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  • 1 Post By patrickt
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Old 03-10-2019, 06:58 AM
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Default Float Level

Hi, I have a ERA w/427 FE block stroker with 2- 4 barrels (4160 600 cfm) on a Ford motorsport manifold (C7ZX-9425-A). I recently had both carburetors professionally rebuilt and restored. I assume when they were done most of the parameters were roughly set to specs. However the carbs sit on the manifold slanted forward approximately 5 deg or about .750 from the rear to the tip of the front.That's the way the manifolds were casted. This tells me that the float level will be off. I started the engine let it warm up good and checked the fuel level. Just as I thought gas came poring out the level plugs on both carbs. So I lowered all 4 floats to a point gas just trickled out the bottom of the level sight holes. My question does this sound like the right way to go about the issue? I runs good ( can't take it out for a road test because of the weather) idle is even and I see no issues. Before I adjusted the floats I removed the carbs and the base gaskets were soaked in gas, that told me something is wrong. Any advice would be appreciated.
Thanks.

PS Before all this when the engine was warm and shut down after a couple of hours gas would drip from both secondary throttle shafts. Now that issue is gone.
Thanks again....
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Old 03-10-2019, 01:33 PM
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Originally Posted by classical glass View Post
So I lowered all 4 floats to a point gas just trickled out the bottom of the level sight holes. My question does this sound like the right way to go about the issue?
Yes, that's the first step in finding the float adjustments that are right for you. The angles of the carbs, when your engine is in an ERA car, is different than if it was sitting in, say, a light weight Galaxy. Plus, the gas is way different than it was when Holley wrote their instructions (and they haven't changed in 50 years either). If "the bottom of the sight hole" is too high for your particular carb angle/gas quality combination, then you will know it by one of three ways: 1) you will smell, and even see, gas percolating out of the top of the carb; 2) you will have hot start difficulties on summer days; 3) you will see wet spots around the carb shafts. If you have none of these, then keeping the level right at the bottom or the sight hole is right for you. FWIW, I cannot set my floats right at the bottom of the sight holes as it causes all three problems. For me, about an eighth of turn down, or even a hair more, eliminates all three problems with no performance impact. It's a trial and error proposition to find what's right for you.
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Old 03-10-2019, 04:22 PM
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Assuming that Ford intake is like most Ford dual quad intakes, there are other issues. The carbs are reversed and the Holley fuel level sight opening in the primary bowl is higher than in the secondary bowl. Since the primary bowl is on the rear on a 2x4 427 intake, if the float level is set right at the bottom of the sight opening you stand a good chance of flooding your engine on a hard stop and killing it. And if you lower the fuel level too much in compensation, under hard acceleration fuel stacks against the rear of the bowl and risks starving the primary jets. Issues you don't have with a normally mounted Holley carburetor.

I even called Holley up once and asked them what changes/setting they would recommend for Ford reverse mounted carbs. Only response was "what" and "huh". The old Ford guys install a Holley whistle vent extension in the vent hole at the top of the Holley metering plate. That helps avoid flooding the engine on hard stops and I've installed those on my Holley 1850s. They also install jet extensions in the primary side to prevent the jets from being uncovered by fuel stacking against the back of the float bowl. I looked into this and Holley makes a special float for it on a Holley 4150 carb. But on the 1850 with the nitrophyl floats, huge notches would have to be carved in them to clear the tube extensions. Some guys on the FE forum said they have done so but didn't look like a good idea to me so I didn't try that.

So in short I put in vent whistles on my primary bowls and dropped the float level down a little bit below the sight port. I set the secondary float levels at the bottom of the sight port.

Your set up may need to be played with a little more as a 4 deg slope on the carbs sounds greater than my 427 low riser dual quad intake. From memory I think my carbs are sloped about 2 degrees or something around that. Wedge base plate adaptors are available from a variety of sources to adjust the carb angle, but the lowest angle one I've seen is 5 degrees. Supposedly Cobras were equipped with these originally but I don't know what angle the original ones used.
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Old 03-10-2019, 05:02 PM
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Doesn't say much for whoever overhauled your carbs, if they can't give you a dry float level a fraction under the final wet level that you can sneak up to rather than having the engine flooding, etc.

4160 side pivot floats are easy enough, top of float parallel to bowl.

I run many of my carbs at "number of flats" down from just a trickle.

I do not set any at factory float level.

I run any carbs with windows at 3/8 up the glass.

Gary

Last edited by Gaz64; 03-11-2019 at 03:18 PM..
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Old 03-11-2019, 05:07 AM
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Thanks all for you,r input. Good info.
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Old 03-11-2019, 07:11 AM
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Supposedly Cobras were equipped with these originally but I don't know what angle the original ones used.
427 Cobras with 2-4V (CSX31xxs with early 1965 model year Galaxie engines and CSX30xx SCs with 1966 Fairlane engines) got 5° spacers added to the engines by Shelby American to level the carburetors. Offenhauser® made them as a slight modification to a catalog item. In 2011 I was hunting some originals for a friend’s CSX31xx car that had gotten misplaced over time. I put out want ads widely. I eventually found some ex-427 Cobra ones for the repairs but before I did my inquiries got all the way to Offenghauser via Glenn at the Salem Speed Shop in Salem Oregon. Glenn was a family friend of the company owners. Glen asked if Offenhauser by chance had any. The answer was yes, a batch that never got delivered to Shelby American. I bought them all and they got distributed to CSX31xx car owners quickly. The interest shown (by me) and the suggestion that Offenhauser could probably sell some of them got them reissued in the product line. The modern production ones are not 100% just like ones used in new 427 Cobras but installed it is not an issue for most people.





For a few years they were available through Summit Racing® but I don’t know if they are a current catalog item or not.

f.y.i....Somebody commercially made some poor quality reproductions for 427 Cobras prior to 2011. At a distance they looked correct but they were machined poorly. We had a pair before I started hunting originals. Not all the bores aligned with bores in the intake manifold and both sides were milled hour glass shaped with something like 0.03" out of plane on each face. Their poor quality triggered the hunt for originals.

I don't know their part numbers but a few of the Ford 4V plain or PCV spacers were angled something less than 5°.

Dan
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Last edited by Dan Case; 03-11-2019 at 01:58 PM..
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Old 03-11-2019, 09:14 AM
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Originally Posted by Dan Case View Post
427 Cobras with 2-4V (CSX31xxs with early 1965 model year Galaxie engines and CSX30xx SCs with 1966 Fairlane engines) got 5° spacers added to the engines by Shelby American to level the carburetors. Offenhauser® made them as a slight modification to a catalog item. In 2011 I was hunting some originals for a friend’s CSX31xx car that had gotten misplaced over time. I put out want ads widely. I eventually found some ex-427 Cobra ones for the repairs but before I did my inquiries got all the way to Offenghauser via Glenn at the Salem Speed Shop in Salem Oregon. Glenn was a family friend of the company owners. Glen asked if Offenhauser by chance had any. The answer was yes, a batch that never got delivered to Shelby American. I bought them all and they got distributed to CSX31xx car owners quickly. The interest shown (by me) and the suggestion that Offenhauser could probably sell some of them got them reissued in the product line. The modern production ones are not 100% just like ones used in new 427 Cobras but installed it is not an issue for most people.



For a few years they were available through Summit Racing® but I don’t know if they are a current catalog item or not.

f.y.i....Somebody commercially made some poor quality reproductions for 427 Cobras prior to 2011. At a distance they looked correct but they were machined poorly. We had a pair before I started hunting originals. Not all the bores aligned with bores in the intake manifold and both sides were milled hour glass shaped with something like 0.03" out of plane on each face. Their poor quality triggered the hunt for originals.

I don't know their part numbers but a few of the Ford 4V plain or PCV spacers were angled something less than 5°.

Dan
Yes that's exactly what I need.
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Old 03-11-2019, 12:40 PM
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Moroso makes open plenum ones at 5 deg. There are 4-holers made but they all seem to be 8 deg or more. Possibly someone makes a 4-holer 5 deg one somewhere.
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Old 03-11-2019, 12:51 PM
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Moroso makes open plenum ones at 5 deg. There are 4-holers made but they all seem to be 8 deg or more. Possibly someone makes a 4-holer 5 deg one somewhere.
Offenhauser® part number 5584 was the 1960s-1980s general catalog 5° degree model the 427 Cobra version was based on.

Summit Racing® lists that number online but there is no picture.

https://www.summitracing.com/parts/ofy-5584
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Old 03-11-2019, 03:33 PM
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There are two reasons why the carbs lean forward.

Any Holley suffers incorrect metering from acceleration g force.

Dual quads facing BACKWARDS is even worse for the first carburetor that you spend the majority of time on.

The Primary of the front carb is closest to the middle of the two primary, hence why it leads first, and only this carb needs the choke mechanism.

Adding wedges now to correct this places the carbs on different levels, so the linkage could be wrong.

One piece aircleaner also won't fit.

Gary
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Last edited by Gaz64; 03-11-2019 at 03:38 PM..
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Old 03-11-2019, 05:22 PM
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Adding wedges now to correct this places the carbs on different levels, so the linkage could be wrong.


Gary
Based on the CSX31xx car induction system I repaired, two each modifications were day one required of the stock Ford linkage system to eliminate serious binding. Shelby American also replaced one of the fuel inlet fittings with a banjo type fuel inlet fitting for inlet hose clearance because of new system geometries. The special fitting was 427 Cobra unique.
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Old 03-12-2019, 05:06 AM
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Quote:
Originally Posted by Dan Case View Post
Offenhauser® part number 5584 was the 1960s-1980s general catalog 5° degree model the 427 Cobra version was based on.

Summit Racing® lists that number online but there is no picture.

https://www.summitracing.com/parts/ofy-5584
Yes, Summit has them, I just ordered 2 of them. I don't think it will be a problem with the throttle binding with a ERA car. Thanks for the info....
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Old 03-12-2019, 12:02 PM
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You are welcome.
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