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Hairspring valve springs 1964 onward G80 short stroke

Posted: Tue Nov 14, 2023 9:55 am
by g80csp11
Who would know it got so confusing in the later years. Im just rebuilding a 1965 G80 engine and though while i'm doing the head i would check the hair spring valve springs . only o discover that the part number changed in 1964 onward
Ive no idea what the correct part looks like
Does anyone have any idea
hairspring valve spring.jpg

Re: Hairspring valve springs 1964 onward G80 short stroke

Posted: Tue Nov 14, 2023 10:35 am
by g80csp11
Just measure wire thickness and my 65 has 0.181" gauge springs , and an odd one from my parts bin 0.152" so may be what I have is correct and looks like the RH picture. Thanks to Steve Surbey for mentioning gauge thickness as a clue

Re: Hairspring valve springs 1964 onward G80 short stroke

Posted: Tue Nov 14, 2023 4:53 pm
by Expat
That’s interesting Peter. Although a different bike, when I first removed the rocker cover of my 1960 G3 some years ago, it was apparent that three coil valve springs, as in your rh pic, were fitted and bike seemed to run fine. Amongst the parts that came with the bike was a complete set of used four coil springs, as in the lh pic, in good condition, so it seemed. Can’t remember if forthcoming advice persuaded me but I fitted them and they’ve been there ever since. Bike runs fine still.
At the risk of hijacking your thread, does anyone have an opinion on if I did the right thing or not, or if it even matters? I will measure the wire gauge of the removed springs out of interest.
TIA Steve

Re: Hairspring valve springs 1964 onward G80 short stroke

Posted: Sat Jan 27, 2024 1:35 pm
by mdt-son
Hi g80csp11, I have just received a complete '63 G80CS cylinder head. I can measure the spring's wire diameter and other dimensions, if you need further info.

Expat, please note the difference between coil valve springs and hairpin valve springs. I guess you meant the latter when describing your engine.

- Knut

Re: Hairspring valve springs 1964 onward G80 short stroke

Posted: Sat Jan 27, 2024 3:58 pm
by Expat
Knut, My poorly worded description is to blame for any confusion, maybe I should have described my two sets of hairspings as three turn and four turn springs.They’re most definitely not ‘coil’ springs of the generally accepted type. :)