The Ford Barn

elwood · 02-05-2018, 10:59 PM

Hey guys, Im looking to try using smaller power valves, Im running 2 Holly 2110 carbs, with a 400JR cam, and it seams like the PVs are dumping fuel right off the get go.
Are the power valves the same in Ford 8ba 94s as Holly 2110s ?
And what is the smallest PVs I can get, and where would be a good place to order them from ?
Thanks ...

Bored&Stroked · 02-06-2018, 05:40 PM

In Holleys, it is not about being "smaller" - it is about coming in at the correct vacuum level. When you run multiple carbs and a big cam, you might not have enough vacuum to be using the 'stock ones' - they open too early or all the time (ones supplied with the kits).

The PVs "should" be marked with the vacuum level they open at --> like "6.5" for 6.5". Some of the carb kits have PVs with no markings - so I can't tell you where they open. Guys like 'Charlie NY' (on this board) can probably supply you with good (and tested) power valves . . . it is worth PMing him.

You may also want to contact these guys:

Daytona Parts
386-427-7108

What I can't tell you is whether or not they have the correct sealing surface for the 2110's - ask them. Most of the newer Holley PVs have an incorrect (large) radius and they'll leak gas. I "fix" them on my lathe.

Selecting the right one:

Some Good Tips: If you take CRUISE vacuum, divide it in half and add about 2" you will be close. You want the PV to be closed while running at steady cruise, and open when the load is enough to require more fuel. Idle has nothing to do with it, even if the PV is open at idle the idle feed restriction is so much smaller the open PV will have no significant effect. Much like drinking through a coffee stirrer, it doesn't matter whether it's in a cup or a gallon jug, you will only flow so much through it.

elwood · 02-06-2018, 09:00 PM

Thanks for the help Bored&Stroked,
So Im thinking I need to put a vacuum gauge on the intake, below the carb base plates, and see what my cruse idle is..
So since Im running 2 cabs, should I add the PV values together ? I ordered 2 2.5 Power Valves today, so that would be 5, correct ?
So if my cruse vacuum was 6, divide that in half, add 2, Id at 5 ... lol ..

40cpe · 02-06-2018, 09:36 PM

You don't add them together. They both see the same manifold vacuum. I'm going out on a limb and predict your cruise vacuum to be about 15-17" judging from what my engine does. This is at about 2000 rpm, unless you have a really high (low numerical) gear ratio.

elwood · 02-06-2018, 11:20 PM

Ford 9 inch, 384 ratio, Tremec 6 speed. I try to keep cruise around 2000 also ..
Thanks 40cpe, so lets say 15, devided in half, say 7.5 and add 2 .
I took 8.4s out, and it seamed like the Power Valves where dumping gas right off the get go..
I thought I knew the basic function of power valves, guess im just not getting it, or the big cam is acting so different its confusing me ...
thanks for bearing with me ...

donald1950 · 02-07-2018, 09:02 AM

Sponsored Links (Register now to hide all advertisements)

when i had two 2110s on my otherwise stock 8BA in my 1941 pick up i had 3.5 PVs and 49 main jets in both carbs. that combination seemed to work very well.

Mart · 02-07-2018, 09:50 AM

I run 2 2100s. (not 2110s) on a 4" stroke 3-5/16" motor with a Schneider cam.

I use 54 jets and stock power valves with slightly shortened springs.

94 type carbs can run rich for a lot of reasons. Once you solve all these issues that cause it to be over rich you can then start to fit suitable jets and power valves. Personally my opinion is that if it runs ok on 49 jets it is getting extra fuel from somewhere else. Mine ran bad on 49s.

Best test to see if the mixture is good and you have no leaks is to see if it starts with just the slightest stab of the starter after sitting for 15 minutes. If fuel has leaked in you will have to crank and pump some air through it to get it to fire.

Mart.

Bored&Stroked · 02-07-2018, 08:13 PM

Another place you can order power valves from (and I would think they'd be okay - but have not ran them myself) is from Edelbrock - given they make the "new" 94.

I would imagine that the stock power valves are somewhere between 6.5" and 8". I would probably try a 5.0" power valve (if they make that size). As noted, if you put a quality vacuum gauge in the manifold (beneath the carbs), you'll soon get a good idea as to what type of vacuum profile you're actually generating. As somebody noted above - both carbs will see the same vacuum.

38 Ford Guy · 02-07-2018, 08:41 PM

I have an Isky 88 two 94's. after lots of testing front carb 3.5 PV back 1.5pV. Sounds goofy but works. Great mileage too. Both dumping at mild acceleration is too much gas.

Crankster · 02-08-2018, 11:57 AM

While I'm no expert I have studied these issues enough to note that each engine & carburetor combination is different, plus gearing, weight, cam selection, add to that variables such as elevation, seasonal variations, fuel quality and it quickly becomes apparent that while "what power valve/jetting/timing are you using" is useful for a starting point, it will be just that. The main thing with power valves (economizer) is to be assured that it is NOT opening at steady, low load cruise. As a power circuit it is tuned independent of the others.

A mechanic's vacuum gauge is VERY useful for engine tuning and diagnostics. I don't know how anyone would get along without it. Wideband O2 sensors are worth your time as well.

02-05-2018, 10:59 PM	#1
elwood Senior Member Join Date: May 2010 Location: Dallas Posts: 1,053	power valves Hey guys, Im looking to try using smaller power valves, Im running 2 Holly 2110 carbs, with a 400JR cam, and it seams like the PVs are dumping fuel right off the get go. Are the power valves the same in Ford 8ba 94s as Holly 2110s ? And what is the smallest PVs I can get, and where would be a good place to order them from ? Thanks ...

02-06-2018, 05:40 PM	#2
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,068	Re: power valves In Holleys, it is not about being "smaller" - it is about coming in at the correct vacuum level. When you run multiple carbs and a big cam, you might not have enough vacuum to be using the 'stock ones' - they open too early or all the time (ones supplied with the kits). The PVs "should" be marked with the vacuum level they open at --> like "6.5" for 6.5". Some of the carb kits have PVs with no markings - so I can't tell you where they open. Guys like 'Charlie NY' (on this board) can probably supply you with good (and tested) power valves . . . it is worth PMing him. You may also want to contact these guys: Daytona Parts 386-427-7108 What I can't tell you is whether or not they have the correct sealing surface for the 2110's - ask them. Most of the newer Holley PVs have an incorrect (large) radius and they'll leak gas. I "fix" them on my lathe. Selecting the right one: Some Good Tips: If you take CRUISE vacuum, divide it in half and add about 2" you will be close. You want the PV to be closed while running at steady cruise, and open when the load is enough to require more fuel. Idle has nothing to do with it, even if the PV is open at idle the idle feed restriction is so much smaller the open PV will have no significant effect. Much like drinking through a coffee stirrer, it doesn't matter whether it's in a cup or a gallon jug, you will only flow so much through it. Last edited by Bored&Stroked; 02-06-2018 at 05:55 PM.

02-06-2018, 09:00 PM	#3
elwood Senior Member Join Date: May 2010 Location: Dallas Posts: 1,053	Re: power valves Thanks for the help Bored&Stroked, So Im thinking I need to put a vacuum gauge on the intake, below the carb base plates, and see what my cruse idle is.. So since Im running 2 cabs, should I add the PV values together ? I ordered 2 2.5 Power Valves today, so that would be 5, correct ? So if my cruse vacuum was 6, divide that in half, add 2, Id at 5 ... lol ..

02-06-2018, 09:36 PM	#4
40cpe Senior Member Join Date: May 2010 Location: Star, MS Posts: 4,024	Re: power valves You don't add them together. They both see the same manifold vacuum. I'm going out on a limb and predict your cruise vacuum to be about 15-17" judging from what my engine does. This is at about 2000 rpm, unless you have a really high (low numerical) gear ratio.

02-06-2018, 11:20 PM	#5
elwood Senior Member Join Date: May 2010 Location: Dallas Posts: 1,053	Re: power valves Ford 9 inch, 384 ratio, Tremec 6 speed. I try to keep cruise around 2000 also .. Thanks 40cpe, so lets say 15, devided in half, say 7.5 and add 2 . I took 8.4s out, and it seamed like the Power Valves where dumping gas right off the get go.. I thought I knew the basic function of power valves, guess im just not getting it, or the big cam is acting so different its confusing me ... thanks for bearing with me ...

02-07-2018, 09:02 AM	#6
donald1950 Senior Member Join Date: May 2010 Location: san antonio, texas Posts: 461	Re: power valves Sponsored Links (Register now to hide all advertisements) when i had two 2110s on my otherwise stock 8BA in my 1941 pick up i had 3.5 PVs and 49 main jets in both carbs. that combination seemed to work very well.

02-07-2018, 09:50 AM	#7
Mart Senior Member Join Date: May 2010 Location: Solihull, England. Posts: 8,755	Re: power valves I run 2 2100s. (not 2110s) on a 4" stroke 3-5/16" motor with a Schneider cam. I use 54 jets and stock power valves with slightly shortened springs. 94 type carbs can run rich for a lot of reasons. Once you solve all these issues that cause it to be over rich you can then start to fit suitable jets and power valves. Personally my opinion is that if it runs ok on 49 jets it is getting extra fuel from somewhere else. Mine ran bad on 49s. Best test to see if the mixture is good and you have no leaks is to see if it starts with just the slightest stab of the starter after sitting for 15 minutes. If fuel has leaked in you will have to crank and pump some air through it to get it to fire. Mart.

02-07-2018, 08:13 PM	#8
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,068	Re: power valves Another place you can order power valves from (and I would think they'd be okay - but have not ran them myself) is from Edelbrock - given they make the "new" 94. I would imagine that the stock power valves are somewhere between 6.5" and 8". I would probably try a 5.0" power valve (if they make that size). As noted, if you put a quality vacuum gauge in the manifold (beneath the carbs), you'll soon get a good idea as to what type of vacuum profile you're actually generating. As somebody noted above - both carbs will see the same vacuum.

02-07-2018, 08:41 PM	#9
38 Ford Guy Senior Member Join Date: Jul 2010 Location: Central MN Posts: 108	Re: power valves I have an Isky 88 two 94's. after lots of testing front carb 3.5 PV back 1.5pV. Sounds goofy but works. Great mileage too. Both dumping at mild acceleration is too much gas. __________________ "If you always do what you have always done then you will always get what you always got." Henry Ford

02-08-2018, 11:57 AM	#10
Crankster Senior Member Join Date: Oct 2017 Posts: 563	Re: power valves While I'm no expert I have studied these issues enough to note that each engine & carburetor combination is different, plus gearing, weight, cam selection, add to that variables such as elevation, seasonal variations, fuel quality and it quickly becomes apparent that while "what power valve/jetting/timing are you using" is useful for a starting point, it will be just that. The main thing with power valves (economizer) is to be assured that it is NOT opening at steady, low load cruise. As a power circuit it is tuned independent of the others. A mechanic's vacuum gauge is VERY useful for engine tuning and diagnostics. I don't know how anyone would get along without it. Wideband O2 sensors are worth your time as well. Last edited by Crankster; 02-08-2018 at 12:02 PM.