1925 3.49hp E3 Crank Pin Advice Needed

Information relating to Matchless and AJS Models built prior to 1939
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1925 3.49hp E3 Crank Pin Advice Needed

Postby Andy.Dunn » Sun Dec 03, 2017 10:15 am

Hi
Have family owned E3 needing some engine attention (has not been running for 50 years!). Investigations suggest it was originally taken off the road due to damaged crank pin (it is very scored and part of roller collar has broken). Big end looks worn but should be serviceable. Have tried to locate a replacement crank pin but no luck.

So, question is do we get another crank pin machined to original design or would a better option possibly be to make/obtain straight pin (or possibly machine existing) and fit a modern bearing with big end machined to match new bearing?

Hope that makes sense.

Any and all advice gratefully received!

Thanks
Andy

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby Rob Harknett » Sun Dec 03, 2017 1:58 pm

http://www.alpha-bearings.co.uk/home.htm
These people could supply/make a pin or complete assembly. I understand they are busy and may take time.

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby Rob Harknett » Sun Dec 03, 2017 7:36 pm

another suggestion, Godden Engineering,

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby Andy.Dunn » Sun Dec 03, 2017 7:51 pm

Hi Rob
Many thanks for your suggestions. Will give both a call and see what advice they can provide about best way to move forward.
Best wishes
Andy

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby g80csp11 » Sun Dec 03, 2017 8:52 pm

Alpha are very slow and expensive , im just having a new pin for my 1927 H4
can you measure yours , if its narrower than the 1927 then I might have a new one in stock . NOS
its to narrow for 1927 hence I did not use it
it says SV , def AJS

send me details , I'm much cheaper than alpha but you will need to fit it your self !

PS my new one is being machined at work , then hardened and ground

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby Andy.Dunn » Sun Dec 03, 2017 9:02 pm

Thanks for the reply. Don't have any measurements to hand and too cold and dark for garage now but will give it a go tomorrow. I understand the 1925 and 1926 are same while 1927 on is different but no idea what difference might be. Fingers crossed...

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby Andy.Dunn » Mon Dec 04, 2017 7:47 pm

Okay. The old man has knocked up the following giving rough details of the crank pin dimensions. How does this compare?

Image

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby g80csp11 » Mon Dec 04, 2017 7:57 pm

I will have a look tomorrow at work it's on my desk , I think !

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby g80csp11 » Tue Dec 05, 2017 8:58 pm

good news is that I have a new crankpin and outer ring for your bike
send me a pm with your contact details
have to use second hand nuts as I don't have new ones

the outer ring will need machining to get the running clearance correct , this is normal on all big end assemblies
you can even have it before Christmas ( much quicker the Alpha )
last one NOS , that's what Les at Russell motors always tells me


Once I have my new one made for my 1927 H4 ( bigger pin ) , I could always make more to order


Peter

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Re: 1925 3.49hp E3 Crank Pin Advice Needed

Postby Andy.Dunn » Tue Dec 05, 2017 9:25 pm

Hi Peter
PM sent
Andy

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