Old Sckool 5 cc model Diesel engine build

[sladey]

Looks great Graham

[911hillclimber]

Thank you Mark.
I see that the 'attendance' to this long thread is tailing off sharply so many getting bored!

Gaskets cut out of brown paper just and i think all the machining is behind me.

Been a slog at times, and great at other times!

Typical stuff really when pushing yourself a bit.

[Bruce M]

It’s been an education to follow along… & has convinced me that I shouldn’t buy a lathe

[911hillclimber]

Or at lest not one 100 years old!
It would have been much easier with a modern lathe and a modern milling machine...
And someone who had the right skill-set of course.

[911hillclimber]

This will make a nice paperweight!

It will NOT start no matter what I do or try.
Do not feel inclined to keep on trying as I feel there simply is not enough compression to get to the ideal mixture.

In the meantime I've bought another design to make on the Drummond. It is a 1933 design spark ignition, 6.3cc and more complex to machine.

Tinkering is better than using.

The audience has all but dissipated now, so thanks for following the adventure.
I won't do a thread on the next engine.

[neilbardsley]

Why do you suspect lack of compression? You to have gone from too tight to too loose?

PS congratulations to getting this far.

Sent from my 22011119UY using Tapatalk

[911hillclimber]

To get the right compression on these designs needs a near interference fit right close to TDC.

This means a clearance of about 1 or less thou, and this can be achieved only by honing or lapping the piston to size or the bore to the piston.

First you need a very 'dead-on' clearance and this is hard to do on this old lathe, and such fits have to be estimated or felt more than by taking a cut of a known depth.

I think the piston is far too loose in the bore for the entire stroke.
Thus, I will have to make a new piston, #4 if I'm counting.

I will make an electric starter this weekend and try that, but will probably just clean it, remove the prop and put it on a display stand.

[911hillclimber]

Posted just now
I smell of ether...

I smell of blood sweat and tears...
This engine (if I dare call it that) will not start.

both wrists hurt from trying and the wood prop looks like firewood.
I have decided to leave it for a while or for ever (preferably) and let it sit on the shelf and remind me that this is a Bad Day.
Found a fancy brass engine stand, so this is the final picture:

[sladey]

Never mind Graham. You might feel better about it when you’ve left it alone for a while.

[impmad2000]

Not all the audience is gone, just watching quietly. Shame it didn’t run, but that’s not unusual I think for these motors. I think the tolerances are pretty tight. Remember the photo of the tiny motor my dad made? I remember him telling me that that never ran either. I might try one day, but I’ve got no fuel… curious what fuel you got and where from ? I might try…

[911hillclimber]

I think the root problem is compression both primary (crank case) and cylinder.

The piston should be all but an interference fit at the TDC position.
I also need to check the piston top to the exhaust ports and the transfer port, but not feeling the LUV yet to strip it down and check.
More homework to do.

The right fuel is getting hard to get.
Found some on ebay which a few other shops sell too, v expensive at £26 per 1/2 litre!!
Made by a company trading as MT in a white can, 2 grades, 1000 and 2000.

As to the thread, not sure the counting system is working.
It shows 50K hits and was ticking over at 1000/day (!) which i can't believe, but recently down to 10's a day or less which I believe to be more like it.

[RobFrost]

Speaking as somebody who owned a few flying toys as a kid, this is a lot of work for something that's going to get stuck in a tree.

Great work - keep moving forwards!