Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: TheBoy on 08 September 2007, 10:49:53

Title: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 10:49:53
Seeing as whatever option I take, the head has to come off, I need to get a new HG.  Does anyone know where I can find the thickness of mine - I can't find these 'notches' anywhere (not that I know what they look like)?
Title: Re: 2.5TD Head Gasket - Notches?
Post by: Martin_1962 on 08 September 2007, 12:07:07
Get the head off and measure tha gasket.

At least spares should  be available from a lot more places than some engines
Title: Re: 2.5TD Head Gasket - Notches?
Post by: Dazzler on 08 September 2007, 16:08:29
Make your own marks for ease of reassembley and cable tie the top sproket to the chain...
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 20:08:39
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Get the head off and measure tha gasket.

At least spares should  be available from a lot more places than some engines
You need the notches to be able to get the right gasket.  Now surely, even BMW aren't so stupid as to make those invisible??
Title: Re: 2.5TD Head Gasket - Notches?
Post by: Martin_1962 on 08 September 2007, 20:12:11
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Quote
Get the head off and measure tha gasket.

At least spares should  be available from a lot more places than some engines
You need the notches to be able to get the right gasket.  Now surely, even BMW aren't so stupid as to make those invisible??

Take old one in and get the same?
Title: Re: 2.5TD Head Gasket - Notches?
Post by: hotel21 on 08 September 2007, 20:16:16
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Get the head off and measure tha gasket.

At least spares should  be available from a lot more places than some engines
You need the notches to be able to get the right gasket.  Now surely, even BMW aren't so stupid as to make those invisible??

No direct experience of these beasties, but others similar....  Apologies if you already know this....  :-[

The 'notches' should either be small peaks showing out of the edge of the head/block face towards the front (easy access) and to one side.  (dohh!!   :D)  Sometimes the sneeky beggars make them as valleys instead of peaks (prinking shears type effect) so that you are minutely looking for 'valleys' in the head/block join rather than peaks sticking out, if you follow.  Over time the dust/dirt/oil/crud fills these valleys so that they dissapear.

The peaks/nicks are intended as a means to ID the new gasket thickness in the packet rather than what size required on the original machine before stripdown.

Reason being that if a head is removed for machining, a correspondingly thicker gasket, as referenced from manuf manuals for orig thickness and tables including machining removed, is requested to maintain comp ratio.

As said, no experience of Beemer bits but played with assorted engines/piston compressors over the years.....  

HtH


Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 20:16:27
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Get the head off and measure tha gasket.

At least spares should  be available from a lot more places than some engines
You need the notches to be able to get the right gasket.  Now surely, even BMW aren't so stupid as to make those invisible??

Take old one in and get the same?
I cannot believe even BMW designers are that stupid.  I want one before I start stripping down - is that too much to ask?
Title: Re: 2.5TD Head Gasket - Notches?
Post by: hotel21 on 08 September 2007, 20:19:14
Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 20:22:25
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Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
No dealer around here stocks them...
Title: Re: 2.5TD Head Gasket - Notches?
Post by: CaptainZok on 08 September 2007, 20:37:11
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Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
No dealer around here stocks them...
No mention in TIS/EPC for either marque?
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 20:42:23
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Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
No dealer around here stocks them...
No mention in TIS/EPC for either marque?
yup, 2 or 3 notches. No clues to notch location.
Title: Re: 2.5TD Head Gasket - Notches?
Post by: Martin_1962 on 08 September 2007, 20:44:57
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Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
No dealer around here stocks them...

Land Rover?

BMW?
Title: Re: 2.5TD Head Gasket - Notches?
Post by: CaptainZok on 08 September 2007, 20:45:43
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Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
No dealer around here stocks them...
No mention in TIS/EPC for either marque?
yup, 2 or 3 notches. No clues to notch location.
Bugger.
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 20:56:05
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Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
No dealer around here stocks them...

Land Rover?

BMW?
no landie or beemer dealers for a good few miles round here.
Title: Re: 2.5TD Head Gasket - Notches?
Post by: Martin_1962 on 08 September 2007, 21:17:38
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Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
No dealer around here stocks them...

Land Rover?

BMW?
no landie or beemer dealers for a good few miles round here.

I'm surprised = living where you do that there aren't these dealers
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 21:19:08
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Why not speak to the friendly parts guy at the local helpfull dealership and view a new one and get a clue as to where to look on the head?  
No dealer around here stocks them...

Land Rover?

BMW?
no landie or beemer dealers for a good few miles round here.

I'm surprised = living where you do that there aren't these dealers
John Deere maybe...
Title: Re: 2.5TD Head Gasket - Notches?
Post by: LFF64 on 08 September 2007, 21:27:52
Hello TB I have a digital caliper at work if you want to measure the thickness, is the head off sorry not been following too closely. I am not even sure if the measuring would be any good do you know the different sizes of the different gaskets    
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 21:41:20
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Hello TB I have a digital caliper at work if you want to measure the thickness, is the head off sorry not been following too closely. I am not even sure if the measuring would be any good do you know the different sizes of the different gaskets    
Head not off.

Seriously contemplating swapping engines back tomorrow though....  ....at least with old engine, the car was drivable.
Title: Re: 2.5TD Head Gasket - Notches?
Post by: LFF64 on 08 September 2007, 21:45:13
Well if you want a hand I am not doing much  :y
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 21:47:07
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Well if you want a hand I am not doing much  :y
Thats incredibly kind.  PM me your mobile, and I'll drop you a text in the morning once I've made a decision....
Title: Re: 2.5TD Head Gasket - Notches?
Post by: LFF64 on 08 September 2007, 21:50:42
Done  :y
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 08 September 2007, 21:54:17
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Done  :y
msg received :y

I shall text you in morning once I've considered options....
Title: Re: 2.5TD Head Gasket - Notches?
Post by: JezInBrum on 10 September 2007, 05:14:00
Sorry for late respomse to this, only just seen it. From memory heads get machined when produced & matched to a gasket at assembly.
If head is just coming off you replace like for like. Eg if it has two notches replace with same. If head is wasped or requires skimming you need to fit the next gasket up, 3 notch.
Where they are on the gaskets i cannot assist with i am afraid but it is a strip to locate job in most cases. You also find alot of dealers will not stock them due to the variables involved.
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 10 September 2007, 22:12:26
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Sorry for late respomse to this, only just seen it. From memory heads get machined when produced & matched to a gasket at assembly.
If head is just coming off you replace like for like. Eg if it has two notches replace with same. If head is wasped or requires skimming you need to fit the next gasket up, 3 notch.
Where they are on the gaskets i cannot assist with i am afraid but it is a strip to locate job in most cases. You also find alot of dealers will not stock them due to the variables involved.
I think we found the notches - small square holes punched in gasket.

Original engine has 2 holes, donor has 3.

I want to put donor head on original block. Which gasket?
Title: Re: 2.5TD Head Gasket - Notches?
Post by: hotel21 on 11 September 2007, 13:19:30
I would suggest the size that goes with the doner head in case that head has been machined at some stage previously.  

Feasable that a head has been machined but unlikely that the top of the block has been done so that should be as per factory original specs....
Title: Re: 2.5TD Head Gasket - Notches?
Post by: Martin_1962 on 11 September 2007, 15:15:18
As above - base on head - 3 hole
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 12 September 2007, 09:03:10
All valid points, any more views?
Title: Re: 2.5TD Head Gasket - Notches?
Post by: Dazzler on 12 September 2007, 09:10:37
If you are using the donor cars head and that has 3 notches then you will need a 3 notch gasket for when you refit it to your engine. Because the 3 notch gasket signifies that the head has been machined already once before. IMHO.
Title: Re: 2.5TD Head Gasket - Notches?
Post by: hotel21 on 12 September 2007, 09:17:27
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If you are using the donor cars head and that has 3 notches then you will need a 3 notch gasket for when you refit it to your engine. Because the 3 notch gasket signifies that the head has been machined already once before. IMHO.

......or conversely, it has not been machined and the other, with the 2 hole gasket, has.....

Without knowing the significance of 2 or 3 hole gaskets - which one is for which purpose - then it makes more sense to me to stay with whatever gasket goes with whatever head.

Agreeing with you, just trying to avoid assumptions as to machining....  :y   :D
Title: Re: 2.5TD Head Gasket - Notches?
Post by: TheBoy on 12 September 2007, 09:22:37
LFF64 measured them, I think the 3 notch was thicker....  ...but my memory is poor ;D
Title: Re: 2.5TD Head Gasket - Notches?
Post by: Dazzler on 12 September 2007, 10:01:43
Good point Hotel21, one should never assume......