What would cause this to happen??
Thread Starter
Racer
Joined: Mar 2008
Posts: 487
Likes: 48
From: Ocala Florida
What would cause this to happen??
These gaskets are only about 6 months old. Bought the Felpro high end ones but this is what happened to them. As per a former post I had a tank of pretty bad gas couple weeks ago. Think that could have done this or am I running that much too lean? I thought it was fine but now I'm beginning to wonder.
Had a 1976 L-82, 4-sp
Joined: Mar 2011
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From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
Faulty gasket? Not making a proper seal?
I would use a dead soft aluminium laminate gasket like Percy's sells. Costs a bit more but they are also reuseable.
I would use a dead soft aluminium laminate gasket like Percy's sells. Costs a bit more but they are also reuseable.
Burning Brakes
Joined: Mar 2014
Posts: 904
Likes: 46
From: Crestline CA
Warped manifolds very possible. Also, with those types of gaskets you need to retorque after a heat cycle and few more times after that, eventually the bolts will stop turning when you retorque and then youll know that the gasket has compressed all its going to.
Drifting
Joined: Jan 2011
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From: Hamilton Virginia
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
I'm assuming that the 'wasted' [center area] piece is from the right bank. If so, it is highly likely that the heat riser valve in your exhaust header is locked-up in the "closed" position. This will cause an enormous amount of heat to be concentrated on the center exhaust outlets on the right side. I've actually seen a cast iron exhaust manifold that was 'ballooned' outward...almost melting the iron!!
You can 'repair' that heat riser valve; or you can permanently 'fix' it by just cutting the valve plate off the shaft. No more risk!!
You can 'repair' that heat riser valve; or you can permanently 'fix' it by just cutting the valve plate off the shaft. No more risk!!
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Drifting
Joined: Mar 2011
Posts: 1,886
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I'm assuming that the 'wasted' [center area] piece is from the right bank. If so, it is highly likely that the heat riser valve in your exhaust header is locked-up in the "closed" position. This will cause an enormous amount of heat to be concentrated on the center exhaust outlets on the right side. I've actually seen a cast iron exhaust manifold that was 'ballooned' outward...almost melting the iron!!
You can 'repair' that heat riser valve; or you can permanently 'fix' it by just cutting the valve plate off the shaft. No more risk!!
You can 'repair' that heat riser valve; or you can permanently 'fix' it by just cutting the valve plate off the shaft. No more risk!!
Reasoning that, why do we install an expensive dual exhaust system, and have one side blocked off a lot of the time?
Long story short, when I changed over to an aluminum intake manifold, I removed the heat riser entirely and replaced it with a spacer that the repro houses sell. The aluminum heats up much faster than the cast iron, and the choke opens up fine.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If I used my C3 as a daily driver to get to work and back, and the car sat outside...even in winter..., I would want a heat riser, so that the engine would warm a bit quicker.
As it is, the C3 is a "hobby", and one where I don't drive it much in winter...and certainly NOT on very cold days. So, I don't really need the heat riser. To that end, I decided long ago to remove ALL risk of that sucker ever binding up in the closed condition again.
As it is, the C3 is a "hobby", and one where I don't drive it much in winter...and certainly NOT on very cold days. So, I don't really need the heat riser. To that end, I decided long ago to remove ALL risk of that sucker ever binding up in the closed condition again.
Melting Slicks
Joined: Feb 2006
Posts: 3,105
Likes: 96
From: Sunrise FL
If I used my C3 as a daily driver to get to work and back, and the car sat outside...even in winter..., I would want a heat riser, so that the engine would warm a bit quicker.
As it is, the C3 is a "hobby", and one where I don't drive it much in winter...and certainly NOT on very cold days. So, I don't really need the heat riser. To that end, I decided long ago to remove ALL risk of that sucker ever binding up in the closed condition again.
As it is, the C3 is a "hobby", and one where I don't drive it much in winter...and certainly NOT on very cold days. So, I don't really need the heat riser. To that end, I decided long ago to remove ALL risk of that sucker ever binding up in the closed condition again.
As to the OP looks like warped manifolds to me
2026 Loser of the Year
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From: New Or-leens Loo-z-anna
When your wife isn't home.................one night place the exhaust manifolds--one at a time---onto her nice clean granite counter-top....turn the kitchen lights off....shine a bright light into the manifold outlet....you will be able to easily see any warped areas because of the light shining between the manifold sealing areas and the granite
Thread Starter
Racer
Joined: Mar 2008
Posts: 487
Likes: 48
From: Ocala Florida
I don't have the original manifolds. I have headers and side pipes. I haven't checked the flanges yet to see if they are the problems.
Wouldn't do me any good to place them on the wife's countertop since they are laminate and probably have more waves than my header flanges.
So far the aluminum gaskets are holding. I have re-torqued them once already and will do again today after they cool down a bit.
Wouldn't do me any good to place them on the wife's countertop since they are laminate and probably have more waves than my header flanges.
So far the aluminum gaskets are holding. I have re-torqued them once already and will do again today after they cool down a bit.
Race Director
Joined: Aug 1999
Posts: 18,126
Likes: 174
From: WI
I don't have the original manifolds. I have headers and side pipes. I haven't checked the flanges yet to see if they are the problems.
Wouldn't do me any good to place them on the wife's countertop since they are laminate and probably have more waves than my header flanges.
So far the aluminum gaskets are holding. I have re-torqued them once already and will do again today after they cool down a bit.
Wouldn't do me any good to place them on the wife's countertop since they are laminate and probably have more waves than my header flanges.
So far the aluminum gaskets are holding. I have re-torqued them once already and will do again today after they cool down a bit.
your flanges are most likely warped, a saw cut with a hack saw or a Sawzall between the front and center pipes and another between the rear and the center pipes will help, once cut you will see exactly how warped the flanges are and yes they will bolt back to the head.