The Ford Barn

Robert Legner · 09-19-2017, 05:10 PM

I checked the oil after the car sat for a few weeks and found the oil level higher on the oil stick. I ran the car then removed the top of the carbuerter and found the fuel level low in the float chamber only a few hours after the car was ran. It would seem the power valve is leaking down the throat of the carb. There are several power valves to buy depending on the inches of vacuum, supposedly if the vacuum is 20 then the PV should be a 10. The vacuum on this car is 8 inches with the PVC system connected to the vacuum port. With the PVC disconnected the vacuum runs at 16 inches. The 8BA is stock. It is difficult to set the idle with a leaky Power Valve, and when starting it cold I need to crank the engine until the fuel pump fills the float chamber before the choke will give it more fuel. So what is the advice I can get to solve my problem.
Thank you in advance!!!

Bob

flatjack9 · 09-19-2017, 05:27 PM

You have a bad or wrong PCV valve. It is normally closed at idle. 8" of vacuum at idle is a definite problem.

Charlie ny · 09-19-2017, 06:28 PM

Hmmm pcv, is it really necessary ? I use a vent tube piped into the 8BA fuel pump stand
in back and a breather cap on the oil fill tube up in front. The road draft tube hole in the intake has been plugged. So far so good, 14,000 miles and counting.
Charlie ny

Pete F · 09-19-2017, 07:36 PM

From what engine did the pcv come out of.
You know all valves have different vacuum ratings and since flatheads never had valves it's a crap shoot to find a valve that will work properly.
Also if you have a leaky power valve you better get a couple new valves and plug the pcv to balance the carbs , than add in the pcv.
But I agree with Charlie
Is it really necessary!!

Sent from my iPad using Tapatalk

Robert Legner · 09-19-2017, 08:42 PM

Charlie ny, someone in this forum suggested you sell power valves for my 8BA with the Holley 94. If so can you give me some information what to buy and pricing?

Bob

flatjack9 · 09-19-2017, 10:10 PM

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Are you sure your power valve is leaking? Could be engine heat boiling the fuel out. I would remove the top and fill the bowl when the engine is cold and see if it leaks out.

Charlie ny · 09-20-2017, 05:45 AM

x2 on what Jack says.............let it sit for 5 or 6 hours............be sure sure to cover
the bowl to slow down evaporation.
Charlie ny

rotorwrench · 09-20-2017, 09:12 AM

Modifications can certainly muddy the water sometimes. Did the growing sample of oil on the dip stick have a heavy odor of fuel? Growing oil level could also be coolant or condense since it doesn't evaporate as readily as fuel does. If there is condense or coolant in there then you will notice it the next time you pull the drain plug. It will be the first thing to come out. It's rare that that much fuel would leak down into the sump. The carburetor float bowl is just not all that large a volume.

Robert Legner · 09-20-2017, 09:54 AM

I ran the engine so the float chamber was filled to the level the float called for. I removed the top of the carb and monitored the level. Over a period of two hours the fuel level had dropped 1/2 inch. The power valve has to be the culprit. Your comments.

Charlie ny · 09-20-2017, 12:56 PM

Robert,
Yep that much loss in that short period of time SEEMS like a PV issue.
If you are interested I can send you 5.5 PV that I machine for proper fit with an
integral nylon gasket, which I also make, a new base to bowl gasket and a carb to intake gasket with shipping.......$32.
If you are [email protected]......
Charlie ny

09-19-2017, 05:10 PM	#1
Robert Legner Member Join Date: Nov 2010 Location: Odell, Illinois Posts: 50	Power Valve on 8BA with Holley 94 I checked the oil after the car sat for a few weeks and found the oil level higher on the oil stick. I ran the car then removed the top of the carbuerter and found the fuel level low in the float chamber only a few hours after the car was ran. It would seem the power valve is leaking down the throat of the carb. There are several power valves to buy depending on the inches of vacuum, supposedly if the vacuum is 20 then the PV should be a 10. The vacuum on this car is 8 inches with the PVC system connected to the vacuum port. With the PVC disconnected the vacuum runs at 16 inches. The 8BA is stock. It is difficult to set the idle with a leaky Power Valve, and when starting it cold I need to crank the engine until the fuel pump fills the float chamber before the choke will give it more fuel. So what is the advice I can get to solve my problem. Thank you in advance!!! Bob

09-19-2017, 05:27 PM	#2
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,527	Re: Power Valve on 8BA with Holley 94 You have a bad or wrong PCV valve. It is normally closed at idle. 8" of vacuum at idle is a definite problem.

09-19-2017, 06:28 PM	#3
Charlie ny BANNED Join Date: May 2010 Posts: 3,019	Re: Power Valve on 8BA with Holley 94 Hmmm pcv, is it really necessary ? I use a vent tube piped into the 8BA fuel pump stand in back and a breather cap on the oil fill tube up in front. The road draft tube hole in the intake has been plugged. So far so good, 14,000 miles and counting. Charlie ny

09-19-2017, 07:36 PM	#4
Pete F Senior Member Join Date: Feb 2017 Location: Bloomfield,ny Posts: 130	Power Valve on 8BA with Holley 94 From what engine did the pcv come out of. You know all valves have different vacuum ratings and since flatheads never had valves it's a crap shoot to find a valve that will work properly. Also if you have a leaky power valve you better get a couple new valves and plug the pcv to balance the carbs , than add in the pcv. But I agree with Charlie Is it really necessary!! Sent from my iPad using Tapatalk

09-19-2017, 08:42 PM	#5
Robert Legner Member Join Date: Nov 2010 Location: Odell, Illinois Posts: 50	Re: Power Valve on 8BA with Holley 94 Charlie ny, someone in this forum suggested you sell power valves for my 8BA with the Holley 94. If so can you give me some information what to buy and pricing? Bob

09-19-2017, 10:10 PM	#6
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,527	Re: Power Valve on 8BA with Holley 94 Sponsored Links (Register now to hide all advertisements) Are you sure your power valve is leaking? Could be engine heat boiling the fuel out. I would remove the top and fill the bowl when the engine is cold and see if it leaks out.

09-20-2017, 05:45 AM	#7
Charlie ny BANNED Join Date: May 2010 Posts: 3,019	Re: Power Valve on 8BA with Holley 94 x2 on what Jack says.............let it sit for 5 or 6 hours............be sure sure to cover the bowl to slow down evaporation. Charlie ny

09-20-2017, 09:12 AM	#8
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,440	Re: Power Valve on 8BA with Holley 94 Modifications can certainly muddy the water sometimes. Did the growing sample of oil on the dip stick have a heavy odor of fuel? Growing oil level could also be coolant or condense since it doesn't evaporate as readily as fuel does. If there is condense or coolant in there then you will notice it the next time you pull the drain plug. It will be the first thing to come out. It's rare that that much fuel would leak down into the sump. The carburetor float bowl is just not all that large a volume.

09-20-2017, 09:54 AM	#9
Robert Legner Member Join Date: Nov 2010 Location: Odell, Illinois Posts: 50	Re: Power Valve on 8BA with Holley 94 I ran the engine so the float chamber was filled to the level the float called for. I removed the top of the carb and monitored the level. Over a period of two hours the fuel level had dropped 1/2 inch. The power valve has to be the culprit. Your comments.

09-20-2017, 12:56 PM	#10
Charlie ny BANNED Join Date: May 2010 Posts: 3,019	Re: Power Valve on 8BA with Holley 94 Robert, Yep that much loss in that short period of time SEEMS like a PV issue. If you are interested I can send you 5.5 PV that I machine for proper fit with an integral nylon gasket, which I also make, a new base to bowl gasket and a carb to intake gasket with shipping.......$32. If you are [email protected]...... Charlie ny