Carburetor casting leak.

[celticwarlock]

The stock carb on my 1969 NY is leaking from the casting. I don't know if this can be repaired from the inside, but it seems unlikely (and probably unwise).

Has anyone ever seen anything like this? I sure haven't, and I've been messing with cars for over 30 years. In any case, my first instinct is to simply replace the secondary fuel bowl, but then, I wonder where else the casting might be ready to fail.

I had to cap the circular area on the fuel bowl just so I could start the car and move it back into my garage. There was a small stream of fuel spraying out of there from the side. This leak was definitely not from the o-ring. I watched it spray out of the casting.

 

[Big_John]

I've seen them leak there before. I even seem to remember my Dad's '68 Chrysler doing the same thing back when it was only a couple years old.

So, either replace the float bowl or replace the carburetor.

 

[saforwardlook]

Those Holley 4 barrel carburetors were the 4160 models if I am recalling correctly. They were well known for the middle metering blocks warping over time and heat cycles that resulted in significant leaks in both those and the fuel bowls on the ends. I joined Chrysler Corporation in 1969 and worked in their engineering department in Highland Park, Michigan. I was allowed to choose what department I wanted to work in and I chose the fuel system lab because I wanted to be a part of cleaning up the smog mess in California. In any case, both Carter and Holley stationed one of their employees in the Highland Park lab full time to deal with engineering problems. The Holley rep at that time was Gary Congden. One of the first cars I bought that was a used one is my avatar car at the upper left, a 1970 Chrysler 300 coupe that I bought used from a dealer lot with only 30K miles on it and no rust at all. After a couple years of use I also ran into a leaking carburetor problem that I tried to repair with a rebuild kit, but was ultimately unsuccessful due to continuing leaks because of the warped center metering blocks. So I asked Gary why I could not seem to get it fixed. His immediate response was to wait just where I was and he would bring me a fix. That "fix" turned out to be a brand new Holley 4160 and he told me to just replace mine with the new one. I used that replacement one for another two years before it too warped. Ultimately I replaced the Holley with a more modern Carter 4 bbl and never had another problem that I couldn't fix.

These days Holley makes great carburetors, although they are quite expensive, but I always found the early Holley's had better acceleration off the line and better overall driveability than the Carters back then. The other less expensive route these days is to buy an Edelbrock 4 bbl that mimics the Carter 4 bbls back in the day but have greatly improved performance - I am not sure whether the intake manifold has to be changed as well, as that was 55 years ago. Don't waste time messing with the carburetor you have.

Best wishes.

 

[celticwarlock]

This carburetor was rebuilt 20 years ago, and in that time, it has never failed, warped, or needed meaningful adjustment of any kind.

I've heard all sorts of stories about how crappy these early Holleys are, but honestly, this one has been awesome since I got the car in 2005. I am aware that it needs replacement and can't be reliably repaired. I mean, if it failed this way spontaneously, what other horrors await down the road for this 56 year-old casting? I didn't assume ownership of this car to watch it burst into flames.

Does anyone have one of these they'd like to sell? This stock Holley has all the correct linkage and pops right on and off. A direct replacement would be nice, but really anything that fits, is square-bore, has a vacuum secondary, is properly sized, and has the correct linkage should be suitable.

 

[CBODY67]

I will NOT discount the earlier leaking issue with Chrysler Holleys back then! I heard way too many stories from different people about that, too. Never heard anything about that from the Chevy guys who had Holleys, though, which made me kind of suspect OR if the Chevy guys took it in stride as "a cost of doing business"? We DO know the current gaskets are far superior than what they used back then.

ONE thing not mentioned might be that ethanol in fuel will degrade sealing solder in carburetors. Usually it takes the form of the soldered and staked-in ball checks at the end of machined channels in the main body, which always tend to connect to the bottom of the float bowl. But it could also happen in other places the solder might be a bit thinner than normal. Use this an "an awareness issue", especially for Carter 2bbls and similar, with a visible ball check seal on the front lower section of the carb's main body.

BEST THING would be to shop the current sales for an AVS-2, get any throttle linkage adapter needed, swap the carb throttle stud with what is on the Hplley, and go on down the road.

Enjoy!
CBODY67