Recommissioning 1929 long two

[george garside]

Am back now Ihave got the hang of sorting out password after several attempts.

Whilst I was aware of 79 and 80 tooth flywheels I have no idea when which was fitted to what or whether a different matching starter pinion is needed.

As far as Barrys car being somewhat lethargic I agree with Keith that its more likely to be distributor than carb jets that is causing the problem. Assuming the static timing is spot on it seems to be down to it not advancing as revs increase or maybe not advancing sufficiently to take it beyond around 2000rpm ( engine speed at 30mph). It should be able to reach or exeed 3250 rpm which equates to 48 ish mph in top. It should also be able to idle steadily at around 300rpm

With the presumably lightweight 2 seater body it should be a real flyer i.e much more lively than a 1934 saloon wighing around 15and a half hundredweight

The autocar road test figures for a 1934 Kestrel :

timed speed over 1/4 mile 55.5 mph

''3rd gear can be used freely up to about 43mph''

''2nd gear maximum just below 30mph''

''The maximum timed speed was 55.5mph , yet for many miles on end the needle was kept at 53 and under normal road conditions free of traffic was seldom under 47'''

The light car magazine came up with a max of 54.2 mph over a quarter mile and commented that ''a run of 184 miles down the great north road was accomplished at an average speed of 37.5 mph.

george

[BarryCambs]

I have set the timing at 6 BTDC as per the Bob Holmes Technical Notes, but I'm not going to claim it's always spot on due to the slack in the distributor. The technical notes give a maximum advance of 38 degrees. The spindle in the distributor is marked 16 degrees, so 32 plus the initial 6 would be right once it's properly calibrated. I haven't yet marked the 38 on the flywheel, as I knew the distributor was completely wrong, and just eye balled it with the strobe to make sure it wasn't advancing dangerously. While there is some advance showing using the strobe, I doubt it's going far enough. The engine runs sweetly once warmed up and rolling, but it doesn't want to rev.

It's a bit frustrating having to wait so long for the distributor overhaul, but it seems every specialist I speak to (radiator, dynamos etc) has a 3 month turnaround, so business must be good! I'm wondering if JCS might have the distributor off the Kestrel that donated the carb I could either buy or hire for a while to keep me going until mine is done. That said, I must sort the steering before the performance improves, as it's really not safe any faster than it is. When I say of has 4" play on the wheel, that's in each direction, though it's an old repair, so was clearly driven like this for some time.

The good news is, mechanically the engine seems pretty good. Compression is perfectly balanced, I haven't seen a wisp of smoke and oil pressure is right up, even after an hour or so of running. Someone has stamped "rebuilt 1967" on the crankcase, which would be 7 years before it came off the road. One man's rebuild is another man's wipe over with an oily rag and a set of plugs, but it could be it was done professionally and to a good standard. I've be surprised by how quiet the gearbox and diff are.

George's performance figures are interesting and better than I'd expected - something to aspire to and hopefully the Austin 7 Owners Club, who were out in force on Sunday, won't be looking so smug next year. We were using a GPS speedo to get 30mph, but I'd be surprised if it is doing 2000 revs at that speed, as it feels just off tick over and very high geared. I do have a test meter with a tacho, so I will give it a try. This reminded me that a long time ago, I did jack it up to see if I could determine the back axle ratio, again using the figures from the technical notes. It does look like it still has the 1929 back axle ratio, which is higher than the 1934 one, but it wasn't clear to me what size wheels the 1934 car had and what difference this would make to the calculation. I do think 55mph would probably be enough for the chassis though!

Barry

[BarryCambs]

Just looking at the technical notes again and it says 19 inch wheels for 1934, the same as mine, so presumably it is going to be a bit high geared.

[george garside]

Barry, I think yours is actualy a 1930 model ( introduced Sep 1929) Unfortunately you wont be able to tell by the engine number but the chassis number should be somewhere and will begin with 0 for 1930 model year or 9 For 1929 season starting Sep 1928.. The 4 wheel brakes only came in April 1929 on the Black Prince but as far as I aam aware not on the whole range until Sep 29 (1930 model year)

Top gear overall ration 1930 5.12 to 1. 1934 5.37. vintage models 4.56 to 1.

4.56 equates to 17 mph per 1000rpm and 5.37 to 15mph per 1000. which would of course mean 30 mph at 2000rpm. the vintage models would be 34 mph at 200rpm. I don't have a mph per 1000 for the 5.12 axle.

The cause of it not revving up properly could be wrong springs in the distributor or knackered once that have lost their springiness. Have you tried advancing the ignition manualy by rotating the distributor with the engine running at about 2000 rpm to see if it suddenly comes to life

george

[george garside]

Barry, The reason why your car does not sound like its doing 2000rpm is because to do its 2000rpm it only fires half the number of times than would a 4 cylinder engine. This is why in their day the Jowett twins performed in a much more relaxed way than their 4 cylinder contempories and even when running flat out it didn't sound as if it was getting its knickers in a twist in the way that other contempory small cars did

I once managed Torquay to Manchester in 8 hours (pre much motorway) running pied a plancher probably 90% of the way and with the engine sounding relaxed throughout. I would not have fancied attempting that in eg an Austin 7!

george

[BarryCambs]

Hi George. I think it's is definitely 1929, or at least bits of it are. The registration DF comes from Gloucester and some time ago, I spoke to Gloucester County Council Archives as part of my effots to put its history back together. Within a couple of minutes of putting the phone down, they rang to say they'd found the original registraion in their ledgers.

registration gloucester.jpg

Registered to a Mr Williams in Massey Hampton on 8th June 1929. The Chassis number is 925663. If it was registered in June, it could well have been built in April so if they had 4 brake axles around .................. Of course, there is nothing to say it has the front axle it left the factory with! Could it be off the 1934 car that donated the engine, steering column/box or are they completely different?

The current springs are new, but were a "best guess" by Martin at the Distributor Dr, along with the weights which he sent to get me on the road. I think he said they're Autin 7 springs, but are clearly wrong, as they are slack at fully retarded. The ones that were on it probably went in the bin in a fit of disgust, along with the home made fly weights - I think it was fitted with 2 thicker springs, rather than 1 thick, 1 thin. It was also fitted with a 4 cylinder distributor cap, which left the centre brush hanging in mid air, so all in all, it was going nowhere fast. Martin told me the problem is he doesn't have a reference set of springs for this engine, so the best thing is for him to set it up properly on his test bed and that seemed a good way forward. EDIT - Doing some research this lunchtime and it looks as though the Austin 7s have a very conservative advance of around 20 degrees so this would explain a lot.

Luckily, my ear is quite well tuned to twin engines I have a Moto Guzzi 1000cc V Twin languishing in the shed. Owned since 1988, I built it from parts and then did 131,000 miles on it, until a slight electrical problem took it off the road a few weeks before my first child was born. 8 1/2 years later, it has now been stripped down ready for rebuild this winter. One of the first things I did in 1988 was to chuck the twin points set up in the bin and fit electronic ignition, but you will pleased to hear, that this time I will perserve!

[Keith Clements]

See Forumadmin's post of 25th April. You need to get the advance curve correct as well as the max advance. One of the weights should be slack at zero revs. This is the higher speed spring as it comes in later (around 800 rpm) to flatten off the slope created by the lower speed spring.
Is the dizzie in this list in the Gallery

[BarryCambs]

Hi Keith

Both springs are slack at the moment. I had a look at your link, but I can't see it listed and the furthest the list seems to go back is 1939. The distributor is a DJ2 with, I'm told, a later DK base plate. I don't know which distributor the cam is from (Could a Bradford one have been used?) but the fly weights were being clamped between the cam and spindle when the centre screw was tightened, which is presumably why someone went at them with a hacksaw. The good news is, I had another look at the photos I sent to the distributor Doctor and assuming the body is original to the engine, I hope the plate will tell him all he needs to know.

http://www.distributordoctor.com/process.html

distributor.jpg

Distributor_2.jpg

I assume 1905 is RPM it should have reached maximum advance, "6 & 12" is degrees of first and second advance and 933 is the curve?

If I add the second advance to the static timing to get a total advance I get 24 + 6 so 30 degress maximum advance? This doesn't match anything on the technical notes completely but I'm still a little confused at to where my engine number 43 6395 fits in on the table.

http://jowett.org/jowettnet/dt/tech/jti/pw.pdf

In the short term, Paul is checking to see if JCS have any old distributors when they reopen Monday week and has kindly offered me a Bradford track rod from his own stock I can hopefully use to graft a new ball joint onto my drag link before we all end up in a hedge, rendering the distributor rebuild unnecessary anyway!

Barry

[george garside]

1929 was a funny year as some 1930 model year modifications were introduced in April 1929 , the main mechanical one being the introduction of 4 wheel hand and foot brake ( some early 29 models had 4 wheel foot brake with external ccontracting bands on the back drums for the hand brake) Also the central ball change came in both mods being introduced for the Black Prince with 4 door fabric body.

Presumably early 29 models ( made in 28 and early 29 had the early 20's 2 wheel brake , right hand gearchange and 2(on the nearside) door fabric saloon.

I think it is quite likely that the 1930 model year modifications were made piecemeal in 1929 as the 2 wheel brake 1928 chassis was way out of date when compared to other makers models. So Barry's car could have been made with some unpublicised 1930 features??

george

[Forumadmin]

Both springs IMHO should not be slack as this would mean the rotor is free to move a few degrees and so static timing may be variable.
We cannot be certain what the numbers might mean and they are irrelevant since the modern petrol has a different burn rate to that for which the original curve was designed.
Modern petrol should be able to take more advance before it knocks or pings. Find a hill with a slight incline and see if the engine knocks when climbing it at 80% your max revs. Keep advancing the ignition until it does. Then note this max advance point with a strobe light back in the garage.
It is likely the car will be difficult to start at this setting and static advance will need to be brought back to the spec. (say TDC). So the max advance stop may need to be filed away! Then you need to choose weights and springs to give you a curve between these two points. The revs at which max advance starts depends on lots of things and a modern car does not rely on the intersection of two sloping straight lines to approximate to a curve but maps a continuous curve. It may also have a dwell map as well rather than a compromise with a static dwell angle. (The dwell governs the power of the spark). The revs at which the second spring starts to operate also has to be chosen but about half way (or a bit more say 60%) between tickover and when you want max advance to be reached is a good start.

[george garside]

just a thought if the distributor man can't come up with the correct spring specification for a 1934 engine he may be able to come up with the spec for the 1946 CA Bradford which while it may not be identical is probably near enough so to speak. The CA has the same distributor as the pre war models i.e driven off the back of the dynamo . The CB and CC were driven off the camshaft . I think the springs on the CB may be the same spec as the CA but have a feeling that they were different on the CC but not absolutely certain

george

[george garside]

search for 'tuning the lucas distributor -mgaguru.com for an interesting paper on advance curves and how different ones can alter the performance of an engine etc. Interesting stuff if even not specifically relevant to Barry' engine

[BarryCambs]

The rotor is indeed free to turn a few degrees when static, but I couldn't be bothered to spend much time with it as it was already planned to send it off for a proper rebuild, so I set it about 6 BTDC best I could at tick over using the strobe, hoping it would have taken up the slack when running. It actually seems to hold this point, but it was only ever intended for a few local runs before I can get it sorted properly.

I'm still hoping I can find a loan or cheap distributor to improve things in the short term so we can venture further from home and George's news that a Bradford one might fit will widen the search. I was trying to remember the last time I worked on a points distributor. I do remember servicing an early eighties Volvo 240 and being shocked to find it still had points and condenser which I hadn't bothered to order, but they must have been about the last things with them. I remember replacing spring sets, bushes etc in worn distributors, but it seems a problem getting parts now. The Distributor Doctor seems to be the only place I can find with either parts or a calibration service.

The MGA Guru paper is an interesting read and backs up Keith's view that even if I can get back to the factory spec, it will still be wrong! I had read about ethanol giving a leaning effect, but I didn't realise there were timing issues. I'll speak to the chap who's doing the calibration to see how he deals with the older distributors, but the idea of finding the maximum advance does seem sensible. We do have 2 hills in Cambridgeshire which we are very proud of. One of them is around 10 minutes drive away and has a good run up past the Radio Telescopes at the Mullard Observatory. A thought occurs to me though. Once you get to the bottom the other side, about the first thing you come to is a Rolling Road run by the much respected Peter Baldwin. Maybe a bit over the top, but I'd have more confidence in him getting it right than me and I could probably get a check on the main jet size at the same time. Once strapped down to the road, I'd guess it's reasonable quick to determine the optimum advance at a various points up to maximum advance and pass them on to the guy doing the calibration if he doesn't do more than adding x degrees to the original map to compensate for modern fuel?

[BarryCambs]

I found 10 minutes to go over the dynamo with a meter this weekend. Cut out was fine and the continuity through the armature was ok. The resistance through the 2 shunts for the field windings were 2 and 4 ohms which looked hopeful, so inspired by Tony's kind gift of a new 3rd brush, I thought I'd slip the cover off to see what the existing one looked like. It was no where to be seen. As I half suspected, it has been converted to 2 brush, presumable regulated by the strange looking system in the photos.

The options are to fit one of the new Solid State Regulators and I see there is at least one specifically rated at 8 amps for this purpose, or convert it back to 3 brush. I had already asked JCS to see if they have a spare I can overhaul at my leisure, rather than take the car off the road again, so I am tempted to go back to 3 brush if they have one. If the car was more modern, I'd have no issue at all converting it to solid state (and electronic ignition), but I have tried to keep, or return things back to original and the new loom etc is all set up for 3 brush operation. With it's new modern 50AH battery, the car has been running around for 3 weeks with no charging system at all and still shows 13 volts on the meter someone fitted, so I'm guessing overcharging on a long run would be more of a problem than undercharging and I doubt I will be driving long distances at night.

I'm assuming the vast majority of the Pre War cars are still using their original set ups?

As an aside, I was looking at one of the many uprated brushless alternator conversions for classic motorcycles, including one for my Moto Guzzi (at a cost of a few hundred pounds) which will apparently "solve the problems of the original system". I was tempted to treat myself, as part of it's upcoming rebuild, but it suddenly struck me that I don't remember ever having a flat battery in 20 odd years and 131,000 miles, so I'm not sure what problem it would solve. I think I changed the brushes once, but I can probably live with that.

[Tony Fearn]

........or convert it back to 3 brush. I had already asked JCS to see if they have a spare I can overhaul at my leisure, rather than take the car off the road again, so I am tempted to go back to 3 brush if they have one, to keep, or return things back to original as the new loom etc is all set up for 3 brush operation

Hello Barry.
I have come across a C418A AJ 12 volt dynamo in the garage today which needs work. If you have no joy with JCS, then let me know and I'll elaborate and send some photos. It weighs around 16lbs (approx. 7.3Kg).
Tony.