OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Engines Villiers marvil

i found this little gem . and fell in love its awesome.
its a mar-vil engine from 1937.

http://www.villiersengines.co.uk/html/marvil.html

Love it Gizmo! I came across one a while back,wished I had bought it. Did a bit of quick research when it came up. Theres a bit of info on them which is good. Anyways great score and a very interesting piece for resto. Villiers sure where diverse when it came to engine styles and applications...

yes i found the lack of a throttle. fuel tank on bottom, and the carbie of sorts on the crankcase end? and generally the quirkiness of how it operates quite fascinating.

well finally got her up and running.
and i found out its a 1934 model which makes it 80 years old . wow

Hi Gizmo,[b][/b]

Wow! You've got it purring like a kitten... mate, it sounds just perfect. A great score there!

Congratulations on getting it looking and running well so quickly. That carburetor seems unusually oddball for 1936, but it has lasted a very long time and still works - you can't quarrel with success.

yes the carbie is on the crankcase end of the engine. something i have never seen before. and it uses crankcase suction to suck up the fuel from bottom tank through a disc valve.
it has no throttle or air filter so the engine revs are limited by using a fly out cam to keep the points fully open when it gets up to speed then collapses as it slows once again.
the screw on top of carbie is needle adjustment for fuel intake.
i will need to fix the baffle on end of exhaust to create a little back pressure. i just wanted to get her running before a full stripdown.now is to be packed away for a later date. cheers bazz

Morning
Carby on crankcase is quite common in outboard motors, I have a V6 Mercury EFI and the injectors are in the crankcase, I had a V6 Yamaha as well with 3 carbs and reed valves on crank as well.

I love your little Vllliers, nice job!

Cheers
Jason

Carburetor on crankcase is common on some types of engine, but it is only feasible with reed valve or something that achieves the same effect of only permitting gas movement into the crankcase, not out of it. It isn't the use of a reed valve, though I haven't heard of one as early as 1936, that I was commenting on - it is the layout of the carburetor. It looks as if it is a suction carburetor like a Briggs Vacu-Jet, which uses venturi vacuum to draw fuel up from the tank. It probably has a slide system directly above the fuel entry point, with a fixed spring pushing the piston down the slide: if so it is a constant vacuum carburetor like the traditional SU or the later Stromberg CD. The vertical column to the right of the venturi system probably acts as a choke, but that doesn't tell us how the engine is speed- or load-controlled. You can't throttle an engine from upstream of the venturi since that would vary the air/fuel ratio.

ive added a pic of the insides of the carb. there really isn't too much in there.

the camming device on the flywheel to keep points open

The disc valve is doing the job of a reed valve, possibly before reed valves were invented. It isn't a controlled carburetor or a constant vacuum one. The restrictive hole in the left side of the vertical cylinder with the fuel pipe, is the venturi, and creates a lower pressure (slight vacuum) on the crankcase side of it, which draws up the fuel from the tank. I'm guessing you can, and are intended, to adjust the amount of air entering the left cylinder, and you also adjust the position of the fuel needle with the external adjustment, to select load and speed. Adjusting either of these on its own would change the air fuel ratio, but adjusting both of them should be able to give you a range of operating conditions. The second disk valve in the top of the left cylinder might be to assist in cold starting: you choke the machine by blocking off the air intake completely, and let the disk valve supply enough air for starting rich. Then you open the air intake until you get the right air fuel ratio. If that occurs at too high or too low a speed and load, you adjust the fuel needle position - but being a 2 stroke it probably wasn't all that fussy, and for most purposes just adjusting the amount of incoming air would be sufficient.

If I'm right, this seems an extraordinarily crude piece of equipment for 1936. By then there were V16 cars going more than 100 mph, with style and class. Mind you, it isn't all that much worse than the early Victa slide carburetors with no needle. I guess people used not to expect much from small engines.

thats it grumpy youve nailed it. exactly how it works. as it was the first of these models the latter ones did have a proper carbie and top fuel tank

Now you're talking. With that slide carburetor (it's a real one, with a needle), it should run as well as the 1950s Villiers 2 strokes.

Fantastic Gizmo! Cool vid link mate...definately not gonna let another one slip by next time.Ill keep my eye out for the later ext carb variety in the black as well. This will make a great show piece mate:) love it!

Yes nice work Gizmo, nothing wrong with the way that is running, I like it just the way it is and running low revs with that flywheel, love it.

I picked up one of these engines yesterday, adding it to Gizmos thread to keep all the information in one place



It has spark which is a great bonus



Engine number



So lucky that the magneto assembly is all there and working





I am missing the fuel tank, carb and exhaust. I will be searching for them but they may take a lifetime to find. I found that a later Villiers carb bolts straight on so all that's left is to sort out fitting a later type Villiers fuel tank and it will be up and running :-)