Anyone tried this? Post shut down cooling.

[Old Henry]

The heat has nothing to do with this other than aggravating the smell.
When you pull up and shut down hot, Put a rag around the fuel line connection at the fuel pump to soak up fuel and SLOWLY unscrew the fitting nut.
This will immediately release the residual pressure. Retighten the nut
and observe if there is any fuel leaking down the carb and smelling.

What it "boils" down to is if the float valve doesn't leak, there is no problem.

It still seems to me that if the float needle valve had any problem holding back any residual pressure between it and the fuel pump when the pump wasn't even running that it would, a fortiori, have an even bigger problem holding back the even greater pressure that's always there when the fuel pump(s) are running and would be flooding the carb all the time. Even if the needle valve let some gas through, what little would be pushed through from pressure in the short line from the pump to the carb would not flood over the carb bowl.

(a fortiori: One of our little legal phrases that means "even more so" in Latin.)

 

[oldford2]

C'mon Professor,
Looks like just a bunch of guesses. My advice: live with it and go to Walmart and get some car fresheners to hang on your rear view. Get old Henry out for a another adventure. That's what we enjoy seeing. Any plans for your next trip? Winter is coming quickly in your "neck of the woods"
John

 

[Old Henry]

C'mon Professor,
Looks like just a bunch of guesses. My advice: live with it and go to Walmart and get some car fresheners to hang on your rear view. Get old Henry out for a another adventure. That's what we enjoy seeing. Any plans for your next trip? Winter is coming quickly in your "neck of the woods"
John

I'll probably end up doing just that - nothing. But it's fun to speculate on a new mechanical approach to a problem.

Here's the picture of my jaunt to historic Spring City for their arts festival last Saturday with Betsy and her friends. (Just the two standing next to her.)

Or, in color if you prefer:

 

[Lawrie]

On the post about the fuel in the line between the pump and the carb expanding when getting hot,This may be so,AS on pulling a heap of old pumps apart from early Holden 6,s so I could get the guts and valves from them, I found several with a VERY small hole drilled between the pressure and suction chamber of the pump, I think this was to cure such a problem.
Lawrie

 

[oldford2]

Where is Pepi???

 

[Pete]

It still seems to me that if the float needle valve had any problem holding back any residual pressure between it and the fuel pump when the pump wasn't even running that it would, a fortiori, have an even bigger problem holding back the even greater pressure that's always there when the fuel pump(s) are running and would be flooding the carb all the time. Even if the needle valve let some gas through, what little would be pushed through from pressure in the short line from the pump to the carb would not flood over the carb bowl.

(a fortiori: One of our little legal phrases that means "even more so" in Latin.)

The amount of fuel that leaks by while running is run through the engine.
It is a very small amount. When stopped it doesn't take much leakage to smell bad.
There are Mickey Mouse fixes for this but it is much better to fix the carb.

As far as the Viton(neoprene) needles, I have used them for years with no problems, BUT, and that is a great big BUT, it depends on what part of the country you live in and the gas they feed you. I am still working on a supply I bought from a company in Denver back in the 50's and they are impervious to straight methanol and/or 30% nitro.
Here is an article that pretty well sums up all of this. It pertains to aircraft but the basics are the same.

http://www.bowersflybaby.com/tech/stromberg needles1.pdf

 

[Pete]

On the post about the fuel in the line between the pump and the carb expanding when getting hot,This may be so,AS on pulling a heap of old pumps apart from early Holden 6,s so I could get the guts and valves from them, I found several with a VERY small hole drilled between the pressure and suction chamber of the pump, I think this was to cure such a problem.
Lawrie

Absolutely correct.

 

[ford38v8]

I'm wondering, when pressure builds in the line from pump to carb due to heat expansion, just how much volume would be required to relieve that excess pressure? Surely not so much as to overflow the float bowl, as there is very little volume in that short 1/4" line to begin with.

A related question here, the Shewman flexline with the checkvalve would contribute to an over-pressurized carb line. I never saw a need for a checkvalve there anyway.

 

[Old Henry]

I thought of doing that since I have the wireless indoor/outdoor thermometers but they only read up to 151°. I'm pretty sure my engine compartment gets way above that. It's gotta to boil the gas in the carb. I'll give it a try and see.

Duct taped my wireless thermometer to the carburetor and headed up Squaw Peak Road (4 miles of 10% grade). As I expected, the temperature of the engine compartment exceeded the limits of the sender (150°) so I don't know what it got to. But, I did confirm my previous calculations of what engine temperature the water would push past my radiator cap and it turned out to be right on. At my elevation with the 4# cap I figured 223°. When I got to the lookout the engine was 225° and spitting out the overflow tube. I watched the engine temperature and, sure enough, the puking stopped when the engine temperature dropped to 220°. Didn't have any gas boiling up there though so it may be back to the drawing board on that one.

 

[Old Henry]

Where is Pepi???

He stayed home while wife went north with her mother to her sister's for the day and I went south with Betsy and friends, none of which are Pepe fans.

 

[Bluebell]

Henry, I dont think that carb in the picture has an internal vent. I could well be wrong. When you take your air cleaner off, What do you see? Do you see the steel pipe at an angle at the top?
Is you float level set correctly?
What is your fuel delivery pressure?
What model is the carb?
(basics first)

 

[Old Henry]

Henry, I dont think that carb in the picture has an internal vent. I could well be wrong. When you take your air cleaner off, What do you see? Do you see the steel pipe at an angle at the top?
Is you float level set correctly?
What is your fuel delivery pressure?
What model is the carb?
(basics first)

As explained in earlier posts on this thread, the carb is a Ford 59 and has the internal vent through the steel pipe at an angle at the top. Carb was just recently rebuilt. Float level set correctly. Fuel pressure 3.5 psi and under. Good float needle valve.

 

[52merc]

well i see were back to cooling in 1 form or another have you ever checked your float level i have never ever herd of a v8 flathead that does what yours does

 

[G.M.]

C'mon Professor,
Looks like just a bunch of guesses. My advice: live with it and go to Walmart and get some car fresheners to hang on your rear view. Get old Henry out for a another adventure. That's what we enjoy seeing. Any plans for your next trip? Winter is coming quickly in your "neck of the woods"
John

John you got it, all guess's. Didn't anyone ever hear of a putting a pressure gauge in the fuel line between the pump and carb?? This would show you what's going on. The simple answer to a lot of these problems might be a return line after the pump back to the tank. This line would have to be restricted with about a .100 ID hole so enough gas would be delivered to the carb which has about a .100 ID hole limiting the flow into the carb. I believe this would stop the vapor lock in the pump by keeping it cool because gas from the tank would be circulated through the pump all the time. I found out the gas in the pump don't boil and vapor lock over 55 MPH because more gas is flowing through it. The gas don't push back through the needle valve. That problem if a good carb spacer is installed is from heat build up after shut down. This new gas starts to boil at 125 and causes vapor lock in the pump at 135. The bubbles mentioned in a post at the bottom of the glass fuel bowl are from the bale, upside down metal cup and the thumb screw that holds the bowl on. The heat from these starts the bubbles. Measure the heat on the intake manifold near the thumb screw and it's worse on stock aluminum manifolds than steel ones. G.M.

 

[Pete]

"The simple answer to a lot of these problems might be a return line after the pump back to the tank. This line would have to be restricted with about a .100 ID hole so enough gas would be delivered to the carb which has about a .100 ID hole limiting the flow into the carb."

That is exactly one of the Mickey Mouse fixes I referred to earlier but didn't think it needed explaining. IT DOES GET THE JOB DONE THOUGH.

I was hesitant before to quote a famous Smokey Yunick saying but I will now just for the Prof.
"Your failure to comprehend doesn't compel me to explain".

Actually the bypass line only needs to go around the pump. It doesn't need to go back to the tank and the restrictor hole only needs to be .040.

 

[Old Henry]

Looks like we've shifted away from my original problem and proposal to an entirely different topic of vapor lock and one of the ideas to deal with that by a recirculating fuel line. That has been discussed at length previously here: http://www.fordbarn.com/forum/showthread.php?t=83952

and considered by me fully here: http://www.fordbarn.com/forum/showthread.php?t=76173

and found wanting, at least by me. I solved that problem a different way.
Each to his own.

 

[Old Henry]

.
I was hesitant before to quote a famous Smokey Yunick saying but I will now just for the Prof.
"Your failure to comprehend doesn't compel me to explain".

Pete, you did fine explaining - eventually - and I fully understand what you're saying. I just disagree with it. Is that OK?

Alan said in other words what I was trying to say about any seepage through the needle valve from pressure in the line between it and the pump not being enough to flood the bowl.

I'm wondering, when pressure builds in the line from pump to carb due to heat expansion, just how much volume would be required to relieve that excess pressure? Surely not so much as to overflow the float bowl, as there is very little volume in that short 1/4" line to begin with.

 

[Bluebell]

Henry, how old is the needle valve? Does it show any wear? (or is it smooth down the taper.
The reason why they brought out the (lets say rubber tipped ones. I know it's not rubber) is because it has a much slower wear rate. (they lasted for ever with the old gas)

The heat does have an effect after you stop, because the airflow through the carb has the effect of cooling the carb. When you switch off, that cooling medium has stopped. You have 3.5lb per sq. in. pressure in the line. That fuel in the line is exposed to the heat from the engine, as is the bowl full of petrol in the carb.
What happens to the fuel in the line? It expands a little.
What happens then? It forces its way into the float chamber.
What happens to this extra little bit of fuel, and the expanding fuel in the float chamber? they overflow through the jets and down into the manifold, by which time the heat has evaporated it up through the air cleaner.
I assume you have an oil bath air cleaner.
Is it full to the line.
It might be worth a little of you money to try another needle valve?

BTW, You put your questions up on this fairly public forum prompting responses. When people offer you an idea, try not to poke them in the eye, as you have done to Pete.
You love you old car right. Do you really want to change everything about it?
Or would you be happy to get it up to spec, like original, and maybe put up with some of the short comings of an older car.

In answer to your last question, How much does it take? Nearly nothing.
Try sniffing a dry old petrol tin. Dry as a wooden god, but still stinks.

 

[Bluebell]

[QUOTE=BILL WZOREK;Bluebell, Ford Barn is like a 2nd home, So what should I expect nobody listens to me at the 1st Home. to think of it I have had people tell me I BELONG in a home.

Bill, Half of us on here probably should be in one
I enjoy you humour. Cheers.

 

[Lawrie]

Surely if you put a small hole say .010 between the outlet and the inlet side of the fuel pump it would bleed off any pressure built up in the line from the pump to the carb,why not get an old pump body and try it.
What it would do is bleed off the pressure when stopped,when running the pump would pump FAR more fuel than could leak through the small hole.
Worth a try.
Lawrie