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MG MGF Technical - Head skimming ..how much can be taken off?

Hi all ..just been to the garage who is fixing the head gasket failure.
They have got the head back which has been presure tested and skimmed.It has had .008" skimmed off.
This is the second time it has been skimmed so with them not knowing how much was taken off the first time (different owner/garage)they were going to use one of the head saver shims.
Now they have seen the shim they would prefer not to use it if they don,t have to as it is only a thin sheet which you bond to the head or block.
I,ve asked the garage to hang fire before they do anything else so i/we can make some inquirys
So a few questions if anyone can help.
1)
is there a measurement which can be taken to determine weather the head is re usable??or is there a visual check.
2)
Has anyone had ther head done with one of these head saver shims and did it last!!!!!
3)How much is a re con head.
4)What happens if the head is used if to much has been skimmed off...i presume the valves will hit the block??
5)is there a thicker single gasket that is available which will make up the .008" taken off??
Thanks Mel..
m e johnson

Just thought of something else... had a look at the landrover head gasket on Robs site.....is this one designed to be used with the shim or on it,s own as well???
Cheers
m e johnson

The LR gasket includes its own shim, my understanding of the threads that were around at the time is that the new gasket needs the shim to bite into, without it it may cause damage to the alloy head.

And yes, if the head is too hightly skimmed there are two possible problems, the compression could get too high leading to detonation and/or at very high RPM's the valves may not receed fast enough to avoid the upcomming pistons
Will Munns

The way to measure is to take the head and install the valves. Invert it, and use a water filled graduated buret and fill the combustion cavity in the head until you've completely filled it - and make a note of the volume. I don't remember the OE figures off hand, but Dave Andrews has them (they might be on his website actually...!)

The LR MLS gasket does indeed already include a shim - and is a little thicker than the standard gasket, so will have a small impact upon CR - and in this case, is a gasket I would use.
Rob Bell

So it was the hg after all?
Guess that was good news compared to what was thought - damage is lower down.
Good luck, thought would "bump" replies to your query as well!
Kate
KS Gould

Thanks Kate
Yes it was the head gasket after all!
Cheers Mel
m e johnson

Having had a 2nd HGF on a skimmed head, and I'm talking about a weep not a total coolant dump both times, the 2nd failure being 6 years after the 1st I would say say Mike - you never know.

The K series head has a certain thickness of hardening and the pronouncement of the duration of time between HGFs and the reusability of the head is entirely down to the experience of the garage.

Heads are anything from £100 to £300 from Mike Satur and the MGF centre but thats the naked head and all the valve gear has to be put back on assembled heads are more. Salvaged engines aren't much more.

If the head is to be skimmed the valve gear etc has to be stripped off anyway so that would have been the time to change to an unskimmmed used head.

However I would add that if I had a PRT available to fit after the first HGF the 2nd may not have happened.

Basically K series engine has a hgf track record in all rovers and the jury is still out on if it can be prevented. That includes Land rover gasket and oil rail, PRT, steel dowels etc. The only thing to recommend for sure is a low level coolant alarm to stop you cooking your head if the head gasket/coolant pipes/ radiator leaks before you spot it.

Jon Baker

" Yes it was the head gasket after all!"

O yee of little faith. ;0)
roy bridge

Cheers John......if mine lasts 6 years that will do for me!!

Roy.....Yes it was..i know ,i know...you told me so....:0)))...
Mel..
m e johnson

Stripping your existing head and transferring everything over to a new 'naked' head is not that difficult - certainly Tim's instructions make it look easy! http://www.mgf.ultimatemg.com/group2/engines/head_strip/index.htm
Rob Bell

Thanks Rob,

Given a bit of time it's pretty straight forward and certainly not out of the relms of DIY.

Tim
tim woolcott

Mel, this might of interest: http://forums.seloc.org/classified.php?action=ad&id=1587

A standard K-series cylinder head going for £99...
Rob Bell

to fit a head saver or head shim you need to remove 25 thou off the cylinder to get the compression back to std,also this will enable you to set your camshaft timing correctly
if you would like i will get the std thickness of a new cylinder head as i sell plenty of new ones to garages.
mf sturge

Cheers Rob / mf sturge...
got the f back last week and only taxed it today.I,ve only done 20 miles (took over one hour in the traffic!). All seems ok.I got tht LR gasket fitted which seemed the best option. If i get a couple of years out of the head , i can now budjet for a replacement one as i,m sure a third skim is not an option!!
I got the cam belt done at the same time ,pre tensioner and water pump. The cost was very reasonble at £493.00 all in (i supplied the lr gasket)which was £27.03.
I,m really pleased to get it back as it took some 9 weeks to get sorted.One lesson i have learned from this hgf failure is to trust my local garage who did offer to take the head off for a diagnosis after initially thinking it was "land area failure at the bottom of the piston liners" which they had seen before in another "k" series engine when dismantled.
They completed the work after seeing a breach in the head gasket on inspection and was patient with all my questions etc..
Another garage which is recommended by the MGOC diagnosed it as a cracked piston liner "as a deffinate" charged me £107.00 for there expert "wrong" diagnosis.
The second garage contacted advertising engines (now searching for a new engine i now needed due to the none existint cracked piston liner) talked me into letting them take a look and said they could either sort out what sounded like a HGF or get a re con engine for me . Don,t drive it sir ...£40.00 to tow away it,s way to risky with a possible hgf. This inspired me with confidence and i parted with my hard earned £40.00 and off it went on a saturday morning .
We will ring you on monday sir.......to cut a long story short they went bust when they had my car and couldn,t fix it although they said it was the head gasket.They then drove it back to me after saying i shouldn,t drive it.
All in all a nightmare.
Now looking to get the b&g low water level kit and hopefully some trouble free motoring.
A BIG THANK YOU TO EVERYONE WHO OFFERED THERE ADVICE as i would have gone for the recon engine if it was not for you guys and girls which was running into £2,000 at least
Cheers Mel..
m e johnson

Glad to hear that alls well for the moment and at a good price. Have confidence in the fix thats been done as theese engines seem to take a fair beating before they die so just enjoy driving your F again.
Andrew W Regens

Cracked piston liner - to be fair to the garage I have seen this happen but the truth is you need to get the head of to determine.

As a warning story about jumping to conclusions I had a K series with a water leak within 10,000 miles of a previous HGF. A leakage test almost no leakage and when the water system was pressurized a small seep appeared at the bleed valve!

The jury is definitely out on the LR gasket but to the first post I suspect it was a Payen saver shim that does require bonding to the head. If your head is out of tolerance on thickness this is a recognised solution and may even help with a slightly soft head.
Derrick Rowe

Good result there then Mel - even if it has taken a while to bring the saga to a neat conclusion! :o)
Rob Bell

Thanks Derrick...Just out of curiousity ...do you know how /what with this payen saver shim is bonded to the head??
The local garage thought it was something else they was ordering...
They did not want to use it as they said it was just another place for the gasket to blow??
thanks mel..
m e johnson

Hi , me again!!!!
mgf sturge...
Just noticed you are located in Cheshire.
There are a number of mgf tf owners who meet up once a month at the hollow tree at stretton ...just thought i,d mention it incase you are pretty local???
Not sure when the next meet is (this month) but if you are interested just email i,ll find out the date.
Its a good night and not all hgf talk!!!
Mel..
m e johnson

This thread was discussed between 19/10/2006 and 07/11/2006

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