Thread: I pulled the heads, have a look

G`day

Can you post pics of both sides of the head gasket around #8 ?

Can you post pics of the block around #8 ?

Can you post a pic of the head around #8 ? ( better if before clean )

I can see the leak between the 2 cyls , this would account for some power loss .

From your pics so far i can see no reason for pressurising the coolant system .

Your pic of the block near #8 , there is no sign of leakage from the coolant port , the gasket may show more .

None of the pics give indication why #8 plug would show rust .

If it were mine i would use 14 bolt comp gaskets , they are a little thicker compressed than tin compressed but not as thick as 10 bolt comp .

These 14 bolt would give a higher comp ratio than 10 bolt and will work better with lpg .

If you use the 10 bolt comp you will find your economy may not be a good as it has been .

Cheers

Originally Posted by PLR

G`day

Can you post pics of both sides of the head gasket around #8 ?

Can you post pics of the block around #8 ?

Can you post a pic of the head around #8 ? ( better if before clean )

I can see the leak between the 2 cyls , this would account for some power loss .

From your pics so far i can see no reason for pressurising the coolant system .

Your pic of the block near #8 , there is no sign of leakage from the coolant port , the gasket may show more .

None of the pics give indication why #8 plug would show rust .

If it were mine i would use 14 bolt comp gaskets , they are a little thicker than tin compressed but not as thick as 10 bolt comp .

These 14 bolt would give a higher comp ratio than 10 bolt and will work better with lpg .

If you use the 10 bolt comp you will find your economy may not be a good as it has been .

Cheers

Too late for pics now, the block I've cleaned the block and the gaskets are in the scrap bin.
On advice of a forum member I used seal up a months ago, to try and stop the 'rusty' plug on 8, ( rusty is the way I describe it as it was brown with a thick rusty crust on the electrode, and there was coolant loss, so I presumed it was coolant leaking in there, it didn't look like a fouled plug from fuel or carbon, ) this was one that was getting inoperative very quickly. Since I used the 'seal up' the problem went away. The plug from 8 was ok when I pulled the heads
I wonder if combustion gases travelled back into number 8 from 6 also and maybe that was stuffing the plug too?

Originally Posted by Rovernaut

Too late for pics now, the block I've cleaned the block and the gaskets are in the scrap bin.
On advice of a forum member I used seal up a months ago, to try and stop the 'rusty' plug on 8, ( rusty is the way I describe it as it was brown with a thick rusty crust on the electrode, and there was coolant loss, so I presumed it was coolant leaking in there, it didn't look like a fouled plug from fuel or carbon, ) this was one that was getting inoperative very quickly. Since I used the 'seal up' the problem went away. The plug from 8 was ok when I pulled the heads
I wonder if combustion gases travelled back into number 8 from 6 also and maybe that was stuffing the plug too?

No problem , you must work too quick .

I`d suggest you if you happy you could see the leak signs on the head gasket , it may be worth checking .........

Where the leak was between cyls use a straight edge , like a metal rule and see if you can measure any clearance on the block , as in a hollow .

Look closely at the block around #8 , the change from the block to the liner should be no more than a colour change , as in the aluminium grey should all look the same right up to the liner steel . The liner is an obvious different colour , but should see no signs of distortion of the alloy near the liner .

The liner doesn`t have to have actually dropped to show a problem .

You need to look very closely but if you know what your looking for it`s sometimes possible to pick a leaking liner .

Also if you use your thumb nail or similar and scrape it across , starting on the alloy and running across the liner and back the other way with a smooth movement . If anything`s amiss yiour nail will catch .

By the amount of carbon inside whatever internal coolant leak it has or had is very little .

If a liner leak it is in the very first stages and the gunk will help .

The the liner was recently leaking the piston would have little or no carbon on it .

2 signs of a liner leak without taking things apart are plug rust and more than usual liquid from the exhaust from cold .

It seems that gaskets will fix the obviious problem now and if suss about the liner run it with gunk and water for awhile when you put it back together and later use coolant .

Only suggestions .

Cheers

ps .. your heads are the small chambered ones so other than a skim don`t require an amount of metal removed for an acceptable ratio .

Originally Posted by p38arover

Nice and clean!

I don't understand why a combustion chamber leak between 6 and 8 would only affect 8 (rusty/burned plug).

this can happen with the tin gaskets and a warped head.

the lifting of a corner of the head allows the tin gasket to act like a one way seal in much the same way as ducks bum works.

Picked up my heads today.
Verdict was pressure tested ok, hardness ok.
Valve guides good, but exhaust valve seats were U/S and had to be replaced. Seats re cut, heads only need a slight shave as they were pretty straight.
I couldn't supply them new valve stems seals , so the had to supply them and one head needed to have the inlet port thread holes heli coiled. ( I can understand this as the previous tin gaskets made fitting the inlet manifold difficult and apparently stripped the threads
So it ended up costing me $760, the Valve seats and the VS seals brought it up over the $500.
I fitted the heads yesterday arvo.( used new Payten torque to yield bolts - $50.85 complete set from Karcraft in Sydeny)
As usual the rear lower head bolt ones are ARPITA to get to and use a Degree guage. But after a bit of using unis on the socket and bars it installed.
So the rest of the week end will be refitting everything.

Originally Posted by Rovernaut

used new Payten torque to yield bolts -

As usual the rear lower head bolt ones are ARPITA to get to and use a Degree guage.

When I had my 4.6 rebuilt by Davis Performance landys they used the older conventional 3.5 bolts, not TTY bolts.

Not wanting to steal this thread but I am having similar problems, except I havent pulled the engine down. When I replaced the auto box after a couple of days without the auto attached coolant ran out of the left hand header (oh bloody yay) did a temporary fix which was radiator leak fixer in it and off I went.

My quandary is I think the engine is cactus, but by being gentle with it am keeping it going. So my question is would it be better to get a 4.6 short block and build it up out of the 3.9 bits or take the chance on a second hand one from the likes of Triumph Rover Spares or someone similar?

Blythe

Blythe,
I'd save up and go the 4.6 shrt.


JC