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1960 Navigator Rebuild Part TWO

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1960 Navigator Rebuild Part TWO

Posted by Ulrich Hoffmann at June 24. 2017

So to make it more comfortable to follow an post  I start part two of the story..

I found No 20873 rocker oilway grub screw(8) in the 1961/62 parts list. Guess these go into the holes on the spindle towers?

Thread size?

Does a sealing ring go between the head and  push in headers?

None mentioned in the parts list.

Re: 1960 Navigator Rebuild Part TWO

Posted by patrick_mullen at June 24. 2017

Grub Screw;  the screw hole pictured seems bigger than the screw hole on a spare head I have here and it looks to be the same size as the rocker cover screws. The rocker cover screws on mine are 1/4" Whitworth but the grub screw is definitely smaller.  It is impossible to measure in position but my guess is 3/16"and I would expect the thread to be Whitworth.  Maybe someone knows better.

Front Pipes;these are just a push fit- no gasket or sealing ring.

 

 

Re: 1960 Navigator Rebuild Part TWO

Posted by andy_sochanik at June 25. 2017

Here are a couple of pictures relating to '20873 rocker oilway grub screw'

There are 8 of them, two on each rocker post. They are normally installed at the factory after making the oilways to blank them off, and would not be expected to come out in service.

Having said that, I found this one had come out on its own on my most recent engine strip.

Attachments

Re: 1960 Navigator Rebuild Part TWO

Posted by andy_sochanik at June 25. 2017

Here are a couple of pictures relating to '20873 rocker oilway grub screw'

There are 8 of them, two on each rocker post. They are normally installed at the factory after making the oilways to blank them off, and would not be expected to come out in service.

Having said that, I found this one had come out on its own on my most recent engine strip.

Re: 1960 Navigator Rebuild Part TWO

Posted by andy_sochanik at June 25. 2017

picture1

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Re: 1960 Navigator Rebuild Part TWO

Posted by andy_sochanik at June 25. 2017

picture2

Thread appears to be less than 3/16" of an inch - about 4.5mm - and around 22TPI - but not quite!

Attachments

Re: 1960 Navigator Rebuild Part TWO

Posted by Ulrich Hoffmann at June 25. 2017

Thanks Andy for the posts an pics. I wondered where the other for screws would go.. SInce I have NOS heads from Russell motors none of these grub scres were installed.

I have some Jubilee heads and was able to get two screws out.

 

 

 photo 15976f0c-1ec8-425c-9341-db58b9e3498f_zpsfp5sf1x5.jpg

 

Then I looked around my spare parts boxes and found one screw with the same size and thread.

 

 photo IMG_20170625_134210_zpsc1u6fv2f.jpg

I sawed it in half and so I had two other grub screws.

Ok, now I need for more, but no more screws..

Timing:

Seting at 30° I marked the rotor and housing.

 photo IMG_20170625_121807_zpsvzzss5sl.jpg

 

 photo IMG_20170625_125818_zpsi1dm7n1i.jpg

And I installed the pick up disc. There was a modified Commando pickup disc but this one I made for the lightweight ignition housing.

 photo IMG_20170625_125839_zpsahsrposd.jpg

Re: 1960 Navigator Rebuild Part TWO

Posted by patrick_mullen at June 25. 2017

Hi Uli and Andy,

Your pictures of the grub screw are very useful.  It immediately reminded me that I had seen a screw(as in Uli's picture) identical to this- it is the screw(3 of them) on the float bowl of the HS4 SU carburettors on my 1963 MGB.  So I tried one of these MGB screws on the old Jubilee head and it almost certainly fits. I say almost certain as I cannot unscrew any of the old Norton screws and only a few threads are visible to test on. The screws on this head have been centre punched.

I measure the MGB carb screw as 3/16 of an inch UNC and it is 24TPI. These carbs were fitted to loads of old British motors of the sixties.  So easy to get. Later HIF carbs are different.

 

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