Holley carb whistles - engine stalls

[Noel B.]

I have a 66 327/300 PG with Holley carb. Recently noticed that the carb whistles after the engine is warm. Other posts suggest that this might be the carb base gasket so I will check this. Also wondered if the PCV valve could be involved. Also, the engine tries to stall sometimes but usually recovers after a hesitation - but not always. When it stalls I can restart immediately.

I recently had electrical trouble which seemed to be burnt wires at the starter solenoid. After replacing these wires everything seemed fine until the carb started whistling. When it began stalling I wondered if the electrical problem was back but the clock continues to run and I can restart immediately - when I had the electrical problem everything was dead (clock stopped, total silence when I tried to restart).

Any ideas? You guys have been very helpful.

Thanks,

Noel Barbulesco

[Curt S.]

Re: Holley carb whistles - engine stalls

I am assuming you are running the original 600 cfm carb. So it sounds to me like a vacuum leak probably caused by a warped surface that used to be straight. Base to body, base plate butterfly rod to base plate, metering plate to body are typical culprits. Hope this helps Curt

[Noel B.]

Re: Holley carb whistles - engine stalls

Will this cause the engine to stall?

[Russ S.]

Re: Holley carb whistles - engine stalls

It sure can.

Will this cause the engine to stall?

[Curt S.]

Re: Holley carb whistles - engine stalls

Yes it may stall because the mixture is too lean and the coolant temp may increase in my opinion. Hope this helps

[Ralph E.]

Re: Holley carb whistles - engine stalls

Noel, I had the whistle issue as well. Try changing the carb base gaskets and taking care to tighten down carb bolts evenly.
But before you do any of this work you need to verify the carb base is the cause of the whistle. Try spraying carb cleaner around the base when it is whistling to verify the source. I believe there is a slightly thicker gasket that be used which might help if the base is slightly warped.

[Noel B.]

Re: Holley carb whistles - engine stalls

Thanks Ralph,

Interesting information. The engine has been running a bit hotter and I didn't know why. The cooling system is all new with a DeWitts radiator and expansion tank so I was wondering. After the whistling started I noticed that my temp gauge was up to the middle when I sat in traffic. Normally I never got over one quarter (160-180).

I've been thinking about getting the carb rebuilt anyway so this might be the time since some of the gaskets may be leaking. It's probably the original and I don't know if it's seen a rebuild before. Can anyone recommend a good carb rebuilder that I can send it to? I would want it completely set up since I don't have the skills to tune up a Holley carb.

[Ralph E.]

Re: Holley carb whistles - engine stalls

Thanks Ralph,

Interesting information. The engine has been running a bit hotter and I didn't know why. The cooling system is all new with a DeWitts radiator and expansion tank so I was wondering. After the whistling started I noticed that my temp gauge was up to the middle when I sat in traffic. Normally I never got over one quarter (160-180).

I've been thinking about getting the carb rebuilt anyway so this might be the time since some of the gaskets may be leaking. It's probably the original and I don't know if it's seen a rebuild before. Can anyone recommend a good carb rebuilder that I can send it to? I would want it completely set up since I don't have the skills to tune up a Holley carb.

Before you do anything, have you plugs the heat cross over under the carb or wired open the heat riser. Check out John Hinckley's post about it.

[Curt S.]

Re: Holley carb whistles - engine stalls

I sent my 427 3x2 carbs to Holley in Bowling Green KY. They did a very good job were recolored correctly and ran very well with minimal adjustments. That was 4 years ago so you may want to call to see they still rebuild their products. Hope this works. Curt

[Bob K.]

Re: Holley carb whistles - engine stalls

Noel,When the carb whistles, can you recognize the tune? You can locate the problem by identifying the name of the song. Now that I have your attention, you can bet that it is a warped casting. The 3367 carb will generally show up at the drivers side rear bore..You can check it with either spraying water at that location, or using a piece of vacuum hose inside of the carb to locate the sound. The 4160 series carbs will generally leak there because the do not use a screw in the center of the base. Hope this helps.

[Noel B.]

Re: Holley carb whistles - engine stalls

Hi Bob - If I listen closely it sounds like Prince's Little Red Corvette...

If I find that the casting is warped, what is the solution? Does it have to be machined or can it be repaired with new gaskets? I'm planning to have the carb rebuilt anyway - I don't think it has been serviced in a long time.

[Frank E.]

Re: Holley carb whistles - engine stalls

Send it to Bob Kunz!!! I had the same problem with my 3367 and had them rebuild it 12 years ago. The carb performed perfectly until last fall when it started leaking externally. I tore it apart and found all surfaces were still straight. Put a Holly kit in it and it is working perfectly again. No leaks internal or external. Adjusts perfectly. I can't say enough for Bob Kunz's work.

[Bob K.]

Re: Holley carb whistles - engine stalls

Noel, Machining is a must do. These are very good carbs if done properly. If you don't know the history of your carb, I recommend rebuilding.

[Paul K.]

Re: Holley carb whistles - engine stalls

I had the same trouble, It was the base of the carb being overtighted through years and causing the base to warp
I order a new carb from Holley, best thing I did, the vette runs great.

Paul Klemetson

[Noel B.]

Re: Holley carb whistles - engine stalls

I believe my carb issues are resolved. I sent the Holley carb to a local hot rod mechanic for rebuild. Got it back today and installed it with a new base gasket. Started right up and whistling is gone. Took it for a long test drive and so far it's running fine.

The rebuilder noted that he had to machine one of the surfaces to get it level. Also found issues with one of the floats - he replaced both floats. I hope this keeps my Vette going for a while. Thanks for your guidance as always.