Stu @ Claims Care Centre

iTrader: (1)

and valve is fully closed should it seep the liquid.

i know in a perfect head it shouldnt but i put water down my ports of my 2wa head and when valve closed the liquid very slightly leaks through valve but only very slightly.

anyone tried this?

Toe Knee

iTrader: (2)

Shouldnt leak thru really tbh mate, have you tried to do it the other way round ie fill ie lay head flat and fill the combustion chamber and see if it seeps thru?!

I bought head many moons ago off someone on here on my first cossie, fitted it and was hardly any compression on 1 cylinder, everything seemed ok and looked like it was seating fine ok but lost fluid somehow, they were spot on and refunded me and had it checked out turned out the one or a few of the valve guides were damaged slightly!!

Lambchop

iTrader: (1)

Does heat expand it and stop that?

Garage19

Your valve seats should seal perfectly. Anything less needs to be fixed.

Stu @ Claims Care Centre

iTrader: (1)

tbh im sure all my heads have done it.

if someones got a head about could they test theres?

costina

iTrader: (1)

Its a sad fact that most 2wd heads have a one point valve to piston contact due to incorrect timing(as per pinto)

which in turn bends the valves a little if your unlucky

Paul

westus1

iTrader: (6)

valves should seal perfectly
any leaky valves will cause more probs in the future

tabetha

It's also a fact that they can clip the pistons at high revs even when timed perfectly on yb's.
tabetha

fraser9764

iTrader: (3)

Surely not if everything is working 100% eg valve springs, clearences etc.

westus1

iTrader: (6)

every yb i've ever stripped down(if its been used properly)
has had some kind of valve contact, usualy just clipped at high revs
but very very common

costina

iTrader: (1)

correct mainly on the 2wd have yet to see a 4x4



Here you go one of my old lumps

Steven_RW

When you do a leak down test, cars are not 0% leak. So I was guessing that SOME % of the leak has to be past the valves?

RW