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Herald 1200 manifold


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Hello, I've had the manifold off to remove my manky exhaust studs and fit new ones, horrible job! I ended up drilling them out and re-tapping the threads they all went in in the end but it wasn't fun.

My question however relates to a pipe that screws into the manifold on the back, it is a piece of copper brake pipe with a brake pipe fitting screwing into the manifold. There appears to be a tiny hole in the manifold where the pipe screws in but I can't work out where this tiny hole goes? The pipe is open at the other end and just points down at the side of the engine.

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36 minutes ago, Tom said:

Hello, I've had the manifold off to remove my manky exhaust studs and fit new ones, horrible job!

Are all head manifold (including inlet) studs always so difficult to remove?. Any tips, rather than drilling out much appreciated, as may have to do some of them soon.


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yes drain pipes were common on downdraft carbs so any build up of fuel  like when on excess choke, there is  often a well in the manifold to catch the fueling

some cars have a small drilling in the casting  some have the tube formed into a jet at its end yes it sucks a little air but thats all taken care of with the carb jetting.

the small hole/jet acts as some restriction 


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Ok Pete, I'll try to clear it out.

Dave, I tried everything I know.....maybe I should have asked 1st!

Drill and tapping is always the nuclear option. This what I did.....( please insert 'drink tea' in between each of these steps!

1. Filled a small container with GUNK and dipped the stubs in it for 2 days.

2. Lock-nuts wouldn't grip it as the threads were so poor so I held the stud in a vice and gently wiggled the manifold, this didn't work.

3. If I had access to oxy/acet I would have heated the casting around the stud but I only had a plumbers torch so I tried that again wiggling the casting, again no joy.

4. I then abandoned the vice, I wondered if it was acting as a big heat sink? I then heated the casting again  and then used my best most unworn mole grips on the stud.

5 Sensing some movement I very moved it back and forth periodically spraying with wd40 until the stud actually fatigued and snapped off with about 10mm poking out the casting! A*SE!!

6. Proceeded to do the same on the other two....double A*se!!

7. I then MIG welded an 8mm nut to one stud and it came out!!! The other two snapped of almost flush!!!!

8. I have NEVER had success with an easyout but I tried it no the less and true to form no joy.

9. I made sure I drilled the easyout hole dead square in the center as I knew I'd be drilling it out.

10. I then drilled it out with a drill that fitted neatly into a 5/16 nut, I didn't look at the size, my imperial and metric drills are mixed up in a box!

11. I then sharpened a scriber and carefully used it to collapse what was left of the stud into the hole squirting with wd40 regularly until most of the stud was out.

12. Finally I ran a 5/16 UNF tap through to clear the threads and tidy it up.

13. My new studs only had a short bit of thread so I ran a die down it and added a couple of mm, I wanted as much thread in the casting as possible!!

Pic attached  and yes I know One didn't quite turn out square but they are all nice and tight and the exhaust gasket and flange fit over no probs.

Then I had 2 cups of tea and 3 hobknobs.


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