My findings after removing head! - Page 15

WillyHeckaslike · 2nd April 2014, 14:49

It is not unknown for some of the head bolts to bottom out on the sump and prevent proper clamping of the head, this can happen after after a head is skimmed and insufficient consideration is given to head height and bolt length. The bolts affected tend to be the two closest to the gearbox and the fix is to either shorten the affected bolts by a few mm or to use washers when fitting them.

This is unlikely to be the problem in this case given the shim being used but it is worth remembering nonetheless.

Simon.h · 3rd April 2014, 18:50

Hi all,
Well I removed the head today and this is my findings-
1st- picture is the head just after I removed it from the block, still has shim and HG fitted.
2nd- Is the HG after removing it from the head (skim still on head) note all the sealer over it.
3rd- The head with shim still fitted after removing HG.
4th- The shim after its been removed from head showing the face which was mated to head.
5th- Head after shim removed.

Simon.h · 3rd April 2014, 18:54

But not sure about this in this picture, its the corner of the block which has a inprint from the HG-

MG Tom · 3rd April 2014, 18:56

I think the issue is the sealer between the shim and the gasket.

Simon.h · 3rd April 2014, 19:03

Quote:

Originally Posted by MG Tom

I think the issue is the sealer between the shim and the gasket.

Thanks Tom, thats what I'm hoping for!

Saga Lout · 3rd April 2014, 19:10

Quote:

Originally Posted by Simon.h

Hi all,
Well I removed the head today and this is my findings-
1st- picture is the head just after I removed it from the block, still has shim and HG fitted.
2nd- Is the HG after removing it from the head (skim still on head) note all the sealer over it.
3rd- The head with shim still fitted after removing HG.
4th- The shim after its been removed from head showing the face which was mated to head.
5th- Head after shim removed.

The first picture seems to show the two fire rings almost touching on the right of the shot, maybe a sealing fault?

kaiser · 3rd April 2014, 19:25

Quote:

Originally Posted by Saga Lout

The first picture seems to show the two fire rings almost touching on the right of the shot, maybe a sealing fault?

I can't see that.

I think it is the sealant all over the show. If you put a head gasket on, it is supposed to be on a clean, dry and grease free surfaces.

This does not look inspiring to me.

I really am not sure why one would bother with a shim, unless the head has been skimmed too much.

beinet1 · 3rd April 2014, 19:48

Quote:

Originally Posted by MG Tom

I think the issue is the sealer between the shim and the gasket.

Yes it is!

WillyHeckaslike · 3rd April 2014, 21:16

Quote:

kaiser: I really am not sure why one would bother with a shim, unless the head has been skimmed too much.

The heads can suffer from hidden porosity, porosity which Rover chose to hide by way of its unique skimming method, and it can be uncovered by the standard skimming method used by most machine shops. A shim offers some protection against any uncovered porosity and I tend to think that is the main reason for its inclusion with the MLS HG

beinet1 · 4th April 2014, 04:13

Quote:

Originally Posted by WillyHeckaslike

The heads can suffer from hidden porosity, porosity which Rover chose to hide by way of its unique skimming method, and it can be uncovered by the standard skimming method used by most machine shops. A shim offers some protection against any uncovered porosity and I tend to think that is the main reason for its inclusion with the MLS HG

Agree

It also prevents fire ring indentation into the cylinder head. The MLS saver shim (0,3mm) helps preventing this, but not if the cylinder head is annealed due to overheating. The 0,5mm saver shim is nearly twice as thick and will spread out the point load from the fire rings over a larger area on the cylinder head and preventing fire ring indentation. By this way, it may make an annealed cylinder head serviceable.

3rd April 2014, 18:56	#144
MG Tom Posted a thing or two ex. MG ZT+ Join Date: May 2013 Location: Northampton-ish Posts: 1,484 Thanks: 156 Thanked 98 Times in 95 Posts	I think the issue is the sealer between the shim and the gasket. __________________ '03 MG ZT+ 1.8T X-Power Grey with Monogram 'WTD' black alcantara trim. [SIGPIC][/SIGPIC] My project thread HERE

2nd April 2014, 14:49	#141
WillyHeckaslike This is my second home Rovers 75 & 25 Join Date: Oct 2010 Location: Wearside Posts: 4,522 Thanks: 543 Thanked 709 Times in 511 Posts	It is not unknown for some of the head bolts to bottom out on the sump and prevent proper clamping of the head, this can happen after after a head is skimmed and insufficient consideration is given to head height and bolt length. The bolts affected tend to be the two closest to the gearbox and the fix is to either shorten the affected bolts by a few mm or to use washers when fitting them. This is unlikely to be the problem in this case given the shim being used but it is worth remembering nonetheless.