Cylinder Head

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
Locked
Oldcarguy
Posts: 30
Joined: Tue Apr 16, 2019 9:36 pm
Location: UK

Cylinder Head

Post by Oldcarguy »

Are the 250 & 350 heads the same as the head gaskets seem to be for both?
User avatar
clive
Member
Posts: 5657
Joined: Mon Jan 01, 1990 12:00 am
Location: LONDON UK

Re: Cylinder Head

Post by clive »

Iain welcome. As a guest your first few posts are moderated before they appear, so please wait patiently for them to show. Fraid I cannot answer your question for sure but it seems unlikely as the bore for the 350 will probably be different to the 250 as it is likely the stroke is the same.
clive
if it ain't broke don't fix
User avatar
Ozmadman
Posts: 2651
Joined: Wed Dec 14, 2011 1:02 am
Location: ESSEX UK

Re: Cylinder Head

Post by Ozmadman »

Oldcarguy wrote:Are the 250 & 350 heads the same as the head gaskets seem to be for both?
The gasket is the same, the 350 is a bit larger bore but much longer stroke so I presume that the barrel walls are thicker on a 250. The heads are different as the 350 and the 250 CSR have different valves than the 250 but could be used, the later heads had coil valve springs instead of the original hairpin type
Paul
1960 Model 8
1974 Yamaha RD250B US Model 6 speed
User avatar
Martin.S
Posts: 443
Joined: Sun Mar 18, 2018 12:02 pm
Location: Bristol UK

Re: Cylinder Head

Post by Martin.S »

I found that the G5 inlet throat size is a 1/16th I think bigger than a 250CSR at the carb face but other than that they're the same - regarding the gasket size - that fits around the spigot or lip around the top of the bore - and this has the same outer diameter whether a 250 or 350.
Cheers
Locked