ESO engine machining

[Blogwitch]

I understand completely K, think nothing more of it.

Just carry on with what you are doing, you are doing great.

John

 

[kadora]

Thank you John.

Valve retainers is simple job not worth to describe.
Picture shows everything.

 

[Hopper]

Brilliant in its simplicity - just like the ESO itself.
I like the countersunk screw idea.Those things are as tough as, er, nails as the saying goes. Actually, much tougher though. Probably a great material for valves. And I like the way you use the Phillips slots to grind the valves in. I have noticed some model IC builders simply machine the seats in one setting and then the valve guides in another, then press the guides into the head and expect everthing to line up and seal, something we would never do in a full sized engine. Love your simple low-tech solution.

 

[kadora]

Valve lifters again easy job.
On first picture you can see small holes in the middle of the lifters.
These holes have two purposes.
First is to release pressure in valve spring cavity when lifter is
pressed down by cam shaft lobe.
Small amount of oil is always leaking between valve sleeve and
valve stem into spring cavity . Pressure created by lifter escapes through this
small hole together with drops of leaking oil and lubricate
cam shaft lobe.
On my first eso engine I checked if it works and it works perfect.
Lifters are machined from drill rod.

 

[kadora]

Gun metal bushings for cam shaft.

 

[eborengineer]

Kadora - I too liked the novel use of screws as embryo valves. I would have predicted that the material was strong enough but would have questioned the surface finish and possibly the roundness. Have you had to hone the stems in any way?
Mike

 

[kadora]

Mike
You are right . Majority of screws on market have rough surface "stem"
but i have found screws with surprisingly nice surface and roudness of stem
good enough for valves.

 

[kadora]

Before drilling holes for screws which fasten head to the cylinder
is needed the alignment of teeth pulley shafts.
So I applied low temp. melting epoxy between cylinder and head ,
pushed rods through bearings in the crank case and in the head.
Then I put rods on a glass sheet and by vice weight both rods.
By this way is easy to get both shafts perfectly parallel .
Picture says more.

 

[kadora]

Epoxy is dry so I can copy head holes to the cylinder 1. pic.
Black tape protects spring cavities away from drilling chips.
2. pic. Making threads M3 depth 15 mm.
Next will be cam shaft machining - terrible boring job

 

[Hopper]

Camshaft machining, maybe boring to you but I'm interested to see which technique you use. A cam grinder is on my list of "to do" jobs.

 

[kadora]

Today just shaft with blank lobes.
1. pic. teeth pulley and shaft.
2. pic. checking if is everything OK before
lobes milling. Material drill rod Dia 10 mm.

 

[kadora]

For milling lobes i have built simple fixture.
Fixture contains stationary unit with attached protractor
and rotational unit with attached arrow 1. pic.
On 2. pic. is backside of fixture .On the top of orange cylinder
/stationary unit/ you can see screw X by which is possible to fix
rotational unit to the stationary unit.
3. pic. blank cam shaft is secured to the rotational unit
by small screw /see allen key above arrow/.
4. pic. fixture fasten in vice and thick allen key to secure
rotational unit to the stationary unit /screw X/and arrow set in 0 degree position.
So cam shaft is ready for milling lobes.

 

[kadora]

Milling lobes starts in 0 degree position.
1.pic. here is milling depth of lobe in my case 2 mm.
Then secure height of milling bit for rest of work.
2.pic. milling lobe in CCW direction , turning lobe in 2 degrees increments
till 120 degrees is reached.
3.pic. return lobe to 0 degree position and mill lobe in CW direction
till - 120 degrees.First lobe done.
4.pic. return lobe to the 0 degree and attach second arrow points to 0 degree.
Then release screw what secures camshaft pull camshaft out
to see second lobe./DO NOT MOVE ROTATIONAL UNIT/
5.pic. turn camshaft till second arrow points to 100 degrees CW and secure it in this position.
6.pic. milling second lobe in the same way as described above.
Lobes timing angle is variable for CW and CCW running engines.

 

[kadora]

To finish camshaft the washer needs to be "riveted"
on the end of camshaft.1. pic.
2.pic. steel ball rivets end of shaft under press.

 

[kadora]

Teeth belt tensioner.
First cutting thread M3 for tensioner shaft 1. pic.
Here is important to consider what direction engine will turn.
In my case CCW. /if CW pulley must run on opposite side of belt/
2.pic. tensioner pulley has gun metal bushing.
3.pic. assembled pulley.
By changing diameter of pulley is possible to adjust the tension of teeth
belt./engine has to be assembled for this tension setting/

 

[Hopper]

Looking good!

 

[kadora]

Thank you Hopper.
1.pic. shows small teeth pulley on the carrier shaft
This is only for illustration how it goes together.
2.pic. carrier,belt and small pulley assembled in crank case.
3.pic. head gasket cut out from 0.4mm thick hard paper.
/office file/
Everything ready for final engine assembly 4.pic.
I had time for machining carburator adapter and exhaust
port so i attached these parts on cylinder head.
Sorry for watch /my second addiction/i did not notice it
when i took picture.
Now I need head cover hopefully i will have time to cast this part during weekend.

 

[Hopper]

Great little device for machining the camshaft with. Much cheaper than a rotary table too!

 

[kadora]

1.pic. blank head cover .
2.pic. drilling 2.5 mm holes for cover screws.
3.pic. milling decorative fins.
4.pic. milling angled rim for better approach to the glow plug.
5.pic. head cover glued to the cyl.head to be able to copy cover holes to the cylinder head. //I like this epoxy because of its low melting temperature//.
Epoxy label says 30 min. drying but I prefer 2 hours cure time.

 

[Hopper]

Clever idea gluing the two pieces together before drilling the holes through both for perfect match. I'll file that one away for future use. Thanks for the tip!