DIY Head Gasket Change tips and tricks?

[Mark Serj]

Or even wheels.....

[Marco Polo]

All I can say is, I've run my car on 93, 95 and 98 octane and the engine runs and responds better with the higher octane fuel. A "mate" once filled it with E10 and it ran like a dog! I have now forgiven him but he doesn't borrow the Stag anymore! The best it ever runs is when I'm able to get AVGAS 100/110 or 130. The engine idles perfectly, far more responsive, the plugs have a nice sandy colour, the exhaust outlet goes that nice light grey colour and the temp gauge indicates a tad lower. The MPG is better too. I wish I could get it more often. The engine is standard, apart from extractor manifolds and a modified Ford V8 distributor with electronic ignition statically advanced to 14Deg BTDC

[Guest]

All I can say is, I've run my car on 93, 95 and 98 octane and the engine runs and responds better with the higher octane fuel.
A "mate" once filled it with E10 and it ran like a dog! I have now forgiven him but he doesn't borrow the Stag anymore! The best it ever runs is when I'm able to get AVGAS 100/110 or 130. The engine idles perfectly, far more responsive, the plugs have a nice sandy colour, the exhaust outlet goes that nice light grey colour and the temp gauge indicates a tad lower. The MPG is better too.

Sorry but I keep saying this is pure imagination.
The engine has such a miserably low REAL compression ratio, that the condition you describe is physically and scientifically in all ways impossible.
That engine will run perfectly on anything from 80-90octane as incidentally will the equally awful detuned BMW 850i V12....

On one occasion I set out to prove you could run the TR6 Pi on 95 octane unleaded with fuel with NO loss of power and no ill effects whatsoever, and no matter where you bought the fuel from.

That engine has a CR of 9.5:1, which is higher than the heavily detuned STAG.
In fact the Lucas pi has almost no restriction at all.

I paid for the morning on the rolling road and all the fuel samples, including Shell 95 UL and Shell Optimax 97.
We had all the same old bollox repeated ad nauseam by the TR fraternity, how bla bla their cars make more power and run better on that expensive fuel, and how bad Total fuel was.....

Each time I emptied the tank and made no changes to ignition advance or fuelling.
Hey presto, all the graphs of torque were absolutely the same.
No measurable difference in power.

There was none of this mystique and bollox possible.

I have no doubt with avgas it would be identical, in fact AVGAS is designed to be run LEAN.....which is what A/C do when they get to altitude, (to optimise A-f ratio and lower fuel consumption where the A-P is much lower)
+
so that the vapour pressure remains stable at high altitude and frosting temps in carbs etc....nothing whatsoever to do with octane or power output.

Avgas is also designed for SLOW RUNNING ENGINES...cos guess what, have you ever seen an aircraft engine making peak power at 5000rpm.
NADA, don't exist, no reason to want anything but SLOW BURNING.

Sorry to disappoint you, the last stuff you want in a high powered competition engine is AVGAS, there's much better concoctions available trackside, which will make peak power typically like for a Honda Vtec at 7800-8500rpm...

Shock - horror even 10% alcohol makes a fat lot of difference to such engines.

[flying farmer]

E10 is horrible stuff as it makes the engine run lean as you need a far greater volume of fuel to get the correct AFR, the lean mixture makes them run hotter too. I could see the difference on my AFR meter when I have on holiday in France. Modern engines run closed loop management so can compensate for different fuels.

The lovely exhaust colour is due to the lead oxides from the Avgas, the old 4 star was dead easy to set up cruising fuel mixtures. With unleaded you need to run a wideband lambda sensor to make any sense of the mixture

[Guest]

It depends on the engine.

4V engines LIKE running lean, they actually run better.
Some of them like the K series and others are designed for lean burn.
The Stag combustion chamber has loads of squish and (really hot) N12Y plugs which means it's almost incapable of misfiring. (apart from the antique dizzy).

I would blame the French more for putting roundabouts every 800 yards, chicanes, concrete flower beds in the centre of their roads, and a flash radar every 3 miles, then reducing the max speed limit to 50mph instead of their already "escargot" 55.

I wouldn't blame them for their fuel, it hasn't ever caused me a problem on any of my cars.
(6000kms in Nov and Dec alone).

[jakesmig]

You tune your engine for the fuel you are going to most frequently use. If you tune on high grade fuel, it will run poorly on lower grade fuel, if you tune on low grade, using high grade will make no difference.
Generally all fuel in any given location will all come from the same refinery, out of the same distribution tank. The only difference in fuel between a named brand and joe blogs down the street is in the additives which, generally, the branded garages add when filling their forecourt tanks. One of our local supermarket outlets increases the amount of detergent in their diesel so that a 'full' tank at their outlet is about 3/4 litres short compared to a branded garage down the street when the filler continuously clicks off. You can only brim the tank at the store outlet if you wait ages for the foaming to dissapear.
As an anal end to this diatribe, I 'tested' a so called super fuel a few years ago and found little difference in mpg between a store outlet fuel and a 'top'branded superfuel. On the outlet fuel in 1 year over 26500 miles I averaged 53.6 mpg, the next year on the 'superfuel' over 28750 miles I averaged 54.2 mpg. Admittedly that is all subjective because it was just driving. not controlled comparison, but the end result is that the superfuel cost more per mile than the outlet. The superfuel allegedly cleans the engine as it wafts its way through, perhaps, perhaps not.
These days I use the standard quality fuel from the branded garage.

John

[Ctwidle]

Ian, despite my car being in Aus I suspect both our cars had the same PO as I am finding so many of the same problems with my HG replacement! No lock tabs, misaligned gaskets, repaired threads, liberal use of blue sealant etc.
I am contemplating messing up my shed by poking the wand of a very high pressure washer (claimed to be up to 4000psi) into the water galleries while the heads are off as there is still some Mansfield red casting sand lying around in there. There will be a lot of water going in all directions so I will be plugging the oil ways and cylinders carefully. I have made some wooden discs that fit into the top of the bores with grease around the edges to keep as much out of them as possible.
For cleaning the heads I bought a couple of kilos of baking soda and used a cheap sandblasting gun. Bit slower than some mediums but, as it dissolves in water, a pressure washing leaves no abrasive residue. Works well on carb bodies etc.
i will be going back through the threads about HT tank plumbing carefully as, although I can't blame it for the HG failure, (corrosion and pitting on the lower edge of the RH bank caused a leak to the outside between 5 and 6, found when I added fluorescent dye to the coolant) I am beginning to think that there may be better systems than tapping into the horseshoe hose.
The heads have been extensively skimmed in the past so 65 thou gaskets are going on with a liberal amount of JB weld in the corrosion pits - fortunately none of these affect the fire rings. Still contemplating whether to rely on a light clean up with a fine abrasive paper on a block will be enough as they are quite flat (can't get a 1 thou feeler under a straightedge in any direction) or if I can trust a machinist to take off the bare minimum.
It has been suggested to me that removing the plug in the end of the oil gallery behind the water transfer cover allows for more efficient cleaning out of any remaining sand from the oil gallery. This reduces the risk of sand causing further damage to the rearmost cam bearing. I haven't been able to shift the plug yet (slotted head with a blind 5/16w thread in it for one of the cover bolts) so I am considering drilling through it and relying on some sealant on that bolt after a blast from the pressure washer.
Who will get his engine running again first?
Hope the shared experience helps,
Chris

[Guest]

You tune your engine for the fuel you are going to most frequently use. If you tune on high grade fuel, it will run poorly on lower grade fuel, if you tune on low grade, using high grade will make no difference.

This is all very well in theory, but how an engine & its behaviour runs depends on FUEL DROPLET SIZE.

The Stag engine with those Strombergs is quite incapable of being sensitive to fuel quality, because it has an impossibly bad induction system and even worse carburettors.
I have to insist on this.
The way such an engine runs at 4.5-5:1 compression ratio with great gobs of fuel droplets unequally metered between different cylinders out of 8, means it has areas in the chamber which simply are incapable of burning properly.

This is the reason why they put such damn hot plugs in there, and try to get it to use as lean needles at is physically capable of using.
The whole thing is a gigantic bodge up, and the emission control is a joke.

The world experts on making engines combust properly is BMW, which is why their engines actually deliver the claimed output, or very close to it, and have done since the 60s.
In fact their M series engines were used for motorsport for decades cos they work.

The British for decades made engines which deliver nothing remotely close to their claimed output, and used 1920s carburettors designed by a shoe repairer, which is why the power outputs and claimed fuel sensitivity is exactly that.

A load of cobblers!

[Mark Serj]

Ian, despite my car being in Aus I suspect both our cars had the same PO as I am finding so many of the same problems with my HG replacement! No lock tabs, misaligned gaskets, repaired threads, liberal use of blue sealant etc.
I am contemplating messing up my shed by poking the wand of a very high pressure washer (claimed to be up to 4000psi) into the water galleries while the heads are off as there is still some Mansfield red casting sand lying around in there. There will be a lot of water going in all directions so I will be plugging the oil ways and cylinders carefully. I have made some wooden discs that fit into the top of the bores with grease around the edges to keep as much out of them as possible.
For cleaning the heads I bought a couple of kilos of baking soda and used a cheap sandblasting gun. Bit slower than some mediums but, as it dissolves in water, a pressure washing leaves no abrasive residue. Works well on carb bodies etc.
i will be going back through the threads about HT tank plumbing carefully as, although I can't blame it for the HG failure, (corrosion and pitting on the lower edge of the RH bank caused a leak to the outside between 5 and 6, found when I added fluorescent dye to the coolant) I am beginning to think that there may be better systems than tapping into the horseshoe hose.
The heads have been extensively skimmed in the past so 65 thou gaskets are going on with a liberal amount of JB weld in the corrosion pits - fortunately none of these affect the fire rings. Still contemplating whether to rely on a light clean up with a fine abrasive paper on a block will be enough as they are quite flat (can't get a 1 thou feeler under a straightedge in any direction) or if I can trust a machinist to take off the bare minimum.
It has been suggested to me that removing the plug in the end of the oil gallery behind the water transfer cover allows for more efficient cleaning out of any remaining sand from the oil gallery. This reduces the risk of sand causing further damage to the rearmost cam bearing. I haven't been able to shift the plug yet (slotted head with a blind 5/16w thread in it for one of the cover bolts) so I am considering drilling through it and relying on some sealant on that bolt after a blast from the pressure washer.
Who will get his engine running again first?
Hope the shared experience helps,
Chris

Hi Chris,

I had no ides there was a core plug as you have mentioned. I did wonder why there was what looked like a thread insert in mine - thought it was a repair, although somewhat coincidental on both heads! Has anyone had any experience of removing this?
I used a black granite metrology surface table, taped sanding sheets to it, put some water on them and floated my heads on it in a fig 8 pattern. I let the weight of the head do the work to ensure as best an even loading as possible and it did a fab job. Came out as flat as you can get, and with fire rings removed. Probably only removed a couple of thou tops.

Regards

Mark

[jakesmig]

This is all very well in theory, but how an engine & its behaviour runs depends on FUEL DROPLET SIZE.

The Stag engine with those Strombergs is quite incapable of being sensitive to fuel quality, because it has an impossibly bad induction system and even worse carburettors.
I have to insist on this.
The way such an engine runs at 4.5-5:1 compression ratio with great gobs of fuel droplets unequally metered between different cylinders out of 8, means it has areas in the chamber which simply are incapable of burning properly.

This is the reason why they put such damn hot plugs in there, and try to get it to use as lean needles at is physically capable of using.
The whole thing is a gigantic bodge up, and the emission control is a joke.

The world experts on making engines combust properly is BMW, which is why their engines actually deliver the claimed output, or very close to it, and have done since the 60s.
In fact their M series engines were used for motorsport for decades cos they work.

The British for decades made engines which deliver nothing remotely close to their claimed output, and used 1920s carburettors designed by a shoe repairer, which is why the power outputs and claimed fuel sensitivity is exactly that.

A load of cobblers!

Nice rant, bit harsh on Timpkins.

PS, our rally outfit has had 4 class wins in the SRC rally championships in the last 6 years without resorting to poxy German crap to do it.

[Guest]

Nice rant, bit harsh on Timpkins.

PS, our rally outfit has had 4 class wins in the SRC rally championships in the last 6 years without resorting to poxy German crap to do it.

Never mind.
Why bother?

http://speedqueens.blogspot.fr/2013/03/les-autres-1980-present-day.html

While we're at it let's forget the machos and remember another fast woman?
Seems she didn't mind the poxy German stuff too much.

http://speedqueens.blogspot.fr/2010/07/michele-mouton.html

[jakesmig]

Don't know who Norma is but Martini is usually made with gin and vermouth, and garnished with an olive or a lemon twist

[jagorstag]

Now lads, shall we get back on topic again before someone's feelings get hurt...

Thanks,
Joakim

[Scar]

The British for decades made engines which deliver nothing remotely close to their claimed output, and used 1920s carburettors designed by a shoe repairer, which is why the power outputs and claimed fuel sensitivity is exactly that.

A load of cobblers!

Rover came close to getting it right with the T and K-series engines. Just a shame about those head gaskets...

[jakesmig]

I've a good K series in my Midget, 30K mostly abusive miles including numerous track days without heating problems. When i did the head up I drilled out the water ports, about 10 if I recall correctly, which are unfinished ex works castings. Drill them out to 10mm and smooth off and the port is probably 300% larger. Even at up to 8500 rpm on track days the temperature doesn't rise.