7 replies to this topic

[Chris M]

Hi all I’m know reassembling my cylinder head in my MPI.
However 4 of the new valve stem seals have a little spring around the top like most engines do & the other 4 don’t !
Which seal goes on the inlet & exhaust?

[Ethel]

Not sure but if I had to guess I'd say with is for inlet as there's more purpose in sealing against inlet suction. 

[1330RG]

Yep sprung one on the inlet unsprung on the exhaust

Edited by 1330RG, 09 March 2019 - 03:55 PM.

[neal]

Yep sprung one on the inlet unsprung on the exhaust

Some like this for track day cars that are driven hard and revving all the time, some like a bit of oil on the exhaust valve stems due to the constant high heat so they remove the springs, some people don't even have the seals at all on the exhaust valves. For a road car, i'd have the seals and springs on all valves as I don't rev hard and hold the revs high for long. Besides, they are good for lowering the emissions.

Personal choice

[1330RG]

Yep sprung one on the inlet unsprung on the exhaust

Some like this for track day cars that are driven hard and revving all the time, some like a bit of oil on the exhaust valve stems due to the constant high heat so they remove the springs, some people don't even have the seals at all on the exhaust valves. For a road car, i'd have the seals and springs on all valves as I don't rev hard and hold the revs high for long. Besides, they are good for lowering the emissions.

Personal choice

I completly agree with you. However the op states he has 4 sprung and 4 unsprung and so in that situation id fit the sprung to the inlet and the unsprung to the exhaust ?

[Retroman]

MPi valve stem seals should all be brown ones with a spring on each

[Chris M]

Thanks guys ?

[Chris M]

Just been round to a mate & got a set fitted with springs on all 8.
I’ll feel happier with the full set.