coolant flow - (follow up to cooling diagram)

[widdowson2008]

Hi widdowson2008,
Did you find the extent of the crack.

It appears to be a surface crack - not deep at all. Having said that, it's deep enough to have let exhaust gasses into the inlet port. Quite scruffy in there compared to the other inlet ports.
Not 100% sure (perhaps Allan could verify) but I think No.3 cylinder (where the crack is) had water in it, which would suggest that the crack extends into the waterways. Allan needs to confirm this. LORNA!!!!!!!!!!!!!!!!!!!
The one thing that is of possible interest here is that at the crack point, the thickness of the aluminium is only 6mm. Would that have a bearing on owt?


On the plus side, I have traced the many waterways and found out the path of all entry passages through to the exit ports. Will post diagram soon.

Info gathered using this pic

The head has a main chamber running the entire length of the head. All ports eventually lead into this chamber.
There are 2 exit ports (at the front end of the head), one going to the radiator and one to the thermostat bypass.
Using colours on attached pic:
BLUE PORTS - Lead directly to the main exit chamber.
RED PORTS - feed jackets around the inlet valve seats, then to the main exit chamber.
GREEN PORTS - go to feed jacket around the exhaust valves, then to the inlet valve seats, then to the main exit chamber.
YELLOW PORT - is directly from the oil cooler (I think) and straight into the main exit chamber

Diagram will explain it easier

oops - forgot some ports
MAGENTA PORTS - Lead directly to the main exit chamber

Looking at maxs post, the crack on both these heads is in exactly the same place (between inlet and exhaust valve seats) but on a different cylinder. Weak spot?

[widdowson2008]

Been pondering how to do this and I'm afraid, in order to get this lot down on record, I can't see an alternative to bombarding the post with pics, so I apologise in advance.

This first set of 3 pics shows where I made the cuts.
Pics of the individual cuts will follow, but I warn you, this could get messy.

1 - Full head


2 - Rear section removed


3 - Mid setion top removed

[mikexgough]

Looking at maxs post, the crack on both these heads is in exactly the same place (between inlet and exhaust valve seats) but on a different cylinder. Weak spot?

Seems to be common on these heads..... happens to Ford Ranger and BT50 pick ups in the same place...

[mister munkey]

Looking at maxs post, the crack on both these heads is in exactly the same place (between inlet and exhaust valve seats) but on a different cylinder. Weak spot?

Seems to be common on these heads..... happens to Ford Ranger and BT50 pick ups in the same place...

Me too.

Pm sent Steve.

[widdowson2008]

OK - onslaught of pics
FRONT SECTION




Mid section to follow

[widdowson2008]

MID SECTION


NOTE: This pic is a section through the cracked No.3 cylinder. Exhaust valve on left.







REAR SECTION TO FOLLOW

[widdowson2008]

REAR SECTION

Rear offside


Rear offside


Rear offside


Got more, but that should get a few folks grey matter stirred

Would someone care to start a discussion on this lot cos I wouldn't know where to start.

[dave_aber]

My first thought was "how does trapped air in the main chamber get down to the 3-way union to get back up and out the bleed tube?"


(Oh, and great work by the way.)

[widdowson2008]

My first thought was "how does trapped air in the main chamber get down to the 3-way union to get back up and out the bleed tube?"

Didn't want to be the first to mention this but that was the first thing I spotted too. It's a good 10mm BELOW the roof of the main chamber.
AND - to make the situation worse, the bleed hose is 20mm ABOVE that.
ie - Bleed hose is 30mm above the roof of the main chamber.

The top of the radiator connection is at the same level as the roof of the main chamber, suggesting to me that any air trapped in the head has got to leave via this connection - or am I missing something?
Does a sensor fit in the screwed bit at this point?

[dave_aber]

I'm not sure that the extra height of the bleed hose is an issue - it's just that for air to leave the head chamber via the bleed hose it has to go downhill first, which it isn't keen on doing! Ideally, the top surface should rise all the way to the point where the bleed hose stock enters the head, and then continue to rise outside the head.

[g8dhe]

Do you have a view of where the Temperature Sender fits into the head ? I think its always been on the other side of the photo's as it were;

[mikexgough]

The top of the radiator connection is at the same level as the roof of the main chamber, suggesting to me that any air trapped in the head has got to leave via this connection - or am I missing something?

Nope, your missing nothing....

[widdowson2008]

Do you have a view of where the Temperature Sender fits into the head ? I think its always been on the other side of the photo's as it were;

I didn't, but I do now
This the one you're looking for? If so, it is fitted at roof of the main chamber level.
Have you got some radical theory to share?

[widdowson2008]

I'm not sure that the extra height of the bleed hose is an issue - it's ........

Quite right Dave - extra 20mm height has no bearing on it - I was talking a load of c**p - again. I'm getting punch drunk with this head thing.
Beggining to wish Kirsty had never dropped it off
(Sorry Kirsty - didn't mean it.)

[teenmal]

Do you have a view of where the Temperature Sender fits into the head ? I think its always been on the other side of the photo's as it were;

I didn't, but I do now
This the one you're looking for? If so, it is fitted at roof of the main chamber level.
Have you got some radical theory to share?

That looks like an ideal bleed point..