I got this engine of ebay from a guy about 8 houses down my street. With it being close I got to look at it before buying
It's now fully stripped down, and every bolt still had grease on it! Somebody has obviously rebuilt it with the incorrect carb and then left it in a shed when it would not work. It also had a seagull tank fitted.
The cylinder has an alluminium water jacket and a cast iron liner. The pinion gear is clever in that it sits on the square end of the drive shaft, so can be easily removed, clever bit of engineering.
After the initial scrub, it looks like this one will clean up into a nice addition to the collection. No markings on it at all, not sure about the age? Late 1950s?
I'm also after a tank and the odd reed valve carb that is missing, if anybody has such an item?
This is what was actually fitted to this engine, looks like the original poppet valve got broken or lost, so this homemade reed valve was fitted, along with a non original tiny amal carb.
The idea is that the engine sucks the fuel it needs via this one way valve which the amal carb was fitted too...Control of RPM is by adjusting the timing advance/retard lever, which moves the magneto backplate. Wonder if this arrangement actually works?
With a poppet valve how is the mixture controlled?
I trhink the engine should have a cylindrical tank, which would mean production of that style ended around 1957, when Mallard and others came under the Coventry Apex umbrella.
The carb is a casting with two chambers - the first chamber just receives fuel direct from the fuel tank and has a needle adjustment controlled by a small external lever to regulate incoming fuel, and is very sensitive in the success of getting the engine to start (or not!).
The second chamber has the poppet valve in it - the valve is approx 1" diameter and works against a soft spring, where on the piston 'suck' stroke, the valve lifts and fuel enters via a tiny hole in the valve seat rim. Engine speed is regulated by use of the advance/retard lever.
In spite of the foregoing, the engines are in fact willing starters/runners when the base settings are known, especially with the Miller ignition, as also fitted to the small Anzanis amongst others.
The poppet valve has a spindle which protrudes below the carb, which if held up stops the engine like its been poleaxed!
Don't know what emote means (American?) Poleaxe used latterly to stun animals and simultaneously make holes in skulls as part of the slaughter process- more commonly used as an expression to stop someone dead in their tracks.
In the case of a poor little Mallard, lifting the poppet splindle has the same effect - ie. no spluttering or couhging as the last bit of fuel expires - just sudden quiet. (well maybe with a bit of wheezing). Same as opening the tap in the bottom of the float chamber on some Amal carbs - instant death!
The normal route to obtaining spares is to buy a rough but complete motor on ebay,I don't think I've ever seen an unrestored complete one fetch more than £50, 4 or 5 a year get sold on there.
Fully restored, running, top value might reach £125.
Here's one I bought for a register member who only has access to the internet at work in November.
350504878641
Make it idiot proof and someone will make a better idiot.
There are quite a few differences when comparing with my engine.
Gearbox - Mine has an end cap similar to a seagull
Cylinder - Smooth, almost polished finish, no evidence of any paint.
Water outlet just a small 1/8th inch hole
No markings on my engine at all
Everything else looks the same.
Nice to see what the poppet valve looks like, and the graduated markings on it also. The transom bracket screw is also visible, which I will have to make. All good fun.
If anybody has a Mallard they don't want please let me know!
Oyster - curious that your cylinder donst have any lettering cast in - the few I've seen have 'Mallard' cast on one side, and 'C H Haley - Leicester' on the other. Maybe this was part of the transition into the Coventry Apex lot.
Photograph - yeah - the poppet sits under that ally cap. The markings on the right hand side are for the position of the fuel mixure lever which you can make out - this moves throough about a 90 degreee arc.
The engine number should be on the top half of the crankcase on the flange that touches the cylinder, my gear box cap is a different shape with a grease nipple just below the top fixing screw.
Make it idiot proof and someone will make a better idiot.
(which does not emote)