Massive Coolant Flooding - Cylinders And Sump

[Mike Allfrey]

This also applies to Jupiter engines. Also, due to our Stalag IV lock-down situation, I have not been able to have a look at the engine in question. Current symptoms are coolant filling cylinders 1 and 4, and also the sparking plug wells, on left hand bank, also filling overnight.

This is the engine that has been nothing but trouble ever since I first became involved with it. One cylinder head gasket situation I could cope with, but now three? That is a bit much, even for me.

My current theory is that there may be a massive leak that allows coolant into the carburettor balance pipe and thence, due to radiator height, into cylinders on the other bank. I have never experienced this type of concern, but there are always firsts for all manner of concerns.

Has anyone out there experienced such a problem with a Jowett engine? Cylinders 1 and 4 filling overnight? Plug wells filling as well, and assume coolant is migrating through the push rod tubes that nature's sealant (rust) has not effectively sealed. However, every engine I have worked on, I have used a taper punch and hammer to seat the push rod tubes. My Jupiter does leak oil there, but not on a consistent basis, somewhat baffling, but I have learnt to live with that little problem!

I have asked the owner to remove the tappet chest covers and find out what is in there. Next stage will be sump off and oil splash plate off and a good inspection up inside.

Fearing the worst, are there any Series III crankcases, complete with front and rear timing covers available??

Any comments will be greatly appreciated,

Mike Allfrey.
JCCA.

[Forumadmin]

Yes I have! It was caused by a crack creeping around the block which is why I now do the feeler gauge test all around the heads without a gasket and torqued to 20 lbft and left for a week to see if it will creep.

[David Morris]

Hi Mike,

My first thought would be to do a dry air pressure test on the block, to detect any cracks in the block. We get about a 15% success rate, with more duff blocks than we can count.

But water filling the plug wells? That's a new one on me. I suppose water could be getting into the transfer pipe, but why is it getting into just the wells on one side?

As for Series 3 blocks, our experience is that those are the ones to avoid! The earlier blocks are much more likely to have survived without significant corrosion on the bottom edges of the crankcases or to have internal cracks. Go for an E0 block. The oil ways can be enlarged to Series 3 standards, as the factory did when reconditioning. I realise there won't be the stiffening webs that the Series 3 blocks have, but suspect this was an attempt by the factory to upsell later engines to anxious customers?

Also, we have seen several Series 3 blocks that, because they are so much thinner castings, have been welded in the past to 'cure' cracks. Steer well clear! They are prone to distortion and are a nightmare. When torquing up the crankcase through bolts, to their 75ft lbs torque, it is enlightening to see the crankshaft being completely solid until you hit that magic value when it suddenly spins freely! It shows the accuracy of the original line boring that can easily get corrupted by welding a block.

Hope this helps and let's hope we get a vaccine soon,

David

[Mike Allfrey]

Many Thanks Keith and David,

Interesting to note that experience with the Series III crankcases shows up faults. I am on the verge of supervising the repair of this engine by using a Series III crankcase that I have here. It is stamped '286' into the Engine Number plinth, with 26716 stamped into the front faces of both halves. Just above those numbers are stamped '518'.

It is reasonably sound, corrosion wise, it has benefited greatly from Melbourne's soft water. However, there are some worrying points:

The cylinder head gasket faces have been machined, and the balance pipe flares are no longer present.

There have been weld repairs at the usual rear faces between the coolant inlet ports and the head gasket faces. The head stud threads have been threaded through the coolant inlet ports.

Otherwise, after a casual glance, the crankcase looks fine. It is my intention to air pressure test both crankcases, with my hearing instruments set at full volume! What pressure is recommended?

It is my intention to pressure test the failed engine as a complete unit, and the Series III crankcase as a tie-bolt and top row of bolts properly tightened unit. Could be interesting.

Have previously used the cylinder head as a feeler gauge template to monitor cylinder liner protrusion. I think it will be monitored over one month this time around!

We are currently under Stalag IV lock-down and are very limited in what we can do.

I will keep this topic posted on what happens. Incidentally, I have not yet received E-mail notifications of your responses. Probably due to broad band concerns of a local nature.

Stay well, wherever you are,

Mike A.

[Forumadmin]

I only use about 10 psi and use soapy water to test for leaks. I doubt if listening will tell you anything.
I use a pond liner to make the head gasket and block off water inlet . A transfer tube has an air inlet and pressure gauge inserted in a drilling

viewtopic.php?f=153&t=4206&start=180#p23458

should take you to the pressure test post

[Mike Allfrey]

Good Morning Jowett Folk,

Melbourne time.

The engine is now on my work bench. We overcame the Stalag IV COVID-19 lock-down by being in our own 'bubble' and me wearing my bright orange McLaren F1 face mask and Phil sporting his sinister black mask with deluxe one-way valve - so, we should be OK.

It is now, almost positively, established that the concern lies at No. 1 and 3 cylinders. We are in the process of making wooden bungs to insert in the coolant inlets and the coolant outlet hoses. First we will try a dry air test at about 10 psi to find out which of the two plug holes most air exits from. The valve rocker shaft will be loosened-off so that all four valves are shut. That should put a stop to any antics on the other side of the engine. Then we will try the soapy water test to gauge an inkling of how much leakage there may be.

Now, to theoretical causes of cylinder head gasket concerns. In my working life I have had considerable experience with wet type cylinder liners, first with Ferguson petrol/TVO engines (Standard Vanguard and Triumph TR2), and then with Caterpillar 3208 diesel engines, and finally, with Ford tractor engines (no wet liners in the Fords, just parent metal bores). Back to the Ferguson cylinder liners - in our workshop we had a policy of not boring out the cylinder liners, but replacing with new piston and liner kits when overhauling an engine. Some customers demanded liner boring and oversize pistons from outside suppliers. Often they got into trouble, due to cylinder liner vibration and breakage at the skirt where, like the Jowett, the liner seats in the crankcase. Being vertical, the skirt would drop towards the big end of the connecting rod and create havoc that we apprentices had to sort out. Moral, new genuine parts, no problems. Also noted at these times was pitting around the water jacket area - cavitation erosion - more on that later.

Moving on to the later 1970s, when Caterpillar 3208 engines were introduced in New Holland combine harvesters. New Holland service staff were provided with service training on the Caterpillar 3208 diesel engine. Caterpillar Australia absolutely hammered into us the consequences of poor cooling system maintenance procedures and the resulting cavitation erosion at the wet cylinder liners. We were told that a combination of bored out cylinder liners and the lack of coolant maintenance (corrosion inhibitor - antifreeze) would most definitely result in mixing of engine oil and water. This was due, we were told, to abnormal vibration at the liners' coolant jacket area, causing bouncing bubbles in untreated cooling water (no inhibitor). Farmers here in Australia, just like their cousins in Britain, are/were very reluctant to buy antifreeze when they think they did not need such protection. Jowett owners have had the same attitudes.

Ford tractor diesel engines, even with parent metal cylinder bores suffered rather badly from cavitation erosion if plain water was used in the cooling system. We called it 'block rot'. Ford did a better job of making mayonnaise, due to a thin-walled oil gallery drilled low down on the thrust side of the cylinders and oil, under pressure broke through into the coolant. Proper use of antifreeze and the problem did not exist.

All of this brings me to the fact that I have observed severe pitting (cavitation erosion) on Jowett cylinder liner coolant jacket surfaces, mostly close to the copper seal shoulder. To me, such erosion is not caused by electrolysis due to the presence of cast iron, aluminium, copper and brass metals associated with the cooling system. Cavitation erosion, in my experience is caused by vibration brought about by compression and combustion activities when the engine is running. With cylinder liners that have been bored to various over-sizes, that vibration increases. I will have to look up the information, but I understand that Jowett Cars Limited, at some stage, introduced thicker wall section cylinder liners. Over-sizing the bore compounds the vibration problem, particularly with respect to the earlier cylinder liners.

Hopefully, most of us are using a corrosion inhibitor (antifreeze) in our Jowett engines, and that should reduce the cavitation erosion concern. However, I still have concerns about cylinder liner vibration and how it may affect the copper spacer rings and shims (some are brass) and, consequently, the outer liner lip seal at the cylinder head gasket. If bored cylinder liners are vibrating more severely, are the annealed copper spacer/shim packs yielding under that added vibration?

I firmly believe that there is not a problem with the quality of the cylinder head gaskets we have been using. What I do not know, however, is how much crankcase distortion the gaskets have to cope with. That could be a great ask, and super-careful assembly procedures should provide some answers. However, in this engine's case, the cylinder liner seats in the crankcase were 'cleaned up' to remove corrosion valleys and the outer head gasket surfaces were machined in the same milling machine setup to repair distortion that was the result of considerable welding repair after No. 3 connecting rod broke, probably due to filed cylinder number notches at the web, by he who did not have any idea.

I could well be wrong about some of my theories, in relation to the Jowett engine, but my thinking goes back to apprenticeship and technical college training. Our foreman was a very experienced engine enthusiast and he also insisted that new cylinder liners were used for engine overhaul purposes. We were not allowed to have pistons re-grooved for oil control rings either!

Am I on the right track?

Mike A.

[Forumadmin]

You clicked my link and did not go to the post on pressure test?

[Nick Webster]

Keith,
The link goes to a page of various subjects headed Josephine Rebuild but none of them about pressure testing.

Nick

[Mike Allfrey]

That is right, Keith, all about Josephine.

Mike A.

[PJGD]

Mike,
Cavitation erosion of liners is caused by the shock wave induced in the liner by the high rates of cylinder pressure rise creating the vibrations that you mention. This was more common on diesel engines in the pre common rail days where the fuel injection process was less well controlled than it is now where they use pilot injection to moderate the pressure rise rate and combustion noise. The Cat 3208 had a mechanical pump-line-nozzle system with pencil injectors that were poor for combustion noise.

Another issue with wet liners is that unless they are well restrained in the cylinder block, piston side thrust on the power stroke will cause the liner to deflect or fidget which can wear and/or abrade the head gasket, eventually resulting in a leak. Normally "mid-stop" liners as in the Jowett engine are less susceptible to that than other arrangements, but our liners are not evenly clamped as Keith's assembly check shows, so they probably do move. I would prefer to see the top flange of the liner be a close fit in the block at that location to inhibit this rocking.

Philip

[Forumadmin]

Try this
viewtopic.php?f=153&t=4206&p=23469&hili ... ure#p23458

or
viewtopic.php?f=153&t=4206&p=23469#p23469

The reason may be I order my posts in descending order in the User Control Panel , Board Preferences, Display option.

one way to search is add terms with plus sign e.g.
+Pressure +test +bubbles +block +leak

also do it in the topic search rather than the whole JT search box.

[Mike Allfrey]

Hello Folks,

Sorry, I have been out of the loop recently, due to a Ford tractor 'concern' three-hundred kilometres west of here and, due to the lock-down have not been able to get near the beast. The lock-down eases a bit at midnight (Melbourne time), so things should start to move.

Thanks for the comment about cavitation erosion, sounds just like Caterpillar training material!

On Thursday I am hoping to carry out the soapy water test and will report what happens. First, I will have the rocker shafts loosened-off so that all valves will be closed. Also, the breather pipe will be disconnected to see if bubbles exit there.

You are correct, Phil, about the pencil injectors. The Cat 3208 was a very noisy engine for us, but on a combine harvester, with a grain tank between engine and cabin, that was not much of an issue in a 400 hectare wheat paddock! For us it was a damn good engine, but also Caterpillar really hammered their training into us. Good times!

Will report on findings,

Mike A.

[David Morris]

Hi All,

Very interesting series of posts. Do you think Jowett's use of 'O' rings in the liner seal area in very late engines would have helped to solve this problem?

All the best and stay safe,

David

[PJGD]

For the bulk of production, the Jowett engine used a Klinger brand composite gasket sealing ring between the mid-stop liner seat and the crankcase shelf. This moderately thick gasket could, and did, collapse, probably due to the effect of repeated cyclical heating and cooling of the engine from the differential expansion between crankcase and the iron liner. With a cold engine, the load on the gasket was high, but this would relax in a hot engine (essentially the opposite of what you want for effective sealing at the head gasket interface). That thermal cycling is not great, it only amounts to a change in compression of around 0.002" which would be split between the liner seal and the head gasket, but it is not helpful.

With the later arrangement that was proposed I believe by Donald Bastow (an engineers engineer, if ever there was one) who was in a consultancy role with JCL at the time, either the liner or the crankcase were dimensionally different from the earlier production and the liner sat metal-to-metal on the crankcase shelf with only the very slim section o-ring wedged into the chamfer providing the essential segregation between water and crankcase oil. Thus the liner protrusion dimension [0.008 - 0.010" in the early manual, 0.008 - 0.012" in the later manual] is now down to manufacturing precision rather than dependence on engine build skill and conscientiousness. The 0.002" thermal cycling is still there, but now it is all taken up by the relatively thick cylinder head gasket that is probably better able to accommodate it. Note that the manual recommends rechecking the head bolt torque when the engine is hot, and I believe that this is an essential action to take but it often gets missed, however this makes sure that the clamp load is correct in the "expanded" condition. Of course, none of this overcomes the inherent lack of rigidity of the crankcase, most evident between the top row of studs and the lower row.

[Keith Clements]

As the ravages of coolant erosion take place the poor initial rigidity is reduced. Also the sensible precaution to reduce head stud torque on such crankcases reduces the ability to seal.