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MG MGF Technical - How much can a head be skimmed?

Hi,
following my HGF, rover are saying that they may not be able to skim enough off the head to fix the pitting. I was just wondering, how much can I have skimmed off?
Cheers
Darren
Darren

In Car Mechanics mag there was someone saying that they had fitted a shim to alow a head that was past tolerances to be fitted, but I have not heard of this anywhere else (and not here), but it was a 1.6 k-series head (same as the MGF)
Will Munns

Check out the Elise Archives - I suspect the answer that you are seeking can be found there!
Rob Bell

According to the engine overhaul manual:
Cylinder head max warp 0.05mm
Cylinder head height:
New 118.95 to 119.05mm
Reface limit 0.20mm

Spyros
Spyros Papageorghiou

The shim that allows the head to skimmed further is £25.00 plus vat.They have to be bonded to the head before refitting the head.Saves scrapping a useable head.HTH
Mike.
mike

Hi,
I've managed to take a look at the head in question and it has been skimmed down to the point where some of the valves on the outer cylinders have been nicked. There are still black marks on the head face.
This says to me that rover are indeed telling the truth when they say that it cannot be skimmed anymore.
so, in defiance of giving rover 800 quid (+vat?) for an exact replacement, I am looking for other options. any suggestions (with prices) ?
D Edwards

DE, read previous post from MS.
David

Oh, have I misunderstood how the shim works?
I thought the shim still needed a flat head face to bond to and was just used to decrease the compression ratio.
Can the shim be bonded to a misshapen face?
Darren
D Edwards

My guess is you need a flat surface if the shim is to seal onto the head withuot leaks or distortion.

I don't know how much it would cost to strip out the valves in order shave a bit more off the head to get it properly flat, but worth a try?

Chris
Chris

I'm guessing but it seems clear to me, the 'maximum' only means the max while keeping the head intact in its original form. If you need to skim more than this 'maximum' then you strip the head, skim to a 'beyond maximum' figure, then bond the shim to the head face, re-check for flatness, re-assemble the valvegear, and refit.
David

Aha!
Good thinking batman! ;)
that never occured to me. theres hope for the old head yet (the cars not mine).
Anyway, tomorrow, i'm going to tell my garage that I want to give it to mike to sort out so i'm confident that he'll be able to do whatever's possible.
cheers all for your help,
Darren
D Edwards

Good move - Mike is top man....
David

The other option is to go for a second hand head. There are plenty to choose from - not least because the 1.8i head is identical to later 1.4 and 1.6 K16 cylinder heads.

Given the availability, prices should be reasonable.
Rob Bell

>not least because the 1.8i head is identical to later 1.4 and 1.6
Not the 1.4 (smaller bore), but yes to the 1.6 (used a lot in 216 and 416 cars)
Will Munns

go get new head
Neil

This thread was discussed between 22/11/2002 and 28/11/2002

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