Webster Head Material choice

[Johann]

As I proceed with my first Webster, more and more questions are popping up in my mind. For the barrel I used something that must have had Stainless steel in it (typ stainless swarf). Scrap piece, beautifull finish, very happy. I did not have a large enough aluminium piece, so I made the head from mild steel...and the more I ponder on that one, the more I question it !
Any comments from the gurus perhaps ? Bear in mind that this will obvious be more of a showpiece as a model running for prolonged periods. I've put so much effort into making the head, and therefore I would not like to redo it. The valve box will still be Alu.

I must say that the manufacturing of the rings was a real rewarding part of the build.

Thanks

 

[Johann]

I have changed some of the manufacturing dimensions to be round metric figures, and would therefore rather make sure the comp ratio is optimal. Any suggestions ? The next question will obvious be the fuel choice for a spark plug configuration, combined with an ex RC engine carb. I have a lifetime supply of CASTROL M oil that I used to mix with Methanol for RC fuel. I am also worried about lubrication on the cylinder, whould you suggest a fuel mix perhaps ? Should I use petrol, or can I use RC fuel ? Any suggestions on the SAE Grade of the oil in the cylinder oiler ? A seized piston will not be welcome after so many hours in the shop! The main and big end will be roller bearings.

Thanks guys

 

[Brian Rupnow]

Use gasoline with a small amount of 2 cycle motor oil in the gasoline to keep the cylinder lubricated. Making the head from mild steel should not cause you any problems.----Brian

 

[Johann]

Thanks Brian. What % would you suggest ?

 

[Brian Rupnow]

Use 30 parts gasoline to 1 part oil. Use oil recommended for a chainsaw or weedeeater. A lot of us i.c. model guys use Coleman fuel (Naptha gas) to run our engines because it has far less odour than burning gasoline. Still, you must use the 2 cycle oil with it.

 

[Johann]

Thanks Brian

 

[gus]

Use 30 parts gasoline to 1 part oil. Use oil recommended for a chainsaw or weedeeater. A lot of us i.c. model guys use Coleman fuel (Naptha gas) to run our engines because it has far less odour than burning gasoline. Still, you must use the 2 cycle oil with it.

Hi Brian,

Thanks for the fuel mixture ratio. Now moving towards cutting the timing
pinion gear.

 

[gus]

Hi Johann,
Please post W.I.P.Work in progress) fotos. Will be following your thread and contribute my 2 cents worth. Brian is my Guru and always ready to pitch in to give expert advice.
My Webster will take another month or so to do.

Regards,

Gus Teng,from faraway Singapore.

 

[crankshafter]

I have changed some of the manufacturing dimensions to be round metric figures, and would therefore rather make sure the comp ratio is optimal. Any suggestions ? The next question will obvious be the fuel choice for a spark plug configuration, combined with an ex RC engine carb. I have a lifetime supply of CASTROL M oil that I used to mix with Methanol for RC fuel. I am also worried about lubrication on the cylinder, whould you suggest a fuel mix perhaps ? Should I use petrol, or can I use RC fuel ? Any suggestions on the SAE Grade of the oil in the cylinder oiler ? A seized piston will not be welcome after so many hours in the shop! The main and big end will be roller bearings.

Thanks guys

Hi Johan.
I use petrol right from the pump and squirt some W40 or 565 in the tank ewery now and then. And my Webster have many houers runtime whit no problem
Best reg
CS

 

[Johann]

Thanks CS. Anybody any comments on compression ratio perhaps ?

 

[Johann]

The work in progress will follow Gus, as soon as I sort this attachment procedure out.....

 

[Lawijt]

You can also mix petrol with Castor oil. I drive my Aprillia 250 RS with that fuell.

 

[Brian Rupnow]

Castor oil is bad juju. It has wonderful lubricating properties, but once it has been warmed up and then cools off it turns into a kind of dreadful jelly. That's why ww#2 fighter planes had their crankcases drained after each flight before the engines cooled down.

 

[Johann]

I would't even know where to find caster oil. Castrol M is a proper oil specificly made for model RC engines. I will settle for ordinary 2 stroke oil, easily available and proven for this application.
Very interesting fact on the old fighter planes, thanks