Go Back   The Ford Barn > General Discussion > Early V8 (1932-53)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 06-12-2019, 08:20 AM   #1
46woodie
Senior Member
 
Join Date: Jun 2010
Posts: 169
Default Power valve failure

I have a 59A in my 46 Ford. Car runs excellent but when I'm done driving gas is seeping out of carb (stock Ford) between base and throttle body. Charlie has rebuilt this twice and it had a bad power valve when I sent it to him so this is 3rd valve gone bad. Have had to change oil couple times due to gas in it. Also have excellent fuel pump that Charlie rebuilt. Like I said,car runs incredible but leaks gas. What is the problem? Thanks!
46woodie is offline   Reply With Quote
Old 06-12-2019, 08:44 AM   #2
Russ/40
Senior Member
 
Russ/40's Avatar
 
Join Date: May 2010
Location: Santee, California
Posts: 2,853
Default Re: Power valve failure

This isn't going to help you much, but that is why I run a Stromberg. Never another power valve problem. The holly power valves must seal to the casting, or they will leak, even if the diaphragm is good. Take the top off the carb and fill the bowl with fuel. The power valve must be sealed and not leak down.

If you have a backfire, it may blow the power valve diaphragm.
Russ/40 is online now   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 06-12-2019, 09:02 AM   #3
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 9,671
Default Re: Power valve failure

Charlie usually modifies for the late type valves to work since no one makes the old style. If an engine is running too lean, it will backfire through the carb. This canl cause the vacuum diaphragm to blow out. Modern fuels are hard on carbs too. Rubber parts don't hold up well.

My old Mercury uses the Holley 885 and they used a power valve set up similar to Stromberg in those. They can have problems with the extensive vacuum circuit for that type power valve due to poor sealing of the shroud parting surfaces but when they work, they work well.
rotorwrench is offline   Reply With Quote
Old 06-12-2019, 11:57 AM   #4
46woodie
Senior Member
 
Join Date: Jun 2010
Posts: 169
Default Re: Power valve failure

No backfiring and like I said it runs great. I'm sure Charlie did a good job tighteningthe power valve so Its has to be sealing ok but will double check. Thanks
46woodie is offline   Reply With Quote
Old 06-12-2019, 12:43 PM   #5
Ken Henry
Junior Member
 
Ken Henry's Avatar
 
Join Date: Jul 2010
Location: Rochester, NY
Posts: 29
Default Re: Power valve failure

It could be percolating after heat soak. If you look down the throat of the carb after shutting off, you will see fuel dripping out the nozzle bars in this scenario. It tends to run out at the base of the carb near the throttle plates. Ken

Last edited by Ken Henry; 06-12-2019 at 12:57 PM.
Ken Henry is offline   Reply With Quote
Old 06-12-2019, 07:16 PM   #6
nbrskn
Senior Member
 
Join Date: Feb 2011
Posts: 103
Default Re: Power valve failure

read her I think that the power valve can be pluged off/ Is this true ?
nbrskn is offline   Reply With Quote
Old 06-12-2019, 07:27 PM   #7
ford38v8
Senior Member
 
ford38v8's Avatar
 
Join Date: Jul 2011
Location: SF Bay Area
Posts: 4,924
Default Re: Power valve failure

Quote:
Originally Posted by nbrskn View Post
read her I think that the power valve can be pluged off/ Is this true ?
I'm sure it can, but why would anyone want to? Maybe in a stationary engine?
__________________
Alan
ford38v8 is offline   Reply With Quote
Old 06-12-2019, 10:40 PM   #8
Ol' Ron
Senior Member
 
Ol' Ron's Avatar
 
Join Date: May 2010
Location: Chester Vt
Posts: 6,821
Default Re: Power valve failure

Just curious, how often do you hear of a PV failure? Can't remember the last time I heerd of one???
Ol' Ron is offline   Reply With Quote
Old 06-13-2019, 07:31 AM   #9
chap52
Senior Member
 
chap52's Avatar
 
Join Date: Jun 2013
Location: Marana Arizona
Posts: 1,396
Default Re: Power valve failure

I was running dual 94's and Charlie advised to block off pv's. So I purchased a couple of correct pv plugs from him and it ran wonderfully after that. Don't know why, it just did? Chap
chap52 is offline   Reply With Quote
Old 06-13-2019, 07:52 AM   #10
Ol' Ron
Senior Member
 
Ol' Ron's Avatar
 
Join Date: May 2010
Location: Chester Vt
Posts: 6,821
Default Re: Power valve failure

I like to tune a street engine for economy, which would be too lean for WOT.
Ol' Ron is offline   Reply With Quote
Old 06-13-2019, 07:44 PM   #11
my4dv8
Senior Member
 
Join Date: Aug 2010
Location: New Zealand
Posts: 782
Default Re: Power valve failure

It probably does run fine without PVs ,until you stomp on the go pedal and it will likely fall on its face. Maybe you have masked the no PV with bigger jets?
A common solution is to stick to stock size jets and a PV with a lower value than stock so it opens at a later at lower vacuum.
my4dv8 is offline   Reply With Quote
Old 06-13-2019, 09:43 PM   #12
Charlie ny
Senior Member
 
Join Date: May 2010
Posts: 2,240
Default Re: Power valve failure

46,
Time to send the carb back again. I'm thinking the PV gasket face on the
bowl is not square with the PV threads....possibly creating a strain when tightening

the PV.....we'll get it done.....N/C
Charlie ny
Charlie ny is offline   Reply With Quote
Old 06-15-2019, 07:19 AM   #13
46woodie
Senior Member
 
Join Date: Jun 2010
Posts: 169
Default Re: Power valve failure

Thanks Charlie!! Better if you have a carb that you know works correctly and send that and I'll send this back. 3rd time taking this off and shipping, not only expensive but pain taking on and off. You do great work,car runs great, but have had to change oil few times also because of gas leaking through.Car Starts alright after fuel bowl refills but drains into crankcase if car sits overnight. Going to run into major problems here. Thank you again
46woodie is offline   Reply With Quote
Old 06-15-2019, 07:44 AM   #14
Charlie ny
Senior Member
 
Join Date: May 2010
Posts: 2,240
Default Re: Power valve failure

46,
Check your PM's
Charlie ny
Charlie ny is offline   Reply With Quote
Old 06-15-2019, 11:36 AM   #15
rotorwrench
Senior Member
 
rotorwrench's Avatar
 
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 9,671
Default Re: Power valve failure

Back in the days of round aircraft engines, they used fuel dilution in the oil tank to make the oil thin enough to flow through the engine for cold weather starting. The oil tanks had a tank within a tank (down in bottom center) to do this so they were pretty special tanks. After the engine was warmed up sufficiently, the dilution was no longer necessary and system was shut down. During the flight, the fuel would quickly evaporate out of the oil since only a part of it was affected. Some big round motors still have systems like this but are not used in semi-arctic conditions much anymore. These systems necessitated changing the oil by proper schedule which is about every 25-hours. most engines now days have spin on filters so that the interval can go up to 50-hours between changes. With dilution, an operator has to remain on the 25-hour schedule. This system was better than draining the oil after shut down then heating it on a stove and pouring it back in before a flight. That was even more work. Aircraft operators had it rough back in the day operating in northern countries anywhere near the arctic circle.
rotorwrench is offline   Reply With Quote
Old 06-15-2019, 11:56 AM   #16
Charlie ny
Senior Member
 
Join Date: May 2010
Posts: 2,240
Default Re: Power valve failure

46,
Your address please

Charlie ny
Charlie ny is offline   Reply With Quote
Old 06-15-2019, 12:23 PM   #17
46woodie
Senior Member
 
Join Date: Jun 2010
Posts: 169
Default Re: Power valve failure

396 21st st se
Cedar Rapids
Iowa,52403
Thank you,Richard C
46woodie is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 10:17 AM.