Re: Whistling from the carb, no power from motor.
[Re: hp383]
#758311
07/26/10 04:33 PM
07/26/10 04:33 PM
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Joined: May 2004
Posts: 679 N.E Indiana
repad
super street
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super street
Joined: May 2004
Posts: 679
N.E Indiana
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Quote:
A friend recently did a motor swap, and changed carbs at the same time.
The old engines carb was in bad shape, so he replaced it with a different unit on the new motor.
Now there is a whistling coming from the carb, he can find no obvious vacuum leaks. And while the motor does run, the truck is really low on power.
The motor was a good one, used for several years in another truck.
Any ideas what the cause of the whistle might be?
Did he use the correct carb for the intake? Spreadbore vs squarebore?
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Re: Whistling from the carb, no power from motor.
[Re: hp383]
#758312
07/26/10 05:18 PM
07/26/10 05:18 PM
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Joined: Jan 2003
Posts: 28,069 Irving, TX
feets
Senior Management
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Senior Management
Joined: Jan 2003
Posts: 28,069
Irving, TX
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It's a vacuum leak. Many carbs have a large port in the back for feeding vacuum to a brake booster. Some of them use a pipe plug to seal it. That's a common area for leaks.
What kind of carb is it?
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
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Re: Whistling from the carb, no power from motor.
[Re: rustbuckett68]
#758315
07/26/10 08:14 PM
07/26/10 08:14 PM
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Joined: Jan 2007
Posts: 10,160 A Red State
SNK-EYZ
I Live Here
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I Live Here
Joined: Jan 2007
Posts: 10,160
A Red State
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Stock or after market intake????
What type of carb????
Kayse can't keep up at all now. lol
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Re: Whistling from the carb, no power from motor.
[Re: SNK-EYZ]
#758316
07/26/10 08:36 PM
07/26/10 08:36 PM
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Joined: Oct 2007
Posts: 3,903 Oregon
hooziewhatsit
master
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master
Joined: Oct 2007
Posts: 3,903
Oregon
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Probably not the case, but I had a fuel injected car that whistled and had no power when the catalytic converter element came loose and plugged the exhaust.
If he does have a Cat, bang on it and see if it rattles from the pieces bouncing around.
If you ever find yourself in a fair fight, your tactics suck.
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Re: Whistling from the carb, no power from motor.
[Re: SNK-EYZ]
#758317
07/26/10 08:51 PM
07/26/10 08:51 PM
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Joined: Jan 2003
Posts: 12,043 State of Confusion
hp383
OP
Just a normal tag again
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OP
Just a normal tag again
Joined: Jan 2003
Posts: 12,043
State of Confusion
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Quote:
Stock or after market intake????
What type of carb????
aftermarket alum intake, eddy i think, carb is a 600 eddy as well.
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Re: Whistling from the carb, no power from motor.
[Re: moparmojo]
#758320
07/27/10 12:56 AM
07/27/10 12:56 AM
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Joined: Jan 2007
Posts: 10,160 A Red State
SNK-EYZ
I Live Here
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I Live Here
Joined: Jan 2007
Posts: 10,160
A Red State
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On a buddy's car (440 with M1 intake) and a Holley carb it had a vacuum leak at the rear of the carb because he used one of the thin paper gaskets. With that particular intake when using a Holley carb it exposed a vacuum passage to the outside at the rear center of the carb. The manifold had a cast pedestal for one of the rear mounting bolts and a very thin flange around the throttle bores. He had problems for months. He would pull the carb, install a new thin gasket and it would run okay for a short while. Then it would start running bad, backfire and really start running bad and start whistling. It was at the point that he needed someone else s opinion on it. I helped him pull the carb started looking at it. The gasket looked funny, like it had been blown down. I turned over the carb, saw the large vacuum passage (pcv) and figured out that nothing was supporting it on the intake (since that area was open on the intake).
The fix was use either one of the 1/4 inch thick gaskets or 2 thin gaskets with a metal gasket/carb spacer in between them. He chose the latter option.
It cured the vacuum leak problem permanently.
Kayse can't keep up at all now. lol
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