The exhaust manifold has studs for a protective heat shield and also studs to hold the air cleaner on top. All these studs were quite badly pitted and rusted and the manifold itself looked very rusty. I decided to replace the studs and repaint the manifold.
I'm planning to use a high temperature manifold paint. It should really be cured at a high temperature - higher than the oven in the kitchen can produce. Alternatively you can cure the paint by running the engine. I think that's the way I'll have to go.
Where I'd expected to find studs between the manifold and downpipes, I found a couple of bolts.
I'd already bought and fitted new studs to bolt the manifold to the cylinder head. In addition I'd gone ahead and bought replacement manifold to down pipes studs, and studs for fixing the heat shields to the manifold.
One Sunday afternoon in November 2017 I set to work trying to remove from the manifold, the rusty stumps they were going to replace.
Double-nutting did nothing. I just stripped the threads on four nuts. Tackling each stud, I had to use my biggest mole grips set as tight as possible to get any purchase on the studs. They had to be repositioned copious times to maintain any grip and the threaded studs were starting to shred.
With an insistent wiggling action I began to sense microscopic movement in a stud and blasted it with some Plus Gas. A little more wiggling, a little more Plus Gas and I could feel definite movement. Persevering in this way - lots of wiggling and Plus Gas - I was gradually able to great greater rotation on each stud and teased them all out this way. Well, most of them. One snapped and had to be drilled out.
With all the studs removed, I put them back in again! Just loosely. I was sending the manifold off to be blasted and didn't want all the stud holes blocked up or the threads damaged. My workshop guy blasted the manifold and downpipes, then he gave them a squirt of WD40 to stop them rusting.
I actually wanted them as grease-free as possible to give the high temperature paint I planned to use the best chance of adhering. Never mind. I think I will probably have him blast them again but leave them dry next time.
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| Stud for Mounting Air Cleaner - 19 November 2017 |
Where I'd expected to find studs between the manifold and downpipes, I found a couple of bolts.
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| Bolts Instead of Studs? |
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| New Studs and Nuts for the Refit |
Double-nutting did nothing. I just stripped the threads on four nuts. Tackling each stud, I had to use my biggest mole grips set as tight as possible to get any purchase on the studs. They had to be repositioned copious times to maintain any grip and the threaded studs were starting to shred.
With an insistent wiggling action I began to sense microscopic movement in a stud and blasted it with some Plus Gas. A little more wiggling, a little more Plus Gas and I could feel definite movement. Persevering in this way - lots of wiggling and Plus Gas - I was gradually able to great greater rotation on each stud and teased them all out this way. Well, most of them. One snapped and had to be drilled out.
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| Out With The Old, In With The New.... |
I actually wanted them as grease-free as possible to give the high temperature paint I planned to use the best chance of adhering. Never mind. I think I will probably have him blast them again but leave them dry next time.
