It turns out that I do not know everything. Who would've thought it? About a month ago I installed the new Summit racing carburetor on my 1975 Ford F2 50 with an in-line six. The carburetor makes the engine run real well and I'm very happy with it, but there is one problem which is been driving me a little bit batty. When I'm accelerating it makes a whistling noise, a high-pitched whine or whistle that I can no longer ignore. I haven't come across something like this before, so I'm turning to my fellow forum members who might have more experience than I. Has anybody come across something like this? And if so, can you point me in the right direction so that I can stop it?

 

What kind of air filter setup are you running?

 

Find out where air is speeding through, and look for anything which might cause the whistle. You can poke your finger or another object into the air stream for the purposes of disrupting the flow, and see if the noise changes.

Multiport EFI Fox Mustang 5.0s will exhibit that type of noise when using a larger Mass Air meter and an aftermarket throttle body. It is said that sharp edges in the IAC passages in the aftermarket throttle bodies is the cause. Apparently those sharp edges can be dulled to quell the noise. I know that those apples aren't going to be able to help your orange, but this will hopefully provide some insight.

Is there a choke-horn on the Summit carb? If so or if not, then maybe that is where the whistle is occurring? If there's a choke blade, will changing its position affect the noise?

Good call on the air filter assembly - I didn't even think of that.

 

Turn up the radio

Seriously though use the above suggestions.

Maybe rotate the air filter a 1/4 turn or so and see if there is a change. Or check to see if it is properly seated in the base and cover. (Just spit balling)

My 08 4.6 has what sounds like a turbo whine when entering freeways etc... I kinda like it. It is not very noticeable.

 

I just took off the stock air cleaner (not going to need it until smog again next year) and installed a 14x3" traditional air cleaner which now makes it whistle whenever I get on the throttle a bit. I want to say it's just more airflow or the air cleaner isn't installed perfectly flush all around or you may have a vacuum leak some where.

 

Thanks guys. I knew it had to do with incoming air, but didn't know where to begin. At this time I'm using an aftermarket 10 inch diameter air filter that sandwiches the element between the top and bottom. I've used it on a couple other carburetors and didn't have this problem.

That's a good point about the choke plate. I'm still in the process of adjusting the fast idle setting, and dialing in the choke. I'll try to pay more attention to if the choke is fully open when the whistle is sounding. I'm actually wondering whether or not it could have something to do with the PCV valve, and or the routing of that vacuum hose. That is the one major change that occurred during the installation of this carburetor. Before I had the PCV vacuum hose install at a vacuum port in the intake manifold. Now I have it at the front of the carburetor. We shall see. I'll do some testing. Thanks again. Below is the air cleaner.

Attachment 280513

 

I'd look for a vaccum leak

 

Honestly, I think it could be the Air Cleaner. I've got a similar air cleaner on the Buick V6 in my Jeep, and with the shorter filter element, I got a whistling noise when hard on the throttle. I went through a catalog and found a "Taller" air filter to expand the surface area that it draws air through, and I don't get that whistle anymore.

 

Thanks. I guess it's time to fab up that cool air intake that I've wanted for a couple of years.