ESO four stroke SOHC engine

[kadora]

Hello friends

Two years ago i started to design this single cylinder
based on JAWA ESO speedway engine.
My goal was to create as simple engine as possible,
suitable for beginners of for experienced machinist
to machine it during lunch break.
I had to do some amendments on cylinder head
to be able to accommodate SOHC valve train.
SOHC is pretty simple system - no need for pusher rods , gears ,
rocker arms .
Cam shaft is driven by teeth belt which forgive small mistakes
during machining process./see last picture/.
5 pieces of lost wax castings are easily machinable on small lathe and small mill no needs for special tools.
Engine capacity is 10 ccm , 3x ballbearings , glow plug ignition.

 

[kadora]

Of course maiden run

[ame]https://www.youtube.com/watch?v=7Bx4rOKwevQ[/ame]

 

[John S]

Don't you mean SOHC ?

 

[kadora]

Hello John
Maybe yes but D for Direct OHC ?

 

[petertha]

5 pieces of lost wax castings are easily machinable on small lathe

Very nice. I would love to see some of your build pictures, especially the wax patterns & casting process. Did you manage this aspect in home shop, or do you have access to more professional/commercial casting facilities?

Also curious about your piston & liner materials & selection. Ringed piston? Lapped cast iron liner or...?

 

[John S]

Hello John
Maybe yes but D for Direct OHC ?

Well your right to call it what you like but there are precedents.
SOHC is just a single cam operation one or more valves.

DOHC is double [ 2 cams ] operation one or more valves.

 

[kadora]

hello Petertha
All castings are cast in my garage.
At this moment I do not have any wax pattern available
but this week i intend to cast cylinder heads for my next project so i will
send some pictures.
As i mentioned before my intention was to create as simple engine for
beginners as possible so I designed it for liner , piston and piston ring
from RC engine ASP FS 64 AR . Spares bought at Hobbyking.
/price around 30 USD/ .

 

[kadora]

Thank you John i will try to fix it.

I have fixed it on youtube but I am not able to
do it here on HMEM

 

[ZAPJACK]

Nice & very clean engine "hat-off" Kadora
What about lubrication of crankshaft, piston & camshaft?
LeZap

 

[Hopper]

Very nice indeed. We know the Jawa/Eso engine quite well here in Australia from many speedway bikes. They are an awesome bit of gear.

 

[kadora]

Thank you guys.

The lubrication of crankshaft and piston is the same as in RC model air plane four stroke engines by oil added to fuel .
Cam shaft is lubricated by oil liking around valve stems and sprayed
//when valve pushers are pressed down by camshaft//
through 1mm holes drilled in the middle of valve pushers straight on
cam lobes.

Hopper one time i had opportunity to ride JAWA ESO bike
power of engine is really brute.

Thank you
Kadora