1968-70 Commando type oil filter kit

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
jack clegg
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1968-70 Commando type oil filter kit

Post by jack clegg »

Hi Folks,

Now that Andover Norton are selling an oil filter kit with 1/2 inch diameter pipe fittings, I am planning to fit one in the return line of a 1963 G80CS (being otherwise devoid of any filtration whatsoever). I gather others have done this to singles with the old plunger type pump. Just wanted to check that the pump can cope OK. Paul Goff advised against it.

I have one fitted to my N15CS, but had to use the 3/8ths type, which involves sleeving down the 1/2 inch bore pipe to 3/8ths both into & out of the filter head. A right pain with too many clips & joins.

Reassurance sought.

TTFN Jack
John Marshall
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Expat
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Re: 1968-70 Commando type oil filter kit

Post by Expat »

Hello Jack,

Wondering what your concerns are.......the fact that the Norton fittings are 1/2 inch diameter?

Like you I fitted a kit with 3/8 fittings from Goff to my G3 and found some brass reducers at the local motor factors. Seems to work fine with good oil return flow and no excessive wet sumping.

Having said that, I've no experience with the query you raise so can't offer any reassurance, sorry.

:)

Regards, Steve
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jack clegg
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Re: 1968-70 Commando type oil filter kit

Post by jack clegg »

Hello Steve,

Goffy reckoned the pump might not cope with returning oil through the filter. Personally, I think it will. It'd be a sad old pump otherwise. I'm sure I found posts on here about folk fitting them to plunger pump type singles, but thought I'd ask to check.

I dislike having clips, reducers & joins in the oil lines. It looks rubbish & is much better to have the same bore size continuous in one length of pipe to & from each orifice. Thanks to Andover Norton, I just have to change the filter head on the N15CS for theirs with the new barbed 1/2 inch spigots (& dump all clips, reducers & 3/8th pipe for 1/2 inch pipe, as AMC intended).

Isn't your G3 a plunger pumper?

TTFN Jack
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Pharisee
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Re: 1968-70 Commando type oil filter kit

Post by Pharisee »

jack clegg wrote:Hello Steve,

Goffy reckoned the pump might not cope with returning oil through the filter. Personally, I think it will. It'd be a sad old pump otherwise. I'm sure I found posts on here about folk fitting them to plunger pump type singles, but thought I'd ask to check.

I dislike having clips, reducers & joins in the oil lines. It looks rubbish & is much better to have the same bore size continuous in one length of pipe to & from each orifice. Thanks to Andover Norton, I just have to change the filter head on the N15CS for theirs with the new barbed 1/2 inch spigots (& dump all clips, reducers & 3/8th pipe for 1/2 inch pipe, as AMC intended).

Isn't your G3 a plunger pumper?

TTFN Jack
I seem to remember a thread a few months ago where somebody had fitted a pattern felt filter in the oil tank that had effectively blocked the return line. The oil pump generated enough pressure to split the rubber return oil pipe. If it can do that, pushing oil through a cartridge filter shouldn't be a problem.
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Harry44
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Re: 1968-70 Commando type oil filter kit

Post by Harry44 »

A properly designed oil filter should have a spring holding the element in place or a bypass valve so that if the filter becomes blocked it can lift and allow oil to bypass the filter and continue on its way. My 57 18S has the wrong oil tank that has a felt filter built in. If that gets blocked the oil pressure should lift the metal disc against the spring above it and allow oil back into the tank.

What puzzles me is why AMC stopped using it ?
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dave16mct
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Re: 1968-70 Commando type oil filter kit

Post by dave16mct »

It isn't the filter that gets blocked. It's that the poor pattern filter is turned back further at each end. The top part blocks the oil return hole in the tank. You see these rubbish pattern filters for sale on ebay all the time.
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Re: 1968-70 Commando type oil filter kit

Post by Expat »

jack clegg wrote:Hello Steve,

Goffy reckoned the pump might not cope with returning oil through the filter. Personally, I think it will. It'd be a sad old pump otherwise. I'm sure I found posts on here about folk fitting them to plunger pump type singles, but thought I'd ask to check.

I dislike having clips, reducers & joins in the oil lines. It looks rubbish & is much better to have the same bore size continuous in one length of pipe to & from each orifice. Thanks to Andover Norton, I just have to change the filter head on the N15CS for theirs with the new barbed 1/2 inch spigots (& dump all clips, reducers & 3/8th pipe for 1/2 inch pipe, as AMC intended).

Isn't your G3 a plunger pumper?

TTFN Jack


Jack, yes my G3 has a plunger pump, works well. :)
Keep shiny side up.

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raffles
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Re: 1968-70 Commando type oil filter kit

Post by raffles »

Why bother yourself with all these mods I have been running my G80 1956 for thirty seven years and 36,000 miles rebored once same bigend as fitted in
1980 still no up or down movement ,run on sae 50 oil changed every 1,000 miles or as close to as I could get.
Tony
jack clegg
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Re: 1968-70 Commando type oil filter kit

Post by jack clegg »

Hi Tony,

My G80CS has no filtration whatsoever, not even a gauze in the oil tank. I think it might be beneficial in this & all cases.

Thanks to Steve for testifying as to his plunger power.

TTFN jack
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Re: 1968-70 Commando type oil filter kit

Post by Expat »

raffles wrote:Why bother yourself with all these mods I have been running my G80 1956 for thirty seven years and 36,000 miles rebored once same bigend as fitted in
1980 still no up or down movement ,run on sae 50 oil changed every 1,000 miles or as close to as I could get.
Tony
Guess it all comes down to individual preferences Anthony and what each of us feel happiest with and spending a few squids on....let alone the tinkering around aspect of whatever it is. :)

Btw, I too use straight 50 for the engine, though only owning the bike for around 18 months and two oil changes. The previous owner, twelve years plus, used 20/50 multigrade everywhere with no problems!

Jack, you are welcome.

Regards, Steve
Keep shiny side up.

These are my principles, if you don’t like them, I have others. (Groucho Marx)
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