Evening all,

So the lovely day which all RS owners come to finally arrived. The head cam off due to the cam and a tappet being munched as suspected.

The head was removed(been on car for 3years) and noticed the pistons looking rather caked! along with the top end, is this from running rich?








Also I noticed the head had been welded as seen here:





So should I ditched the head, is this bodged? Also what are the standard inlet/exhaust port sizes?

Many thanks

Dave

 

Is that a zvh as my pistons didn't look like that, if it is that may be why the head has been welded

 

Yes it is a zvh,

Ah i see

 

I'm no expert but I'm sure I've read somewhere that when the heads been welded its to allow use of a differant headgasket, focus rs springs to mind

 

I'll have a look into that, cheers dude.

The one removed looked to be a triple layer type?

 

http://www.quantums.info/zvh.htm#Cylinder Head gasket

 

cheers mate

pinched this from the site

"The oil feed to the Zetec head goes closer to the edge of head than on the CVH and if you put a Zetec head gasket on a CVH head the oil just leaks out the gap. You can get the side of the CVH head built up with weld and then the head skimmed to enable you to use Zetec head gaskets."

 

Just another question, what are the normal exhaust port sizes in compared to a ported type.

Here is mine:

 

It looks like your exhaust ports have been opened up mate, they are no where near that size stock, and are flat bottomed. I've got an old thread some where showing some standard ports if you wanted a comparison.

Rob,

 

Not sure what the pistons are, is it a 1.8 or a 2.0? What does the bore measure?

The head has been welded up to use a Zetec headgasket. Much better.

The exhaust ports are very big. They look like 39mm. Mine have been worked and are 37mm

 

On a side note though, the valves themselves look standard, in size and material? What do they measure?

 

i'll have a check and update you guys, would be good to get info on what has been done previously.

Its a 2.0 zvh

 

inlet is 40mm

exhaust is 35mm

does that mean anything?

 

Valve sizes? Standard valves should be 42mm inlet 37mm exhaust. I think most heads can only accept a 43mm inlet 'oversize' valve without a crosshatch head but keep the same sized exhaust valves.

 

i'll having a measure with my rule once out, sounds like they are more or less standard sized.

 

i'll having a measure with my rule once out, sounds like they are more or less standard sized.