Your Thoughts.....

Ok stripping down a block due to oil & water mixing somewhere came across a likely reason why but on the way i noticed on the valves a crack in between them all bar one pair....

what you think oversize valves causing a weakness in the head?

also on the bottom block you will see a 3 way crack going into the waterways now do you think the water could track up the headbolt into the rockercover?

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Originally Posted by IANMM

Ok stripping down a block due to oil & water mixing somewhere came across a likely reason why but on the way i noticed on the valves a crack in between them all bar one pair....

what you think oversize valves causing a weakness in the head?

also on the bottom block you will see a 3 way crack going into the waterways now do you think the water could track up the headbolt into the rockercover?

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the cracks between the valves will not cause oil and water mixing.

- the valves dont look much bigger than standard to be honest - have you measured and confirmed they are actually bigger?

that block is scrap. i dont think the water will track up into the thread into the head area. - someone hasnt gotten all the water/oil out of the thread and then tightened up the headbolts and cracked the block.

if oil is in the water, then suspect the oil way through the head is cracked. - look beneath the plate on the side of the head. - there is a casting defect, that always cracks there.
if water is in the oil, suspect the liner seals, rad oil cooler (unlikely) or the turbo core (unlikely)

no havent measured them as it was late and i had had enough :) is there any effects as they are cracked now ie loss of compression?

if you take the valves out, check to see if the crack has spread around the valve seat insert.... thats bad news if it has.

Seen loads of heads with the cracks and as sparkie has said aslong as its not cracked into the seat it should be fine. Ive refitted heads like this and its never come back on me.:)

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Originally Posted by ROB C2GTT

Seen loads of heads with the cracks and as sparkie has said aslong as its not cracked into the seat it should be fine. Ive refitted heads like this and its never come back on me.:)

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mine has cracks there too..... i just put it back on and turned up the boost... so far so good