razzle308

What shop do u have???

If you have stepped retainers how many mm's over stock will this gain me??
How much?
Thanks.

 
I don't have a "shop" so to speak, just an equipped workshop and alot of parts.
 
I have s/hand stepped retainers for $60.
 
Would have to measure the exact step as I can't remember off the top of my head, I think you gain around .080" (2mm).  I can confirm if you need
 
Cheers
Woz

If you could that would be awesome as I think that just may solve the problem.
Otherwise its a new lower cam :-( $$$$

razzle308

If you could that would be awesome as I think that just may solve the problem.
Otherwise its a new lower cam :-( $$$$

 
No Probs, will measure them up for you tonight.  I can't stress how important it is to have the installed height and rates correct, so I would suggest contacting Newman as well.  What brand are your springs?
 
Cheers
Woz

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

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

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.

I woudn't have thought valve length would be as important as the fitted height of the spring.  For instance, some valves have 4 locking grooves, permitting 2 different valve spring heights depending on which 3 grooves are used.
 
For reference, I believe that the standard fitted height is 36 mm, and you can eek another 1.5 mm out by machining the underside of the retainer.

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.
 

I have custom valves with a single "square" groove.
I can determine retainer height on my own here.
But without taking the head off i have no reference for where the tip should be to see it's relativity to retainer placement along the stem or valve length or position.
If the valve tip is where is should be then I can determine if the retainer is low etc.

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."