Cylinder Head

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
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Cylinder Head

Postby Oldcarguy » Fri Apr 26, 2019 3:01 pm

Are the 250 & 350 heads the same as the head gaskets seem to be for both?

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Re: Cylinder Head

Postby clive » Fri Apr 26, 2019 3:53 pm

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.
if it ain't broke don't fix

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Re: Cylinder Head

Postby Ozmadman » Fri Apr 26, 2019 11:04 pm

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
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Re: Cylinder Head

Postby Martin.S » Sat Apr 27, 2019 7:58 am

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.

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