Minimum Head Thickness Before Skimming

[PUGugly 0]

Got several heads off 205's, needed to know what the minimum thickness the head can be before skimming becomes impossible any more. Also where bount the measurement is taken.

[PUGugly 0]

Anyone??? pls!!!

[ALEX 98 1 Cars]

Aparently you can take over 1mm (which is Sh!t loads) off the standard head to bring the compression up on a XU head without worrying about the valves hitting the pistons.

Edited November 7, 2006 by ALEX

[welshpug 1,626]

depends which XU head, they do vary a little, post whichj one and I'll se if its covered in the haynes manuals i've got.

[PUGugly 0]

They are XU9JA's

[Higgy 0]

Ummm. I thought Haynes said 0.2mm is max to take of Mi head.

 

Is it something like 137mm? cant remember numbers off top of my head. I did get mine measured before the skim, I'll try and remember to have a look later for the numbers.

 

Higgy.

[Higgy 0]

Right here are the measurements of my head at various places before a 0.2m skim:

 

132.0228mm

132.1358

132.1447

132.1258

132.0457mm

 

The minimum thickness is 132mm, but I cant remember the tolerance. Anyhow, even after a 0.2mm skim I have no running problems. Engine revs up past 7k rpm with no piston smacking

 

Higgy.

[SweetBadger 91]

Right here are the measurements of my head at various places before a 0.2m skim:

 

132.0228mm

132.1358

132.1447

132.1258

132.0457mm

 

The minimum thickness is 132mm, but I cant remember the tolerance. Anyhow, even after a 0.2mm skim I have no running problems. Engine revs up past 7k rpm with no piston smacking

 

Higgy.

 

Mine was skimmed to 131.3mm (measured with verniers at each end), was not well pleased! But it runs well and I haven't got any problems with piston-valve clearance running the catcams inlet-only cam which is higher lift than standard.

[PUGugly 0]

Mine was skimmed to 131.3mm (measured with verniers at each end), was not well pleased! But it runs well and I haven't got any problems with piston-valve clearance running the catcams inlet-only cam which is higher lift than standard.

 

Were do you measure too? Obviously head face but whats the top point

[petert 554]

Aparently you can take over 1mm (which is Sh!t loads) off the standard head to bring the compression up on a XU head without worrying about the valves hitting the pistons.

 

Would you believe 2mm! The valves will never hit the pistons.

[PUGugly 0]

Would you believe 2mm! The valves will never hit the pistons.

 

Yeah but where do i measure from and too pls?

 

If you were to take 2 mm off what sort of comp ratio would it be running?

[Higgy 0]

From the flat side of the cylinder head where the combustion chambers are, to the top of the cylinder head (take the cam ladder/carrier off and remove the cams).

 

Try this pic

 

 

 

Higgy.

 

P.S. I take it you have the head off and valves removed? Makes life a lot easier.

[PUGugly 0]

Cheers Higgy!

 

Thats what I thought but was a little unsure! The fact that the part to take the top measurement from is at an angle on the 8v (prob same on Mi but me not know these engines) threw me a little. Must of been blonde in a former life