1955 AJS 18CS - Fire Ring dimensions

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
Mick D
Posts: 2886
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: 1955 AJS 18CS - Fire Ring dimensions

Post by Mick D »

Hi

The damage to that head gasket is more likely to be the result of a bad head to barrel joint, lack of clamp up where the gasket has spread and leaking hot gas causing the heat damage.

Regards Mick
Halfwhelk
Posts: 37
Joined: Wed Jan 09, 2019 6:27 pm
Location: Kent UK

Re: 1955 AJS 18CS - Fire Ring dimensions

Post by Halfwhelk »

Thanks Dick,
What is the source of this detailed information? Is it publicly available? None of the manuals/instruction booklets I have found and downloaded are anywhere close to a 'Workshop Manual'.
BTW, thanks for your YouTube videos, they are the most detailed source of instruction I've yet found.

Matt
Dixter
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Joined: Mon Oct 02, 2017 8:27 pm
Location: Seattle area, WA USA

Re: 1955 AJS 18CS - Fire Ring dimensions

Post by Dixter »

Hello Matt, the instructions are on page 36 of FW Neil's Manual at this link.

http://archives.jampot.dk/book/Workshop ... models.pdf

The page looks like this.
F6C17AE9-C1B3-4263-92A9-C0CC4EF3F10A.jpeg
When I find poor gas tight joints on AMC engines, with ALLOY barrels, I first flatten the head by careful use of grinding compound rubbing the head on a sheet of thick glass. Alternatively, adhesive backed sanding discs on a granite surface plate. Once the head is flat, invert head and secure to bench top, and grind barrel to head with short rotating strokes, as used on seating engine valves with grinding paste. When a nice even flat matte appearance is obvious, clean up and assemble with 40 lbs/ft torque. No gasket, no leaks!

Ciao, DC
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Last edited by Dixter on Mon May 06, 2019 7:28 am, edited 3 times in total.
Dick Casey
The RideNut
Dixter
Posts: 102
Joined: Mon Oct 02, 2017 8:27 pm
Location: Seattle area, WA USA

Re: 1955 AJS 18CS - Fire Ring dimensions

Post by Dixter »

Matt, here is the info archives we all use for detailed information on AJS / Matchless bikes. It's maintained by a hard working Dane named Christian Gyde.

Here is the page leading to many technical books.

http://archives.jampot.dk/book/

At this level, you can find Owners Manuals, Workshop Manuals, and Spares Lists.

Moving up one level (we all fondly recall navigating on DOS based computers) we get this link.

http://archives.jampot.dk

Now at the “parent” or Root Level, you can see the entire wealth of Christian's collections of books. Please also note, a PayPal link. Christian pays for server time, space, and hardware and appreciates a donation. Toss the Lad a Kroner or two!

Ciao, DC
Dick Casey
The RideNut
Halfwhelk
Posts: 37
Joined: Wed Jan 09, 2019 6:27 pm
Location: Kent UK

Re: 1955 AJS 18CS - Fire Ring dimensions

Post by Halfwhelk »

Dick,
Thanks for this. It was the information I had been seeking. Thanks also for the link to the archive. All duly bookmarked and Christian appreciated.
Cheers
Matt
Andy51
Member
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Joined: Thu Mar 31, 2005 1:00 am
Location: BERKS UK

Re: 1955 AJS 18CS - Fire Ring dimensions

Post by Andy51 »

Apologies for delay, but I have just measured spigot height on cast iron 500cc barrel at 0.115 ins. Cheers, Andy
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