Are all 6 volt coils created Equal?

[Frank DuVal]

10 hours ago, JWLawrence said:

These were used when the fuel feed to the carburetor was by gravity. Vapor lock occurs in the unpressurized part of the fuel system.

All of a typical rear tank front engine vehicle fuel system is under negative pressure from the tank to the fuel pump inlet. 

 

Geavity feed is is under pressure from the tank to the carburetor. See Model T underseat tank or Model A cowl tank. 

 

Modern cars do not vaporlok because with an in tank pump all of the fuel piping is under pressure. 

[PFitz]

9 hours ago, Frank DuVal said:

All of a typical rear tank front engine vehicle fuel system is under negative pressure from the tank to the fuel pump inlet. 

 

Geavity feed is is under pressure from the tank to the carburetor. See Model T underseat tank or Model A cowl tank. 

 

Modern cars do not vaporlok because with an in tank pump all of the fuel piping is under pressure. 

 

 

With a lab-grade test gauge, I've measured 3/4 PSI fuel line pressure between a vacuum tank and the carburetor with a height difference of about 18 inches.

 

Vapor lock can be very tough to solve because there are about a dozen things that can cause, and/or, contribute to causing it.  One of the worst offenders being the gasoline, which can vary by State/location.

 

When the gas was really bad about 27 years ago, I had one car on a tour vapor lock all the way back to the electric pump near the gas tank (one of twelve cars stuck on the roadside due to vapor lock that week of tours).  I opened up the line at the pump and there was a long hiss as the vapor pressure bled off.  Then the owner was able to get it running again.  That car still goes on tours and has not had that problem since the Government got after the oil companies to keep within the vapor pressure limits. 

 

But, vapor lock is not the problem here since by removing and plugging the vac advance line the car runs well.

 

Paul

Edited July 27, 2018 by PFitz (see edit history)

[1956322]

On 7/20/2018 at 11:11 AM, philipj said:

Very interesting things happening here... Started the car and plugged the vacuum port in the carburetor and went for a ride 10 minures or so, Its pretty hot outside and the engine is plenty warm... About 185F° The car runs fine. Does not surge or bog down. There may be a very slight hesitation to the gas pedal but it is almost imperceptible. I can actually go through the gears without a shudder... It also starts right up when hot at the first crank... I really don't understand why all of the sudden it runs as it should this way. The minute I connected the vacuum line to the carburetor, the car did not want to go anywhere! all the old symptoms came back. Is there any logic to this? Scratching my head...

I've come across this before on an old Ford.. Just got the truck it was running fine but of course I had to check things out.. Discovered the vacuum advance was shot.. No big deal I'll get a new one .. Got it installed no problem go for a drive and as soon as any throttle is applied all hell would break loose..wtf... Pull over and disconnect vacuum advance.. Running great again.. Hook it up and awful awful again.. Hmm.. Get back home and pop off cap.. Suck on vacuum line and there was the problem.. The advance plate bushing was shot so anytime the vacuum can would pull on it it would go cock eyed and really mess with the points.. Turns out a very common problem on old Ford distributors 

[Bloo]

22 minutes ago, 1956322 said:

The advance plate bushing was shot so anytime the vacuum can would pull on it it would go cock eyed and really mess with the points.. Turns out a very common problem on old Ford distributors 

 

Yes. I have replaced a bunch of those.

[philipj]

I just found a reference that the 1110801 distributor is for a series 40-50 models and that 1110805 is for a series 60, 70, 80 and 90 model cars; however, they seem identical...

[Spinneyhill]

Maybe the static advance curve is different?