[leejoy]

help

I am rebuilding my BB chevy in my 72 nova and will be running new automatic trans cooling lines to my new radiator mounted trans cooler. what type and size lines should I run? I am thinking about steel lines 5/16" and making my own bends with flared ends. Also I am putting in a new fuel pump and carburetor and need ideas of what type of fuel line to run from the mechanical block mounted pump to the carb. the carb will either be a Holley 750 or 800 double pumper. thanks.

[techinspector1]

I've never had a problem running 5/16" lines for the cooler lines. I would, however, incorporate a short length of cooler line hose in both the supply and return lines (maybe 6" or so). If you think about it, the radiator/cooler is rigidly mounted to the core support, but the engine/trans is on rubber mounts so it can twist slightly in the car, so short lengths of hose will prevent fatigue and subsequent rupture in the steel lines. I'd also include a filter in one of the lines while I was doing it.

If you're using the stock fuel lines from the tank to the pump, I see no need for anything larger than 3/8" hard line from the pump to the carb. Incorporate a fuel pressure gauge at the carb inlet and monitor for 5 1/2 to 6 psi max at full throttle power. Add a regulator if necessary.

[leejoy]

Dear TechInspector

is there a problem if I get a high volume high pressure fuel pump that delivers 130 GPH at 9 PSI instead of the standard 5-7 PSI. I'm using a Holley 4BBL street series carb.

[techinspector1]

The needle and seat in the carb can only control pressure into the bowl up to about 6 psi. Anything over that pressure will overpower the system and flood the motor with fuel.

[BIGSKY]

Originally Posted by leejoy

I am thinking about steel lines 5/16" and making my own bends with flared ends.

If you don't already have a flare tool, I suggest the Ridgid tool, #345. It doesn't come with the double flare dies, you have to buy those separate, but it is the way to go. I just went through this with some custom brake lines. I got my tool at Home Depot for $37.

[leejoy]

bigsky

what is a double flaring tool? i know what a regular flaring tool is and enough about flare fittings, etc but not about a double flaring tool.

[techinspector1]

Originally Posted by leejoy

bigsky

what is a double flaring tool? i know what a regular flaring tool is and enough about flare fittings, etc but not about a double flaring tool.

You must double flare brake lines because of the pressure involved. It will not be necessary with trans/fuel lines.

[jimfulco]

http://www.carcraft.com/howto/50919/index.html