Bob Postill's Stag Head-Gasket replacement

Wings covered and ready to start

 
A few photo's to remind us where all the bits go when we put it all back together

 
Coolant drained via lower hose

 
Air box lid, filter and housing removed

 
This leak on the top-hose was probably the cause of coolant loss!

 
Vacuum hoses

 
A kink in one of the breather pipes will be sorted during the rebuild

 
The carbs are retained by a single stud and nut

 
Vacuum fitting removed for access to securing nut

 
Fuel hose disconnected from fuel filter

 
Carb securing nut removed

 
Carb assembly lifted away from inlet manifold

 
Ignition coil and bracket removed

 
Inlet manifold coolant hose removed

 
Evidence of long-term leakage from top-hose connection and possibly water-pump cover

 
Inlet manifold bolts being removed

 
Manifold lifted away from heads - coolant everywhere!

 
View of heads with the inlet manifold removed

 
Evidence of sealant used during the last rebuild - also helicoils fitted during the same stage

 
Corrosion on the water-pump cover - it was decided to replace the cover

 
Power steering pump bracket removed

 
Rocker covers off next

 
Lifting the cover away from the head

 
Excellent cams, no evidence of any wear at all

 
Radiator bolts removed

 
And radiator lifted out

 
After a good soaking in penetrating oil it's time to remove the down-pipes

 
No problem at all getting the nuts off the exhaust manifold studs

 
It's raining, it's cold, but at least the exhaust is coming off easily

 
Tangs bent away from the camshaft-sprocket retaining bolts, one bolt removed and the cam rotated with the aid of a large spanner on the crankshaft nut.

 
The sprocket is loosely bolted to the hanger using a spare nut. Don't use a nut from the camshaft bearing housings - you don't want to disturb the bearings! Remove the second bolt from the sprocket being careful the bolt or the retainer is not lost down into the block

 
Bolts removed from the timing chain housing

 
Ports covered with packing tape - Gaffer tape would have been better but we didn't have any

 
View showing sprocket bolted to hanger

 
The valley is cleaned ready for head removal

 
Clean and ready for head removal

 
Loosening the head bolts in sequence

 
Using a stud extractor on the upper row of studs

 
One head off in short order - no sign of a head-gasket failure but there was bad silting of the coolant passages. These have been cleared out before this picture was taken. This would have affected the coolant flow in the rear cylinders.

 
As is obvious from the photo above, one of the studs failed at the extent of the upper thread. This was due to corrosion that locked the stud to the head. Fortunately, only one stud caused a problem. We used a tool fashioned to lift the head slightly by levering between the block and the rear head overhang. We could manage to lift the head by, at most, 1mm at the rear - the head was then pulled back down with a bolt to move the failed stud in the head by a small amount.

Using this method (and others) the head was eventually raised enough to get a hacksaw between the head and the block and the stud sawn off. This allowed the head to be removed. The remains of the stud was drifted from the head with no problems. The 20mm of remaining stud was removed from the head by using a sequence of penetrating oil - a gentle tap with a sledgehammer - heated up with a blowtorch - another tap with the sledgehammer and then removed with a pair of Stilsons (pipe wrench)

Hylomar in abundance when refitting the inlet manifold. The bolts were tightened in sequence with the head bolts and studs. The head had already been Helicoiled but one of the long bolts felt like it was failing. We removed the plain washer and were very careful not to over-torque that particular bolt.

Studs being torqued-down in sequence. We did this in around six stages

Painted rocker covers in place

New water-pump cover fitted - The bolt from where the coolant leaked can just be seen under the thermostat-cover's connection to the top-hose. We managed to remove this with a bendy ring-spanner. The washer was removed (this was a split-washer), the bolt coated in silicone sealant - and then replaced - this stopped the leak completely.

Fully re-assembled

The car is canted so that the coolant filler is at the highest point. Heater set to HOT and coolant system refilled