Fuel has to go thru the needle and seat first.
if it’s closed, no fuel. But you’ve made sure that’s not the issue.
I’ve seen floats sink due to a hole in the hollow style, but it seems you’ve already verified that isn’t happening by checking the float level.
strange one.
interested to see what you find.

 

Any tiny small particle in the fuel line can keep the needle from seating. This small fragment was about the thickness of a hair. Fuel was coming out of the top of the carb.

 

Welcome to the site first of all. Clean car.

I didn't know Holley produced double pumper carbs with vacuum secondaries.

As to your problem, how are you checking the fuel pressure? Does it drip only after shutting down with hot soak?

All the fuel has to go through the needle/seat (as mentioned above.)

I have heard about quality issues with the new Holley carbs. It could have an issue with a bad casting.

I would take it apart (again) and triple check everything.

 

I was having the same issue and finally put new needle and seats in and it seems better. The ethanol in the fuel now causes issues in these carbs.

 

This carb is on a brand new Blueprint 383 Stroker. Carb has less than 100 miles on it. Everything looks clean but it has to be getting by the needle somehow.
I checked the fuel pressure at the fuel line with a pressure gauge connected to the line and cranked it for about 10 seconds.
I was hoping there was something obvious but I can’t figure it out. If the rear seat was bad/blocked open or something, wouldn’t I see the level rise in the site glass while running?it isn’t coming out the overflow tube. When I shut it down I get about 3 tablespoons of fuel on the intake dripping from the shaft mentioned above. And it floods the engine making it hard to start. I’m scratching my head.
Bill

 

I would immediately replace both needle and seats as it only takes about 3 minutes. Does it do it with the engine cold or just after it is good and hot? Could be heat soak boiling the fuel in the carb when it is turned off. I had that issue and a heat shield like this solved the issue.

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Any rust or crap in the tank that could be making needle stick open?

 

New tank. But no I don’t see anything. And I have a very good filter in the line before the pump. I’m starting to this gasket or block issue.

and to answer the other question, yes it does it when cold.

 

It possible something is "bad" with the new carb. Fuel should not be leaking from around the butterfly shaft onto the intake. I would call BPE.

 

I think I’m with you on this answer. It is brand new. I shouldn’t have to be fooling with a new carb right? I know some of them come not adjusted properly. But there is something weird wrong here. Gas shouldn’t be pouring out that shaft. And, it does run a little like a vacuum leak. But that could just be the cam. And it runs rich. When you stand behind it, you can smell fuel.
I’ll call BPE Monday.

 

Float level too high or crud in the needle and seat.

 

Blown power valve maybe. Open all the time ?
if it’s not floats or needle Valve open idk.

 

The flooding issue and running rich are things you can "tune" to clear up.

Fuel leaking from the secondary butterfly shaft is a different (and probably) non related issue. If fuel can leak out in the volume you mentioned, air can get in, and there is a vacuum leak there for sure. I would be most concerned about the fuel leak. Grab the shaft, is there play? This would be bad. Get that fixed, then work on the tune. Just my opinion. I have read several threads and FB posts where people have had carb issues on a new BPE engine and BPE sends them a new carb. Knowing the little I do about your problem, I hope this is what is offered to you.

Can a sticky or bad needle and seat cause the float bowl level to be too high, of course. With the float level too high can fuel overflow, run down and leak out the butterfly shaft, possibly. But if you can see the fuel level in the bowl and it is mid sight glass, and the conditions you mentioned are still happening, my guess is the carb has an internal leak of some kind and not something you should have to deal with on a new set up. But as the others have said, it could be something very simple, like a metering plate gasket or needle and seat, so there could be an easy fix.

I cant tell for sure, but your carb looks to be manual choke, vacuum secondary, and have dual feed. I doubt there is a metering plate between the rear float bowl and the body like there is on the front. Like @ZZ_430 mentioned, I dont think that is called a dbl pumper, but it is dual feed.

 

Fuel should never leak out the throttle shafts. Sounds like something is wrong with the secondary shaft or the base plate. They don't have seals but if you spray carb cleaner at that spot at idle does the RPM increase? If it does the baseplate is bad and you have a vacuum leak.

 

While BPE dynos each motor, IDK if they use their "house" carb or the one that comes with the engine. While I had zero issues with my motor, it did not come with intake or carb. I did however find BPE tech support to be very helpful and responsive to any ?'s I had.

Like any new part, they can be bad out of box. I am sure BPE will respond to OP's issue.

 

I talked with the BPE rep. He asked a few questions and then agreed the carb has an issue. They are sending a new one. They stand behind their product.
Thanks for all the help and suggestions here. I appreciate this resource.

Crusher

 

Thank you for following up. Glad to hear BPE is helping. This kind of support from an engine builder is great information. You may consider editing the thread title to include BPE, so others researching engines builders and problems find this easier.

 

I talked with the BPE rep. He asked a few questions and then agreed the carb has an issue. They are sending a new one. They stand behind their product.
Thanks for all the help and suggestions here. I appreciate this resource.

Crusher

Thanks for the update.

Many times we never hear anything back. Let us know how the new carb works out.

 

Thanks for the update.

Many times we never hear anything back. Let us know how the new carb works out.

Will do. Thanks to the admins who maintain this forum.
Crusher

 

Expecting to receive the new carb on Friday. Should get it installed on the weekend.
BPE says it is something with the block and gasket. Maybe I'll pull the block before I send it back and see if there is anything obvious.

 

It would bug me. I don't like unexplained anomalies.

Best of luck. Beautiful car.

 

^^^, I agree. BPE is standing behind their product, even though they don't make the carbs, and likely could say the carb was tampered with if OP pulls it apart.

 

Right. Maybe messing with it isn’t such a good idea. But it will bug me that I never found the cause of the issue. It’s my OCD I suppose.
The new Carb came today.
Crusher

 

Right. Maybe messing with it isn’t such a good idea. But it will bug me that I never found the cause of the issue. It’s my OCD I suppose.
The new Carb came today.
Crusher

We have all seen this on New carbs as well as rebuilds, someone along the line dropped this carb to the throttle side causing this issue. finding the one responsible
will be difficult and is always the responsibility of the seller. I assume you have another on the way, most likely this will solve the issue for you. let us know how it turns out. BTW Your paint job is awesome!!

 

While BPE dynos each motor, IDK if they use their "house" carb or the one that comes with the engine. While I had zero issues with my motor, it did not come with intake or carb. I did however find BPE tech support to be very helpful and responsive to any ?'s I had.

Like any new part, they can be bad out of box. I am sure BPE will respond to OP's issue.

I'm getting ready to buy a 396 from them. They've been very responsive to all my questions. So I reached out and asked if the carb that comes with the engine was dyno'd with the engine. So far, crickets.

 

Did you just pick up the phone and call?

 

Did you just pick up the phone and call?

No, I've been communicating via email. I'll give them a ring on Monday, but it doesn't really matter. Just curious.

 

Thanks Wonderer. Yes they sent me a new carb. I have installed and there is no more leak!!! From working most recently in the PC world, I know that new from the box doesn't always mean it works like a new part.
Something a little mysterious though. The first carb worked very well with the idle mixture on the block turned out about 1.25 turns. This one won't run there at all. You have to nurse the throttle to keep it running. So I have backed them both out to somewhere around 2.25-2.5 turns. I wonder what the difference is that it needs that much mixture to run. I've also noticed that I can back the curb idle screw up until there is no tension at all on the throttle and it still idles at about 1100 rpm. I wonder if something is holding the plate open, maybe? Or? Thoughts?

Crusher

 

Thanks Wonderer. Yes they sent me a new carb. I have installed and there is no more leak!!! From working most recently in the PC world, I know that new from the box doesn't always mean it works like a new part.
Something a little mysterious though. The first carb worked very well with the idle mixture on the block turned out about 1.25 turns. This one won't run there at all. You have to nurse the throttle to keep it running. So I have backed them both out to somewhere around 2.25-2.5 turns. I wonder what the difference is that it needs that much mixture to run. I've also noticed that I can back the curb idle screw up until there is no tension at all on the throttle and it still idles at about 1100 rpm. I wonder if something is holding the plate open, maybe? Or? Thoughts? at me because

Crusher

In
Dude Look... all Holley carbs come with quirks, most are do to non inspectable flaws.
In your case I would have from factory hooked it up the way it was from factory and also hooked up the vacuum
gauge in first avail and adjusted the carb based on vacuum but thats me. As far as the idle goes it should have been set
for 900 rpm or less from the box. need to see the specs on the engine for recommended idle settings. Glad to see you got a working unit installed.
It pays to have the locals within 3 miles from each other like I do. My instructors from the 70"s would always yell at me because of the grease I left on the tops of the fenders!!
I always had great teachers and knowledgeable friends, Hate to go boo who on ya but I would give my pair to talk to anyone of those people again. I find sites like this GREAT for the gap between now and then. Great talking with ya Mr. Crusher takes us out 300 KPH.

Charlie

 

lol. Yep I checked the factory settings to be sure where they were before I started. All I was saying is that this carb is a lot different than the first one. What my question was is, does 2.5 idle mixture fall outside “ normal”. I wasn’t crying or complaining.

 

Holley has tuning videos online. It’s not enough to plop it on and go.

 

lol. Yep I checked the factory settings to be sure where they were before I started. All I was saying is that this carb is a lot different than the first one. What my question was is, does 2.5 idle mixture fall outside “ normal”. I wasn’t crying or complaining.

No offensive crying or complaining was ever detected Mr. Crusher...For the record your metering settings is considered average for a newer carb or its replacement and its acting the way it should. Take me a shot of the intake to the Power brake hose and booster. It will explain before and after settings variations. Some others may have installed a vacuum plate in between the carb and engine and plugged it on the wrong side in a prior install or disassembly. It's hard for most of us to act without graphics. Fortunately for you I store over 2 billion gigaquads on most available configurations from most small blocks and even the P word such as firebird. Anyway Jean Luke I have to bounce as we have received 5 inches of rain here in Houston and I installed some new graphics on my wifes 69 with soap and water only 12 hours ago and they are sliding a bit.
I promise next messages will not include Mr. Data.. Later