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83-84 L69 305 H.O. - Camshaft and Lifter Replacement
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Corrosion is a constant enemy. It develops chemically from water intrusion into the jointed parts, gets a lot worse if road salt or sea water is involved. It happens mechanically in a process called “fretting” this is where vibrations and or micro sliding moments occur between contact points of metals, in this case the heating and cooling of the exhaust system is the energy source. As you have found it is pervasive where greatly dissimilar and even similar metals meet, where there is wetness and vibrations.
Solutions or at least reductions are achieved with chemistry that can be as simple as anti-seize greases or sacrificial coatings like galvanize which can be plated or coated to as complex as using self-passivating materials like stainless steel or sufficiently different materials like brass that offer a softer surface that frets less against a harder surface or in a chemical sense is less likely to trade electrons with a dissimilar metal.
Galvanize is a zinc coating that can be plated on resulting in a silvery shiny layer or hot dipped resulting in a dull hammered looking layer. These are sacrificial coatings that decay with time. They are often chemically reactive with aluminum, brass, copper, titanium, etc so they can’t be used in every case.
Self-passivating forms a non reactive micro corrosion layer that is self healing. Stainless steel is good at this the chrome and nickel does this naturally. When either or both are alloyed with steel in small amounts the action of forming a non reactive oxidation layer provides protection for the ferrite part of the alloy as well. To some extent aluminum in pure form will do this by itself but aluminum in its pure form is nearly useless as a structural material so it is highly adulterated with silicon, copper and other semi to actual periodic metals to give it useful structural properties. In these cases aluminum can be anodized to force the formation of a stable oxide layer, that interestingly enough can be colored. While at the surface layer this acts a lot like self passivation of stainless steel it is not self-healing and though can be made very restart to wear in hard-anodize it has a terminal life span out there somewhere.
Basically you an expect dissimilar metals especially in the presence of a conductive fluid like water, saltwater, acids or bases to trade electrons which plates them out, the more chemically reactive to the less. This is the principle that makes batteries work and allows the plating of expensive metals like chrome to base metals like iron or copper, etc. It is the bane of engine cooling systems that gets especially bad with iron blocks with aluminum heads as a for instance or brass radiators held together with tin and or lead based solder.
Then there is fretting corrosion in fastened joints simply do to micro movements of the metals against each other. Here a thread lubricant reduces the molecular level of metal to metal rubbing and to some extent seals water out. Like everything else this is not a forever solution to the problem. All chemical elements and compounds are seeking their lowest energy state. Our job is delay or prevent that. Sometimes hard to fathom but the universe has a temperature that is about 2 or 3 degrees above absolute zero which is the energy that runs the whole damn thing.
Bogie
Solutions or at least reductions are achieved with chemistry that can be as simple as anti-seize greases or sacrificial coatings like galvanize which can be plated or coated to as complex as using self-passivating materials like stainless steel or sufficiently different materials like brass that offer a softer surface that frets less against a harder surface or in a chemical sense is less likely to trade electrons with a dissimilar metal.
Galvanize is a zinc coating that can be plated on resulting in a silvery shiny layer or hot dipped resulting in a dull hammered looking layer. These are sacrificial coatings that decay with time. They are often chemically reactive with aluminum, brass, copper, titanium, etc so they can’t be used in every case.
Self-passivating forms a non reactive micro corrosion layer that is self healing. Stainless steel is good at this the chrome and nickel does this naturally. When either or both are alloyed with steel in small amounts the action of forming a non reactive oxidation layer provides protection for the ferrite part of the alloy as well. To some extent aluminum in pure form will do this by itself but aluminum in its pure form is nearly useless as a structural material so it is highly adulterated with silicon, copper and other semi to actual periodic metals to give it useful structural properties. In these cases aluminum can be anodized to force the formation of a stable oxide layer, that interestingly enough can be colored. While at the surface layer this acts a lot like self passivation of stainless steel it is not self-healing and though can be made very restart to wear in hard-anodize it has a terminal life span out there somewhere.
Basically you an expect dissimilar metals especially in the presence of a conductive fluid like water, saltwater, acids or bases to trade electrons which plates them out, the more chemically reactive to the less. This is the principle that makes batteries work and allows the plating of expensive metals like chrome to base metals like iron or copper, etc. It is the bane of engine cooling systems that gets especially bad with iron blocks with aluminum heads as a for instance or brass radiators held together with tin and or lead based solder.
Then there is fretting corrosion in fastened joints simply do to micro movements of the metals against each other. Here a thread lubricant reduces the molecular level of metal to metal rubbing and to some extent seals water out. Like everything else this is not a forever solution to the problem. All chemical elements and compounds are seeking their lowest energy state. Our job is delay or prevent that. Sometimes hard to fathom but the universe has a temperature that is about 2 or 3 degrees above absolute zero which is the energy that runs the whole damn thing.
Bogie
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So is the manifold out of the car now? How do the two sets of threads in the manifold outlet look? Closeup photos please.
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No i didn't take out the manifold once I seen the bolt and nut just fell out and all it needed was the bolt replaced, I left the other side bolt alone because it's still connecting the manifold to the y pipe...
Unless you think it looked bent in the video I shared, and I should change it out with a new one.
The new donut gasket doesn't arrive until tomorrow sometime.
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I was assuming the remaining stud would be replaced because the nut was siezed onto it. Figured it would come out with a little penetrating oil soak and some patience.
But I think you can try however you wish with no harm done. I have my doubts that what you are planning will seal or hold, but I've been wrong before. If it doesn't work we can fix it.
Are threads OK in the manifold where the stud fell out?
Also looking forward to hearing about the bolt in the head removal being a big success! Do photos!!
But I think you can try however you wish with no harm done. I have my doubts that what you are planning will seal or hold, but I've been wrong before. If it doesn't work we can fix it.
Are threads OK in the manifold where the stud fell out?
Also looking forward to hearing about the bolt in the head removal being a big success! Do photos!!
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I don't think the threads would be any good on the manifold because it slid right out I figured if I take those brass nuts at the top and the bottom of the flange and tighten it down with the new donut, that would seal things up... but you're right, we can only try it if it doesn't work do it the other way.
Yeah I just got the message and he's on his way and should be here at about 2:00 which is in about 45 minutes.
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Broken Exhaust Stud Removed !
youtube.com
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Yay!!!Broken Exhaust Stud Removed !
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Is there anything I need to check with the lifters and rods before I install the intake manifold?
What do I need to do to make sure that my lifters and rods are spinning? Simply just turn the motor over by the crankshaft and watch the rods and lifters spin?
What do I need to do to make sure that my lifters and rods are spinning? Simply just turn the motor over by the crankshaft and watch the rods and lifters spin?
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Excellent work! I see that what I thought was a tube in the manifold was the O2 sensor. Your manifold and messed up bolts really turned out nice for you!
Time to check for lifter rotation was before cam gear was installed. Just turn cam by hand and watch lifters. Too late now. You don't want to crank the engine over any more than necessary to get the distributor in correctly, at this point. Chances are they will be just fine. If you really want to see them rotate, then after break in run with the valve covers off and watch the pushrods rotate.
If your valves are adjusted you are ready for the intake to go on. You can dump your oil down the distributor hole before putting the intake on. That way you don't wash anything off the camshaft.
Again, excellent work!
Time to check for lifter rotation was before cam gear was installed. Just turn cam by hand and watch lifters. Too late now. You don't want to crank the engine over any more than necessary to get the distributor in correctly, at this point. Chances are they will be just fine. If you really want to see them rotate, then after break in run with the valve covers off and watch the pushrods rotate.
If your valves are adjusted you are ready for the intake to go on. You can dump your oil down the distributor hole before putting the intake on. That way you don't wash anything off the camshaft.
Again, excellent work!
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Yes, get a new one!
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The only question I have about installing the intake is using the cork China Wall gaskets that came with the gasket set.. should I use them or just put a really thick bead of RTV on the China walls ?
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