Cylinder head gasket

[alexander]

Daft question which way round does the head gasket go.i have a gasket stamped "gasket specialtis Ltd Auckland." Copper on one side grey material on the other. Does the copper face go towards the block or the head.

Also if I find the cylinder liners don't have the 008"-012" projection can shims be added with the engine in the car. I'm hoping that I don't have a problem but thought I'd check before starting the job as the reason for the head gasket is water leaking from the front lower corner of the near side head, no sign of water in oil so here's hoping it will be just a head gasket replacement.

Thanks in advance

Dave

[Nick Webster]

Dave,
This sounds like a litltle job that if you are not careful can turn into a big one!

I have always installed head gaskets with the plain copper side inwards, so that the projection of the liner presses into the soft copper. Having said that I have a gasket where the turned over edge from the grey side turns over onto the copper side and hence presents a hard surface. If you were to put that on then I do not see how it would dig in and seal. I have heard that there were some dodgy imported gaskets at one time. I do not propose using my strange gasket!

The figure you quote for liner projection sounds straight out of the original Jowett hand book. This is the projection required for when the original fibre lower liner seals were used. These old "Hallite" gaskets still turn up in old gasket sets (if you find one at an autojumble) but you would be very unwise to use them. I see from your profile that we are mutual Triumph TR owners, and so you may know that the 4 pot TR uses metal liner seals - these days not the original plastic coated steel, but copper. This is current perceived wisdom with Jowetts too. In this case the liner protrusion should be less, circa .005-.007". You can re-use the copper seals after annealling and use a combination to get the right height. Just possibly you may have a late engine that has rubber O rings but this is quite rare so unlikely. Keith Clements goes into different types of liner in an article on a Jupiter engine rebuild archived on the site.

The most likely cause of your water leak is corrosion of the aluminium block. Just possibly there may be a fine crack. Clean and carefully examine the bosses where the studs screw in to the block. Frankly if the engine has been assembled correctly with copper seals they are much more likely to leak water outwards than acutally suffer the typical head gasket failure with water entering the bores or sump. Especially if it appears to be running without misfire. Personally, in the short term I would be very tempted to try something like Barrs Leaks and see if the external leak stops.

If the problem is so bad that you do take the head off there is every chance that you will find the block corroded and or cracked and require welding repair (actually where I am at with one of my current projects). Taking out a liner without removing the engine is possible and I have done it but it is not a job for the faint hearted. Unlike a Triumph TR with an iron block, the Javelin liners will be most reluctant to slide out (despite what it says in the manual), so you will need to drop the sump, remove connecting rod & piston and get a proper puller on the job. As I have said, if the "modern idea" of copper liners have been used it is unlikely the liners are at fault, but more likely that the aluminium block is your problem.

Nick

[David Morris]

Hi Dave,

As Nick says, this could very easily turn into a big job, so I suggest treading very carefully. Nick's figures for the liner projection are spot on...please forget the original figures, They are likely to crack the block! nothing worse than the sound of a block cracking as you tighten the head studs...I know and have heard it! By the way, please also ignore the head stud torque figures in the manual. 35lb.ft is plenty.

In my experience, using the New Zealand gaskets is essential and follow their initial tightening instructions to the letter. However, they do seem to 'relax' over time, so the first thing I would check is to check the torques on your head studs, to the figure I have given...no more. I would suspect that you will find some are quite slack. By the way, don't tighten the centre drilled stud that feeds the oil to the rocker shaft to this figure. It is delicate and just needs to be tight enough to provide a good seal to the oil feed banjo. You can only get a spanner on it anyway!

Next, I would suggest that you get yourself a bottle of K-Seal sealer, rather than Bars Leaks. There are two grades of K-Seal, one is about £10 and the other is around £30, and is the more professional product, which they claim is permanent. Amazon is a good stockist. It's worth a try with a sealer before you dive into anything more serious. It may save you a lot of time and worry?

Again as Nick says, we now only use the copper shims at the bottom of the liners. JCC stock them in various thicknesses, as well as the NZ head gaskets. I would advise using a smear of Wellseal on the shims, to help seal them. If you do decide that the liners have to come out, ready for fitting new gaskets and you will therefore require to correctly set the protrusion, it can be done with the engine in the car. You will need to release the big ends, take out the liner support tubes on both sides and pull out the liners, after you have pushed out the pistons from the bores. You will need to fabricate or borrow a puller, that is no more than a disc that is slightly larger than the outer diameter of the liners, drilled centrally with a hole to take a length of studding to a cross bar you can make up across the appropriate head studs. Once you get the liners moving, they will come out with a bit of persuasion! On the bench, polish up the sliding surface and do the same with the holes in the block. Oiled and clean, they should slide back easily. They are superb chrome steel and shouldn't rust much. Keep both the liners and the pistons matched and use a bar across the head studs, if you try and rotate the crank, to keep the liners fixed in position.You will need a piston ring clamp to reassemble the pistons in the bores. Use new spring or grover washers under the big end bolts and check carefully that the bolt heads don't foul the internals of the crankcase, once you have tightened the big end bolts. This is why you will need to rotate the crank, as there is only about 1-2mm clearance on some of the big end bolt heads and the internal castings.

Anyway, do have fun and I wish you the best of luck. I have a feeling that you might be successful with the sealer as a starter for 10, and I also expect that my comments will create a lot of creative alternative solutions from other colleagues. We have all been in your position and there are lots of ways to solve the problem. I have just suggested my potential way out of situation.

All the best,

David

[David Morris]

Hi Dave,

Reading through my earlier post above, I have realised that I made an error. The disc that you may need to fabricate to slip over the bottom of the liners, as the foot of the puller, clearly needs to be slightly smaller than the outside diameter of the liners, but larger than the inner bore, otherwise it will foul on the casting. I know we made a simple puller, as I have described, but I am sure that you could borrow one from JCS, who now are the caretakers of all the previous club special tools. Following an engine rebuild recently, we needed to use K-Seal and their more expensive product worked a treat. Not sure if there is any connection with the name, but a Jowett colleague, who previously had a Rover with the K series engine, used this product to overcome the water leakage difficulties with his K Series engine....Strange?

Anyway, all the best and do please keep in touch if you have any questions.

Regards,

David

[Nick Webster]

Part of my liner puller, the base of which is a tiny bit smaller than the OD of the liner but has cut outs to allow for use on a webbed series 3 block.

web.jpg

Nick

[alexander]

Nick and David thanks for your informative posts, I would have used the setting in the manual/handbook if you had not put me wise. I have the head removed now. Liners are set ok so that's a relief, head looks fine but the alloy block is showing a little corrosion on the the front lower edge but other wise not to bad. There did seem to be a good seal on the old gasket re liners . Can't get back to the car till Saturday but will post again once it back together.
Thanks again for your advice

Dave

[David Morris]

Hi Alexander,

Thanks for your post and I am very glad that you have found the liners don't require re-seating. Where you describe wastage on the block is, unfortunately, quite normal. Can I guess that your block set is numbered after around 15,000? We have found the earlier blocks are much less prone to corrosion here.

All is not lost however. We have managed to reclaim blocks with quite severe corrosion in this spot with a product called Devcon 10611 Aluminium Putty. Have a look on eBay? It's quite expensive, but if you are careful and neat with a putty knife, you will be able to build-up this area quite successfully. You need to get the metal surfaces here nice and shiny first and then apply the putty, as per the instructions, smoothing and grinding the result ( possibly with a Dremmell for initial grinding and later facing up ) to exactly align with the remaining block faces. I know some colleagues would suggest having the block welded, and of course this might be more successful, but using the putty, the job can be done with the engine in the car. No chance of distortion either! Some might recommend removing the studs in this area, but I suggest best left alone. You don't want to create another problem.

Hope this helps,

David

[alexander]

Update. Changed the head gasket, still had leak but seemed more so, added Kseal but still have water leaking from the joint between head and block.
Will strip again and see if
1. I've done something stupid
2. If I can see any area of the block that needs repair
3. Check head is flat

Will keep you posted once I've taken the head off

Dave

[David Morris]

Hi,

Sorry to hear that you still have a leak. It would be a good plan to have a close look at the block surfaces and the head. I can remember we once had a head that had been skimmed so much that the water passages, which should have been invisible, were exposed! Talk about overdoing it! Of course, it leaked like a sieve. If, for any reason, you find the head is suspect and you need a replacement, do let me know and I will sort one out for you.

I know that the heads look as if they are handed, but they are not, if you are prepared to drill and tap a hole for the water transfer connection, if needed. Jowett's drilled and plugged the hole for the stud on later heads.

Good luck,

David

[alexander]

Hi David
Thanks for your kind offer, I was lucky that the car came with loads of spares including heads, engines in bits, gear boxes etc. My intention is to keep what I may need and pass the rest to Jowett spares, but first I need to get the car usable. The good news is that this is one of the last. I hope.
Dave

[alexander]

Stripped down the car on Sunday, checked head with a straight edge and it seems fine. Can not see any cracks in the block so at a bit of a loss.
But I did have oil in the barrels, which was not there on my first strip down.
One thing I did do which may be the root of my problem with the oil and the water leak is I used blue hymer on the gasket.
I have a new gasket and will try again without the hymer.
Dave

[Keith Clements]

Fitting a head gasket on the Javelin needs a methodical approach. I torque the head without gasket down to 20lbft and check for even clearance all around with feeler gauges. I leave it for a week to check for stretch and see if any measurement has changed. In this way you know you have even pressure all around.

Before assembly I first crack test with a kit. See SA rebuild thread. Then pressure and vacuum test with soap and water. But that may not be necessary.

Fitting instructions for the New Zealand gaskets should come with the gasket.

The leak seems to be coming from the base so the test above may show the reason. I have had blocks which stretch and close up along this face.

[David Morris]

Hi Dave,

Keith has given you some good advice. I am a bit concerned about the oil in the bores? There is an oil 'O' ring supplied with the NZ gaskets that is used in the central stud that supplies the oil to the rocker shaft. Have you fitted this as per instructions with the gasket? I know that you have checked the block for flatness, but how about the head? They are notorious for cracking between the valve seats. I suggest that you clean up this area, look carefully between the seats and, if you have the head off, try putting some light oil, like paraffin or WD40, into the valve chamber overnight and see if any leaks out?

As for gasket sealant, almost everyone has their own theory. Some use none at all, others use their own favorite. Personally, I use Stag Wellseal, but I think the important thing, whatever gunk you use, is to apply it sparingly, let it set before clamping down and tread carefully.

All the best,

David

[alexander]

Thanks for suggestions everyone.
I've checked the valve chambers with paraffin no loss after 48 hours so that a plus.
I've torqued the head down to 20lbft without gasket and have .008" alone the bottom of the joint. Question I have copper washers on the lower head nuts but steel on the upper is this correct or should they all be steel to get an even pressure when tightening down?

I've found the instructions for the New Zealand gasket on the forum but can not find
reference to the SA rebuild thread can you point me to the correct section please Keith.

Thanks again for the help, being new to Javelins these suggestions have been very helpful.
Dave

[Keith Clements]

for pressure test
leak test

But there is a wealth of information there for rebuild in the long topic.