Crankcase Set 16104

[Mike Allfrey]

CYLINDER LINER SLEEVES
Following on from the missing valve gear feed pipe story that was posted yesterday.
This is a crankcase set that the current owner has had Jupiter Number E1 SA 136R on the plinth that had been milled smooth and freshly stamped. Following on from my post yesterday, I have now discovered that the cylinder liner bores, all four of them, have been bored and fitted with cast iron or steel sleeves for the liners to slide into. I have never seen this done to a Jowett crankcase before, and it makes me wonder – what has gone on before? I have seen such a repair in a Ferguson TEA (Standard Vanguard) engine, but on one cylinder only. We then thought it was a repair to damage sustained from a broken connecting rod.
The sleeve had been installed in a cast iron cylinder block, so heat generated expansion would have been very similar between repair sleeve and cylinder block. In spite of that, the sleeve did migrate towards the connecting rod’s big end and the crankshaft, to then cause havoc. We sold the farmer a works reconditioned engine.
In the Jowett’s case, the crankcase being aluminium, tells me that the cast iron sleeves could easily come loose and again, could possibly cause internal havoc. There appears to be no lip adjacent to the cylinder liners’ seating ledges. A quick measurement has shown that the sleeves’ ring sections are the same at outboard and inboard ends of the bores. Maybe the sleeves are secured with a Loctite, or similar, product?
It seems that this crankcase may have been bored to accept larger bore cylinder liners, and then converted back to standard, when other problems may have arisen. Has anyone heard about such modifications being tried?
Another explanation could be damage caused by a broken connecting rod, but then, why modify the other three or, did all four rods break at the same time?
I understand this engine was stored under blackberries and gum trees for forty-plus years. There is severe corrosion in the aluminium, at the head gasket surfaces, above the balance pipes. Any near new condition Series III crankcases out there?
Any comments will be greatly appreciated.
Mike Allfrey.

[Mike Allfrey]

Further to my previous post, here is an update.
Because of the sleeves in the cylinder bores and the severe corrosion at the head gasket surfaces, we have decided to start all over again with another crankcase. I have noted other examples of stripped threads etc., yesterday while removing studs I discovered that two of the 1/4" B.S.F. threaded holes for the anti oil splash plate had been opened out to 5/16" B.S.F., with one of them crookedly threaded.
Jowett engines may well help keep Helicoil/Recoil/Keysert/Keensert profitably in business!
All of this reinforces the requirement that ALL threads must be carefully checked well before any other work commences on the crankcase set. Just imagine having to repair an anti-splash plate thread (or an oil pump mounting thread) after all the careful assembly work that goes into the engine before fitting the plate.
I still haven't been able to work out the threads used to 'repair' the rear timing cover hold down studs - 9.5 mm metric fine?
This means that crankcase set 16104 has been, technically, 'scrapped', but the owner will probably still treasure it for semi-sentimental reasons.
All the best,
Mike Allfrey.

[David Kemp]

As you are working on a series 3 , does the bell housing have numbers stamped on it ?
If so do they match the engine?
Or what are they for?
The one I bought with my crankcases , have numbers but they do not match the engine.
My PC & PA bell housings do NOT have numbers.

[Mike Allfrey]

Hello David,
Crankcase 16104 was, I think, a PC Javelin set which has 3/51 (March, 1951) stamped into the rear of one half. At present, the engine I am involved with, belongs to Richard Homersham. Currently, Richard is organising another crankcase set. I have no idea which version it will be.
The situation with regard to flywheel and front timing covers is rather loose, matters are sort of mixed up by now and and you will have to work out the best option for your crankcase set. Should a flywheel housing, or a front timing cover, fit snugly over the dowels you will be partly home. The next aim is to achieve a concentric result at the main bearing tunnel at both ends of the crankcase set and and the two housings (oil seal bores), finally a flush surface for the sump gasket to seat on.
I have also found a PA set with a '4' stamped into each component close to the sump flange. Other sets have no numbers at all. Seventy years on, it is all a bit confusing to those of us who were not involved all those years ago.
We have to appreciate that all Jupiter and Javelin crankcases have aged and been treated badly in the past. Crankshafts are ground undersize and cylinder liners have been bored oversize, so, something has to yield. Also, needing to be taken into account are the facts that the hardware has been over tightened at some stage in the past, and that severe corrosion may have taken place in the coolant jackets. Both are crankcase weakening factors. We need to be well aware of such and drive our cars accordingly - personally, I have set myself a cruising rev limit of 3,000 E.R.P.M., which in my car relates to close to 100 K.P.H. At that speed on the open road the engine feels quite relaxed and that suits me.
I hope this helps a little,
Mike Allfrey.

[David Morris]

Hi,

I have been aware that, for Javelin/Jupiter engines, later flywheel bellhousings carried the serial number of the matching crankcase set that they were paired with at the factory. As mentioned above, it is important that the rear oil seal aperture is concentric to the rear seal face on the crankshaft. Otherwise, you are asking far too much for the oil seal to accommodate. We have found 'out-of-concentric' values of up to 0.015" or more. About 0.003" or less in diameter is acceptable. To help matters, we have been fitting a SKF 'Speedi-Sleeve' to the rear crankshaft seal facing. This adds about 0.025" in radius to the seal face, due to the thickness of the sleeve. It also conveniently 'hides' any grooves worn in the original running face. I am sure that John Airey could help with the SKF part numbers, as he has fitted several.

I am not aware that, similarly, the front timing case was also marked, but then anything seems to have been possible at the factory? I strongly suspect that, during engine assembly, the fitter had piles of bellhousings, front timing covers and also rear timing covers to choose from. They just picked ones up that gave the best fit? I had to rewrite this to change, in these PC days, my original 'He' to 'They' after having met two delightful elderly ladies who were resting from their shopping in the Morrison's Supermarket at Idle and who explained that they were both machinists in the original Jowett factory!

Hope this helps?

David

[Mike Allfrey]

Thanks David (M),

I think the best way to identify a Series III flywheel housing could be the openings for the clutch throw-out fork, which are sort of pear shaped instead of the more common rectangular openings. I have not yet seen a crankcase set number on a flywheel cover.

One point about the rear main oil seal running area on the crankshaft, is that many grinders 'clean-up' the seal lip groove. Some have also made the flywheel a very loose fit!

Best wishes,

Mike Allfrey.