Gasket ordered from Bob Johnson who quoted £96 and 2-3 weeks delivery.
I looked for a source of new big end bolts and found that the MGs from TB to TD, and the 1950’s Wolseley 4/44 which use the XPAG engine have a bolt which is suitable, being M8 x 1mm pitch, a size which was used in the UK from the 1920’s to the 50’s and known as System International (SI). The only variation being that the MG bolt has a filet radius under the head whereas the Lancia bolt is relieved at that point, a slight countersink on the seating on the rod would solve that. They are available either as very high tensile (12.9 grade) which are very carefully torqued up to a measured amount of stretch and do not need locking nuts, or in a more normal (presumably Grade 10.9) variety with a castle nut and split pin. I dismissed the extra strong variety as there is no way to set the torque so accurately since no torque wrench will fit through the crankcase side panel. (Picture 46). Unfortunately the other variety when I bought a set turned out to be a disappointment as they were not accurate in diameter and a slack fit to the rods. So at the moment I shall content myself with checking the existing bolts, which seem OK and not stretched or otherwise dodgy.
The head is away to have the face resurfaced in honour of the new gasket and the exhaust seats ground. The valves and guides seem good, the guides new and the valve stems a very good fit so nothing needed there. However I’ve just been advised that the number 4 exhaust valve head can fall off due to the excess heat in that corner and that there is a stainless steel Nissan valve which can be fitted so I’ll mull that over.
The next job was to look at the water pump body for corrosion, to replace the ball race at the pulley end which was noisy at tickover, and check the bronze bearing and seal on the spindle at the impellor end.
They are a bit fiddly to dismantle and at least one special tool is needed. The bearing is retained in the pulley by a threaded disc which has four peg holes to take a tool rather like those used to take the disc off an angle grinder. Luckily I had an adjustable version of this which worked well, provided the pegs are kept tight into the holes. A hydraulic puller with claws long enough to bite on the solid part of the pulley removed the pulley from the bearing.(Picture 47)
Next to remove the ball race from the housing another tool was made following Morris Parry’s design with four short pegs on the rounded end which fits into the plug. The pegs were cut from the shank of a 4mm drill bit and were pressed with drop of Loctite into slightly undersize holes in the end of the tool. I found that putting the pump body in the chuck of the lathe and pressing the peg spanner with the tailstock allowed the plug which retains the bearing to be unscrewed. The bearing was then pulled off using another puller which by chance was exactly the right size. (Picture s 47,49,50,51)
So with it all dismantled I found that the alloy pump housing was fairly corroded but that although the spindle is worn a little by the traditional asbestos gland seal, the rest of the spindle and the bronze bearing are sound. As the gland does not leak in use I shall leave that alone and just replace the ball race. This is an odd size, but available from Simply Bearings. KG Brand 98305 Deep Groove Ball Bearing 25x62x12mm. I would have preferred a higher quality SKF but the KG seems to be the only one around and for £6.24 plus post and VAT I can hardly complain. A similar size double sealed bearing is used on the crankshaft of a Vespa scooter and seemed a good choice for the pump. However these are C3 grade which means a relatively slack clearance for use in very hot situations and I am told would probably be noisy at radiator temperature.
The corrosion of the pump casing is not terminal (he said hopefully!) so I shall use JB Weld Original metal filled epoxy putty to protect the corrosion. I have even used ordinary Araldite in similar situation before so the JB Weld should do the trick. (Picture 52)
Mike
