The Ford Barn

Bill Lee/Virginia · 07-24-2011, 12:27 PM

I am rebuilding my Zenith 1 and Zenith 2 carbs. I drilled out all the plugs and cleaned the passageways with long shank drill bits turned with a hand-held brace-and-bit-device. My flow tester is a self contained 4 gallon unit with a head of 37 1-4 inches. In prior testing, I used 4 gallons of distilled water. Do you recommend using a different liquid medium such as plain tap water, a percentage of alcohol such as 3 gallons water and 1 gallon alcohol, etc or some other liquid mixture? Do you recommend changing the flow rates of the jets (in the past I used Steve Pargeter's flow rates) to compensate for the alcohol in fuels today? I value and appreciate all information, advice and your recommendations.
Bill Lee/Virginia Peninsula

MCHinson · 07-24-2011, 01:43 PM

Tap water has worked just fine for me when flow testing jets. I guess gasoline would technically be the best fluid to use, but I think that tap water is close enough for this sort of testing.

I am lucky enough to still have a non-ethanol gasoline station within a mile of my house. I would think that if you were always going to run ethanol fuel, perhaps about a 7% increase in flow rate would be about right to offset the lower energy content of the ethanol fuel.

cars56 · 07-26-2011, 02:20 PM

Soldered jets closed then re-drilled them to specs, never flow tested them. Very big difference in performance all the way around.
Used the Dallas Model A Ford Club's specs from the Carbs and Carbohydretes video.
The repo jets were so far off, amazing how the car even ran.

RonC · 07-26-2011, 03:38 PM

You should flow test the jets with the liquid used in determining the flow rates you are using for comparison. All the rates I have seen are for water.

Blessyouboys · 07-26-2011, 04:50 PM

Quote:

Originally Posted by cars56

Soldered jets closed then re-drilled them to specs, never flow tested them.

Re-drilled them to what specs?

Brian T · 07-26-2011, 05:00 PM

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There are several books and websites that give the jet sizes and flow rates, however there maybe some additional resizing to do after road testing to suit your engine or geographic area, apparently the Zenith is very forgiving.

07-24-2011, 12:27 PM	#1
Bill Lee/Virginia Senior Member Join Date: May 2010 Posts: 295	Rebuilding/Flow Testing Jets in Zenith Carbs I am rebuilding my Zenith 1 and Zenith 2 carbs. I drilled out all the plugs and cleaned the passageways with long shank drill bits turned with a hand-held brace-and-bit-device. My flow tester is a self contained 4 gallon unit with a head of 37 1-4 inches. In prior testing, I used 4 gallons of distilled water. Do you recommend using a different liquid medium such as plain tap water, a percentage of alcohol such as 3 gallons water and 1 gallon alcohol, etc or some other liquid mixture? Do you recommend changing the flow rates of the jets (in the past I used Steve Pargeter's flow rates) to compensate for the alcohol in fuels today? I value and appreciate all information, advice and your recommendations. Bill Lee/Virginia Peninsula

07-24-2011, 01:43 PM	#2
MCHinson Senior Member Join Date: Jul 2010 Location: Wilmington, NC Posts: 401	Re: Rebuilding/Flow Testing Jets in Zenith Carbs Tap water has worked just fine for me when flow testing jets. I guess gasoline would technically be the best fluid to use, but I think that tap water is close enough for this sort of testing. I am lucky enough to still have a non-ethanol gasoline station within a mile of my house. I would think that if you were always going to run ethanol fuel, perhaps about a 7% increase in flow rate would be about right to offset the lower energy content of the ethanol fuel.

07-26-2011, 02:20 PM	#3
cars56 Senior Member Join Date: Jun 2010 Location: Queens, NYC Posts: 212	Re: Rebuilding/Flow Testing Jets in Zenith Carbs Soldered jets closed then re-drilled them to specs, never flow tested them. Very big difference in performance all the way around. Used the Dallas Model A Ford Club's specs from the Carbs and Carbohydretes video. The repo jets were so far off, amazing how the car even ran.

07-26-2011, 03:38 PM	#4
RonC Senior Member Join Date: May 2010 Location: Rhode Island Posts: 1,868	Re: Rebuilding/Flow Testing Jets in Zenith Carbs You should flow test the jets with the liquid used in determining the flow rates you are using for comparison. All the rates I have seen are for water.

07-26-2011, 05:00 PM	#6
Brian T Senior Member Join Date: May 2010 Location: San Diego,Ca Posts: 1,377	Re: Rebuilding/Flow Testing Jets in Zenith Carbs Sponsored Links (Register now to hide all advertisements) There are several books and websites that give the jet sizes and flow rates, however there maybe some additional resizing to do after road testing to suit your engine or geographic area, apparently the Zenith is very forgiving.