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right side on my big block with side pipes has a popping sound at idle, andy ideas what this may be. rebuilt engine and new valve job, springs not replaced as they were good.
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Michael
70 Mulsanne Blue LT-1
03 Electron Blue Z06 -
Re: popping thru exhaust
Michael - it might be related to the heat riser valve.....leaking air into the exhaust....Craig -
Re: popping thru exhaust
I do not have a heat riser instead I have the spacer which in effect is just like the drivers side.Michael
70 Mulsanne Blue LT-1
03 Electron Blue Z06Comment
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Re: popping thru exhaust
Have you taken a compression test? That would be my first step, check all 8 cylnders. Is timing correct? Too much timing causes too much heat and burns valves rather rapidly. Been there done that. What year big block?
TerryComment
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Re: popping thru exhaust
Michael,
Where did you get your side exhaust system? The after market ones have the popping sound built in. Allens has the correct machine (bought walker's original) now to fashion correct sounding side pipes. Also, old original pipes have been known to get a little rusted out and become louder.
Regards,
JRComment
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Re: popping thru exhaust
check plug wires and make sure they aren't crossed - been there done that!Rick Aleshire
2016 Ebony C7R Z06 "ROSA"Comment
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Re: popping thru exhaust
If it is not a steady pop, then it might be a bit lean. Try turning your idle mixture screws out 1/4 to 1/2 turn (richer). This may just solve it.
JoeComment
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Re: popping thru exhaust
it is a 67 427/435, rebuilt with stock components, factory chevy side pipes that were bought new from chevy in mid 80s. I will try carb adjust, but it just seems to be on one side and compression checks ok. It does have 2 new valve springs but not sure what head they are on. The pop (backfire) is on left side only....Michael
70 Mulsanne Blue LT-1
03 Electron Blue Z06Comment
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Re: popping thru exhaust
If you have an over tightened exhaust rocker arm, you will get the same results. Not sure if someone posted that yet. Compression check may show it. If it is happening only out of one side of the exhaust, I would suspect that. TerryComment
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Re: popping thru exhaust
Thanks Terry I will check that too.Michael
70 Mulsanne Blue LT-1
03 Electron Blue Z06Comment
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Re: popping thru exhaust
The other thing that can cause this problem is a small exhaust leak. When things get warmed up and under the right circumstances, cool air can get sucked into the pipe through a crack/small pin hole and cause a small popping sound from exhaust gasses reigniting inside the exhaust chamber. Sorry if someone already suggested this. Regards, TerryComment
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