1947 exhaust valve oil drilling

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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Joined: Mon Jan 01, 1990 12:00 am

Re: 1947 exhaust valve oil drilling

Postby zwarts » Mon Sep 18, 2017 7:08 pm

Sorry about the delay in responding. Having a few problems at the moment. I have some other photos to add to yours Peter. Hope to get it done this week, you are definitely correct in your last post - is there any sign of a screw thread in the open hole on the outside of your head, to take a blanking plug? I tapped mine out to 1/4" BSF.

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Location: Somerset

Re: 1947 exhaust valve oil drilling

Postby hatrack » Mon Sep 18, 2017 10:00 pm

No trace of threads at all. I have tapped it 1/4 BSF as well.
Not plugging it yet, until I have dropped the Ex valve out to check that the oil flow is clear all the way to the valve stem.

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Re: 1947 exhaust valve oil drilling

Postby Samuel » Wed Jan 10, 2018 9:19 am

What happened to the photo of the head?

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Joined: Fri Sep 16, 2016 6:51 am

Re: 1947 exhaust valve oil drilling

Postby Chris Berry » Fri Jan 12, 2018 9:30 am

hatrack wrote:On a run at the weekend I saw an iron head Matchless with exactly the same arrangement and the middle oil gallery was blanked off as I expected it should be. The owner who had some experiance of the things, thoroughly agreed. Also looking over an article in Real Classic revealed a picture in which the blanking plug was there. So I am now quite sure how to proceed.
But where did the blanking plug go?
I know that the previous owner had work done on the engine including rectifying a sticking exhaust valve. Maybe the plug was removed to check the oilway was clear, and some how, didn't get reffitted.
I'll never know, but its the only explanation that makes much sense.

does any one have a photo of the head and drilling, particularly where t meets the push rod tube?

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Joined: Mon Jan 01, 1990 12:00 am

Re: 1947 exhaust valve oil drilling

Postby raffles » Fri Jan 12, 2018 7:29 pm

Can we go back to the "O" rings there are several types of material.WHICH one is the best


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