The Wyvern Engine

Hi,I am building the Wyvern Engine.the set of drawings that I got with this set of castings,sheet three is very faded and I cannot read the dimentions of the drill sizes for the fuel inlet and the angle's of the fuel valve.they appear on the prints centre bottom of sheet 3.Has anyone any tips for starting and running one of these engine's,regards.Fred Moon

Hi Moose

The drill sizes for the fuel-inlet are no 70 drill for petrol and no. 50 for gas. The fuel-valve is the normal 45 degrees.

Regards

Jim Service

thanks Jim for the information, I knew that someone of our great model engineering hobby would have the answer, I can now try and finish this model and get it running.regards Moose

Hi Moose

The sizes, I gave were from the drawings of Wyvern. It occurs to me, that when Westbury designed the engine, gas meant, town or coal-gas; so the drill size may not be suitable for butane.

Wyvern was the first I I/C engine, I built, 30 odd years ago, but I cannot recall what drill size I used.

For your info, all of my 17 engines, run on butane. All need only, a whiff of gas. I use a micro-valve in the line. Starting problems are invariably linked to, too much gas, rather than too little. However, this should be no problem, if you are using petrol.

Regards

Jim

Jim thanks again yes I will try to run this on petrol/gas,but could you elaborate on the micro valve do you mean to restrict the flow of gas to the carb,a sort of demand valve. I have never run an engine on gas before so I am somewhat in the dark as regarding this

Regards

Fred

Hi Fred

I used the term micro for want of a better description.

Any small gas-valve, with multiple turns, between "off" and "on" will do. My valve has 16 turns - those used in small oxy-acetylene sets, would probably be suitable. but any, say, from an ordinary blow-lamp, would be too rough.

Regards

Jim

Hi Fred,

Like Jim I have buit several I.C. Engines all of which run on Butane Gas.( I never feel comfortable using Petrol in the workshop). As Jim points out only a whiff of gas is needed, and in my experience the fault is usually too much gas. In order to get the fine adjustment of the gas required, I use in line, between the bottle Regulator and the carb a valve as Jim indicates.The valve I use is made by SMC and is described as-SMC Speed Controller- Metal Body In-Line

Manufacturers Part No EAS2000-F02 1/4G

It is available through RS Components & their part No is RS 197-5191

Other sizes are availble in this range and the valve is throttled in one direct

Regards,

Sandy Petrie

Help!

I have a Wyvern engine completed except for the carb. I have the gun-metal casting for the carb but this is something beyond what I can do. I am looking for somebody that has done one of these that could do all of the machining & assembly of the carb for me. Good winter project??

Many Thanks!

Neil

There is a design for a gas regulator for the engines, I think you'll find it on HMEM or MEM, I suspect Bogs did it, apologies if I'v got it wrong. Ian S C