Valve, valve spring & Pushrod differences 48 to 49

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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JRClark
Posts: 2
Joined: Thu Mar 11, 2010 4:14 pm
Location: NSW AUSTRALIA

Valve, valve spring & Pushrod differences 48 to 49

Post by JRClark »

I am getting back to a long delayed restoration of my 1948 rigid Matchy basket case.
Current dilemma is it appears to have two different length valves. I understand the '49
had hairpin valve springs and different valves (lengthwise) and pushrods. Amongst all the
bits with the bike are two new valves Ex and I/L for 49 onwards which match the length
of the longer of the two valves installed in my cylinder head.
Question- Can I put later valves in my cylinder head, does this involve changing to later
pushrods and Pushrod tubes and are the coil valve springs usable on '49 onward valves?
Jim Clark- Bundanoon
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clive
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Joined: Mon Jan 01, 1990 12:00 am
Location: LONDON UK

Re: Valve, valve spring & Pushrod differences 48 to 49

Post by clive »

Jim the earlier valves were shorter after the collet because they were fitted with a valve cap (the ends not being hardened). The later valves were used without the valve cap and so are slightly longer. So long as used with or without the end cap as appropriate they are interchangeable and can be used with coil or hairpin springs.
clive
if it ain't broke don't fix
JRClark
Posts: 2
Joined: Thu Mar 11, 2010 4:14 pm
Location: NSW AUSTRALIA

Re: Valve, valve spring & Pushrod differences 48 to 49

Post by JRClark »

Thanks Clive,
Amazing how looking at parts lists can sometimes raise more questions than
answers. Having someone to bounce it off (ask) is often of great assistance.
Jim.
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