Is anyone possibly able please, to give me a measurement from the spring seat on the head to the valve stem tip so I can try to determine if my issue is valve length without taking the head off??
I want to get to the bottom of it before I go by new rockers only to find I have the same probs.

Wozzah

Flighter

Wozzah, do you think Des Hammill is on the money with his cam geometry templates? 

To be perfectly honest I haven't studied the Des Hammill book much, and I can't find it!  What does he suggest?

Cheers
Woz

 
He says that the rocker geometry has to be "based on the effective diameter of the rocker pads (85mm/3.346in) represented by the two circles, and the distance from the side of the head to the centre of the rocker pads (63mm/2.480in exhaust, 67mm/2.637in inlet)", which sounds reasonable.  He helpfully provides a diagram that permits gauges to be made that are held against the sides of the head to easily check whether the rockers are at the correct position.  I made some out of a sheet of aluminium, as it was easy to cut and then shape with a file.
 

Don't know if this will help Razzle, but from the Hammill book:
 
"The standard position of the top of the valve stem is 120mm from the cylinder head gasket surface, but this measurement is only good if the cylinder head has not been planed. Also, on used engines, there is likely to be some variation in the valve heights as their seats might have been reground, effectively increasing the height of the valve/s as they are deeper seated in the head."
 
 

As I stated I have never studied the Des Hammill book in great detail.   The references basing measurements on the surfaces of a std head are a concern right from the start, as due to production tolerance no 2 heads are the same.  The factory geometry is all over the shop, and castings vary heaps, valve heights change dramatically etc etc etc.  And chances are you engine has had valves, seats cut or other work carried out at some point is time, so sho knows where things are set now.
 
IMO when doing an engine or cam package the geometry should always done valve by valve for each individual engine, and IMO the only way to do it correctly is with the cylinder head off the car.  That is why when building a decent head that great detail needs to be paid to the valve heights, lengths etc to ensure that they're in the right spot before you even begin trying to get the valve train correct.
 
2 things concern me with what you're trying to do here.
1.  You have no idea of your valve train geometry, valve lengths etc etc.  Chances are it's wrong.  That will either give you bad performance, or poor reliablilty (most likely both).
2.  You have no idea what spring rates you require, or what you have now, or whether the springs you have fitted are even the correct ones for the application. 
 
IMO first of all I would remove the cylinder head and set it up properly.  That will then put your valve where it needs to be height wise. 
Then work out what installed spring height you have (check all 8 of them individually)
Contact Newman for the required spring rates.
Find a valve spring that matches as closely as you can the installed height, and spring rates required, and purchase them rather than try and make something substandard work.
If you need more installed height purchased a set of stepped retainers or have your head machined to suit.
If you need less installed height purchase shims to suit.
 
If you're not confident in setting it up it might be an idea to give it to someone who can, otherwise it will more than likely end in tears.
 
The stepped retainers I have give you .120" extra installed height.
 
Cheers
Woz
 

Ok so - Seems the cam i had, did not have 474 thou lift after all. This meant that the Newman ph4 did not go straight in.
Investigating further found that between valve binding and stem seals I had only 430 thou tops to play with.
So ..... rather than go back a step on cams .... I made the decision yesterday.
The head is now off and at the machinist to have the spring seats machined to fit the phase4.

This thread is lonely!
Fitting stock valves at the moment to test length but certain I am going to have to fit new valves.
Choosing between burtons group1 or ferrea 6000 series valves.
Damn shame to get rid of my custom ones :-(