09-26-2022, 08:17 PM | #1 |
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sbc 350 intake leak
I have a rebuilt 350 in my 65 c10. I have a aluminum intake from a later engine that had a quadrajet on it. Now I have a 600 edlebrock on it. I have a spacer and the correct gaskets to make the 600 fit the quadrajet intake. I have a vacuum leak. When I spray carb cleaner on the passenger side of the intake the motor idle changes. It also changes when I spray the base of the carb on the passenger side. The engine is also smoking out both pipes at idle. Also when I screw in the idle mixture screws the engine revs up above idle. Should I just chunk the intake and buy a new one or just us the original cast one?
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09-26-2022, 08:29 PM | #2 |
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Re: sbc 350 intake leak
You can try tightening down the bolts again if you have not already.
Or you may just need to order up a set of gaskets to redo it. |
09-26-2022, 09:35 PM | #3 |
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Re: sbc 350 intake leak
Smoking blue oil smoke or black fuel smoke?
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09-26-2022, 11:07 PM | #4 |
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Re: sbc 350 intake leak
If you are mounting a square bore carb on a spread bore manifold, you need something that does what this does: https://www.edelbrock.com/square-bor...olds-2732.html
Otherwise, leaks are a near certainty. Your symptom of a leak at the base of the carb are consistent with needing that plate. Did you check the float levels in the carb? Several folks have had trouble with Eddy float levels being wrong out of the box. |
09-27-2022, 06:54 AM | #5 |
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Re: sbc 350 intake leak
Floats are good, It is blue smoke. I think the intake leak is sucking oil into the cylinders
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09-28-2022, 09:10 AM | #6 |
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Re: sbc 350 intake leak
Do you have a pic of your motor?
Could you post one? |
09-28-2022, 06:11 PM | #7 |
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Re: sbc 350 intake leak
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09-28-2022, 06:12 PM | #8 |
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Re: sbc 350 intake leak
I put a vacuum gauge on it this morning. It was about 17 at a cold idle So I am now thinking my fuel pressure is to high or the carb has some issue.
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09-28-2022, 06:19 PM | #9 |
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Re: sbc 350 intake leak
Do your chrome valve covers have a baffle in them where your pcv is located?
Possible your blue smoke is oil being pulled into the intake thru the pcv valve. |
09-28-2022, 07:47 PM | #10 |
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Re: sbc 350 intake leak
Yes they have baffles. I pulled the carb off and there was gas all down inside the intake. The floats are fine and the needles seal off when I blow through the gas inlet when I turn the top the carb upside down. So I think I am getting way to my fuel pressure. But I still cant figure out why my air fuel screws do nothing. When I screw them all the way in the engine revs up.
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09-29-2022, 12:43 AM | #11 |
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Re: sbc 350 intake leak
Can’t help with the mix screws problem but if your carb has been flooding like that for some time then the smoking out te pipes might be fuel washed cylinders have ruined the oil ring seal. All the bearings in your motor can be hurt by fuel wash too.
Have you done a leak down or compression test? |
09-30-2022, 09:05 PM | #12 |
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Re: sbc 350 intake leak
Put a known good carb on it and drive it. Don't use a rebuilt carb unless it has been tried on another motor first.
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10-01-2022, 07:57 PM | #13 |
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Re: sbc 350 intake leak
IT was the carburetor I rebuild another one I had, set the floats, adjusted it out then put it on. Man does it run smooth now and no smoke at all.
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