Gas pressure

Mike speaks the truth. Mechanical pump diaphrams can't handle the pressure from an electrical pump.


Gary Parsons

Mike speaks the truth. Mechanical pump diaphrams can't handle the pressure from an electrical pump.


Gary Parsons

was the possible float issue ever resolved/checked? floats can get a pinhole leak, partially filling them with gas causing erratic behavior. they look fine. if
you remove the float and shake it....there's gas in there.

wcoye wrote: Hi from Raleigh! What is the correct gas line pressure for my 810?

The only place that really counts is at the carburetor. For the needle valve to work right you want about 2 to 3 psi. Sometimes you can get away with 3.5 to 4 psi but I wouldn't try it.

The way to run through the mechanical pump if you are using electric is to take the arm off the mech. pump, put a plate in place of the diagram, put a plate between the mech pump base and the block. For those of you who just turn on your electric pump when you think you are vaper locking or not running good. You risk having a hole in the diagram instead of the car vaper locking and when you turn on the electric pump you fill the crankcase with gas with not good results.
Just a warning.
CORDiallyMike

And at some point I want to see if I can run gas through the mechanical pump for looks and judging purposes.

Terry, Presently the fuel line bypasses the mechanical pump completely. and runs only on the electrical pump. I didn't do it.
At one time gas did run through the mechanical pump. Sometime in the pass year someone who worked on my car bypassed the engine's pump....she generally works well...until this last hiccup

Terry during my carb rebuild and restoration I found the cover to be warpped. The gasket could not take up the gap. So I lapped it flat on a special honing stone. It will not leak air or gas this is for sure...


Gary Parsons

Bill some of the Cord people here in Australia just run an electric fuel pump.
Mine is a low pressure Airtex 6 volt pump. I use it to prime the engine and run on the mechanical pump.
When it was on the road before starting the complete restoration of the car it ran like a steam train. I covered around 10,000 miles in 5 years. At times the engine would start to run rough when going up steep hills at highway speed so I switched the electric pump back on and found the engine powering on again., otherwise it ran beautifully on the mechanical pump.
I figure if I ran it on an electric pump all of the time, if that eventually played up I would be stranded.
I placed the electric pump close to the gas tank and have an in line filter between the tank and pump.
During the restoration work I found some distortion in the carburettor body to float top mating surfaces which allowed air to be sucked into the carburettor throat. This has been carefully rectified. Later this year when it is all back together I can start experimenting again.
Cheers from Down Under.
Terry Cockerell

A fuel pump diaphragm disintegrating can cause flooding by sluffing off small pieces of the diaphragm and blocking the needle valve. That plagued me from a fuel pump diaphragm my good friend JK thought was impervious to everything, but sadly wasn't. Tom Hartz

Hi Gary,

I think that you are correct about my description of disabling the mechanical pump. I am sure that there is a way to have the fuel travel through the mechanical fuel pump but cutting out the diaphragm is likely not the way to do it. I would have to examine a mechanical diaphragm pump to see how to best do it. Likely disabling the pumping drive for the diaphragm would be the best way. Thank you for your correction.

Bill

I drive an 89 F-350 diesel that came with a mechanical fuel lift pump. I belong to a diesel forum and many have found that an electric lift pump works so much better but.. We can't run them in tandem because the fuel pressure of 6 lbs will rupture the mechanical lift pump diaphragm. Then you engine oil is flooded with diesel. If not caught early you ruin the bearings running fuel diluted oil..So we remove the mechanical pump and run only the electric pump. About removing the diaphragm and using our mechanical lift pumps for show is suspect to me.I think that would allow the fuel to flood our Cord engines.I will be checking on this because my Cord mechanical lift pump is apart on my work bench waiting a rebuilt kit. I'm all for electric fuel pumps over the mechanical pumps because we can install them to start pumping when the ignition is switched on. It also keeps pressurized fuel from the tank all the way to the carb helping to stop the fuel from boiling during vapor lock coming to our engines.I have seen all kinds of different fuel line routing on Cords and sometimes wonder what an owner was thinking running the lines so close to the exhaust manifolds.


Gary Parsons

Mike makes a good point about the 7 psi maximum inlet pressure for the regulator, if you go with an electric fuel pump make sure that it does not exceed that rating. 7 psi seems to be a common rating for 12V pumps, I have not looked into 6V pumps but would expect they would be similar. I purchased my regulators from Summit however they seem to be the same price of $33.20.

Terry, I believe that my 812 is actually running completely on the electric fuel pump. I purchased the car from Gail Shaw and when I bought the car he told me that the mechanical pump is disabled and only for looks. I believe that he cut out the diaphragm so that gas pumped by the electric pump just passes through. I have not checked to see what type of electric pump I have on the 812, it is located under the car near the back. If anyone is interested please let me know and I will crawl under the car and take a look.

All of the comments about junk from the gas tank clogging the needle valve or sticking the float are right on. A discretely (or not) placed fuel filter can do a world of good.

Bill

I am unsure about Cords, but all 34-36 Auburns were soldered over the sheet metal screws where the flange meets the tank. I have a few of 2-4 lbs. new Airtex pumps for sale.

I notice it says max inlet pres. 7 psi. You might check Summit Racing for better price.
CORDiallyMike

Thanks Goerge for the great tip. My tank has been cleaned out by a shop Randy Ema suggested. They did a great job too. My tank had a bad gas leak at the fill tube area where it connects to the tank. The flange design was horrible. You can't secure it around about 40% of the flange due to the design. So somebody before me soldiered the flange to the tank leaving the screws still in the flange. It still leaked badly because they did a por job og soldier. Getting those screws that were covered in soldier removed was pure hell. I did a writeup on how I used 2 gallons of water and three lbs of dry ice to create a carbon dioxide blanket in the tank to keep it from exploding when I used my torch to remove all the fittings. The suction line I found was soldiered to the bottom drain plug flange too. I have no idea how that was done because of the baffles and tanks design. I plan now to cad plate the inside and outside of my tank. Then re install the fittings.


Gary Parsons

It has been my experience that carburetor flooding in old cars is caused by iron oxide (rust) coming from a rusty gas tank. These rust particles can penetrate many gas filters . They tend to keep the float needle open causing flooding.If you open your carb and find what looks like fine sand in the float bowl, you can pick it up with a magnet. The answer is to recondition or replace the tank. George.

Bill are you running with just the mechanical pump or do you have an electric pump as well?
The electric pumps are supplied in two types, either low pressure or high pressure.
Obviously low pressure is the way to go. I use mine for priming the engine and on steep hills at speed when the engine starts to run a bit erratically. It will be very interesting to see how she performs after the complete rebuild.

Looks like the way to go. Many thanx!

Additional pictures that I intended to add.

Hi Bill,

I just checked my 812 S/C Phaeton and the answer is unanimous, it has the Holley fuel pressure regulator as well. I have also found it very useful to have a fuel pressure gauge on the system as well although the Holley regulator says that it comes preset at 2.8 psi which should be perfect. Attached are some pictures of the installation on my 812.
Good luck.
Bill

Hi Bill,
I have two Model A Fords running Stromberg 81 carburetors and I am using a Holley low pressure fuel regulator on both. Following is a link:

www.holley.com/products/fuel_systems/fue...ulators/parts/12-804

I have had good success with these with electric fuel pumps. My Cord Phaeton has a regulator on it as well, I will check to see what model when I get home from work.

Bill

I agree with Mike....stuck float. Run stock, they won't burn.

Could have been a stuck float.
CORDiallyMike

I have been shopping around online for a low pressure fuel regulator and haven't been able to make a comfortable decision. Have any of you added a regulator and if so can you recommend a product?

Hi Terry, That's one of the saddest photos I've ever seen. I always have a fire extinguisher in the car.... with the understanding it may only save Lynn and me and not the car.

What's this? Not opening these until I get an explanation.

Bill you are very lucky she didn't go up in flames. One of the members out here with a fibreglass speedster replica had a fire start under the hood that quickly spread and destroyed the whole car. He almost lost his house but was able to push the blazing inferno out of the garage which is located under his house. He put it down to a possible split fuel line.

Hi Jim,
I'm thinking my pressure may be too high. Last evening I was toodling along and the engine suddenly cut out. No coughs or shutters.
I tried to restart, nothing. Popped the hood and found gas pouring out of the carb . I couldn't find any obvious problem. This morning she started right up. I idled her for a good 20 minutes trying to recreate the problem. Runs like a charm . Figure the needle valve was jammed. Gonna install a pressure regulator as a precaution

Hi Bill,
It all depends on where you measure the pressure. The only place that really counts is at the carburetor. For the needle valve to work right you want about 2 to 3 psi. Sometimes you can get away with 3.5 to 4 psi but I wouldn't try it.

Some of the modern electric pumps put out 6 to 8 psi in which case you need a pressure regulator in there somewhere.
Jim

Hi from Raleigh! What is the correct gas line pressure for my 810?