the intake. On a 300, the exhaust manifold is right below the intake.....
Shutting the truck off, when up to full operating temp, and then raising the hood, would show fuel boiling inside the clear-ish plastic filter. Hot restarts were a crapshoot. It might run fine, or it might go a few feet and crap out or even die, due to a vapor lock in the fuel filter/line. Let it cool down fully, and it would run fine.

Relocated the fuel filter, and the issue never came back in the 16 years since doing so.

Not sure I would have figured it nearly as easy, had that filter been the metal case type.....

After making a hard pull, and then shutting it down, pop the hood partly and watch the filter. If you see fuel boiling inside it, then you've found the issue......

 

If the problem is over heating the best solution is running a return line back to the tank with a pressure regulator close to the carburetor (Cool fuel all the time because of circulating ) in that line also you could install a power steering cooler in the supply line ??/ Either one of these ideas might work with out the other ??/ My dad had a problem with vapor locking in a 56 Chevy wagon pulling a trailer over Cajon pass back in the 60's ??/ He popped the hood and fastened about 10 wooden clothes pins to the fuel delivery line and away we went ??/ I was all of 9 or 10 and I was thinking to my self whats next your going to attach your underwear to the clothes pins ??/ Dumb me the clothes pins actually drew the heat out of the fuel line ??/ Never had another problem all the way across the desert from LA (Route 66 ) into KC Kansas ??/ Jeg's or Summit also sell a cool can you pack with ice and your fuel line runs through the can in a coil configuration ??/ This actually cool and condenses the fuel so that your putting more fuel down the throat of the carburetor ( CFM VS expansion )

 

The clothes pins actually keep an air gap around the fuel lines.

 

An update. I finally got around to installing the new gaskets in the moroso super cool can. I mounted that and ran the 3/8" alum. hard line. Its all hard line except for about 12" coming off the fuel tank, and about 3" where it meets the mech. fuel pump. We are supposed to be pulling tonight if the weather works out. Not sure if we will see a pull off though. I hope so just to see if that was the problem, but i would rather not lol.

We have another pull friday night at the local fair that is being ran by the guy that runs the track we pull for points. I may see if at the end of the night if he will let us double hook to test it out.