Hi all, I have just pulled the heads off my 4.6, I think I can see the cause of my woes. You can see the fire rings and where they have been compromised. The water ways at the front and back of the block are fine, you can see the fire rings have not passed into them. A number of the other cylinders have had the fire rings compromised. And one of the cylinders has got a clean section on the piston, 2nd one back on the driver side. If I can, I will take some photos of the gaskets. So new block needed me thinks.

Anyone know a good place to get one from?

Cheers

But can you see if the liner has dropped? it will sit a little lower in the block than the rest, if they are all the same its prob just a h/g problem.

Add some pics of the heads, deck and gaskets.. Your descriptions a bit hard to follow without pictures but it sounds like a head gasket failure to me.... I bet the waterways blown through the fire ring near the shiny piston.... It's not always obvious where the blow is until you look really closely, it doesn't take much...

The head gaskets/fire rings next the water ways look good,(only at the very front and back of the block). I will put some photos on tomorrow. I know what you mean by looking closely. The fire rings are compromised adjacent to some of the bolt holes. Causing the combustion gas to pass, gives a kind of polished look. The areas where a good seal was still present look Matt silver compared to the failed areas. There are a few areas where the exhaust gases have completely passed the fire rings resulting in the composite part of the gasket breaking down. So in a sense the head gaskets have failed anyway. The head bolts where so tight, tighter than I have seen before on an alloy block.

All the liners seem to be in the normal position.

Made some blanking plates today to test the block, I have read this might not reveal the crack or liner prob unless hot, but worth a go.

The engine is comming out anyway, heads are going to get skimmed. Looks like I will be on the bike for a bit. Thought it had been put to bed for the winter.

OK, heare are some photo's

From looking under the bonnet, left side second cylinder back. Rust evident. Past the fire ring.



This is the gasket at that point. You can see the fire ring on the other side is not far off being breached also.



This one shows it was blowing out the side of the engine. I noticed this from underneath the RR when on ramps. It had fired a deposite of combustion crap onto the back of the inner exhaust manifold.



This one is the water way at the back. All look like they have not been breached.



Heads need skimming and block needs new liners.

if you pressure test the cylinder block and use soapy water you will see bubbles from the offending area which you will see hot or cold ! no.4 cylinder seems to be a favourite.
If the top of the piston is washed it is usually caused by a cracked cylinder block as there are no water ways at this point as you say.
A top hat lined cylinder block will sort the problem out.
if you need one drop me a line !

Cheers hallbeckengineering for repairing the block and the parts and advice for the rebuilding. My 4.6 v8 has never sounded sweeter. Cheers.