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.

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

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

Would the name be connected with JCB?

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

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.

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

The capacitor is embedded within the armature. Unfortunately it can only be accessed by a complete strip-down of the magneto.

Edited By Swarf Maker on 26/06/2019 01:00:14

The early magneto's can be reversed but it usually means new mechanical parts including the impulse couplings, changing the direction of a magneto without parts is possible but its not easy and can be hit and miss trying to find the sweet spot. A single cylinder magneto would make life easier to set up and things like the capacitor are usually mounted in the magneto cap and not the windings.

If you can wait until November there is a big bring and buy sale held here where you may find another magneto and parts for the engine.

Martin P

Saturday 2nd November

Cotswold Oil Engine and Preservation Society

Bring and Buy Sales

Oakley Airfield, Worminghall, Bucks HP18 9PH