Problem with valve springs

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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Guille
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Joined: Tue Aug 13, 2019 12:29 am
Location: Punta del Este, Uruguay

Problem with valve springs

Post by Guille »

I bought a set of valve springs from amoc-parts.com

After installing then I see that when the valve y pushed open the piece that holds the valve stem will run against the spring.
This only happens with the narrow spring.

Any tip on how to solve it?

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Mick D
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Location: Aberdeenshire

Re: Problem with valve springs

Post by Mick D »

Hi

Do you have the old springs still? if so compare the bend at the top, does the new spring have a greater bend angle?

Your springs have a different profile to the ones fitted to my G3. Mine are also fitted in the opposite orientation, maybe try swapping the springs to see if it makes a difference:
Valve Springs 2.png
Regards Mick
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Guille
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Posts: 18
Joined: Tue Aug 13, 2019 12:29 am
Location: Punta del Este, Uruguay

Re: Problem with valve springs

Post by Guille »

Mick D wrote:Hi

Do you have the old springs still? if so compare the bend at the top, does the new spring have a greater bend angle?

Your springs have a different profile to the ones fitted to my G3. Mine are also fitted in the opposite orientation, maybe try swapping the springs to see if it makes a difference:
Valve Springs 2.png
Regards Mick
The old springs had a shallower bend angle
Mick D
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Posts: 2811
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: Problem with valve springs

Post by Mick D »

Guille wrote:The old springs had a shallower bend angle
Hi

Is the dimension indicated below smaller on the new spring? If so you should bring it to the attention of Club Spares, they may have received a bad batch.
Valve Spring Dim.png
What was your reason for replacing the springs in the first place?

Regards Mick
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Guille
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Posts: 18
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Location: Punta del Este, Uruguay

Re: Problem with valve springs

Post by Guille »

Mick D wrote:
Guille wrote:The old springs had a shallower bend angle
Hi

Is the dimension indicated below smaller on the new spring? If so you should bring it to the attention of Club Spares, they may have received a bad batch.
Valve Spring Dim.png
What was your reason for replacing the springs in the first place?

Regards Mick
They were worn out at the spot where the spring presses against the metal that attaches to the valve stem
Mick D
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Posts: 2811
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: Problem with valve springs

Post by Mick D »

Guille wrote:They were worn out at the spot where the spring presses against the metal that attaches to the valve stem
OK, so re-fitting the old ones isn't really an option. I think you need to dimensionally compare the new and old ones and report your findings to Club Spares - the new ones seem to be different to my originals and your old ones.

Regards Mick
Guille
Member
Posts: 18
Joined: Tue Aug 13, 2019 12:29 am
Location: Punta del Este, Uruguay

Re: Problem with valve springs

Post by Guille »

Mick D wrote:
Guille wrote:They were worn out at the spot where the spring presses against the metal that attaches to the valve stem
OK, so re-fitting the old ones isn't really an option. I think you need to dimensionally compare the new and old ones and report your findings to Club Spares - the new ones seem to be different to my originals and your old ones.

Regards Mick
The new spring is 8mm shorter than the one being replaced and obviously with a very different curve.
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Guille
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Joined: Tue Aug 13, 2019 12:29 am
Location: Punta del Este, Uruguay

Re: Problem with valve springs

Post by Guille »

Solved, getting a refund.
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ajscomboman
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Location: HAMPSHIRE UK

Re: Problem with valve springs

Post by ajscomboman »

The springs came from a reputable supply line, however it appears that the sample although very old with a label attached to it may not be a genuine original hence the difference. I have an original which I'm about to ship to Kettering to ensure the next batch is factory correct.
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