holley 4160 leak

753 Views 8 Replies 4 Participants Last post by Cobrajet67, 4 mo ago

1carguy

Discussion Starter · 4 mo ago

all,
Please excuse if this a rerun. I may have posted earlier with same leak.

I am fighting a fuel leak on a Holley 4160 carb. The OEM fuel bowl was warped, and I replaced it. I am still getting fuel somewhere along the bottom of the front fuel bowl.
I discovered another leak around the bottom of the metering plate, where the factory drills out the passage for the accelerator pump. The metering plate had some sort of a pop rivet from the factory. I removed the pop rivet, drilled and tapped the hole, and inserted an allen set screw, along with some fuel resistant gasket maker. But I think it is still leaking around the set screw.

What kind of sealer can I use around the threads of the set screw, that gas won't destroy?

Thanks for your opinion

Save

1 - 3 of 9 Posts

Cobrajet67

· #5 · 4 mo ago

1carguy said:
all,
Please excuse if this a rerun. I may have posted earlier with same leak.

I am fighting a fuel leak on a Holley 4160 carb. The OEM fuel bowl was warped, and I replaced it. I am still getting fuel somewhere along the bottom of the front fuel bowl.
I discovered another leak around the bottom of the metering plate, where the factory drills out the passage for the accelerator pump. The metering plate had some sort of a pop rivet from the factory. I removed the pop rivet, drilled and tapped the hole, and inserted an allen set screw, along with some fuel resistant gasket maker. But I think it is still leaking around the set screw.

What kind of sealer can I use around the threads of the set screw, that gas won't destroy?

Thanks for your opinion

Posting a pic would be really helpful to you here.
The front of a 4160 will have a metering block and the back bowl will have a metering plate.
I'm thinking that you probably need a new metering block now that it's been drilled and tapped. I don't believe that modification is going to work.
What it the list # of the carb on the front of the air horn?

Save

Reactions: 1

Cobrajet67

· #7 · 4 mo ago

1carguy said:
The list # is 500931. Turns out it is a 4180 carb.
Hopefully I can attach the pic of the metering block. The pic is the bottom of the metering block, driver side, and it mounts on the front of the carb.
I talked to Loctite they suggested their 262 locker and sealant.
I've talked to 4 different carb shops, nobody has a new metering block. Several on ebay, but no guarantee they or any better than what I got.
Thanks

Where did you get that # from? Holley doesn't show any record of that # in their numerical listing. There's not even a # that's really close to that. The air horn will have the list # stamped on the front with a date code underneath it.
Metering blocks aren't all the same. It turns out that many carb #s don't have replacement blocks available.
You didn't post your pic in the standard way so it can't be enlarged.

Save

Cobrajet67

· #9 · 4 mo ago

The pic issue needed to be mentioned so you'd post one that can be of use i.e. constructive. We all have varying computer skills as I'm also probably behind the average person. Your second attempt with the pic was fine.
There really is no ideal method for trying to fix the metering block. That block is unique to the 4180C carb that came stock on the 1983-85 Mustang 5.0 and is not a typical Holley 4v carb. It looks like a 4160 but very little is actually compatible between them. This page has an article about it but is hard to read:
Holley 4180 (ddilts.net)
These two are much better to view/read:
For 3 Years the 5.0L High Output Was Fitted With the Holley 4180C Carburetor (motortrend.com)
How To Understand The Holley 4180 (motortrend.com)
Holley 3-1346 is the correct rebuild kit for it for new gaskets, needle/seats, power valve, etc.
I would call Holley to ask them what to do to salvage the metering block if it's possible. Maybe they have a good solution. I doubt that it was a rivet in that hole and more likely a small ball of lead or tin or some other malleable plug.
I'm pretty sure that this issue has come up before on here as this particular issue is sparking memories. Perhaps an advanced search for the previous threads here will uncover them.
That factory Holley 4180 wasn't designed to be tuned at all so there wasn't all that much that could be done with it though it was a decent carb as it was pretty similar to a 4150/4160. The mixture screws were plugged, the choke was nonadjustable, and the metering blocks were unique to it. Some modifications were possible to do but likely not worth it. If you can't fix the leak then I would buy a new 4160.

See less See more

Save

1 - 3 of 9 Posts

Top Contributors this Month