Recommissioning 1929 long two

[BarryCambs]

Success!! The rebuilt carburettor was fitted, and for the first time since 1974, the old girl edges out nervously on to the road.

https://youtu.be/l2BRIkbE59g

Once warmed up, the carburation seems pretty much spot on. It might benefit from going up a jet size on the compensator, but I won't mess about with it until the distributor is back from it's rebuild and recalibration mid June.

There is still a reasonably long to do list, but at least we now have a usable car to enjoy for the summer I have investigated the rear axle seals and everything looks fine. The JCS felts fit perfectly and look to be about the right thickness. The tapers on both the half shafts and hubs both sides have been damaged to the point I had a problem getting the nearside one tight enough to stop it wobbling. I plan to have then sorted this winter, but I wonder if the hub is not going on quite far enough to hold the felt? There is however plenty of room to get modern rubber seals in, so I have ordered a pair to try.

I also have a charging issue, but I haven't looked into it other than checking the brushes. It came with a very strange control set up, obviously home made by the previous owner who was an electronics engineer in the 50s. I do wonder if it has been converted to 2 brush at some stage, as I read some people do this and hen use a later control box. I have rewired the car as original. I was hoping to find a spare dynamo to rebuild, so as to minimise downtime on the car, but I'm not sure exactly what model it is and the gear drive is presumably unique to Jowett??

[Tony Fearn]

I love the gear changes,
Well done.
Tony.

[Tony Fearn]

The tapers on both the half shafts and hubs both sides have been damaged to the point I had a problem getting the nearside one tight enough to stop it wobbling.

Pre-war Jowett rear hub.jpg

Hello Barry.
Perhaps you have the problem that I had.
I needed to shim the end of a half shaft before offering up the hub.
This allowed the hub edge to be proud of the flat on the half shaft end, so that when the nut was tightened, the washer still hadn't reached the flat on the half shaft end.
Bit gobbledygook-ish, but perhaps the sketch will give more detail.
Regards,
Tony.

[BarryCambs]

Hi Tony

That's a very good point (and excellent drawing!) and I will check. The existing damage could well have moved the hub back far enough to let the washer touch the shoulder. The modern lip seals have arrived, so I need to take them off anyway, but I have decided to leave everything well alone until we have completed the Yesteryear Road Run on Sunday now it's actually on the road! If the problems are down to the damage, I was thinking about investigating metal spraying or hard chroming to repair them, but I'm hoping it can wait until the winter, as i don't want to take it off the road again. I did try fitting one of the felt seals you kindly sent in additon to the thicker ones from JCS, but that clearly made thing too tight.

The gearbox holds no fear for me. It has a big advantage over those I was used to in that the gearlever is actually attached to the gearbox, rather than via several bendy rods with rubber bushes to try and disguise the fact that although the vehicle is late eighties, the engine and gearbox are from the late 30s and synchromesh is only fit for "foreign rubbish".

What I do struggle with is the accelerator which I'm finding a bit awkward. I have given this some thought and sourced a pair of smooth soled shoes, as I think a lot of the problem is the grips on my others snagging the button.

Barry

[Tony Fearn]

Hello again Barry.
I've just looked at your recent 'Youtube' film again.
The ammeter doesn't seem to show a charge when you're bombing down the road.
Is it connected?
Tony.

[BarryCambs]

Hi Tony

Well spotted! The ammeter is working, but the dynamo isn't giving a charge. When I tried the car before we rebuilt the carburettor it was running so badly, it was a problem to rev the engine and I didn't notice the light on. As I mentioned, the chap who owned the car for many years before it came off the road was an electrical engineer and had his own TV, radio and electronics repair buisness based in London. If you look at the picture of the loom I removed, you will see some sort of contact/relay box in the middle. This has a large solinoid behind it, so I assume is some kind of control box and I assume was a system of his own design. I have no idea as to the circuit board - possibly a voltage converter for the fuel guage? The whole thing was in such a state I didn't bother to try and trace anything, thinking it was just easier to start again.

loom.jpg

My new loom follows the original wiring diagram and the back of the dash switches are labeled so quite difficult to get it wrong........ I hope. I haven't investigated it yet, as I daren't touch anything before Sunday, but it is my next job to look at. I did try flashing the dynamo, as I wondered if it had lost it's residual magnatism. I wonder if the Dynamo has been converted to some sort of 2 brush set up as I know this is sometimes done and I'm hoping it's possible to get the back plate off the dynamo without taking it off the engine, so I can have a proper look at the brush wiring etc. I need to look at the cut out too, if nothing else to see if it has been bypassed I guess.

My plan was to find a spare dynamo which I could rebuild properly at my leisure, rather than taking it off the road during the summer, but as you know, they are a bit unusual, so not the sort of thing you can just casually pick up on ebay.

[BarryCambs]

A better veiw of the control box. I could find no evidence it was ever fitted with a case and no sign of a maker's name

DSCN1081.JPG

[Keith Clements]

You can do some diagnosis with a meter on the dynamo. Check continuity of brushes and windings, check for shorts, check for voltage output by spinning, both open circuit and via a shunt.

[BarryCambs]

Hi Keith

I'm hoping to go over it this weekend with a meter as suggested, to at least check the basics. My Dad did just check the brushes were free a while ago and I'm sure I remember seeing the 3rd brush holder still there while the cover was off. Whether or not it's connected to anything ...........

Normally we walk and cycle to school/work, but today I drove in. It's running better all the time and the brakes are improving as everthing settles down again, which helps my confidence in the traffic. Nothing major identified, good oil pressure and the gearbox and back axle seem completely silent.

[BarryCambs]

Today we took part in the Cottenham Yesteryear Road Run, along with around 300 other cars, motorcycles, commercials and tractors. A round trip of about 35 miles including the road run itself. The weather was a bit bracing and my worries about overheating in traffic have proved to be unfounded. With the newly rebuilt radiator, it's running a bit cool if anything.

13094288_10153636068796365_3217211066284009640_n.jpg

11416196_1079500082122293_5094089647461040327_n.jpg

All still seems good, but there's a healthy oil leak from the pump when the engine's running, with about a litre lost today, so that needs looking at as a priority. It was the first time it's been out on long stretches of open road and while the engine runs well, it clearly lacks power. With 4 people aboard it will cruise at around 30mph at 1/4 throttle, 30mph at 1/2 throttle and 30mph at full throttle! Once out of the villages, it was very noticeable the Austin Sevens etc were disappearing from view rather rapidly. In fairness, 30 is about as fast as you'd want to go with the steering the way it is at the moment with around 4 inches of play. Coming back with just 2 of us, on downhill stretches I felt the terror they must have experienced up on the bank at Brooklands in the glory days!

From looking at it with a strobe, I know the timing is a bit "variable" and it is booked in for a proper distributor rebuild in June. It still splutters a bit pulling away and has to be warmed up a bit before leaving the drive, but everything I read (including the Jowett Club Pre-war technical notes) says a bigger compensator jet is needed to correct these symptoms. Lack of top speed suggests a larger main jet, so I will go up a size on both. I did read in a couple of places (possibly including the FBHV advice in Jowetteer) that the ethanol in the new petrols can cause lean running and may need larger jets in some engines, but I don't know if anyone else has experienced this?

Could be my nice free flowing exhaust has added to the problem, but it does sound good At least I am starting out with a completely rebuilt carb with a set of standard size jets this time.

[Tony Fearn]

Barry,
Have a look at: viewtopic.php?f=4&t=3427&p=19134&hilit= ... val#p19134 before removing the oil pump.
Tony.

The thin third brush (if there is one) on the dynamo wears away much quicker than the other two in my experience.
If the length is shortened too much by wear, then although it seems to be free in the holder, the two-fingered sprung brass prong might be bearing on the brass holder.
It may look like the prongs are holding the brush against the commutator, when they aren't actually doing so.
This would mean that the brush wasn't in contact with the commutator and so no charge would show on the ammeter.

3rd brush wear.jpg

Tony.

[Forumadmin]

Regarding ethanol, I would concentrate on getting the distributor correct before considering rejetting.
Ethanol burns slower so needs more advance.

[BarryCambs]

Thanks Tony for another fantastic drawing! I think these should be collated in a book for future reference I'd remembered the advice about heating the sump, but forgotten about the rest of the thread, so that's very helpful. Might have to wait for the weather to improve again before I can bring myself to get under it though. It was 4 degrees when we set off on Sunday morning and after the 5 mile trip to Cottenham 4 up, the temperature gauge had just made it to the bottom of normal.

The distributor had been butchered with someone taking a hacksaw to the fly weights which were also too thick so jamming the advance anyway. Martin at the Distributor Doctor looked at a photo and advised me it's a mongrel half early, half late distributor someone has put together. He sent me some parts to get me going, but the springs are slightly slack and I don't think I'm getting maximum advance of 36 degrees specified in the technical notes from JCC, so it's going to him to be recalibrated properly on a test bed in June. Strangely, it's one of the only distributors I can ever remember seeing with no detectable wear at all on the bushes, so given the bottom half is the original, what happened to the top half is a bit of a mystery.

As I have a spare, I might just try a larger compensator jet in the interim, as it's a bit tricky trying to pull away in traffic, especially when cold, but rest assured I won't be trying to set it up any further until the distributor is back. It does at least idle nicely now with the correct size slow running jet and once warm, it starts first compression stroke.

I was pondering the easiest way to fix my timing disk to the crank so I could mark up the flywheel and see what was going on when I chanced on a post on the Austin 7 forum suggesting the easier way is to divide 360 by the number of teeth on the flywheel and so I am happy to tell you on a 1934 engine at least, it's 4.5 degrees per tooth!

[Tony Fearn]

the easier way is to divide 360 by the number of teeth on the flywheel and so I am happy to tell you on a 1934 engine at least, it's 4.5 degrees per tooth!

Hello again.
Ian Priestley once mentioned to me that some pre-war fly wheels had 79 teeth, whilst others had 80 teeth, although may be from different years.
It seems to make a difference when a starter is chosen, as the wrong one could lead to incorrect meshing of the pinion and ring, and perhaps even the timing you mentioned.
Mary Ellen has 79 teeth - many more than me!!
Tony.
George - can you confirm?

[BarryCambs]

I checked several times and the car has 79 teeth - I have all mine. I was looking out for a spare starter, so once again, I have learnt something useful.

Barry