Recommissioning 1929 long two

[BarryCambs]

Hi Tony

Paul tells me JCS have reconditioned dynamos in stock, along with a couple which could be used for rebuild, but they are all 6 volts. I know they can be rewound as 12v, but it would make sence to start with the correct one to begin with. Even if I take the existing dynamo off for rebuild, I'm still going to need an end plate with the 3rd brush holder, so if you have one you'd be willing to part with, that would be great!

It seems it wasn't a very common dynamo and coupled with the chain drive and rear mounted distributor drive, it's not the sort of thing you can just casually pick up from ebay. I googled the number from yours and one came up in the Science Museum collection.

I'm about done with the motorbike I'm trying to get out of the workshop for a friend, so hopefully next week I can make a start on the Jowett jobs. Just need to pluck up courage to try and get the oil pump out without breaking it, as per the instructions. I have some distributor weights and springs from JCS to try too, so we could soon be flying.

Barry

[george garside]

not sure if I have mentioned this before. The safest way of removing the oil pump is to heat the crankcase until it drops out (literally!). With engine out I used to just put it on the kitchen gas stove. With engine in a small camping gaz or similer stove under the sump should provide a nice even heat rather than waving a blow lamp around. One of the modern electric heat guns might work but not sure if they are hot enough.

george

[BarryCambs]

Thanks George - you had suggested heating the sump before and I was planing to do this. I have a selection of blowlamps, camping stoves and electric heat gun, but I'm hoping it doesn't need too much heat. Do they get really tight? I was just a bit nervous having seen the pictures of the broken pump in a previous thread.

Barry

[george garside]

yes they can be very tight which is why trying to tap them out using the protruding lug is asking for trouble. Just put a gas stove under it and go and have a brew while you wait for it to drop out all by itself!

george

[BarryCambs]

I found ten minutes this afternoon, so thought I'd have a go at the oil leak. Following instruction I spent 15 minutes heating the sump with an electric heat gun and sure enough, a quick tweak on the puller bolts and it started to ease itself out. I actually felt quite smug ........... right up to the point when two bits of flange fell out onto the drive It was clearly running like this for some time as the breaks are completely blackened.

Further inspection revealed a bent nail holding one drive socket onto the drive shaft and it was at this point I realised I can remain in denial no longer - the 1967 engine rebuild proudly stamped onto the crankcase has been done to exactly the same standard as the rest of the work on the car.

It's clear that while the internals of the engine and gearbox seem fine, it's going to be safest to strip and check the whole lot over the winter before something lets go in spectacular fashion.

As a plan A, I'll ask JCS if they have another pump, but I'm guessing they are a bit thin on the ground given their fragility. So my question for today is, which engines would the pump be fitted to? Was the same pump used in the Bradford engine??

Plan B is to go down to the engineering labs and start crying to see if they take pity on me.

[Keith Clements]

Stick it back together with Araldite, a tried and tested Jowett owner's solution!
It is a period bent nail...

[george garside]

I agree re araldite! If the oil pressure was ok then the pump itself will be ok. No need to use puller bolts if left on stove a bit longer as it really will drop out!

george

[BarryCambs]

Ok - I'll try gluing it, but it needs a good soak in acetone before I start I think. The pump itself has no wear at all and at tick over, the oil pressure is right at the top of "Idle" on the gauge, even when it's been running for an hour or so.

As for the bent nail Keith, I can only assume it was put in during the engine rebuild. This was 1967, so certainly pre decimal, even if not the correct 1930's item. If I can straighten it accurately, I could maybe measure it to see if it is an inch or 25mm? I do have a 1934 parts list, but it doesn't show up on that, however, I have just demolished the old wood shed, so I maybe able to find a replacement there.

Barry

[Keith Clements]

It may be worth drilling a couple of small holes in the casting and put some pins in. Araldite may not have enough shear strength.
Any idea what caused the breakage? Sometimes it is caused by not having a gasket between the joint and then excessive tightening. Or could it have been knocked when the sump was hit?

[BarryCambs]

There's no obvious sign as to how it got broken. I was hoping the leak was down to a gasket failing, but there wasn't one fitted, so it could have been over tightened. The puller bolts are only threaded through the top plate, so I guess could break that if over tightened, rather than the flange. I'll check it all on the surface plate before reassembly, but the marks on the cap are polishing more than wear. Might treat myself to a a rivet too!

[george garside]

the glued bits will not be under any great strain as they will effectively be clamped by the bottom plate. The usual reason for that type of breakage is cack handed attempts at removing the oil pump by force rather than aforementioned heating until it drops out.

george

[Tony Fearn]

I agree with George.

When re-assembling the pump, and putting back into the engine casing, perhaps a bit of blue Hylamar goo between the casing and the pump flange, and very sparingly between the pump bottom and the cover plate will help stem the drips.
The araldited bits will have to be in the same plane as the rest of the flange or the join will break on re-assembly.

George, I can't remember if heat is again necessary on the engine casing just before re-fitting the pump.

When the pump is removed, the driving spindle joining it to the gear on the camshaft just drops out.
Re-assembly may necessitate removal of the front engine cover (timing case) so you can see to marry the ends of the spindle.

If this is removed, and it is the pressed-steel type, then tap the flange level again at the bolt holes before replacing it with a cork gasket and more Hylamar on both gasket faces. Otherwise you'll get more of the dreaded drips .
Tony.

[george garside]

if the pump body does not push into the crankcase by hand I would advise heating the crankcase until it can as this enables the pump body to be rotated slightly if necessary to line up the bolt holes. It also ensures a good tight fit on cooling. To ensure that the araldited bits are in line I would suggest putting some thin polythene sheet over the bottom plate and clamping the pump body and areldited bits together until the glue is well and truly hardened.

george

[BarryCambs]

Thanks for all the advice - it is all duly noted. I hadn't thought about lining the drive shaft up again. I do have a new timing case gasket here, but in truth I was hoping to put off taking the cover off until the winter,as given my experience with the rest of the car, i am a bit scared of what I might find! At least the cover doesn't leak at the moment, but that could be down to the rather generous amount of Red Hermetite oozing out everywhere.

I do remember rebuilding 2 Ford V6 Mk4 Zodiac/Granada engines many years ago, both of which had wrecked their crank bearings when the hexagon shaft driving the oil pump rounded off in it's socket, so maybe the nail is an improvement on this design at least.

[Keith Clements]

Probably best to assemble the unit whilst the Araldite is still setting. A paper gasket will prevent any excess from permanently fixing the bits together.