14 replies to this topic

[MiniElliott]

Hi, I recently bought a cylinder head off a member from here. Its a 12G940 that has been modified. Ported, bigger valves and skimmed. It didn't mention in the sale description and I missed this in the images this damage to the surface.




I assume these are water ports.

Is this serious damage ? Will it cause any problems in the future ?

Thanks
Elliott

[Jacksdad]

Well I certainly wouldn`t want to use it. The potential for water leakes around those areas is, in my opinion too great. Steve.

[holmesy]

2 options. get someone to weld in the gaps then get it skimmed and hope it doesn't distort too much. or scrap it and sell the valves. I have never seen anything like that before

[Artful Dodger]

That may be a mod some people do to the cooling system. They block off some water galleries in the blog and head and re route them. I think this is hat this could be but I wouldn't use that head. Not been done right.

Get the seller to refund you and find another head:).

[BritishRacingGreen]

Surely to such a nice head it would be worth offering it up to a headgasket to see how severe the modification is? Personally I'd chuck it on and give it a shot

[MiniElliott]

That may be a mod some people do to the cooling system. They block off some water galleries in the blog and head and re route them. I think this is hat this could be but I wouldn't use that head. Not been done right.

Get the seller to refund you and find another head:).

I think you're referring to dry decking. Unfortunately this is not dry decking. It appears it has been over skimmed and broken the surface between the two holes.
I have contacted the seller about a refund, but I wont name him unless circumstances change.

Elliott

[MiniElliott]

Original image. This looks more like left over gasket or oil to me.

[mk1leg]

As above over skimmed......usless.....a waste of money.....

[holmesy]

definitely looks like it's been over skimmed, dry decking would mean all the water holes plugged. check the depth of the face and see if it's been taken further than the recommend amount

[tiger99]

It is not ideal, and should be replaced by the supplier, but in reality that damage is unlikely to cause a leak, unless it overlaps on to some hole other than a waterway in the block. There would seem to be more than enough metal still around to form a good seal as long as the gasket has something solid behind it in the block.

If you can, post a photo with the gasket aligned to the head, another with it on the block, and another with just the block. That will give a better idea and people may have more advice.

I know that if certain heads are skimmed too far, an oilway is broken into and is generally repaired by brazing in a piece of copper tube, and then lightly skimming again. However, this seems to be a waterway, as people have suggested.

[The Principal]

Hard to tell from the pic how much that has been skimmed, the chambers do look shallow but hard to be exact in 2D. Did the seller say what the chamber capacity is?

you can check yourself using water and a pipette or easier to ask the seller what the mods are for

[MiniElliott]

It is not ideal, and should be replaced by the supplier, but in reality that damage is unlikely to cause a leak, unless it overlaps on to some hole other than a waterway in the block. There would seem to be more than enough metal still around to form a good seal as long as the gasket has something solid behind it in the block.

If you can, post a photo with the gasket aligned to the head, another with it on the block, and another with just the block. That will give a better idea and people may have more advice.

I know that if certain heads are skimmed too far, an oilway is broken into and is generally repaired by brazing in a piece of copper tube, and then lightly skimming again. However, this seems to be a waterway, as people have suggested.

Hard to tell from the pic how much that has been skimmed, the chambers do look shallow but hard to be exact in 2D. Did the seller say what the chamber capacity is?

you can check yourself using water and a pipette or easier to ask the seller what the mods are for

The chamber CC was quoted to be 16cc. I believe standard are 21cc.

The actual ad is still in the for sale section to view if necessary.

However I don't want to put all the blame on the seller at this time. It could be a genuine mistake, so I will wait for a response from the seller.

Thanks
Elliott

[tiger99]

it looks from the pictures that there will be decent gasket overlap all round so it might not leak. However the gasket you are using has copper rings around these holes, which is normally a good thing, but in this case not helpful as the holes extennd beyond the rings. A plain gasket with no rings would, in this instance, work better.

Best to have it welded up and reskimmed if you are keeping it.

[MiniElliott]

it looks from the pictures that there will be decent gasket overlap all round so it might not leak. However the gasket you are using has copper rings around these holes, which is normally a good thing, but in this case not helpful as the holes extennd beyond the rings. A plain gasket with no rings would, in this instance, work better.

Best to have it welded up and reskimmed if you are keeping it.

Im hoping the seller will refund first, but getting it welded will be the next option. Do you have an idea how much it will cost to get it welded ?

Elliott

[holmesy]

not as simple as chucking some weld in it, the head is going to need to be solidly braced to reduced as much distortion from the heat, but by also doing this there are chances of other problems happening due to the high stress the metal will be under. I would say to have it done properly and then skimmed you'll be looking at 120