Mystery Bamford engine

Hello, I have recently joined a Men in Sheds group at the Wind Energy Museum in N Norfolk and we are restoring old associated machinery amongst which is a Bamford hit & miss stationary engine which has not run for 8 or 9 years. I have checked it over and the compression is good but the name plate is missing so we can't identify the model, can anyone help? I have posted photo's in my album. I have looked at several pictures on the computer and there are very similar engines but the magneto is in a different place. Any help would be greatly appreciated.

It certainly looks like an odd-ball.

It appears that most of their hit-and-miss engines used an EK trip magneto, while this one has an unnecessary and regular spark every revolution (the crank and magneto sprockets appear to be the same size).

Question might be why run the magneto at twice the necessary speed, although it may not have produced such a powerful spark at slow speed?

Furthermore, the magneto is driven by a duplex chain - unusual to fit such a heavy duty chain for such a light duty.

The magneto type may be able to be traced for age, etc - it looks like a quite late model for the hit and miss era.

Just some ideas for you to follow up. I’m not an expert on hit and miss engines at all.

Pat,

I've sent an email to a mate who collects Bamfords.

Martin P

Swaffham, presumably?

Would have expected the Mag to be gear drive. Most engines of that type seem to be, so maybe a "field fix"?

The WaterWorks Museum in Hereford run a Bamford engine, which seems similar to this one. If you can provide some details, they may be able to help

Hopefully Martin's pal will come up with something definitive, but if all else fails, try contactiTWWM. The volunteers are only in on Tuesdays, so don't expect an immediate response

Howard

Thank you for the above very helpful information, the museum is at Repps with Bastwick about 10 miles north of Great Yarmouth. I spent many years working on Londons buses and thought that I knew about engines but it seems I have a lot more to learn. All help is appreciated. Regards Pat

I have finally got back to looking at the Bamford engine with a view to getting running, I am told that it has run in this condition in spite of it being a mismatched collection of bits. The initial problem is that there is no spark, the HT lead seems to be wrong in that it comes from the body of the magneto rather than the bakelite cap, the points look OK. Before I remove the magneto I would like to have a diagram of the layout. The magneto is a Lucas and seems to be a GA or GJ type. If anyone has some information I would be very grateful. Regards Pat

Pat,

What you appear to have there is a 4 cylinder tractor magneto that has had all four ignition leads linked together and even though I collect engines I cant see how it works, can you take the bakelite cap off and show whats inside the cap and the magneto body, there should be a rotor arm, the duplex chain and sockets are incorrect as it would have been a single chain. If you PM me your email address I will put you in contact with my friend so you can talk direct.

I will also ask on an engine forum if there is anybody near you in Norfolk who maybe able to help.

Martin P

Hi Martin, Thank you so much for your reply, that certainly explains the links which I realise now are for HT leads. I was waiting for a diagram before taking it to bits but I will press ahead later in the week with it when I next go to the museum, it can't be that complicated and I did play with 50's motor cycles. I will post the photo's. PM also sent if I can work out how to do it, again many thanks, Pat

Would the name be connected with JCB?

There is a family connection, if you go to this website you can read about the history **LINK**

Martin P

Edited By martin perman on 25/06/2019 16:29:43

I have removed the magneto and stripped the points and bakelite cap. The terminal screws were seized and corroded and I replaced the HT links as there was no continuity probably because of the corrosion and reassembled it. I fitted a new sparkplug which I secured against the magneto body and spun it with a cordless drill, hey presto a beautiful spark, sadly it soon faded and now there is the faintest of sparks. I will strip it again tomorrow just in case I have missed something. The magneto is a Lucas GJ4 which was fitted to tractors as Martin suggested. The easy answer is to get the correct magneto but the museum relies on volunteers and donations so the cash is just not there to fully restore the engine, our aim is just to get it running as an exhibit. I have attached photo's. Regards Pat

Pat,

The correct magneto would be a Websters low tension type, sadly you dont appear to have the mechanism to operate it, which is why it was modified to use a high tension magneto.

if you have not done so remove the points and give them a good clean particularly the contacts as they oxide up, how good is the surpressor/condensor this will kill the spark if dead and remove the coil and put a meter across the two main connections if it reads a dead short it needs rewinding but as you have a spark its unlikely. You may also have a weak magnet, it can be all sorted but I dont know a local mag repairer in your area, my local man is in Wellingborough.

Martin P

Hi Martin, Thanks for your reply, I did a continuity test across the points and there is still a circuit when the points are parted so there appears to be an insulation fault there. I have not looked beyond the distributor cap and points yet but there does not seem to be a condenser fitted anywhere near the points. I think that the reality of it is that it will wind up as a static display but I would like to get it running. Regards Pat

I have just had another look and it seems that the long centre shouldered bolt that holds the points to the shaft is lacking an insulator. I will see if I can locate one or even make one. Regards Pat

That screw is not meant to be insulated. It forms one of the connections to the inner workings of the armature.

Thank you for that information, there must be a short elsewhere in the points. I am recalling my Morris minor days when the two sides of the points were insulated from each other when the points opened to cause the coil to energise, I am assuming that it is the same with a magneto. Regards Pat

A photo of the top of the water hopper and the side of the hopper where the spark plug goes would be most useful for identifying the type. Back in the early 1970s when stationary engine collecting took off it was quite common to find engines where the low tension ignition had been very crudely replaced with a high tension magneto,usually taken from an old single cylinder motor cycle engine.using a four cylinder mag was not a good idea though it was done. Driving the magneto at crankshaft speed was done to spin the magneto faster to get a better spark when starting,though it resulted in two sparks per four stroke cycle,resulting in one unused spark,commonly known as a dead spark.This engines conversion was home made and very crudely done though no doubt it had worked. it would look better if a more common single cylinder h t mag was substituted ,with a single light chain drive ,the Lucas ones used on lister D s would be a better bet, Until I see a photo of the side of the hopper it is difficult to say if this engine had an early Webster low tension magneto or the later Wico type EK .Both would be difficult to replace and expensive ,the Webster was not too reliable and existing ones can suffer from the zinc diecast corrosion/crumbling problems as the body was entirely diecast, yet other makes such as the amanco 4 bolt mag do not suffer the same problems.If you do try and change the mag for a better HT one ensure that the rotation is correct,mags were supplied with clockwise and anticlockwise rotation and conversion is not easy and best avoided.

The resistance that you measure when the points are open is that of the primary coil on the armature. That is as it should be. If there were an open circuit that would be a fault condition!

The fact that there is resistance present is not a positive test however. Shorted turns on the primary coil of the armature will not show up. Also the capacitor is connected across the points and thus across the coil as well. These capacitors are paper/foil/mica constructions and sometimes (but rarely) fail showing a low resistance. More likely is that dampness and corrosion degrades the connections between foil layers and their capacitance value falls dramatically. This failure mode often occurs when a damp/degraded capacitor is exercised after a long period out of service and is the most likely cause of your symptoms. You started with a strong spark, the energy of which the capacitor couldn't cope, and then the capacitor failed, spoiling the tuned circuit and hence reducing the spark.

All repairable/replaceable but not for zero outlay.

Nigel,

The engine has been confirmed as a 2 1/2hp tulip top by a collector of Bamford open cranks and would have had a Webster magneto.

Pat as SM has suggested check the condensor/capacitor.

Martin P