Valve springs

[biddybarfoot]

hi, just wondered what would cause a valve spring to break? is this common or not? Also is it best practice to replace them all? Many thanks George

 

[Waylander]

Very unusual, but not unheard of

replace them all and get the head refurbed

 

[biddybarfoot]

ok thanks

 

[LarJammer]

I had one break last year, one of the guys at promax has a tool to change them in situ without taking the head off.

 

[zcacogp]

Not even that uncommon on an S2 - there have been a few chaps on here who have had a valve spring let go on their machines. Usually exhibits itself as a slight misfire and rough running.

Rose Passion were the cheapest place I could find for a set of new springs when I had my head rebuilt.

 

[TTM]

Not an uncommon issue with 16V engines, they seem to break around the 120k miles mark.

 

[Waylander]

years ago I used to change V8 Mercedes springs without taking the head off, a spark plug with no inner and brazed on PCL air line connector to keep the Valves shut and under pressure when connected to about 50PSI.

pop the collets out and change the spring

 

[zcacogp]

I've done that with the engine from a 928 S2 (16v V8).

Tapping the valve stems with a small hammer while the cylinder is full of compressed air produces an amusingly loud 'pop'. Which may be related to why they are called 'poppet valves' ....


Oli.