Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[ScottieMV6]

Ok. Thanks for the advice Kev.

[Marks DTM Calib]

Given the low value of a pair of 3.0 heads second hand...it might be worth sourcing a set of second hand heads (about 40-50 quid a head tops)

The damage in the quish area looks to be either foreign object (but, you normaly get more than one impact mark) or a casting failure....if the latter then a skim is pointless.

You could change just one head for a second hand one but....if skimming you need to do both heads to keep the compression ratios constant on all 6 cylinders

[ScottieMV6]

Given the low value of a pair of 3.0 heads second hand...it might be worth sourcing a set of second hand heads (about 40-50 quid a head tops)

The damage in the quish area looks to be either foreign object (but, you normaly get more than one impact mark) or a casting failure....if the latter then a skim is pointless.

You could change just one head for a second hand one but....if skimming you need to do both heads to keep the compression ratios constant on all 6 cylinders

What is the quish area?

[Marks DTM Calib]

The squish area is the section in the cylidner inside of the head gasket fire ring....its the bowl which the fuel/air mix is comrpessed into at the top of the compression stroke

[ScottieMV6]

Have I got this diagram labelled up right? (sorry but I am still learning)



If that is correct then is this the damage in the squish area you were talking about?



If so then this is not damage but an oil smear. It is now gone!

Finally I have also found this damage on cylinder 2



What are the chances of this sort of damage being repaired?

[Kevin Wood]

If so then this is not damage but an oil smear. It is now gone!

LOL that just goes to show how hard it is to diagnose from photos.

I think you have got the terminology right. Now, bear in mind that the fire ring area is the critical part of the gasket. This must compress the metal fire ring on the gasket to form a very strong seal to contain the combustion pressures. If there is any damage to this part of the cylinder head the gasket will blow again. Elsewhere, little nicks are not such an issue because the composite gasket material has a little more give in it, there is less pressure to contain and the gasket has sealant impregnated into it.

I would first get rid of the traces of old gasket and oil by scraping with a wooden or plastic implement and then perhaps a light rub down with a fine emery cloth. Then see if there is any pitting or narrowing of the fire ring areas.

Kevin

[megaomega123]

This is a very interesting thread. Can I ask Scottie, did you do all the strip down with the engine in situ or did it come out? Just out of interest 

[Bent valve]

Have I got this diagram labelled up right? (sorry but I am still learning)



If that is correct then is this the damage in the squish area you were talking about?



If so then this is not damage but an oil smear. It is now gone!

Finally I have also found this damage on cylinder 2



What are the chances of this sort of damage being repaired?

Are you sure thats an oil smear? I would have bet money on that being a porous casting :-?

[Marks DTM Calib]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

[ScottieMV6]

This is a very interesting thread. Can I ask Scottie, did you do all the strip down with the engine in situ or did it come out? Just out of interest 

Strip down was done with the engine in situ.

[ScottieMV6]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

[tunnie]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

I found using razor blades cleans the old gasket off well 

[Kevin Wood]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

I found using razor blades cleans the old gasket off well 

A scotchpad from a plumber's merchants is not a bad investment either.

Kevin

[ScottieMV6]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

I found using razor blades cleans the old gasket off well 

A scotchpad from a plumber's merchants is not a bad investment either.

Kevin

I got 2 of those yesterday!

[Marks DTM Calib]

Yes, that was the area of concern.

So, clean the heads really well, the pitting around the coolant passages I am not that worried about but, it just goes to show what damage water with poor antifreeze mixes can do

Thanks Mark and everyone else. I am going to spend some time giving the heads a really thorough cleaning then i might just post some more pics before putting them back on the car!

I found using razor blades cleans the old gasket off well 

A scotchpad from a plumber's merchants is not a bad investment either.

Kevin

I use the ones that magicaly appear in the cupboard....for both plumbing and cleaning head faces.

But yes, you need a blade to get the crudd off first, I have an old chisel that I use