HELP!!!!

[paul wilks]

HELP!!!!!

What a Rally! We enjoyed our trip from the North West to the Midlands, the first rally attended in a Jowett since the Saltaire Rally in 1983(?). ‘Yellow Peril’ ran very well both to and from the rally. She brought some favourable (and unfavourable!) comments from those in attendance re the colour but that was to be expected. On the way home on the Sunday the exhaust decided to join in the fun by rhythmically knocking on tick over. I have since repaired the broken rubber mounting at the rear end of the exhaust.

Of more concern was the oil leak. I am sure some would have compared us to the ill fated Torrey Canyon! On return home I cleaned up the messy engine and changed oil filter and oil.

I ran the car to the local garage (about five miles round trip) and she ran very well however, on return there was black oil in both channels on top of the engine and leaking down the tappet covers onto the hot exhaust! The dipstick showed still quite clean oil.

Given my limited mechanical ability/knowledge and my willingness to part with money to get her running free from really bad oil leaks (I don’t want her off the road for another 30+ years!) can anyone help?

Can anyone suggest a suitable person who could help fix the problem of the leaky engine?

Thanks in anticipation

Paul (Wilks)
Runcorn, Cheshire

[Forumadmin]

There is quite a lot of discussion on this board about this problem. Probably half the owners have suffered from this at one time or another. Do a search here for the ways to fix it. In summary the answer may not be as simple as fitting a new gasket.

[paul wilks]

Thanks for this. I do follow all the categories on this board, regardless of model and have been especially interested in the discussions on oil leaks in Javelin engines. However, as I said, my technical expertise/prowess is somewhat limited to minor servicing procedures and does not stretch to engine rebuilds etc! I realise that the problem might not be as easy as replacing a gasket hence my plea for help.

I just wondered if there was any expertise in the club which I could ‘buy into’ to solve my oily engine problem. As I said in my previous posting, I don't want my car to be off the road another 34 years, and am therefore willing to pay for the help.

[David Morris]

Dear Paul,

Yes, it was a great Rally and we enjoyed it immensely. It was good to meet you again too!

Sorry that you are having problems with oil leaks. These are a pain with the Javelin/Jupiter engines and although Keith Clements mentions 50% of us have experienced oil leaks, I would reckon this is more like 95%! In fact, you are a very lucky owner not to have oil in the valleys along the top of the engine at some time.

There are many sources of oil leaks on these engines, but it seems that most of the problem comes from the joint between the rear timing cover and the faces of the block under this casting.

From hours spent searching for a solution, and over 48 years of having problems in this area, a few of us in Severnside section have experimented with the ‘O’ ring gasket modification. This is also used in Australia and New Zealand. This seems to work, but ONLY when very careful attention is paid to the mating accuracy of the top and lower castings. John Airey has achieved a dry engine when he persevered with very careful fitting of the top and lower faces with engineer’s blue, on his engine out of the car. We repeated this on my current engine in the car, and it’s difficult to reach into the engine bay but my engine is pretty good (touch wood! ).
The key seems to be getting a fit that means less than 0.002” gap along both sloping faces. Over the years, owners and mechanics have tightened-down the two fixing bolts to try and stop leaks and the aluminium castings have warped, with the edges of the threaded holes often lifting and the result is a leak, whatever gasket you use. Gerald Palmer had a definite ‘off-day’ when he penned this part of the design!

So, my advice is take the rear timing case cover off, clean everything down and see what thickness of feeler gauge you can get between the faces, without the bolts in place. I would guess that your rear timing case can probably be ‘rocked’ from one side to the other! We are not talking about 0.002”here, but more like 0.040”! Then, get the engineers blue out and see where the faces meet. Again, I would guess they are probably showing blue only across 5-10% of the mating area. Then the solution is to ‘fit’ by very careful filing/scraping where the blue shows and checking with fresh blue, until you have at least 90% of the mating faces showing blue, ideally 100%.

Then you can fit a new gasket, either going to the ‘O’ ring solution ( which involves making an aluminium ‘holder’ gasket ) or a new composition gasket from JCS or Bill Lock.

Having said that the rear timing case joint is the worst offender, another point well worth checking is the cast boss where the oil pressure take-off pipe comes away from the n/s of the rear timing case itself. This is prone to cracking, as the brass take off union is tapered! What a rubbish design! We get cracks at the base of this tiny casting and these can easily be mistaken for leaks from the rear timing case gasket itself. The solution to cracks here is to get the casting welded and re-machined to a parallel thread, with a matching oil take-off brass union.

Our engines are great but being oil-tight is not one of their better points! I wish you every success and please do check previous contributors on this subject. There is a great write-up by Mike Alfrey in the technical section of the Gallery.

All the best, I hope this helps?

David

[David Morris]

Hi Paul,

Before I get into deep water, I mentioned Mike Alfrey in the previous post. I have just checked Jowett Gallery and I should have also mentioned Leo Bolter in New Zealand, and Philip Dingle, from America. Philip has written the article in Gallery and I recommend this as some bed-time reading!

All the best,

David

[paul wilks]

Thanks David. It was good meeting you and Juliet as well. I enjoyed driving the Javelin down to the rally and back home. It really took me back to my youth when 'Yellow Peril' was in daily use and driven to rallies at Harrogate, York, Cheltenham etc. I could live with a slight oil leak (I think I always have!) but not to the extent of the current leak. It is most unsociable!

Can I ask a stupid question? Can removal of rear timing cover be undertaken with the engine still in the car or does the engine have to be removed?
The more I read, the more I think I shall have to defer to those in the North West who have solved this problem. I might contact our 'adopted' garage in Congleton (Daytona Autos) to see if they can help.

Thanks for you advice (as ever!)

Paul

[Forumadmin]

It can be removed without engine removal.

It is 'easier' to do with the front timing chain case removed; but this means draining the water and possibly struggling with the bolts into the the sump. On a Jav you need to remove the dynamo, petrol pump, crank pulley and release the water pump hose and breather pipe before undoing the many bolts through the timing change cover and 4 sump bolts.

It can be done without taking off the timing chain case; but you may have to remove the tappet cover plates unless you have ground off the vertical flanges on them that prevent horizontal extraction of the housing. Also you will probably need to unscrew the top 3/16in bolt that secures the timing chain cover with a nut behind the oil filler, do this using the lock nut method. You need to take off the two oil pipes, oil pressure pipe, two vertical bolts and the three horizontal bolts after draining the oil and removing the filter.

You should remove the timing chain cover to do a proper job and do all the checks as described; but if you have done the mods above you can change the gasket at the roadside without doing so!

When replacing the timing cover to filter housing just pinch the 5 bolts perhaps only to 10 lbs ft torque so as not to pull the housing over. I tighten these finger tight to align the faces with the timing cover before tightening the two bolts into the crankcase. The bolts into the crankcase should take 25 lbs ft (progressively) but make sure the threads are good and the bolts the correct length. Then torque the five bolts up as described.

[David Morris]

Dear Paul,

Can the rear timing cover gasket be changed at the roadside? Yes, it can! The car park at the Rally Hotel at Crieff saw John Airey and me change mine in about 2.5 hours. I had left a series of oil drips all the way from Bath! There are one or two points to think about first :-

a. as Keith Clements has mentioned above, it is a good idea to swap the central stud that sits just behind the oil filler pipe for a bolt, like the other four. The rear timing cover (RTC) can then be lifted upwards in future and you don’t need to disturb the timing chest covers. This however does mean that you need to lift out the oil filler pipe when removing the RTC but this is easy! Just remember to keep the socket held fast onto the securing bolt in the neck of the filler tube when you are lifting out the tube and putting it back, otherwise the bolt can escape into the sump!

b. the five holes in the front timing case that secure the RTC often fill up with ‘clag’ and you need these to have plenty of ‘up and down’ clearance when settling the RTC back into position. We run a drill through these holes when the five bolts are out to clear them out. You can see that these five bolts are doing exactly what you don’t need! They are pulling the RTC away from the crankcase and they only need to be gently ‘nipped-up’ and only then when the two securing bolts on the RTC are tight, otherwise you are pulling the RTC away from the gasket.

c. I have exchanged the near side bolt of the two on the RTC for a stud, with threadlock. This means that the stud uses the full depth of the available thread in the crankcase, so is less likely to strip. You cannot do the same for the off side bolt, as this fouls the oil pipe just above and anyway the RTC is shaped at an angle ( thanks Gerald....why didn’t you make this mating face flat? )

d. you may need to make up a simple gasket for the inner face of the front timing case cover that is exposed when you take off the RTC. This only prevents splash from leaking out, so can be a plain paper gasket, shaped like a crescent. Use some gasket goo here and I fabricate my gaskets from strong cereal packets. I find Scott’s Oats boxes make a good gasket!

e. On the subject of gasket goo, opinions differ and I am sure we all have our own favourites. I use Stag Wellseal, which as the adverts say has been ‘Developed by Rolls Royce Ltd and manufactured under license, this compound is the complete answer to sealing problems on machined faces’.

f. As for fitting the RTC back onto the block, my earlier post discusses this. They do distort and need to be carefully scraped and fitted. Putting back a distorted RTC just asks for trouble and will not work!

I wish you every success in getting the oil leaks down to managable quantities. I remember parking at the Anderton boat lift when we were at the Daresbury rally where there must have been 25 post-war Jowetts parked on the sloping car park. It was raining and the silvery oil sheens in front of ALL the Javelins and Jupiters told it's own story!

All the best,

David

[paul wilks]

Thanks for the advice David and Keith. I wouldn't attempt this on my own- you haven't seen my handiwork re mechanics!
I will most probably discuss with other North West members but If I do ask Ray of our ‘adopted garage’ Daytona Autos of Congleton to carry out this task, at least he will have very comprehensive guidance to follow! Thanks for all the help.
I was interested in your comment about the post war Jowetts and their oil leaks, David. I wonder what the pre-war Jowett engines are like. Perhaps we could fit a Jowett Ten four cylinder engine (!)

Regards

Paul