Of the 4 manifolds on my '71 V12, 3 had cracked and of those only 2 repairs had lasted. The one repair that failed fell apart as I removed it. At least I found where all of the exhaust was getting into the cockpit.
I had considered going with stainless headers but others have convinced me to just go with cast replacements. What kind of treatments do you find the best for these manifolds?
Right now I’m leaning toward run of the mill high heat exhaust manifold paint.
Thoughts?
Usually a ceramic coating is the answer. Or you could use on of the Eastwood products like Calyx or factory gray.
pic of ceramic coated V12 exh. manifolds.
must work been 23 yrs still like new.
BUT remember its a Pre HE , and exhaust temperatures are much cooler , HEs run extremly hot combustion temps.
are you sure you do not have a retarded ignition timing , that could make extra heat in the exhaust temps?
ron
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Ron, that is a good idea for John to check the engine timing.
Not just the initial advance, but also the whole advance curve. I have frequently found older cars with distributor and timing issues. It is one of those areas of wear that often do not get any attention. Insufficient initial, or non or low functioning mechanical and vacuum advance can result in a hot running engine - which can be a cause of cracked manifolds.
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All of the manifold issues happened well before I purchased the car.
Addressing the timing is still several months away as I am just putting the finishing touches on the engine rebuild. Once that is done, the engine will roll into the corner with the rebuilt transmission and IRS whilst I take on the body.
My garage looks like a Jaguar exploded in it.
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