Massive Coolant Flooding - Cylinders And Sump

[David Morris]

Hi All,

The discussion above prompted me to ask if anyone else has experienced this situation?

I was helping a member to change a head gasket at a recent Jowett Rally and very surprised to see that the torque required to undo the head nuts was a fraction of that specified by the original suppliers of the gaskets in their assembly instructions, which are quite specific.

The owner of the Javelin is an engineer of repute and, I am sure, would have followed the original instructions to the absolute letter. The gaskets were of the approved New Zealand origin, which we should all be using.

But, here we were, a few years later, finding the gasket had failed and the head nuts couldn't have been tighter than a few foot pounds. This, of course, might have been the major factor in the failure of the gasket?

Is there a situation here where, subsequent to the original fitting, we should all be re-torquing the head nuts to the specified 35-37ft lbs, on a regular basis? What is the consensus of advice? Should I rush to the garage this evening with my torque wrench?

All the best and stay safe,

David

[Keith Clements]

Frequent checking of the torque has benefits and consequences.
Certainly headgaskets and liner shims settle during the initial few heat cycles.
Certainly blocks creep over a longer period of time....
BUT
most blocks are now quite fragile and cannot take the torque setting designed for brand new blocks.

So unless you want a cracked block I would reduce the torque setting. I would be very wary about using an uncalibrated and cheap torque wrench and also not checking I was using it correctly by doing a few trial runs on a test bench. I often trust my muscle memory more than the torque wrench. I always feel carefully the resistance as I am torqueing up, any grab or slip makes me suspicious of something about to go spectacularly wrong. Head studs occasionally pull out and sometimes you hear that sickening crack as the block splits. This is usually preceded by a lessening of the resistance. I always run a die down the studs and a tap down the nuts. Some nuts and studs can be worn and strip their threads.
I have said this many times before but I check the gap all around the head face with a 20 lb-ft grip with no gasket. I leave it for a week and see if the gap changes. It sometimes does, indicating a creaping block crack.
The best indicator is to carefully examine the head gasket when you dismantle. This will tell you if you have an even torque and seal.

[Mike Allfrey]

G'dday Folks,

Finally our lock-down has relaxed a little and we had a soapy water session this morning. Rather posh, actually, Phil brought three wood-turned plugs for insertion into the coolant inlet hoses and the front timing case hose. The plugs had been painted white, to help waterproof them. The plug at the top had a 5 mm hole drilled through for air pressure to be applied, both ends were countersunk. Before inserting the top plug, hot water that had a fair dose of Kitten Car Shampoo mixed in, was poured in. The compressor had been set to 9 psi and, after fixing a couple of hose leaks, air was applied at the top plug.

All sparking plugs had been removed, and within very few seconds, the froth commenced to exit at the number 1 cylinder plug well. It was like the Hauraki Gulch in New Zealand! All of the other plug wells remained dry. The crankshaft was rotated and, as number 1 exhaust valve opened, soapy water gushed from the exhaust manifold. It sort of kept the dust down in my workshop.

It was time to withdraw the cylinder head, which was surprisingly tight.

Initial inspection shows there is still cylinder liner protrusion, but not measured yet. That and photos will come in my next report. Further inspection revealed the fact that coolant had been present in the balance pipe, probably due to number 1 inlet valve being open for a spell, while the radiator was being topped up. Hence opposite side cylinders filling with coolant also.

I agree with all of what Philip Dingle has written. However, on the subject of 'O' ring seals, my understanding is that such liners continued using shims? I could be wrong on that.

Now, here is something interesting, I had purchased four coolant drain taps to suit my Rover P6B, from a Rover parts supplier in UK. They are those infernal things with left-hand thread and a handle that comes loose the first time it is used. They were screwed into the Jowett cylinder heads with brass adaptors. All four leaked when turned off, it is about time the Chinese learnt to make a water-tight tap!

I will doctor the photos and post them separately.

Stay well folks,

Mike A.

[Keith Clements]

One out one in. We in UK all now back to lockdown. Walked past the local pub last night and a hundred people crammed together.
Bring in the Army with steralisation guns....or perhaps we just send them to Aus like we used to....very PC....

[Mike Allfrey]

Nice one Keith!

Also liked your reference to 'trusting your elbow'. A 1/4" Whitworth spanner in a man's hand, with just a flick of the wrist is equivalent of 23 lb. ft. Which is just right for high-tensile 5/16" BSF bolts. That was proved to me by an elderly motor mechanic in the late 1950s, and was proved against a Churchill torque wrench. There could be an exception though, Sue has an amazing ability to tighten down hand basin taps!

Have been busy with Ford tractor advice over long distance. We cannot travel more than 25 kilometres from home at present.

I will be accurately measuring the current cylinder liner protrusion on Thursday. I think I will be aiming for 0.004-in.

I have a memory of seeing, a long time ago, Javelin cylinder head gaskets of copper/asbestos/aluminium. Has anyone heard of those? I think it was at that first National Jowett Day in the rain-swept, wind-swept paddock in the Bradford area, 1966?

Keep at it,

Mike A.

[Mike Allfrey]

Hello Folk,

Been back on the job today. Cleaned off the thin film of Loctite sealant and mounted a clean cylinder head with a surface as flat as my Moore & Wright straight edge is. Good enough for the exercise, for me anyway. Torqued the cylinder head to 20 lb. ft. in two stages. All nuts went snug firmly and were torqued twice to make sure, there was no 'give' at any of the nuts.

At first it appeared as if there is no gap between the cylinder head and its mating crankcase face. However, it was quickly found that the gap (cylinder liner protrusion) was at 0.002-in. A 0.0025-in. feeler blade would not fit. This means that, since engine assembly time the protrusion has reduced by just over 0.004-in. The cylinder head is still clamped in place and will be checked again on Monday to find out if the assembly has settled at all.

I think a photo of the cylinder head gasket that failed is attached. The red arrows point to leak points at 1 and 3 cylinders. The green arrows show the extent of the leaning tower of Pisa effect.

For Bill Lock supplied gasket, protrusion of 0.002 to 0.004-in. has been recommended. Anyone know where this specification came from?

What brand/type of sealant should be used?

Regards,

Mike A.

[Keith Clements]

Mike,
Your previous topic on this subject had a response from Neil Moore on the NZ gaskets which I think are the same as you received from Bill Lock. I set to 8 thou for the grey material gaskets from NZ when at 20lb/ft with no gasket.
One in ten engines that I separate have at least one cylinder, if not all four, with carbonised or just discoloured ring around the seal of the cylinder. Some even have a cracked u ring that is supposed to make the seal . This is sometimes because larger bores have exposed it to the hot gases. NZ gaskets come in two sizes to accomodate this.
I cannot recommend a method of how to fix a block that does not have an even distribution of gaps , or one that creeps over the week left to settle , or one that seems to lose torque after a few heat cycles. I cannot be exact on how many such blocks I have experienced but it is probably about half. I know this is not good news. Putting a Jowett engine together does take care to make it reliable as most of us older ones know. Yes you can put one together and it will work for a while and I suspect this happens with many, if not most, of the ones rebuilt in the past. It is only when you use them in competition or on long journeys that you take that extra care. Also the blocks used are getting increasingly frail so the problem will only get worse. The NZ gaskets possibly gave a brief respite as the grey material gives a better grip on the clean metal surface than the copper. I would still put blue hylomar on all but the cylinder face as there is usually less than half the original aluminium left to make the seal. I have built up these faces with aly weld but usually such blocks also have corrosion deeper in which makes them a lot weaker.
It is extremely sad to reject a block with issues. You might use it to get a few miles driving (many Jowetts do less than 500 miles per year) but expect problems if you intend to do more.

Looking at the picture of the gasket. My explanation, which can be argued as it is counter intuitive, is that creep in the weaker lower half of the block closes the gap on the lower half of the cylinder causing the head to tilt and lessen the pressure on the upper half. This assumes both block and head were flat in the first place which may not be the case. I have checked some blocks where they have not been, one even had a clear step where the lower half had crept by 10 thou. Few rebuilders take out the head studs and surface grind the block and head.

[Mike Allfrey]

Many Thanks Keith,

I agree with what you say, however, I think I have been remiss in not mentioning that this crankcase set, is as follows:

It is an early PA version.

A connecting rod broke on a freeway.

The crankcase had extensive weld repairs, too many to list here.

The cylinder liner support surfaces were lightly skimmed to clean them up. Noe it gets a bit gritty, the cylinder head faces were skimmed (in the same milling machine set up as for the liner seats) to tidy up weld distortion. The crankcase join faces were also skimmed so that the main bearing and camshaft tunnels could be resized to suit the bearings. This work was carried out by a skilled workshop (sadly now out of business).

There was also welding at the upper rear cylinder head stud (No. 10).

The crankcase, with respect to the lower coolant jacket area is, very likely, the thickest I have seen. However, the aluminium could still be classed as fragile. This morning I checked the gap at the cylinder head, while still at the 20 lb. ft. setting. It is the same as yesterday, 0.002-in. Will check again tomorrow and on Monday. Then, I am tempted to back off each cylinder head nut by one flat of the hexagon or even a quarter of a turn, to find out what change may evolve.

Having such an even gap, even though 0.004-in. has been 'lost' somewhere, tells me there is no distortion. During the engine's final assembly, I adopted the recommendation of clamping at 20 lb. ft. less head gasket, but did not leave for several days. The gap at that time was a surprisingly even 0.006-in. the lower end of the tolerance because of the damage done previously to this crankcase.

Now to the cylinder head gaskets. I am not at all sure which version of the Auckland gaskets the JCCA is supplying. I do know that there was a change in gasket overall thickness when the manufacturer changed from the Rezine material to what is used now. My thoughts at the time were that the extra thickness would help with distorted crankcase faces. Since then, I understand that Bill Lock & Associates has had cylinder head gaskets manufactured in the Czech Republic, these are of copper/something/steel construction. I ordered four and they have arrived. They do look good, they are thinner than the Auckland gaskets and are probably to original Jupiter specification, as far as we can get these days. What worries me is that the cylinder liner protrusion specification is 0.002 to 0.004-in. for these gaskets. Before I even contemplate fitting these gaskets, I would like to know where that specification came from and, whether the writer of the specification knew about the cast iron liner in an aluminium crankcase when establishing that specification? It does appear to be quite marginal. I strongly believe that specification source should be known and verified.

Below are photos of gaskets that I have here at present:

80-06.JPG

80-05.JPG

I think I got the captions right for the Auckland gasket.

80-08.JPG

80-07.JPG

Will keep you informed - others PLEASE join in!

Mike A.

[Mike Allfrey]

Follow up.

Somehow the system messed up the captions. The upper two are the Auckland gasket and the lower two are the Czech gasket

Apologies for the confusion.

Mike A.

Mike, It is not the system! Except perhaps the last attachment added is the first in the list which probably confused you. I think I have corrected and placed in line with the text.

[Keith Clements]

I will contact Bill.

[Andrew Henshall]

I think a photo of the cylinder head gasket that failed is attached. The red arrows point to leak points at 1 and 3 cylinders. The green arrows show the extent of the leaning tower of Pisa effect.

I've gone back and looked at the photo of the previous head gasket that failed on this engine from 2017, and apart from the fact that it was the opposite bank which failed (Nos 2 & 4, rather than Nos 1 & 3 this time), and the last time cylinder 4 looked worse, and this time it is cylinder 1 which looks worse, the failure looks very similar! (A silly joke.) I don't think that you can read anything into this.

You talk about "a Leaning Tower of Pisa" effect, but surely, as the "crush" on the head gasket reduces as the cylinder pressure builds during the power stroke, the sealing ring eventually no longer does it's job at one point on the periphery leading to the escape of combustion gases into the water jacket. You can't expect the sealing ring to fail instantaneously all around the full 360 degrees; it has to let go somewhere first! I also don't think that this is evidence of the head face being at an angle to the crankcase face in the installed position, and your measurement of a consistent 2 thou gap between the two faces all around the head supports this.

Before you removed the cylinder head, did you mark each nut on the head studs, then back them off, and retighten them again to the same point recording the torque in order to establish the installed torque? This info would show if the pair of liners on that bank still had a uniform head stud torque before you disassembled the engine, and whether the torque value was anywhere near the tightening spec. This check also immediately identifies a head stud which is letting go in the crankcase.

Do you plan to extract the liners and carefully inspect the bottom shims, and the seats in the crankcase? Do you have any measurement of the shim packs which you installed that you can use to compare to the current shim pack thicknesses?

Have you established exactly where the coolant managed to get out of the water jacket & into the oil yet?

I'm confused that there is no mention at all of the usual steam from under the bonnet when the head gasket failed, because surely all those combustion gases in the water jacket would have escaped via the radiator cap with the usual smell of hot inhibitor, if not the telltale coolant on the windscreen!

I bet you are pleased that Melbourne's "Ring of Steel" & 25km travel limit will be lifted as of midnight.

Take care,

Andrew

[Mike Allfrey]

Thanks Andrew,

My understanding is that coolant leaked into the No. 1 cylinder while the car was not in use. There was no steam, because all of the sparking plugs were soaked in coolant when the attempt to start the engine was initially made. All cylinders at that time were with coolant in them, even the balance pipe. Fortunately, Phil had the knowledge to remove the sparking plugs and clean them. Fortunately, the engine did not fire up, otherwise the crankcase would have split wide open, as my Javelin did in Alex Gray's ownership many years ago.

Currently, I feel that I am not too capable with regard to cylinder liner protrusion - that is the feeling that is sinking in. Also, I am becoming very confused with regard to what the official specification for cylinder liner protrusion should be, when copper spacer rings and shims are used at the liners' crankcase seats. Now, I am advised that the specification for the Czech made cylinder head gaskets, at 0.002 to 0.004-in. The lower end of that specification appears to be rather marginal to me.

At the final assembly of this engine, I opted for 0.006-in. protrusion to help preserve a crankcase that had been welded and machined. That protrusion did relate to the crack that appeared a day after tightening the cylinder head to just 35 lbs. ft. I am now of the opinion that crack was the result mostly of the abuse that crankcase had endured.

My worry now, also is that, in cleaning up the liner seats in the crankcase, could they have been machined at a very slight angle? I do not think so, because we currently have a cylinder head attached to the crankcase, minus gasket, and torqued in two stages to 20 lbs. ft. At that situation, the gap between the cylinder head face and the crankcase face is a very even 0.002-in. That gap has stayed the same for three days now. That set up is exactly the same as when we assembled the engine that final time. So, where has 0.004-in. of liner protrusion gone, after a quite low mileage of motoring?

At present I have no desire to assemble the cylinder head until I am given a professional cylinder liner protrusion specification. The matter is becoming extremely confusing - we now have three cylinder head gasket types in circulation - the first Auckland gaskets which were thinner, the second Auckland gaskets which are thicker, and now the Czech made gaskets which are thinner again. On top of that, I understand there are Auckland gaskets with larger diameter(?) liner lip seals to cope with bored out cylinder liners. Hence my confusion. My Jupiter is successfully running what I understand to be the earlier Auckland cylinder head gaskets.

It is my intention to back off each cylinder head nut by one hexagon point and measure the gap to find out if it widens. Next, I intend to (only because I have a spare crankcase here that Phil can have) tighten the nuts to 25 lbs, ft. to find out if the gap reduces. The result of that action will be reported here forthwith.

Regards,

Mike A.

[Forumadmin]

Starting off with 6 thou as a liner protusion measured with a steel rule and feeler gauges, then fitting head with no gasket and torquing down to 20lb.ft compresses or stretches either the shims or the block to reduce gap to 2 thou. It is unlikely the head or the liner distort so the compression might be possible in the copper liner shim or the stretching in the block. Is this normal? I would expect some, but it is something we should document.
Of course, we should make sure the shims are properly settled and we would expect more squash if they have been annealed. So to settle them a couple of torques down to 20lb.ft then relax should help. Even better if they are not disturbed at all after the engine has been run. This should be stated when we document. If there is any gasket goo on the shims this should also be recorded.
As Mike and Andrew suggest the procedure and measurement of the torque and gaps needs to be recorded consistently.
The torque sequence of each stud and incremental steps of 5lbft should be used to reach the 20 lb.ft. Always go around a second time on all the studs with the torque wrench at each iteration as this will even up all over the head.
Marking one face of each nut should give positional information when seeing how much each nut rotates when each iteration of torqueing is done. Some may prefer to record in degrees, others in fractions of a turn. Perhaps this is a over the top for each iteration but at least do it between 15 and 20 lb.ft. Also do it when you do the second tightening at 20lb.ft and the third after a week left alone.
We should agree on a nomenclature . How about the torque, the stud number and the turn in degrees.
e.g. 20/1-1-45, 20/2-2-20 the /1 refers to the change from the second 15 to the first 20 lbft, the /2 for the change from first 20 to the second 20.
20/w-1-10 from the 2nd 20 to the retorquing after a week. This data might give us some idea about how the block reacts when being tightened. Ideally all the studs should be tightened the same amount simultaneously. As we should know, the force on the stud and hence the pressure exterted on the gasket may not be the same as the torque registered on our wrench. It will be affected by the friction on the screw thread and the nut /washer bearing surface.

Recording the change in gap between 10, 15 and 20 lb ft might also be instructive, as it may show the onset of stretch.

If we gather this information we should get a picture of how different blocks respond.
When I do it I mark on a picture of the head tightening sequence where I record the gap at six points around the perimeter at each stage.
But to get this in tabular form would be better.
So I suggest the following nomenclature based on looking at the head when torquing up in situ.
TL= Top Left, TM = Top Middle, TR= Top Right, BR=Bottom Right, BM=Bottom Middle, BL=Bottomleft.
This should be preceded by the torque setting.
e.g. 15TL=.004, 15TM=.003
Some may only have mm feeler gauges so perhaps we need to specify that as well!
The two stats out of this at each stage should be the variance between the smallest and largest gap and the average across all six. The most important stat is the variance of the variance over the stages which should tell you how the block is distorting.

[Mike Allfrey]

Many Thanks Keith,

I will have to find a torque wrench that is accurate from below its 10 lbs. ft. setting. The minimum on my 3/8" drive wrench is, what feels like a rather loose 18 lbs. ft. setting.

I believe that what you have set out above is a good regime.

I am still concerned that for the various gaskets currently available, there is no engineering developed specification for the amount of cylinder liner protrusion, that is directly related to the type of gasket being used.

It is now my firm belief that a large influence on the way a crankcase behaves is due to how it has been handled (abused mechanically) during its seventy years of life. It is now understood that should a crankcase have a host of ill-fitted Recoils or has suffered cracking at the rear faces, it should certainly be scrapped. Not even 'saved in case', for future retrieval.

I will try the suggested method of establishing if the crankcase or liners are yielding, in some way they have to be, because the seal around the crankcase rim has held up well in all instances.

Will report when the suggested method of research has been done.

All the best,

Mike A.

[Keith Clements]

To try to find out what protrusion is required we look at it another way.
If you had a solid copper , aluminium or steel gasket fitted (rather than the composite) what would you decide?
I think it would depend on the yield of the materials involved in the mechanical system with the aim of getting a defined pressure at the cylinder face.
So first start without a gasket. Some Computer Aided Design would certainly help but you should be able to model the system fairly simply as you have a steel cylinder of a defined thickness and a number of bolts delivering a defined force in a base of aly with a steel head. You could make the model more realistic by modeling the moments of force based on the position of each bolt and thus define the strain in the block and head. You could then draw a graph of the torque required to reduce the protrusion to zero, or conversely the protrusion that reduces to zero at 35lbft.

You could then add into the model the lessening of the pressure when you introduce the gasket based on the yield of the gasket under the calculated torque.

You then need to differentiate between the pressure of seal you need at the cylinder versus the other areas of the gasket so would need to know the areas involved.

It would get a bit more complicated with a composite gasket but some empirical evidence based on the compression of the gasket under different torques could be used to understand how that affects the pressure on the gasket around the cylinder.

The shortcut then is simply to see how each gasket type compresses. Let us say at 30 lbft the NZ gasket compresses 8 thou and the Czech gasket 3 thou. This would indicate pretty clearly the need for a different protrusion. You could test this on an assembly without any liner protrusion measuring the free gap on the area at the top of head (with gasket installed) at 10lb.ft, 20 lbft and 30lb.ft

I am lucky in that we won a set of calibrated torque wrenches at the 2010 Classic Car of the Year show!