Airfix - Four Stroke Engine.

[Andi Little]

Well, here's an opportunity to get your own back!!?

With much upheaval and far too much real life lately I've been in need of something simply to keep the juices flowing - Box stock and with definite "play" value. Having got bogged down with the Top Yard [ things may be moving there though]? I thought I'd have a go at this vintage Airfix kit.
Only criteria was to make the best of it and keep it clean. To-wit pretty much as it looks in the instruction booklet, and just trying to improve the engineering aspect to keep it as a definite operating model.



Lots of clean-up required to make everything look as though it was "carved" out of the solid. and mainly "engineering" improvements to make sure things "fit" nicely, move smoothly, and generally didn't bind or foul.



Again lots of clean-up on those cooling fins, nice and tidy. Only the front portion of that cylinder liner is modelled, as it will be seen - most is hidden inside the barrel.
Rather than try and "tool" turning marks on the bottom of the liner I just brushed solvent around neatly, then went for a pretty highly polished metal effect.
No idea who Keith is by the way - this block came with the little watchmakers lathe I acquired - and I'm assuming it's an apprentice test piece as it's a perfect 1" no matter what calliper or vernier I use.



Here it is dropped into the two crankcase halves: only cleaned up as yet but I wanted to check the "turning" of the crank and piston assembly before going much further.
Gordon as ever "taketh the pish" and ordered me to build something proper!! - but as diversionary modelling goes - it's fun. Quite enjoying it actually - even if the bliddy airbrush won't work and I'm having to brush paint everything - but hey, that's how I did it as a kid and I can't ever remember enjoying myself more .................. well, until I discovered girls!!! But it turned out I was really crap at that!!!?

Big hugs ......................

[lab-dad]

That is really cool!
i did a search and cant figure out if the engine is actually operable?
Is it plastic or metal?
I seriously doubt for 20 pounds that it is more than just for show.
I'm looking forward to more of this (and may have to get one to play with)
At the least it would be useful to my students just learning the 4 stroke concept.

-Marty

[Ray Dunakin]

What scale is this?

[Andi Little]

Marty - it's all plastic, but is definitely operable. Back in it's original guise it was meant to be run by a small electric motor; most of those components are still on the sprues, but no motor of course and no mention in the destructions either.
And yes it does work - operated by a hand-crank mechanism. Turns the crank and piston assembly - obviously, but via a gear chain operates a pair of cams which through pushrods actuate a pair of vales. So it really is an operational and educational model of a generic four stroke internal combustion engine.
Ray - I'm not sure of a scale [it's arbitrary I guess though as it doesn't represent any known engine to my knowledge]? although 1/6th does keep popping into my head!! - never the less I included the 1" gauge block to give an accurate sense of scale to the assemblies, does that help?

So, for me the big thing is to build it so that it successfully and properly "turns over" consistently and without fear of breaking it!!!
And it must bring the kid out in me because I really want to turn that handle and see it all working.

[marc_reusser]

Wow. That is really cool. Looks like one of those cut-away dealer display engines from days-of-yore.

What paint did you use for the silver?

[Krusty]

No idea who Keith is by the way - this block came with the little watchmakers lathe I acquired - and I'm assuming it's an apprentice test piece as it's a perfect 1" no matter what calliper or vernier I use.

It used to be fairly standard practice in the British sphere of influence to show you were worthy at the end of a fitting apprenticeship by carving a 1 inch square with files and hand scrapers. None of this lazy man's machining rubbish and if it wasn't perfect you didn't pass.

[Andi Little]

Marc' - glad you like it, it's a fun piece of modelling if not up to the rarefied level normally found round these here parts!

That "silver" is pretty funky isn't it? It's actually a "Mr Metalcolor" from the "Mr Hobby" range. Specifically "Chrome silver" - the crank is done with "Iron" and in the flesh is a more believable metallic effect. Lacquer based it took a little playing with to find its best effect, but I'm sure depending on what you put underneath you could get many and varied finishes.

[Chuck Doan]

I thought from your first pictures that it was die-cast metal-well done!

I knew an old Austrian tool and die guy who still had his square blocks. He had to make 2, and they would stick together due to the fine surface finish.

[Andi Little]

Hey all, it pleases me to think you might be following along - better than just pointing and sniggering I guess?

Seeing as folk are a bit curious I thought I'd follow up with a quick update to show the valve assembly - it will get a bit buried later on so thought it best to show it at this stage.
Mainly involved just sensible clean-up, paying particular attention to any mating or "working" surfaces: e.g, the valve stems were given a layer of BMF, primarily to take up a bit of slack in the guides but also to enable a bit of "graphite" lubrication [pencil shavings] later on.

Here you go then .................



All exposed interior surfaces will be picked out in this "yellow" - pretty much as the destructions suggest. But I'm hoping to "oil-up" the working parts later so it looks a bit more like the cut-a-way engine we used to have in "Engineering Sciences" back when I were a lad.
And yes the valves are operable and will be when I've assembled the cams and pushrod assembly - those springs are surprisingly strong and will result in quite a "tight" engine I'm sure.


More later ...................

[Gordon Ferguson]

Just catching up Andi, looking good.

As always impressed with your "brush" skills even more so when I read you are brush painting laquer!


Now that we have got you back at the bench , how is that Be....d doing?

Don't want you to have too much fun do we !

[lab-dad]

There is absolutely nothing in those images that looks like plastic!
Marty

[nk]

Glad to see you back at it Andi. This cut-away really looks the part...if there were space in the science museum I am sure that they would stick it in a vitrine. It is beautiful and exacting work you do each and every time. Thanks for posting this WIP.

[chester]

hand brushing lacquer alone impresses the hell out of me. The plastic has, without a doubt, the look of metal.

[Andi Little]

Aw Shucks! .............

I'm so glad you cheps are liking this, because I am. And I must admit felt a bit guilty for working so "out of the box".
I shall try and make it a bit more "believable" later on, as it is the barrel and head are just a bit too silver? And hopefully I'll tone it down a touch too, try and get a bit more weight into it - if you know what I mean?
I did forget actually that I had tried to put the "sandcast" texture into the head and around the fins - can you see that? Again nothing mind bending just stippled it with solvent, reducing the pressure as it dried to make shallower marks and then a good dollop of primer to soften it back. ... I hate outlining my techniques as they always sound so oafish and crude by comparison!

However - onward and upward................ Traa for now!

[Ray Dunakin]

The texturing is great, to me that is the main thing making it look so much like real metal. Very well done -- I had assumed that the texture was part of the original kit.