The Bucket Foundry

[WilDun]

Will D, I got lots of ideas, it depends on which one wins on the day of the pattern being made.
No, really, this one will just use standard crank cases and rods. Im trying not to make my usual mistake of cramming too many new things into one development.

Good thinking Neil - That's not what I do when I think about things - (I seldom do things :laugh:) - I cram so much into my mind at the same time and through not coming to any firm conclusions, it all comes out distorted and nothing actually gets recognised!
:rolleyes:

Still good fun though - can't be as bad as my grandkids generation sitting gawping at computer games ( now being played by someone else these days instead!) - they might have to think and strain their little minds!

Grumph
Yeah lots of weird stuff and it puts us all to shame! (also keeps those electroplating people on their toes with all the new challenges!) :shit::

[Flettner]

wax better be doing its job!

[Flettner]

Good wax, did its job, cylinder core box done. Water jacket core box next and second set of transfers core box. All simple enough, just time.

[WilDun]

Good wax, did its job, cylinder core box done. Water jacket core box next and second set of transfers core box. All simple enough, just time.

Was the wax just to prove it or what? - not a wax core ?? - or am I still missing something? :rolleyes:

[Flettner]

Wax release agent, you have to be sure its going to work, otherwise it all becomes one, ugly chunk of useless junk.

[WilDun]

Wax release agent, you have to be sure its going to work, otherwise it all becomes one, ugly chunk of useless junk.

I did think that at first ..... then thought I'd better ask as I do remember you using a dusting of graphite powder for that purpose!

[ken seeber]

OK Will, Jacinda is easing up the C19 lockdown, it's getting warmer or cooler in Auckland, so get your shoes off , your pyjamas on and get casting:

https://www.youtube.com/watch?v=2G3Vk2eUpgM

[WilDun]

Would have problems if I tried to get up after hunkering down for that long! And would prefer to wear at least Jandals (thongs to you) but my biggest problem is that the guy who was storing my foundry gear for me fell out with the missus and left - but the real tragedy was that she cleared the shed of all the stuff she perceived to be "junk" and consigned it to the tip!! ...... Very sad story !

[Flettner]

Isn't it so sad that the modern tip is not what they used to be. When my dad and I would usually come home with more stuff on the back of the Thames Trader than we took there in the first place. Mum hated it! I loved it.

[WilDun]

They just don't bloody understand do they? And we don't understand that it's totally futile to try to get them to understand! - much better to buy some brand new shiny imported crap - its new and looks good and when the shine starts to fade, throw it away and get a new one!

[ken seeber]

Yep, I remember with my brother riding our bikes to the tip, fossicking over all the junk, bringing home treasures. Pull them apart, see how they worked. Interesting in those days there were no plastic bags blowing all over the place.

So Fletto, the Thames Trader. Was that the one with the 4 cyl Consul engine in it? I remember that this and the 6 cyl Zephyr shared the most ugly exhaust manifold. A log circular manifold clamped to a semi circular recess over the length of the head. Even as a pimply faced little kid I was appalled at the shit design and how those poor old exhaust gases ever got out.

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[husaberg]

Yep, I remember with my brother riding our bikes to the tip, fossicking over all the junk, bringing home treasures. Pull them apart, see how they worked. Interesting in those days there were no plastic bags blowing all over the place.

So Fletto, the Thames Trader. Was that the one with the 4 cyl Consul engine in it? I remember that this and the 6 cyl Zephyr shared the most ugly exhaust manifold. A log circular manifold clamped to a semi circular recess over the length of the head. Even as a pimply faced little kid I was appalled at the shit design and how those poor old exhaust gases ever got out.

345942

people likely had chocks or pigs or at least knew how to compost so there were likely no food scraps either

[Flettner]

Yep, I remember with my brother riding our bikes to the tip, fossicking over all the junk, bringing home treasures. Pull them apart, see how they worked. Interesting in those days there were no plastic bags blowing all over the place.

So Fletto, the Thames Trader. Was that the one with the 4 cyl Consul engine in it? I remember that this and the 6 cyl Zephyr shared the most ugly exhaust manifold. A log circular manifold clamped to a semi circular recess over the length of the head. Even as a pimply faced little kid I was appalled at the shit design and how those poor old exhaust gases ever got out.

345942

Haha, yes that one. Dad put a Zepher six in it later on. All that did was up the fuel consumption. I got it gifted later when I was an apprentice, dad was trying to get rid of junk around his place. Gladly received though. Blew a piston on the way to Bay Park raceway, transporting my super charged Honda 100 to its first outing. Thames kept going but used a whole container of engine oil just to get home. Ran the screwdriver across the spark plugs untill I found the offending one, pulled the plug lead off and removed the pushrods, stopped spitting oil out, yay. Didn't seem to go any worse and still used heaps of fuel. But yes, that jolly exhaust manifold, some designer at Ford is probably still laughing about that, just good enough but nearly not.

[WilDun]

Haha, yes that one. Dad put a Zepher six in it later on. All that did was up the fuel consumption. I got it gifted later when I was an apprentice, dad was trying to get rid of junk around his place. Gladly received though. Blew a piston on the way to Bay Park raceway, transporting my super charged Honda 100 to its first outing. Thames kept going but used a whole container of engine oil just to get home. Ran the screwdriver across the spark plugs untill I found the offending one, pulled the plug lead off and removed the pushrods, stopped spitting oil out, yay. Didn't seem to go any worse and still used heaps of fuel. But yes, that jolly exhaust manifold, some designer at Ford is probably still laughing about that, just good enough but nearly not.

345943
Was that the model? - our Traders used the diesel engine from the Fordson Major tractor - wasn't it asking a bit much of a Consul engine? - Anyway, petrol in Europe at that time was much too expensive! ..... Wish I had had one of those the day I found a couple of Bristol sleeve valve radials (from a crashed Wellington bomber at the local tip!).

[husaberg]

345943
Was that the model? - our Traders used the diesel engine from the Fordson Major tractor - wasn't it asking a bit much of a Consul engine? - Anyway, petrol in Europe at that time was much too expensive! ..... Wish I had had one of those the day I found a couple of Bristol sleeve valve radials (from a crashed Wellington bomber at the local tip!).

I remember my old man having a very tidy version of one of these
https://i.pinimg.com/564x/3d/8d/a8/3d8da88426d4c871d71c9c352dd7b566.jpg

[WilDun]

I remember my old man having a very tidy version of one of these............

Ah, that's the one! - not the truck! - I can't remember having seen this model - we did have the van version (but by another name) - I think it was called the Thames 800 - not the Thames Trader and I believe it had the later (Mk 2 ) Consul 375 engine - 1800cc? - so that clears that up! - I guess that one you posted is what Neil was talking about.

[Flettner]

I belive you are right Will, it was a Thames 800
Same colour too but mine had a wee crane on the back, all the better to hook serious shit out of the tip with.

[Flettner]

Uniflow water core, a bit trickier than I though. Has to be made up of three parts, yes they can be the same, one mold fits all. The difficult bit is how to assemble it all in situ.

[WilDun]

Uniflow water core, a bit trickier than I though. Has to be made up of three parts, yes they can be the same, one mold fits all. The difficult bit is how to assemble it all in situ.

Interesting problem I guess but I can't visualize it without a picture (not having actually studied the making of the real thing before!)

[Flettner]

Shell sand molding machine coming together.

[husaberg]

Shell sand molding machine coming together.

Neil ii have been coinfused for a while so its a mixer for temp and air/co2 set binders?

[ken seeber]

Shell sand molding machine coming together.

Neil, looks to me more like a 4th axis for your vertical.:oi-grr::oi-grr:

[Flettner]

Neil ii have been coinfused for a while so its a mixer for temp and air/co2 set binders?

There are still bits missing but this is the
main 'skeleton' of the machine. Metal dies get bolted between the two patterns, hydraulic cylinder pushes the heated die together. There is a sand box, not made yet, that moves up and seals onto the dies. The whole machine turns 180 degrees so gravity can pull the sand into the heated metal dies, there is usually an air assist to help blast the sand into the far reaches of the dies. After a short time the patterns return so the sand box is underneath again, sand box pulls away, dies stay cloesd for a time to bake the sand hard then the platterns / dies open to eject a nicely molded hard sand core. Repeat, collect the money.

[Flettner]

The sand is specialy pre coated with a bonding material that sticks the grains together at 200 degrees C.
At over 400 degrees the bond disintegrates.
A very usefull sand for production casting.

[WilDun]

The sand is specialy pre coated with a bonding material that sticks the grains together at 200 degrees C.
At over 400 degrees the bond disintegrates.
A very usefull sand for production casting.

Looking good! - now well beyond the little backyard foundry any of the rest of us would aim for (except Ken of course) - and all prepared for future work!
Good, especially now with NZ trying to get back on its feet after the Covid thing (the government hopefully is at least looking to help all the small business here??)
Having very few local foundries left here, it could be useful in the agricultural area you live in! (ie if you are interested in jobbing work of course).
..... Those platens look like they are designed to see you out and well beyond!
:niceone:

[Flettner]

The Uniflow water core box begins.

[WilDun]

The Uniflow water core box begins.

Will you be casting these with your new gear, or is that destined for use in production runs of other stuff only?

[Flettner]

Nah, old way.
But when I get back into making these I'll need it.

[WilDun]

I was on the brink of making a decision about moving overseas with my son and his family, but Covid fixed that! and has brought it home to me that I'm a Kiwi (been here 54 years) now and do really want to stay in NZ!

So I am toying with the idea of building another foundry (probably a bit smaller than before) and maybe try 3D printed patterns as well - I have a couple of little 3D printers which are tired of turning out plastic toys for kids to discard or destroy!
There is some material lying around from the relatively successful, (but short) previous attempt - so I'll check through what I've got and see what I can build from it all.

One thing about a home foundry is the fact that you can build it however the hell you like - all that is needed is an ability to scrounge and use whatever is on hand - a little resourcefulness goes a long way of course and maybe just little commonsense in the mix as well (safety being paramount) - so we'll see what transpires!

[Pursang]

Sounds Positive, Will.
Post any progress, I shall be watching here eagerly.

You might have seen this guy on Youtube before? (If it's on here, somewhere, Husa will know)

He does a quite amusing commentary! But it's also the simplest, cheapest, effective backyard furnace I've seen.
In the next video, he cranks it up to 300kW and melts copper and steel.

https://www.youtube.com/watch?v=WbYAYobyB_M

Cheers, Daryl.

[WilDun]

Sounds Positive, Will.
Post any progress, I shall be watching here eagerly.

You might have seen this guy on Youtube before? ............... But it's also the simplest, cheapest, effective backyard furnace I've seen. .......... https://www.youtube.com/watch?v=WbYAYobyB_M

Cheers, Daryl.

Daryl,
Best entertainment (as well as some very useful tips!) I've seen for a while! - despite (apparently) being a bit of a comedian, he has cracked it as far as making a really good backyard foundry is concerned and that bloody (very interesting) monster of a burner easily makes up for any lack of insulation on his furnace! I think I saw one of his videos quite a while back but forgot about it .... I must disagree with my being considered a "sissy" because I use LPG though! :mad: - a thing like that in my backyard would have the authorities on my case in no time!
Good one! - like it! :niceone:

[Flettner]

core copies in place.

[Pursang]

Good one! - like it! :niceone:

Glad you liked that Will!

Here's one for Neil.... Subaru Head Casing...In Reverse!

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https://www.youtube.com/watch?v=n1YB8Ou8ufk

Cheers, Daryl.

[F5 Dave]

[Practices accent] aww the old suba-kangaroo mate.:msn-wink:

[Pursang]

[Practices accent] aww the old suba-kangaroo mate.:msn-wink::niceone:

Sintax lesson: The 'kanga' is silent, Like the first Wagga in Wagga Wagga. Kangaroo is pronounced Roo!

Exceptions: A 'Silent' word may be spoken, so long as the invective 'Bloody' is inserted. egs. kanga-bloody-roo, Wagga-Bloody-Wagga.

Additionally, at any time, a 'Silent' word may be replaced by 'Bloody', so in this instance, we are actually talking about Suba-bloody-roos!

Cheers Mate! Another tube! :drinknsin

Bruce
(Professor of Colloquial Grammar, University of Wooloomoo-bloody-loo)

[F5 Dave]

Fuk its a bit more complex than I realised. Thought it would come naturally as my mother was Sydneysider.

[WilDun]

Fuk its a bit more complex than I realised. Thought it would come naturally as my mother was Sydneysider.

Judging by the accent, I don't think that guy was a "city slicker!" but he is sure good entertainment!
However, his apparent lack of regard for safety does worry me a bit though (I'm a sissy propane user you see!).
BTW I've done a lot of silly things in my day and still bear the scars (from learning the hard way - by mistakes) - I can absolutely assure you that it isn't the best way to go!

[Pursang]

Fuk its a bit more complex than I realised. Thought it would come naturally as my mother was Sydneysider.

Admittedly a Good Start.....But that still only gets you 3 suxth of the way there! ;)

Update: Fuk'n is totally interchangeable with Bloody, but preferably used only when in the company of other Gentlemen, never your Grandmother!

Cheers, Daryl.

[Flettner]

found some old photos.

[Flettner]

a long time ago in a galaxy far far away.

[WilDun]

a long time ago in a galaxy far far away.

Is that the OP engine you used in the boat?

[Flettner]

Is that the OP engine you used in the boat?

This one pre dates the boat engine.

[husaberg]

Is that the OP engine you used in the boat?

go back a few pages to the bike i posted Will
okay in a different thread ..........:doh:


345401345402

[Frits Overmars]

Update: Fuk'n is totally interchangeable with Bloody, but preferably used only when in the company of other Gentlemen, never your Grandmother!Daryl, if I'm not mistaken, in order to become grandmothers, all these ladies first had to become mothers. And how do you suppose did they manage that? :whistle:

[F5 Dave]

a long time ago in a galaxy far far away.
Didn't you win ConcourseDDungheap one year at the GP?

[Flettner]

I believe you are right, most unfairly chosen I thought. They didn't like the house brush paint tank I think, buggers.

Water cooled Kawasaki 100 with a secondary reed and carburetor mounted out back of the cylinder. Special cable connection so it opened only at full throttle, mildish rotary valve timing. But sadly seen as a dungaheap.

[WilDun]

I believe you are right, most unfairly chosen I thought. They didn't like the house brush paint tank I think, buggers.

Water cooled Kawasaki 100 with a secondary reed and carburetor mounted out back of the cylinder. Special cable connection so it opened only at full throttle, mildish rotary valve timing. But sadly seen as a dungaheap.

Probably was a giant step forward for the two stroke but the organisers didn't have the ability to see ahead (stuck in a rut)! :yes:

[F5 Dave]

Or they liked mercilessly taking the piss.;)

Those Ohakea GPs were fantastic fun.

[Pursang]

Daryl, if I'm not mistaken, in order to become grandmothers, all these ladies first had to become mothers. And how do you suppose did they manage that? :whistle:

Oh My, Mofo's? :shit: ........ I was referring to the F'n Adjective and not the F'n Verb. :innocent:

Such are the subtleties and traps of International Communication. There goes my chance to be Secretary-General of the United Nations!

Nice catch!;) Cheers, Daryl.

[Flettner]

Or they liked mercilessly taking the piss.;)

Those Ohakea GPs were fantastic fun.

Absolutely

[husaberg]

Oh My, Mofo's? :shit: ........ I was referring to the F'n Adjective and not the F'n Verb. :innocent:

Such are the subtleties and traps of International Communication. There goes my chance to be Secretary-General of the United Nations!

Nice catch!;) Cheers, Daryl.

Hey Dazza
so why is it ewe aussies'o like a's to the end of names and other vowels to the end of names and other things.
Sharron= Shazza
Daryl=Dazza
Barry=Bazza

Arvo
Bottelo
Povvo


https://www.youtube.com/watch?v=7FLefPaXQ8E

[ken seeber]

Husa, it's a sign of affection …..if you get and a or o or y on the end of a shortened name, enjoy it...:cool:

[WilDun]

My son lives in "Brizzie" now and has become an Aussie - I did become a Kiwi a while ago and was thinking of eventually going to Oz to live near him ..... might give it a miss now! :msn-wink: - and that guy with the 'larger than life' monster furnace didn't help - I thought he was only acting!...... :shit:

Seriously though, when I think about it , Brizzie was a nice place and I didn't see any extreme Aussies like that over there and Ken and Daryl seem fine to me!

Anyway, going through all my old stuff I have a little bit of refractory concrete left over, some fine silica sand and coarse river sand, half a bag of Mullite refactory mortar, a bag of some special American flint, a small bag of fireclay, a bag of powdered limestone, some Plaster of Paris, some of that stuff Neil uses to harden sand for cores etc. (Sodium Silicate I think), ceramic blanket material and some graphite I got from Neil - a household water pump pressure cylinder and sundry bits of steel - (why the hell did I take the rest to the scrapyard - what was I thinking? .... now I remember, I was ordered to!).
Still have my old moulding flask c/w a small bucket of greensand already prepared, two big s/s containers / cooking pots or whatever (rescued from the Raglan tip! ..... best shop in town!).

All the rest of the equipment I will have to scrounge for, or make myself ie except for my two little budget 3D printers (which work very well - ( I hope to try some experiments with lost PLA casting ). - It should all be good fun, but the effort required seems to be increasing these days!

Ah yes and I'll have to manufacture another gas burner for the furnace (my very successful design is lodged somewhere inside my head) - it may be difficult to access though!

So I think I should be able to cobble together a (very) small furnace and its associated equipment for virtually zero dollars, but I'll have to scrounge for a clay/graphite crucible) - and of course it will all require a bit of hard work!

[Pursang]

Husa, it's a sign of affection …..if you get and a or o or y on the end of a shortened name, enjoy it...:cool:

So what should it be.... Husso? Bergy?

Or just leave it as Hussy?:rolleyes:

Cheers, Daryl.

[Pursang]

I'll have to scrounge for a clay graphite crucible - and it will require a bit of hard work!

Well done Willo, (WilDo? Dunno?) pretty good inventory you have there. What size crucible are you thinking?

Clay and silicon graphite ones, in all sorts of sizes, seem to be plentiful on AU ebay & Amazon at the moment, under $40Aud.

If you're starting with Ally (Alu-bloody-minium), one bloke on the www is using the S/S inner from a damaged Thermos flask.
The only thing cheaper and easier would be a Baked Beans can! (Cheaper than dog food).

Cheers, Daryl.

[WilDun]

Well done Willo, (WilDo? Dunno?) pretty good inventory you have there. What size crucible are you thinking?

Clay and silicon graphite ones, in all sorts of sizes, seem to be plentiful on AU ebay & Amazon at the moment, under $40Aud.

If you're starting with Ally (Alu-bloody-minium), one bloke on the www is using the S/S inner from a damaged Thermos flask.
The only thing cheaper and easier would be a Baked Beans can! (Cheaper than dog food).

Cheers, Daryl.

Yeah, I'll have a look - they are getting cheaper now - I got my last one from Ceratec? - Certec ? ..... I do prefer the graphite/ceramic ones, they come clean after a pour and Neil suggested not using metal ones because it "taints" the aluminium and ruins the chances of it being any good for plating! ......Talking 'Alublinium' here, (to refine it further).

Probably round 110 mm outside up top - whatever that translates to - ( no big stuff needed here!) - probably get one for around $50, will make my own tongs burner etc.

Dunno?? - I dunno! - ah well, so long as it isn't Dunny I guess! :rolleyes:

[Flettner]

water core box, first mold out.

[Flettner]

All three water cores in place.
Being just a single cylinder, two pistons, Id like use both crankcases so I need to devise a transfer passage (or passages) from the exhaust piston crank case to the intake piston end. Not that simple, there is a lot of stuff in the way, but I have a plan as you might expect.

[husaberg]

Well done Willo, (WilDo? Dunno?) pretty good inventory you have there. What size crucible are you thinking?

Clay and silicon graphite ones, in all sorts of sizes, seem to be plentiful on AU ebay & Amazon at the moment, under $40Aud.

If you're starting with Ally (Alu-bloody-minium), one bloke on the www is using the S/S inner from a damaged Thermos flask.
The only thing cheaper and easier would be a Baked Beans can! (Cheaper than dog food).

Cheers, Daryl.

Hes gone all gangsta so Wildog or D-willy.

[ken seeber]

All three water cores in place.
Being just a single cylinder, two pistons, Id like use both crankcases so I need to devise a transfer passage (or passages) from the exhaust piston crank case to the intake piston end. Not that simple, there is a lot of stuff in the way, but I have a plan as you might expect.

Fletto, wotcha going to do for the encore ??????????

[husaberg]

Fletto, wotcha going to do for the encore ??????????

take over the world
https://i.imgur.com/3JE7Yiz.gif

[WilDun]

Fletto, wotcha going to do for the encore ??????????

Wait for the introduction to be completed before even thinking about the encore Ken! - the design process is sowly being overtaken by the construction progress here!
As you can see, I can't sleep, up in the night worrying about this project - I had to get up for an hour or so in order to keep pace with it all to allow my mind some time to comprehend Neils foundry pictures! ..... no doubt it will eventually get there, slowly but surely!

Sorry Husa, but WTF are you talking about? - I'm just a simple country boy and I don't understand your sophisticated city talk or way of life - that one trip you went on, over the mountain to Christcurch has changed you! ...... :rolleyes:

[Flettner]

take over the world
https://i.imgur.com/3JE7Yiz.gif

World domination, that was supposed to be last week, didn't happen, bugger it. You will know because when it does happen the 'new' rules will be heavily in favour of motorbikes and gyrocopters, twostroke ones, clearly.

[ken seeber]

Fletto, wotcha going to do for the encore ??????????

Oh I get it now, you meant enCORE, not just an encore....good one Ken..:yes::yes:

[WilDun]

Ken,
This is all becoming a bit too intellectual (and therefore confusing) for me! - I think I'll sit back and just watch the show! :rolleyes:

[JanBros]

take over the world
https://i.imgur.com/3JE7Yiz.gif

OMG , somebody actualy built funnybot's !

[Flettner]

An encore, uniflow.

Also a project underway is the new four port Subaru heads. Here one old Siamese port head had to volunteer for the saw. I need to remind myself whats inside a standard head, its been over twenty years since I built the original patterns. If you think this exhaust is ugly, you should see the inlets.

[WilDun]

An encore, uniflow.

Also a project underway is the new four port Subaru heads. Here one old Siamese port head had to volunteer for the saw. I need to remind myself whats inside a standard head, its been over twenty years since I built the original patterns. If you think this exhaust is ugly, you should see the inlets.

Need to strain to get my head (excuse pun) around all this - the picture on the right is the old standard Subaru head - right? and the picture on the left is your new OP project and so I assume that that is a positive of the water cavity? - so 3 exhaust ports?..... But what are those rectangular blocks/protrusions/or "cavities to be" between the exhausts?..... or is it just all a bit early in the day for me to be able fully understand? :blink: - Think I'll go and pour a cup of coffee! :yes:

BTW, where is a good place (in NZ) to buy crucibles?. - where do you get yours? - (5" OD plenty big enough for me!).

[Flettner]

Will D, the protrusions on the water cores are core prints. Holds the core in place, will leave a rectangular hole behind. These will become water outlet holes. There is a rectangular one and a round one to get accurite core location.

Google Metcast.

[WilDun]

Will D, the protrusions on the water cores are core prints. Holds the core in place, will leave a rectangular hole behind. These will become water outlet holes. There is a rectangular one and a round one to get accurite core location.

Google Metcast.

Thanks,
Now things are slowly coming back to me! - it all feels good becoming interested again! - and then there's challenge of doing it all again mostly using the stuff I have lying around!
Was thinking of making a crucible but perhaps better not to risk it - they don't seem to be as expensive these days.

[Flettner]

Back to the old beads on a string, hot glue gun trick. Bondifill and sand, kind of satisfying.

[Grumph]

An encore, uniflow.

Also a project underway is the new four port Subaru heads. Here one old Siamese port head had to volunteer for the saw. I need to remind myself whats inside a standard head, its been over twenty years since I built the original patterns. If you think this exhaust is ugly, you should see the inlets.


Meh, BMC A series are nearly as bad. I'm going to assume you're doing these heads for export...

There are a number of people down here who have talked to me about engines for post classic sidecars. One lot i spoke to asked about the small early Subaru engine.
I said yes, and there's four port heads coming too....
But then I went looking for an engine. Rocking horse poo. I haven't seen an early Sub on the road for years. Trevor Crowe Subaru have a nice Brat ute as a shop runabout - but it's re-engined with a turbo I think.

Where are you sourcing your engines from ?

[WilDun]

Meh, BMC A series are nearly as bad. I'm going to assume you're doing these heads for export...

There are a number of people down here who have talked to me about engines for post classic sidecars. One lot i spoke to asked about the small early Subaru engine.
I said yes, and there's four port heads coming too....
But then I went looking for an engine. Rocking horse poo. I haven't seen an early Sub on the road for years. Trevor Crowe Subaru have a nice Brat ute as a shop runabout - but it's re-engined with a turbo I think.

Where are you sourcing your engines from ?

I sold a couple about 12 years ago to a guy in Featherston.

Look out all you (so called "VW") aero egine guys I reckon! - (probably about as much VW in them as you would find in a Manx Norton!) yet those "modified V-dubs" are quite popular for light aircraft, but a similarly produced four valve Sub might just be less flimsy and generally better!

I liked my old four valve 1988 Toyota Corolla (4AFE) and later my Camry 2.2 - both had torque to spare - didn't need anything like VVT, they could (especially the Camry) pull away in top gear - but got to admit I eventually burned out the Camry clutch demonstrating it! :rolleyes: ..... significantly, they both had 'under square' engines. (bore < stroke)

Anyway carry on with the OP two stroke, - that gets more intriguing by the day!

[Flettner]

Meh, BMC A series are nearly as bad. I'm going to assume you're doing these heads for export...

There are a number of people down here who have talked to me about engines for post classic sidecars. One lot i spoke to asked about the small early Subaru engine.
I said yes, and there's four port heads coming too....
But then I went looking for an engine. Rocking horse poo. I haven't seen an early Sub on the road for years. Trevor Crowe Subaru have a nice Brat ute as a shop runabout - but it's re-engined with a turbo I think.

Where are you sourcing your engines from ?

West coast, they will all be there.
Ive got about twenty engines, I know of little stashes here and there.

[husaberg]

West coast, they will all be there.
Ive got about twenty engines, I know of little stashes here and there.

there was a few that collected a lot of them as they lasted longer than the bodies did.
I cant say i have found the particular one you wanted
But i think i may have tracked down the guy though at least
There were two rather large collections about 10 and 20km away i think the guy who had the one 20km away has buried his all though.

[Flettner]

there was a few that collected a lot of them as they lasted longer than the bodies did.
I cant say i have found the particular one you wanted
But i think i may have tracked down the guy though at least
There were two rather large collections about 10 and 20km away i think the guy who had the one 20km away has buried his all though.

Well, dig them up then.
EA81's

[WilDun]

Well, dig them up then.
EA81's
Chuck the shovel in the ute, - lets go! (got a map? - X marks the spot!)...... Subaroooo! :yes:

[Flettner]

More beads and bondifill.
Next to make a base plate to glue on with four lugs to hold a crankcase. The top one, exhaust piston crank case.

[Flettner]

Or perhaps six lugs might fit better.

[WilDun]

Hell. this is becoming more complicated by the mniute! - Wish there was a finished product that I could reverse engineer in my mind!

Converting positives to negatives mentally (for me anyway) is much more therapeutic than anything else I can think of! :facepalm:
..... but I know that all will be revealed sooner or later!

[190mech]

All of the KTM engineers are on the edge of their seats with each post!! HA-HA!!

[WilDun]

All of the KTM engineers are on the edge of their seats with each post!! HA-HA!!

Yes, they and 10,000 others are too - nothing is too small or goes unnoticed by some, who put each little idea into the great pool of ideas, sift through them and assemble them to suit - we don't invent, we discover - they were always there!
Something is being gained by someone, somewhere but the problem is, people in this world ( who don't respect intellectual property nor honour the efforts of the enthusiast or "back shed inventor"), will profit!

Sorry, here I go again! :facepalm:

[Flettner]

Its ok, the important stuff is statically hidden. Im really getting into this, intetesting to see how its all taking shape, I guess its as Id imagined it might look. I could just go day and night but I am going to have to stop shortly, customers are starting to get agitated for the real work bugger it.

[WilDun]

Its ok, the important stuff is statically hidden. Im really getting into this, intetesting to see how its all taking shape, I guess its as Id imagined it might look. I could just go day and night but I am going to have to stop shortly, customers are starting to get agitated for the real work bugger it.

Ah! so that's why I'm having problems understanding it! :rolleyes:

Can't get a decent A4 clay graphite crucible in NZ for much less than 100 bucks - can get a fused silica one for around 60 - doesn't sound too expensive maybe, but for a budget foundry, supposedly made from surplus stuff lying around ..... quite a lot!
BTW I found a bag of Flint Clay (no doubt which I scrounged from somewhere a long time ago!) so with that and my Mullite Mortar, sand etc, maybe I can make my own - I dunno! ..... anybody with a bit of knowledge there? ....... just a while ago a bag of 'perlite' arrived (I think I ordered it for the garden!).:msn-wink:

Yes, those customers arriving must be a pain in the ass!

[Pursang]

BTW I found a bag of Flint Clay (no doubt which I scrounged from somewhere a long time ago!) so with that and my Mullite Mortar, sand etc, maybe I can make my own - I dunno! ..... anybody with a bit of knowledge there? ....... just a while ago a bag of 'perlite' arrived (I think I ordered it for the garden!).:msn-wink:

Yo! WilDog, Doesn't seem too difficult, here's a recipe, off the net!

100 grams Kaolin + 300 grams Kyanite, mix dry, add just enough water to make mix like Plasticine, form shape, dry thoroughly, fire it, done.:woohoo:

They need to be cooked in a kiln to around 1260 C. and held near that temperature for around 45 minutes to an hour.

Is there a pottery club near your home? Pottery supply stores often have a firing service available.

Cheers, Dazza!

[Flettner]

There you go Will D, some bosses for the water inlet and outlet.

[WilDun]

There you go Will D, some bosses for the water inlet and outlet.

Ok Neil,
Just give me a day or so to come to terms with it and (maybe) I'll comment! :blink:
Funny how when you look at the photo, those rectangular "passages"? "lugs"? (at the bottom of the pattern) seem to change from ... well ... passages to lugs and back to passages (negatives to positives).... or is it just me being undecided as to what they are?? - something you wouldn't get with a 3D image though!!
BTW The colour coding idea does help visualise things!


Daryl,
I replied before (now it's gone for some reason) but I said that I just want to use what I have on hand, plenty of recipes - from plaster/sand to high alumina concrete mixes on the net, still I think I've got enough stuff to be getting on with now - all experimental of course! - Toying with making my own crucible too but maybe it's a bit dangerous to do that!

[WilDun]

Today I said "what the hell" and ordered a new A4 crucible from Certec for $69, delivered to my door - (worth it from the safety aspect I think) - it's a fused silica type and good for up to 1500 deg C - sorta defeats the purpose of the "budget" exercise I know! - think I've got enough other stuff to be getting on with.
Spent a lot of today thinking up an LPG burner to replace my "lost" one, plus a good set of tongs to replace my lost pair of those! - all good fun so far!

[Pursang]

Today I said "what the hell" ........ all good fun so far!

Well done Will, :2thumbsup - keep us posted.

Cheers, Daryl.

[WilDun]

Crucible arrived today, smaller than the last one (A4 - think the last one was A6) fused silica, easily good for bronze. Also found my adjustable reducing valve but some asshole nicked the burner off it, so continuing with my new burner build (off the top of my head!). Other things to sort out here as well though, so progress will be slow - but I'll get there eventually!

[WilDun]

Well, here goes - the only way is up - it's a start! - now trying to decide which material I should use for the furnace inner and the insulation - or should I cough up and buy a bag of refractory concrete (very expensive!).


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[Flettner]

The last core box for my uniflow , just speeding up the setting of the casting resin in front of the fire.
The wood is I think Rimu, from inside the wall on my daughters 100 year old house. They have done some renovations, so I slipped in and grabbed all the old wood. Waste not want not.

[WilDun]

The last core box for my uniflow , just speeding up the setting of the casting resin in front of the fire.
The wood is I think Rimu, from inside the wall on my daughters 100 year old house. They have done some renovations, so I slipped in and grabbed all the old wood. Waste not want not.

Scavenger! - :Oi:

[Flettner]

Can't show the finished pattern completly but here is one of Claire's plan pots, wood, ideal molding box, even has handles. Dangerously close to a cast.

[jato]

Deeply impressive (and fast) work!. We need to build a cloning machine . . .

[F5 Dave]

Sounds distracting. We'd spend all our time trying to collect Elle McPherson DNA samples .

[Pursang]

Well, here goes - the only way is up - it's a start! - now trying to decide which material I should use for the furnace inner and the insulation - or should I cough up and buy a bag of refractory concrete (very expensive!).

Our old mate, the Oil Burner, would say don't be a Sissy and be worrying about lining it! Build it and run it and if/when you burn the bum out of it , grab another old gas bottle and build a better one. :devil2:
If you're concerned about thermal efficiency, wrap it in Rockwool(R) or whatever you can find handy.🐑

Satisfaction through immediate Action.:done:

Nice crucible, by the way! .:niceone:

Cheers, Daryl.

[husaberg]

Our old mate, the Oil Burner, would say don't be a Sissy and be worrying about lining it! Build it and run it and if/when you burn the bum out of it , grab another old gas bottle and build a better one. :devil2:
If you're concerned about thermal efficiency, wrap it in Rockwool(R) or whatever you can find handy.🐑

Satisfaction through immediate Action.:done:

Nice crucible, by the way! .:niceone:

Cheers, Daryl.

I thought Wills vessel looked like a pressure tank from a water pump.

[WilDun]

I thought Wills vessel looked like a pressure tank from a water pump.

Yes that's what it is ( but looks like a gas bottle) - anyway, having built one before I don't think it matters what you use for a case - the most important part is the hot/hard face part in the middle and the rest can be surrounded by whatever provides insulation! - however I did use two layers of rockwool before (and it was very good too) but as I moved it from place to place in the car, it compacted and the inner started to move around a bit! - so maybe I'll try pumice and/or perlite, which will (only just) be held together by cement of some sort (to keep everything in place), but perhaps I'll still use a thin layer of rockwool between it and the hot face. Maybe try using some of our good old Auckland Scoria as well - this is quite lightweight and rigid and will help support the Perlite (lightweight, very crumbly, but a good insulator).

BTW I think Neil has moved way past the simple bargain basement "rockwool only" furnace now!

But, as you suggest. nothing's really as critical as some people would have you believe it is!

I do still want to build something which can be used over and over and hopefully see me out! (don't have the energy to keep on building them anymore).

Trying to build a burner at the moment, (but, with lots of family matters and junk clearing to be done in my garage - all needing my attention as well, then ...........who knows!).

[Flettner]

The pot plant molding box. Dividers are so the outside sand segments are made and removed in thirds, once they are molded / gassed, the segments can be moved out of the way, pattern removed then returned to position with cores in place. Still need a top and bottom mold box. Perhaps next weekend.
Almost getting a little excited to see the aluminium result. I've got a number of cylinders to pour at the same time ( seeing as I'll have a pot full of LM13 ) so it might be a while before I actually melt aluminium.

[WilDun]

.......
Almost getting a little excited to see the aluminium result. I've got a number of cylinders to pour at the same time ( seeing as I'll have a pot full of LM13 ) so it might be a while before I actually melt aluminium.

Have you got a new furnace now? - has the plating on LM13 been a success?

[Flettner]

Have you got a new furnace now? - has the plating on LM13 been a success?

Yes and yes.
My gyrocopter is running my LM13 cylinders, nikasil. Bonds very well.

New furnace works but needs a few modifications yet, you know, safety and all that.

[WilDun]

Yes and yes.
My gyrocopter is running my LM13 cylinders, nikasil. Bonds very well.


D'y reckon that's because the Nikasil feels more comfortable with the high silicon content of LM13?

[Flettner]

All ready for sand.
Cases will have to change, rotary valve will go on the opposite side now. Flywheel elsewhere.

[husaberg]

bonding iron inserts to aluminium castings
https://web.wpi.edu/Pubs/ETD/Available/etd-042517-105246/unrestricted/Soderhjelm.pdf

[WilDun]

I remember the Poms used the "Al Fin" process successfully and I think the early Kawasakis also used that process, liners had (coated) stub C/I fins and were cast into an Ally finned barrel.

[ken seeber]

The Al-fin process

http://yorkshireferret.blogspot.com/2018/01/wellworthy-al-fin-bonding-cool-at-speed.html

Kawasaki, I do remember their WESC process. Wire Explosion Spray Coating. Around 13 wires of around 1.5 mm were tensioned down the middle of the bore axis. They were high carbon wires then molybdenum wires repeating. Each wire was given around 22k volts giving a well audible bang. So much so, the cyl was contained in a heavy steel box, either for noise and/or electrical safety and/or fumes. All done in fresh air. The carbon wire spray hit the aluminium and instantly formed very hard martensite, due to the very high cooling rate, and the following molybdenum spray acted as a lubricant. I think that it was applied to around 80 microns.

We, when at Orbital, did use a couple of samples on our 3 cyl 1.2 litre dev't engines, no issues. I just thought the process was so elegant, but I guess it was either too slow, too expensive or had field issues, as Kawasaki went the Nikasil route in the end.

[husaberg]

The Al-fin process

http://yorkshireferret.blogspot.com/2018/01/wellworthy-al-fin-bonding-cool-at-speed.html

Kawasaki, I do remember their WESC process. Wire Explosion Spray Coating. Around 13 wires of around 1.5 mm were tensioned down the middle of the bore axis. They were high carbon wires then molybdenum wires repeating. Each wire was given around 22k volts giving a well audible bang. So much so, the cyl was contained in a heavy steel box, either for noise and/or electrical safety and/or fumes. All done in fresh air. The carbon wire spray hit the aluminium and instantly formed very hard martensite, due to the very high cooling rate, and the following molybdenum spray acted as a lubricant. I think that it was applied to around 80 microns.

We, when at Orbital, did use a couple of samples on our 3 cyl 1.2 litre dev't engines, no issues. I just thought the process was so elegant, but I guess it was either too slow, too expensive or had field issues, as Kawasaki went the Nikasil route in the end.

telll us more about the Kawa electrofusion process i knew it was exploding wires i thing cameron descrbed it many yeards ago
what ran the power a Neon transformer on steroids ?
2 stroke suffing was trying diy niksil but it seemed a bit complicated.
the wellworthy was basically described in one of the processes in the PDF
It was first dipped in molten aluminium alloy then cast in place.
the Ribs on the Japanese bikes sleeves give it more surface area and prevent creep.


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Some other interesting stuff
https://www.european-aluminium.eu/media/1575/aam-applications-power-train-3-cylinder-linings.pdf

Honda on saving space and money developing a new engine or changing tooling
http://dwolsten.tripod.com/articles/jan96a.html
WHy the back to the future Steel pistons need steel sleeves
https://www.cycleworld.com/2016/01/14/steel-pistons-part-1-is-steel-a-better-material-cycle-world-motorcycle-technology-feature/

http://blog.wiseco.com/piston-to-wall-clearance-myths-mysteries-and-misconceptions-explained

[WilDun]

.......... the wellworthy was basically described in one of the processes in the PDF
It was first dipped in molten aluminium alloy then cast in place.
the Ribs on the Japanese bikes sleeves give it more surface area and prevent creep...........

McCulloch, I believe were the first to use the ribbed (threaded) cylinders in their Kart/Chainsaw engines. ....... and I seem to remember seeing a few Kawasaki motocrossers with ruined barrels /pistons from using the Electrofusion process!

Regarding piston clearances, the two stroke has always suffered from the possibility of sudden seizure (most probably being brought on by uneven heating of the piston which in turn comes from the hot exhaust and the cooling effect from the transfers on opposite sides of the cylinder. This in some cases was sorted by greater piston clearances, but in the sixties (that's last century to you young guys!), Suzuki (and most others) resolved it all to a certain extent by testing various cam grinds on the pistons till it was close enough, so the one thing which was could still alter things drastically was jetting expertise on the day!

Watching the 125 Ulster GP I remember seeing the two works Suzukis (in the lead on the first lap) both seize about a third of the way round the track at exactly the same spot! - so there was a definite science involved with it all (but someone got it wrong this particular time!).
The exact same thing happened at Pukekohe to Cal Rayborn from USA - unfortunately he did not survive - I did witness that as well - very sad.

I did hear of works test riders being asked to go out on the track and ride the hell out of the bikes till they seized!! - worrying times for them I imagine!

To me the opposed piston concept could be a winner here (with no uneven piston heating) so it could offer much closer piston clearances and that would help outweigh some of it's downsides! - whatever happens, I will be looking on with interest!

[husaberg]

McCulloch, I believe were the first to use the ribbed (threaded) cylinders in their Kart/Chainsaw engines. ....... and I seem to remember seeing a few Kawasaki motocrossers with ruined barrels /pistons from using the Electrofusion process!

Regarding piston clearances, the two stroke has always suffered from the possibility of sudden seizure (most probably being brought on by uneven heating of the piston which in turn comes from the hot exhaust and the cooling effect from the transfers on opposite sides of the cylinder. This in some cases was sorted by greater piston clearances, but in the sixties (that's last century to you young guys!), Suzuki (and most others) resolved it all to a certain extent by testing various cam grinds on the pistons till it was close enough, so the one thing which was could still alter things drastically was jetting expertise on the day!

Watching the 125 Ulster GP I remember seeing the two works Suzukis (in the lead on the first lap) both seize about a third of the way round the track at exactly the same spot! - so there was a definite science involved with it all (but someone got it wrong this particular time!).
The exact same thing happened at Pukekohe to Cal Rayborn from USA - unfortunately he did not survive - I did witness that as well - very sad.

I did hear of works test riders being asked to go out on the track and ride the hell out of the bikes till they seized!! - worrying times for them I imagine!

To me the opposed piston concept could be a winner here (with no uneven piston heating) so it could offer much closer piston clearances and that would help outweigh some of it's downsides! - whatever happens, I will be looking on with interest!

You have a bit more leeway now with gauges hit 1300F on a two stroke and it will almost certainly nip up.
many hours of my youth were spent running and sanding pistons as they nip up slightly, then cleaning up the cylinder and the piston after which you would repeat it about 4 or 5 times afterwards it would be fine unless you did something stupid with the jetting
After a while you could sense it as the engine got quieter when it would be about to happen.
Modern bikes and race pistons i guess would no longer need this ritual.

but i attribute this ritual with the reason i never had a full on piston seizure (along with fat jetting i guess)

[WilDun]

You have a bit more leeway now with gauges hit 1300F on a two stroke and it will almost certainly nip up.
many hours of my youth were spent running and sanding pistons as they nip up slightly, then cleaning up the cylinder and the piston after which you would repeat it about 4 or 5 times afterwards it would be fine unless you did something stupid with the jetting
After a while you could sense it as the engine got quieter when it would be about to happen.
Modern bikes and race pistons i guess would no longer need this ritual.

but i attribute this ritual with the reason i never had a full on piston seizure (along with fat jetting i guess)

Yeah, - poor man's cam grinding! - I did that too (after I had a seizure) - file marks were good for retaining the oil!
In a stroker there is never such a thing as a round piston!
Iron barrels definitely did not help! ..... very dicey things to ride, those old strokers!

[WilDun]

Came across this, might be interesting to someone !

https://www.thedrive.com/tech/34775/porsche-found-a-way-to-3d-print-lightweight-pistons-that-add-even-more-horsepower?fbclid=IwAR2uhybjPVn0xdeTNtFZV_dEXfFzYs bPipFKh6MPDhL2KABk9Bqdj8mhV54

[ken seeber]

Came across this, might be interesting to someone !

https://www.thedrive.com/tech/34775/porsche-found-a-way-to-3d-print-lightweight-pistons-that-add-even-more-horsepower?fbclid=IwAR2uhybjPVn0xdeTNtFZV_dEXfFzYs bPipFKh6MPDhL2KABk9Bqdj8mhV54

Yeah Wil, I think the main feature of the piston is its shape, most likely a product of the "polytropic optimization" method, itself a sophisticated application of FEA. Looking at it, this could be easily a cast item, using sand cores. Cuppla dudes on kiwibiker have come up with almost similar designs, and even parts, for 2 stroke applications. These taking into account the fundamental different design requirement.

[katinas]

On the uni I was attending there was a doctor case about a 2t with valve in piston crown if You can find those docs here's the numbers http://bibliografia.ath.bielsko.pl/cgi-bin/expertus.cgi?KAT=%2Fhome%2Fexpertus%2F0%2Fpar%2F&FST=data.fst&FDT=data.fdt&ekran=ISO&lnkmsk=2&cond=AND&mask=2&F_00=10&V_00=silnik+dwusuwowy+

Another great 2T book by Polish author Tadeusz Rychter 1988

[WilDun]

Yeah Wil, I think the main feature of the piston is its shape, most likely a product of the "polytropic optimization" method, itself a sophisticated application of FEA. Looking at it, this could be easily a cast item, using sand cores. Cuppla dudes on kiwibiker have come up with almost similar designs, and even parts, for 2 stroke applications. These taking into account the fundamental different design requirement.

Ken,
I'm not really up there with all the new terminology or even abbreviated names these days - ( I quite frankly know sweet FA ), but there's no harm in having a stab at things and try to understand what it's all about! :rolleyes:

We are both into 3D printing of course (which in itself isn't terribly exciting) but those guys on Facebook etc who believe that 3D printing consists of downloading .stl files and putting them in the machine, pressing the button and hey presto, pointless perfection pops out! - - they make me feel like a genius! ........ cos we actually know how the damn thing works and don't see it as a supersonic precision machine - as they do!

Like everything else it will all settle down and I guess there will be a niche where 3D printing will become very necessary (as it probably is in this case).

Have you done any 'lost PLA casting to date? - seems that there is a type of PLA filament specifically for the 'lost PLA' process - probably expensive but also probably worth a try!


Another great 2T book by Polish author Tadeusz Rychter 1988

I remember Mike Hailwood giving the EMC a few outings and extracting the best from it .......... also the MZ and the Benelli and various others - made them all look like potential winners! - probably the money didn't pay for his groceries though!

I once did have high hopes for the EMC - and they did make a great effort too!

Wish my Polish was a little better!

[husaberg]

Another great 2T book by Polish author Tadeusz Rychter 1988

Dindnt Wob or someone elese who posted on here work for DR Joe of EMC
prior MZ replica he was using split singles i think based on Puch
Legend was Dr joe received a complete MZ engine in a suitcase someone liberated from the east cloak and dagger style, not sure if its legend or true.
but afterwards his work was i believe closely associated with Rotax?????
he seem to live on for a long time

[Frits Overmars]

Legend was Dr joe received a complete MZ engine in a suitcase someone liberated from the east cloak and dagger style, not sure if its legend or true.The cloak and dagger style is probably legend. Fact is that Joe Ehrlich helped the MZ racing department to Norton Roadholder front forks and got paid with MZ 125cc crankcases.

[husaberg]

The cloak and dagger style is probably legend. Fact is that Joe Ehrlich helped the MZ racing department to Norton Roadholder front forks and got paid with MZ 125cc crankcases.

Odd as i thought these came from Shepard via Francis Beart where was a story of them being sent through checkpoint charlie down the trouser legs one at a time?
I think Beart ended up with MZ brakes in return?

added info from a book i have never read. I think i read it in a test of a Beart bike.

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[WilDun]

Dindnt Wob or someone elese who posted on here work for DR Joe of EMC
prior MZ replica he was using split singles I think based on Puch
Legend was Dr joe received a complete MZ engine in a suitcase someone liberated from the east cloak and dagger style, not sure if its legend or true.
but afterwards his work was i believe closely associated with Rotax?????
he seem to live on for a long time

I didn't know about that, but the fact that Dr Joe was probably a refugee from Germany, I'm sure he had plenty of contacts there! - Degner " of course liberated" a lot of MZ stuff to help with the Japanese effort as well! -
John Hemplemann (from Auckland) also got a ride with MZ! - the name might have had at least some influence (as well as riding skill!).

[WilDun]

Odd as i thought these came from Shepard via Francis Beart where was a story of them being sent through checkpoint charlie down the trouser legs one at a time?
I think Beart ended up with MZ brakes in return?

I think that would have been pure "fable" - can you imagine trying to get past the Stazi with roadholders down your trouser leg - you would have needed some balls to "leg it"if you had to .... (well, you would still have had some at the start of the chase anyway!) :facepalm:

I can remember watching Ernst Degner, Horst Fugner and Werner Krumpholz racing MZ machines and of course Alan Shephard. - that drawing of the MZ engine which reached the 200 BHP/Litre figure.
That was when go Karts were still using deflector pistons! ie except McCulloch who had vaguely the right idea but still in its infancy and Royal Enfield and BSA using the two port Schneurle transfer system (but really, they copied DKW).

That MZ drawing was actually what inspired my thinking about two strokes and ever since, that has been my benchmark! - In those days,we couldn't see past Horsepower figures, not realizing that there was a lot more to it,..... and that has cost the two stroke dearly - horsepower figures were much more important than any thoughts on the way forward!

[ken seeber]

Slowly working on the next version of the UHV.

So 3D printed out the final design, then with a few detail changes, upgraded the design on CAD and removed all the machined features, added machining allowance. Used 1.5 deg of draft on all vertical faces. From this, created an .stl file, sent that thru to the slicer programme (Cura 4.6 in my case) and then allowed a scale up (1.2%) to allow for shrinkage. The slicer creates a .gcode file that is used by the 3D printer. What was printed out was the pattern to create a sand mould.

Yesterday I smoothed the pattern and went over it a few times with spray putty. At this point, I came to the conclusion as to why Neil makes so many patterns. It is the beautiful cellulose smell that comes off the spray putty when sanding. Almost therapeutic.

Today I made the first sand mould. Will have to surround it a bit more as it is too close to the edge of the cavity. The patterns has a projection that makes the pattern take up more space. The reason for the projection is that when I turn the sparkplug boss & thread, I can put it into a 3 jaw chuck and the boss will be on centre. After machining it will be cut off.


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Hours of fun.

I think Wob was scathing of Dr Joe as he ripped off Yamaha with a design of a cylinder head shape (full diametral bathtub ???) that was a dud. Without history, good or bad, we wouldn't be here now.

Wil, I haven't tried lost PLA, but do have some filament which should be a lot better. It's called Polycast. We did a design of a head shell, but haven't cast it yet, another backburner project.

[husaberg]

I think that would have been pure "fable" - can you imagine trying to get past the Stazi with roadholders down your trouser leg - you would have needed some balls to "leg it"if you had to .... (well, you would still have had some at the start of the chase anyway!) :facepalm:

Pretty sure some of the guards are often racing fans.
remember its goods coming in rather than out.
the oil company guys used to do all the deals with the riders et they were the ones that likely paid fo the etries of the MZ as well.
MZ's idssues was always lack of money to pay riders and get top flight stuff like mags and plugs suspension carbs etc.

[WilDun]

Slowly working on the next version of the UHV. ..........


Wil, I haven't tried lost PLA, but do have some filament which should be a lot better. It's called Polycast. We did a design of a head shell, but haven't cast it yet, another backburner project.

That's the one I was talking about, let me know how it goes, if you're going to use that.
Which CAD are you using now?

I guess that it will need some pretty hi tech stuff if you ever want to directly 3D print metal powder (for sintering)? ..... and no doubt expensive!

BTW, I went back to CURA 4.2.1 instead of 4.6.1 as I was having some prints with layers lifting etc - don't really know why, but the older version is working well.


Pretty sure some of the guards are often racing fans.
remember its goods coming in rather than out.
the oil company guys used to do all the deals with the riders et they were the ones that likely paid fo the etries of the MZ as well.
MZ's idssues was always lack of money to pay riders and get top flight stuff like mags and plugs suspension carbs etc.

All I can say is that I wouldn't have been game to try it under any circumstances with guns and young (trigger happy) guards around!

[husaberg]

T
All I can say is that I wouldn't have been game to try it under any circumstances with guns and young (trigger happy) guards around!

was that a roadholder fork in his trousers or was he juat happy to see them.
I think Kaaden himself might have toted the forks in hindsight.
i will see if i can find it.
a net searh atributes it to Shephard via a shell agent
Another gives the joe swaped engine for forks
pretty sure i have something about shephard
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[katinas]

Without history, good or bad, we wouldn't be here now.



Indeed, Joseph Enrich EMC 125 two cylinder engine is awesome. Mr Richards rotary valve Vitesse ( Sun) engine and very interesting, Roger Cramp with his engine. I only found a few photos with Erich Wolf.

[ken seeber]

That's the one I was talking about, let me know how it goes, if you're going to use that.

The pic is of a couple of prints using Polycast. Seems as forgivable as PLA. The wax risers and central downsprue (slightly out of position) are also used to suspend the print using the crossbar (one of two shown) when investing. It is the external water jacket for a KTM 250 motocross engine in a kart. In addition to improving the coolant flow direction, it has the coolant outlet at the back. It's a complex design with lots of lofts and blends that were way above me.

346466

[WilDun]

The pic is of a couple of prints using Polycast. Seems as forgivable as PLA.
The wax risers and central downsprue (slightly out of position) are also used to suspend the print using the crossbar (one of two shown) when investing.............. .... It's a complex design with lots of lofts and blends that were way above me.

You say 'investing' but I'm guessing you are not going to do it in the conventional (thin wall) investment casting way,- will you be surrounding it with plaster/sand in a box?

Those 3D CAD programs are great but it takes a long time with a lot of frustration initially (I'm still at that stage) but I'm loving it - (I have finally settled for Fusion 360 and have done quite a lot of small stuff with it), but nowhere near being a competent user!.

[lohring]

Don't give up on Fusion 360. I'm over 2 years into it and still learning. Solids are fairly straightforward, surfaces are harder, and sculpting is frustrating so far. YouTube has been my source for detail learning. When I get stuck, there's usually someone who has a video on the issue.

Lohring Miller

[WilDun]

Don't give up on Fusion 360. I'm over 2 years into it and still learning. Solids are fairly straightforward, surfaces are harder, and sculpting is frustrating so far. YouTube has been my source for detail learning. When I get stuck, there's usually someone who has a video on the issue.

Lohring Miller

It's good ok - if only it had been around 20 years ago! ...... is it possible to tick a "preference" box to say how you want your reincarnation to be? - then maybe a "resume" box ..... and carry on from there! :msn-wink:

[Flettner]

The process of building sand castles again.
Pattern is black colour because of the plumbago I've rubbed in its surface, makes it slippery as @#$/.

[Michael Moore]

Chris Cosentino has updated his Hypermono project blog to tell about the box of Mg engine castings from 3D-printed molds (not patterns) that he recently received. The newest material on the single is at the top of the blog, the Moto2 V4 project is farther down the page. If you've never looked through the entire blog there's tons of very cool stuff on there about designing and building (everything) the bikes.

http://moto2-usa.blogspot.com/

[Flettner]

One core box is giving some grief.
Family have turned up, shed has been placed 'out of bounds', for the moment.

[WilDun]

One core box is giving some grief.
Family have turned up, shed has been placed 'out of bounds', for the moment.

Two steps forward, one backward! - can't wait to see this one hatch out.
Families? - tell me about them?!

[Flettner]

Glueing one of the three water cores in place, tricky bastard, so easy to break.

[Flettner]

Opps, have I bitten off more the I can chew, this time. This pattern may need some rework bugger it.

This is why the Shell Sand Moulding system for cores is so great. Produces robust high quality finish cores that are are ideal for this kind of fiddly work. But you need a metal die, bugger it. Might have to copy cast the core boxes into aluminium.

[WilDun]

Opps, have I bitten off more the I can chew, this time. This pattern may need some rework bugger it.

This is why the Shell Sand Moulding system for cores is so great. Produces robust high quality finish cores that are are ideal for this kind of fiddly work. But you need a metal die, bugger it. Might have to copy cast the core boxes into aluminium.

Shell sand is good (just like the more flexible crust you would get on a slightly overcooked ginger bread loaf cooked in the oven! ), not so good to eat though! :sick:

[Flettner]

I've got it to this point, slide and glue the last section in. This is a good way to see everything is in place, secured and clean before closing up. Im in the process of building up a second one at the moment, might as well have two cock ups I guess.

[Flettner]

No, its become clear that sodium silicate sand is just rubbish when making fine cores, Ive tried every trick. Thought I might get away with it but Ive spent two more days trying to make a second mold, no avail. I've wasted enough time on this. I guess Ill just have to spend more time and make metal dies, @#$/ it, Shell Sand process to the rescue. Arh, so close too.
I just can't imagine this one mold I have on the floor working first time. Always need a few backups. Pour it and see perhaps? I only want one cylinder after all. To be honest I'm a bit over it at this point.

[WilDun]

No, its become clear that sodium silicate sand is just rubbish when making fine cores, Ive tried every trick. Thought I might get away with it but Ive spent two more days trying to make a second mold, no avail. I've wasted enough time on this. I guess Ill just have to spend more time and make metal dies, @#$/ it, Shell Sand process to the rescue. Arh, so close too.
I just can't imagine this one mold I have on the floor working first time. Always need a few backups. Pour it and see perhaps? I only want one cylinder after all. To be honest I'm a bit over it at this point.

That's too bad! - mind you I have seen cores being made out of all sorts of things (even molasses!) - but the fact that you only need Co2 for Sodium Silicate is a very good reason to go that way.
Pity that most of the others seem to require some sort of heat source to 'cook' them!
I know that you don't care much for 3D printers and the lost PLA process, but sometimes that might come in useful for tricky castings!
However, if your shell moulding isn't too far off, - then maybe not!

Would it help to use some sort of finely chopped fibre in your silicate/sand mix which will be easily broken down by the hot metal? - something which won't make the mix impervious to the Co2 of course! - probably not fibreglass because it wouldn't break down so easily, but something like hemp used in gland packing or rope, maybe even cotton wool! (totally shredded of course) - this might give it the temporary cohesion needed for the process - (just a thought).

OR ..... good old NZ flax!

[Flettner]

I have in the past used wire set inside the sand core, even if it breaks it can't fall apart. Just too awkward to get a wire in with this transfer core. I should have known better, its not like it hasn't presented a problem in the past.
The real bastard was I was fitting the last core in place, it fell out taking with it part of another core. Being it was all glued up, too late, had to throw the whole two days work in the bin. But thats how it goes.

[WilDun]

I'm talking relatively finely chopped stuff like common or garden plumbers hemp etc being completely part of the mix. - wouldn't like to see this not going though!

[Pursang]

I'm talking relatively finely chopped stuff like common or garden plumbers hemp etc being completely part of the mix. - wouldn't like to see this not going though!

I believe that Hemp has been used for centuries as a stabilising influence and support, during difficult processes:doobey:

Cheers, Daryl:innocent:

[Flettner]

https://m.facebook.com/story.php?story_fbid=1795730413898995&id=100003861602582

https://youtu.be/NoXO2LqlqCs

[Pursang]

:killingme

[WilDun]

https://m.facebook.com/story.php?story_fbid=1795730413898995&id=100003861602582

https://youtu.be/NoXO2LqlqCs

Your cat? - I think I'm beginning to see why things aren't going so well at the foundry these days!! :facepalm:
( but on the positive side, it may just open a new perspective on pattern making and could release some creative ability you never knew you had!).

[ken seeber]

Well, cast up 4 heads yesterday for the next version of the UHV system. Used CO2, but in a far more basic application than Fletto's very complex mould .
Open faced moulds, placed face down on a preheated steel plate. Poured into the central downsprue. One had a bit of shrinkage in the downsprue, but can't say whether the plate was too hot or too cold. Better keep a record for next time (????). Gave them a preliminary machine, mainly to create a central hole to hang them on to the tree we use for the solution heat treatment of our pistons and brake discs. The small extension to hold the plug boss on centre worked perfectly.

Must say it is, as Fletto said, therapeutic. Sort of a STONED age thing. :niceone::niceone:

346510346511346512346513346514

[husaberg]

Must say it is, as Fletto said, therapeutic. Sort of a STONED age thing. :niceone::niceone:

primeval responses Ken , who doesn't like setting fire to stuff cooking bbq or clubbing the misses over the head with a club

[ken seeber]

Nah, nothing to do with 2 strokes, nothing to do with casting...

Sometimes you get problems some easy to solve, some hard to solve

and some are just BRAINLESS

346537

[WilDun]

Nah, nothing to do with 2 strokes, nothing to do with casting...

Sometimes you get problems some easy to solve, some hard to solve

and some are just BRAINLESS

Yes, well that one is brainless ok! - his brains have obviously turned to jelly and have come out of his nose! :eek5:

..... Also easy to solve! (ie by using the proper slicer settings!).

[Flettner]

Cast in LM13.

[Pursang]

....:wings:

[Flettner]

Revised cases too shortly.

[ken seeber]

Cast in LM13.

EXCELLENT....:2thumbsup

[WilDun]

Cast in LM13.

That's brilliant!! - looks fantastic! - almost too good to be real!

[Flettner]

The morning after.

Straight into roughing it out.

[WilDun]

The morning after.

Straight into roughing it out.

Guess most foundries look like the morning after permanently! but that's quite an impressive "industrial strength" furnace! and that mobile "10 in 1" crucible holder/ladle/pouring mechanism .....um .....whatsitsname !! - pretty good as well!

[Flettner]

Ive made out that the uniflow casting was a success, truth is its got a blow hole in it. From the water cores not being able to out gas. Could be welded but I'll use this first one as a machining test dummy, so I need to make up another mold or two. I've copy cast my wooden core boxes into LM13 aluminium core boxes. Much stronger cores and added another core print so they can gas out without sending the gas through the aluminium.
Water core box and hot to cold end transfer core box, the troublesome ones.
Shown here the water core boxes, wood and now metal, plus a Shell Sand core.

[Flettner]

Almost, as I look closer I see a water core has broken away and floated up causing the problems. Only one third as there are three cores, bugger it. So not a gassing issue after all.

[F5 Dave]

Devcon mate.

That said i glued an LC head conversion with Devcon as figured it would stay below 70 easy.

Didn't make practice.

[Flettner]

Devcon mate.

That said i glued an LC head conversion with Devcon as figured it would stay below 70 easy.

Didn't make practice.

No, Ill cast again now that I know how to fix the problem. To be fair Im shocked it came out as good as it did, considering the bitch the mold was to assemble, lessons learnt.

[WilDun]

No, Ill cast again now that I know how to fix the problem. To be fair Im shocked it came out as good as it did, considering the bitch the mold was to assemble, lessons learnt.

Best way to learn - by mistakes!

[Frits Overmars]

Best way to learn - by mistakes!Yes, but...
346692

[WilDun]

Yes, but...


I now know that to be true - but could you have told me that when I was making them? - life was "forever" then! :facepalm:

God designed us all that way (ie unable to get off the starting block) in case we got too "uppity"

[Flettner]

Jolly old NZ aye, sent my cases to get them heat treated in Auckland. Oven broke down, one week, two weeks.
With a refurbished oven, the transformer on the poll outside their factory blew up. One week ...... finally have them back, not melted thankfully and nice to machine, clearly at T6.

[WilDun]

I heard that Heat Treatments was in recievership (or was it McGregor Furnaces??) - who does your treatments in Auckland?

[Flettner]

Nice to machine, CC601 heat treated to T6.

[Flettner]

Put a gearbox in it shortly.
Flywheel will run on the right side via a wee gear drive. Drive will step up the flywheel speed say 1.5 to one. Little bit better charging than just bolted to the crankshaft. Pull start will operate off this flywheel.

[WilDun]

Put a gearbox in it shortly.
Flywheel will run on the right side via a wee gear drive. Drive will step up the flywheel speed say 1.5 to one. Little bit better charging than just bolted to the crankshaft. Pull start will opperate off this flywheel.

Looking good so far - relatively new territory I guess! - even if you had shelved something similar ( but successful), way back!

[lohring]

I'm not sure if this is the place to post this, but it's not a clean engine and the cylinder will eventually be investment cast. So far it's a thought project opposed piston design with two crankshafts. It will be piston ported, crankcase scavenged, through standard Walbro carbs. It uses as many standard parts as possible with output planned for each crankshaft driving two propellers. The gear train should be lightly loaded. I need to get at least 20 hp at around 16 to 18,000 rpm to compete with inline twins. More rpm should be easily possible since we've turned 26 cc engines to 25,000 rpm.

The main issue is how to get mixture from both crankcases into the cylinder. Below is my first thought. However, I think the different length transfers will upset the scavenging. Having all the transfers at one end with a passage connecting the crankcases is another option. Can you get mixture between the crankcases with this arrangement? How effective will be exhaust piston cooling and lubrication if mostly air goes into the exhaust end crankcase?

Lohring Miller

347054 347055 347056 347057

[Flettner]

Lohring, I have a design kind of along those lines for an autogyro engine, accept twin cylinder.
The gear train will have the two middle idler gears both become output gears. They are angled away from each other at 24, 12 from center, degrees and phased at 90 degrees each other.
Deep intermeshing, counter rotating. Look at the Anton Flettner intermeshing helicopter.

[Vannik]

Lohring, some thoughts:

1. One problem with OP engines is scavenging - swirl causes an unscavenged central column that can even move down towards the scavenging piston,
2. Using opposed transfer ports to clash the flows and causing an upward moving central column leaves and unscavenged outer region,
3. So how about using the one crankcase to feed transfers that causes swirl and the second crankcase to feed transfers that open slightly later to form the central column?

This swirl vs central column is also a problem for standard uniflow engines and is one of the regions where the ship engine builders are putting a lot of research into.

Why not use a toothed belt to connect the two cranks and have one end with a vernier pulley to adjust phase angle?

[Flettner]

This is the scavenge system used in my boat OP uniflow.
Two transfers opposite each other, upward swirl, 33% fuel.
Four more aiming at each other to create a central plume, 66% fuel, slightly later timing.
The ultimate aim was to head for 0% and 100% fuel respectivly. Creating an air buffer also. This combined with the different size pistons, inlet and exhaust.
9500 rpm. 25 years ago.
https://youtu.be/uiXsPkP9jvw

[WilDun]

Lohring, some thoughts:

1. One problem with OP engines is scavenging - swirl causes an unscavenged central column that can even move down towards the scavenging piston,
2. Using opposed transfer ports to clash the flows and causing an upward moving central column leaves and unscavenged outer region,
3. So how about using the one crankcase to feed transfers that causes swirl and the second crankcase to feed transfers that open slightly later to form the central column?

This swirl vs central column is also a problem for standard uniflow engines and is one of the regions where the ship engine builders are putting a lot of research into.

Why not use a toothed belt to connect the two cranks and have one end with a vernier pulley to adjust phase angle?

First thing I need to ask - is 'swirl' necessary in the first place? and if so, why is it necessary?
Surely this in combination with the curved entry of the transfer ports in a 'conventional' two stroke is the best way known to mankind of separating the components of the petrol/oil/air mix?? ........ isn't that the last thing we need?

I should stress that I am talking about the conventional two stroke here using the (also now conventional ) Schnuerle charging.

Someone here said that this actually was 'tumble' charging but I see it as 'axial swirl' (as opposed to the radial variety, which it is normally assumed to be!) - this must cause the now separated high speed charge to mix with the outgoing gases going into the chamber?

The OP arrangement ( which I have to admit can in certain cases be quite an awkward beast) does however give us a much better opportunity to keep the charges separate and use 'tumble charge' to create an integrated plug of fresh charge which moves down the cylinder, does not disintegrate and mix, but helps to push the charge out through a ring of radial exhaust ports.
This will also ensure that the cylinders/pistons stay a reasonably round shape, due to even heating (giving us the chance to use tighter clearances).

Along with several other 'outlandish' innovations, I believe that I have actually worked out a system on how that could possibly be done.
However, I am really past the stage now where I have the ability to carry out these experiments, so I have passed it on to someone else for evaluation - but no comment! ..... so realistically, I assume and accept it's not a viable solution! - it will no doubt remain just a figment of my imagination - never mind,..... doesn't matter! :laugh:

[Pursang]

I believe that I have actually worked out a system on how that could possibly be done!
However, I am past the stage now really where I have the ability to carry out these experiments, so I have passed it on to someone else for evaluation - but no comment! ..... realistically, I assume and accept it's not a viable solution! - so it will no doubt remain just a figment of my imagination - never mind,..... doesn't matter! :laugh:


Bill, if you really want Multiple evaluations by interested persons, and Plenty of comments, just post your ideas here!

cheers, Daryl.

[Flettner]

nothing can be ruled in or out until its tested. All ideas are valid until then.
OP uniflow is such an unknown, whats right, whats wrong?
Tumble flow may well have merrit.

[WilDun]

Bill, if you really want Multiple evaluations by interested persons, and Plenty of comments, just post your ideas here!

cheers, Daryl.

Yes, but I am such an introvert that I couldn't possibly do that! and what if some big foreign power got hold of it!! - where would it all end! - doesn't bear thinking about! :shit:




nothing can be ruled in or out until its tested. All ideas are valid until then.
OP uniflow is such an unknown, whats right, whats wrong?
Tumble flow may well have merrit.

That's fair comment -
I want to be realistic about my ideas (These thoughts are exactly that ! ie thoughts! - I do realize I could be entirely wrong) so I will not make all sorts of pre emptive claims ..... like someone else we all got to know on ESE a few years ago! and whose ideas possibly could have been enhanced by other peoples' input if only he had been prepared to listen, instead of arguing.
Things could have ended up with a much better outcome for his idea!

[Flettner]

No need to make claims, none of us know enough to do that, yet.
Thats the thing to think about, if you do review your idea here, its public from then on, like TPI for example.

[WilDun]

No need to make claims, none of us know enough to do that, yet.

For sure! but it's fun trying! :niceone:

[lohring]

Thanks for your thoughts, everyone. I'm still thinking about some transfer options. The problem with belt drives is I want opposite rotating crankshafts. The gears are inexpensive, but hardened, RC car gears and should mostly be lightly loaded. I found a CFD study of scavenging with different crankshaft phase angles, but nothing about scavenging port angles. Trying to fit the long transfers around the exhaust along with cooling flow has been challenging, especially in Fusion 360. I'm learning more about lofts than I wanted to know. I think old time pattern making would be easier.

Lohring Miller

[Flettner]

I think old time pattern making would be easier.

Lohring Miller[/QUOTE]

YES.

[WilDun]

Yes, old style pattern making is still king! - and probably a lot less frustrating! - but I do like Fusion 360 now and again and 3D printing can be fun as well! - good for manipulating and fine tuning a design.

BTW have you heard that Fusion 360 is now offering the full deal for around $350/year (permanently.) ie if you buy it now and $450/year after September - that is instead of $1,500 !! for the full program! ........ all subject to you renewing it every year! - That will be USD of course!
The free version for hobbyists and students remains the same! - that's easily good enough for me of course! - great program really!

[Vannik]

Thanks for your thoughts, everyone. I'm still thinking about some transfer options. I found a CFD study of scavenging with different crankshaft phase angles, but nothing about scavenging port angles. Trying to fit the long transfers around the exhaust along with cooling flow has been challenging, especially in Fusion 360.

Lohring Miller

How about two scavenging plenums around the cylinder, one above the other, each connected to a crankcase by one or two ducts, use the one chamber for swirl flow and the other for column flow?

[lohring]

Let me play around with fitting the transfer passages. It's tough to get them around the exhaust and intake ducts. I tried a run in EngMod, but the outputs don't make sense. When I get further along I'll send you a pack file with the passage drawings.

Lohring Miller

[lohring]

I found two papers on opposed piston scavenging. They used CFD to investigate the flows. The first paper looks at crank radius to rod and crankshaft phase ratios. The second looks at two intake flows with flat topped pistons and tumble flow with pistons dished on one side. Their engine scavenged best with uniform, swirling intake flow. However, a symmetrically dished piston wasn't tested. Does the tumble from symmetrical dishing scavenge the center of the cylinder? Does it do better with swirl added? Below are chamber pictures. The double squish chamber should create the tumble I'm talking about. I couldn't attach the papers.

Lohring Miller

347112

[Frits Overmars]

I found two papers on opposed piston scavenging. They used CFD to investigate the flows. The first paper looks at crank radius to rod and crankshaft phase ratios. The second looks at two intake flows with flat topped pistons and tumble flow with pistons dished on one side. Their engine scavenged best with uniform, swirling intake flow. However, a symmetrically dished piston wasn't tested. Does the tumble from symmetrical dishing scavenge the center of the cylinder? Does it do better with swirl added? Below are chamber pictures. The double squish chamber should create the tumble I'm talking about. I couldn't attach the papers.
347112Lohring, where those engines scavenged with air or with mixture?

[lohring]

I believe they used air for the CFD simulations. Below are the links:

https://journals.sagepub.com/doi/full/10.1177/1687814015581569
https://www.mdpi.com/1996-1073/8/6/5866/htm

Building an opposed piston engine should be easy, right? Just take two stock engines and put a cylinder in the middle. So far I've spent days trying to fit all the passages around each other limited by ring pin location and stock piston skirt configuration. We'll see how it ends up.

Lohring Miller

[Niels Abildgaard]

I believe they used air for the CFD simulations. Below are the links:

https://journals.sagepub.com/doi/full/10.1177/1687814015581569
https://www.mdpi.com/1996-1073/8/6/5866/htm

Building an opposed piston engine should be easy, right? Just take two stock engines and put a cylinder in the middle. So far I've spent days trying to fit all the passages around each other limited by ring pin location and stock piston skirt configuration. We'll see how it ends up.

Lohring Miller
Thank you for the links.
Another bunch of academians having fun with CFD and going nowhere.
Opposed piston engines have one problem and that is getting power from the two pistons to the user(s) and keeping the pistons in step.
The lasting solution was first seen by me in 1994 and that was to put an AC generator on each shaft and let them rotate in opposite directions to cancel out torque reactions.
Modern electric maschines can transform up to 15kW/kg with less in pipe.
Bye,bye gears in boxes
What the world now needs is a way to put sparkplugs in center of pistons.

https://web.archive.org/web/20080501215400/http://www.iet.aau.dk/sec2/junkers.htm
.

[Flettner]

I'll say again Neils, there is no problem joining the cranks on OP engines, or at least the ones I've built.
Central spark plug? Why have a spark plug? Not talking diesel either.

[WilDun]

I'll say again Neils, there is no problem joining the cranks on OP engines, or at least the ones I've built.
Central spark plug? Why have a spark plug? Not talking diesel either.

Yes, now that we know that other types of fuel can be used without spark plugs:-
CC shape is now irrelevant.
Cylinder heads - no cylinder heads or associated attachments, (gaskets and fasteners etc.) - expensive to manufacture with high assembly and disassembly costs).
Spark plugs, - not normally required ..... (however they could still possibly be useful as a starting aid or a combustion timing device).

Trying to fit spark plugs between almost touching pistons? - difficult and unnecessary!


Thank you for the links.
Another bunch of academians having fun with CFD and going nowhere.
Opposed piston engines have one problem and that is getting power from the two pistons to the user(s) and keeping the pistons in step.
The lasting solution was first seen by me in 1994 and that was to put an AC generator on each shaft and let them rotate in opposite directions to cancel out torque reactions.
Modern electric maschines can transform up to 15kW/kg with less in pipe.
Bye,bye gears in boxes
What the world now needs is a way to put sparkplugs in center of pistons.

https://web.archive.org/web/20080501215400/http://www.iet.aau.dk/sec2/junkers.htm
.
Niels,
I don't want you to think I am ignoring your efforts in this area (speaking for myself) but I'm sure it's the same thing for the rest of the people here.
All that research is totally relevant and I would be keen to know more about the connection method for the cranks - perhaps I missed something and should have read it properly.
So I will do that, but I'm not totally sold on the idea of an engine without gears as yet!

[lohring]

So far this is what I've come up with for a racing opposed piston twin. It's piston ported with Walbro carbs, just like most of the other engines we run. I tried really hard to use all off the shelf parts. This means some crazy ports and passages to accommodate the stock piston ring pins and cut away skirts. I applied flat tops on the domed pistons, a standard mod. In this case it should give some squish. I could dish the pistons as well.

The long transfers have a straight in flow with a 5 degree up angle. The short transfers have a 15 degree horizontal swirl angle with a 20 degree up angle. I tried to keep all the passages close to symmetrical while maintaining clearance. The tit in the intake port supports the ring gap as do all the dividers above it. The intake width is limited by the skirt width.

Below are the pictures:

347145347146347147347148347149347150

I appreciate everyone's thoughts.

Lohring Miller

[lohring]

This picture gives an idea of the problems involved with fitting everything in:

347151

Lohring Miller

[Pursang]

The lasting solution was first seen by me in 1994 and that was to put an AC generator on each shaft and let them rotate in opposite directions to cancel out torque reactions.
Modern electric machines can transform up to 15kW/kg with less in pipe.
Bye,bye gears in boxes.

Niels, do you have more info on that development?

Connecting the cranks of an O/P engine with synchronised motor/alternators could create a Very compact, high efficiency, generator unit.

Electronic management of the piston phasing might also be used to extend the operating power band, say, for vehicle use.

The next stage is then to eliminate the mechanical, rotary cranks and replace them with linear coils.

This ones a boxer not an O/P, but you'll get the drift.
Perhaps it would be called an opposed free piston engine.

https://i.pinimg.com/originals/48/ab/56/48ab56017187c305e7d6efc5109c2077.gif

Cheers, Daryl

[Niels Abildgaard]

The next stage is then to eliminate the mechanical, rotary cranks and replace them with linear coils.

This ones a boxer not an O/P, but you'll get the drift.
Perhaps it would be called an opposed free piston engine.

https://i.pinimg.com/originals/48/ab/56/48ab56017187c305e7d6efc5109c2077.gif

Cheers, Daryl

It is not my cup of tea.
Unbalanced and low efficiency.

[Frits Overmars]

So far this is what I've come up with for a racing opposed piston twin. It's piston ported with Walbro carbs, just like most of the other engines we run. I tried really hard to use all off the shelf parts. This means some crazy ports and passages to accommodate the stock piston ring pins and cut away skirts.Lohring, I'd love to see how that engine would look without the restrictions forced upon you by the stock pistons. Did you design something like that?


Connecting the cranks of an O/P engine with synchronised motor/alternators could create a Very compact, high efficiency, generator unit. Electronic management of the piston phasing might also be used to extend the operating power band, say, for vehicle use. The next stage is then to eliminate the mechanical, rotary cranks and replace them with linear coils.
This ones a boxer not an O/P, but you'll get the drift.Perhaps it would be called an opposed free piston enginelDaryl, what you show us is neither a boxer nor an opposed piston engine. But let's forget the semantics; something like it has already been running (and shaking like hell).
Now the builders are concentrating again on an opposed free piston engine with the combustion chamber in the center where it belongs (right Neil?) and coils around the cylinder.

[ken seeber]

Frits is so correct, it'd be a shaker.

The central combustion chamber, classic opposed piston would be the go. One would think that this could be crankless. With a suitable encoder, or more correctly an axial position transducer, would enable the linear generator to act as an motor to both start the unit and maintain a movement relationship between the two pistons. Some DMG CNC milling machines use this for movements, rather than screw actuators. This would allow for compression ratio control as well as adjustable phasing. Throw in a couple of MOSFETS, an ECU, the battery and you’re away.

Unfortunately beyond me.

[Pursang]

It is not my cup of tea.
Unbalanced and low efficiency.



Opposed piston engines have one problem and that is getting power from the two pistons to the user(s) and keeping the pistons in step.
The lasting solution was first seen by me in 1994 and that was to put an AC generator on each shaft and let them rotate in opposite directions to cancel out torque reactions.

Sorry Niels, I obviously misunderstood.
I assumed that electrical field synchronicity, between the two AC generators, was the opposed piston timing & power transmission method.
I then extended that idea to using linear generators, to eliminate the mechanical complexity of cranks & con-rods.
As Frits has stated, it seems that someone is now working on this configuration!

Is the 1994 solution just using the counter rotating alternators as flywheels?




Daryl, what you show us is neither a boxer nor an opposed piston engine. But let's forget the semantics; something like it has already been running (and shaking like hell).

Now the builders are concentrating again on an opposed free piston engine with the combustion chamber in the center where it belongs (right Neil?) and coils around the cylinder.

Agreed, Not a Boxer (more of a street fighter, using his fist & elbow) and as admitted in the post, Not an O/P. (couldn't find one)

It was the linear piston motion & linear generator I was using the gif to demonstrate.

Do you have any pics or links to the New engine? Sounds similar to what I proposed.

Cheers, Daryl.

[Niels Abildgaard]

Sorry Niels, I obviously misunderstood.

Is the 1994 solution just using the counter rotating alternators as flywheels?

Cheers, Daryl.

They act as flywheels,synchronizer and generator.
There is an order of magnitude less expensive,children dug out,poissoneous magnetic material involved than in the linear magnetic investor trapping solutions.
These linear solutions surface every 15 years.The cheated former investors have to be dement or dead first.A very cyclic market.

[Flettner]

I agree Neils a good system for a larger instalation BUT
joining OP cranks on say my 175cc off road bike, with generators (x2) would be too big and cumbersome.
This engine Im building now uses a tooth belt but later I'll be going back to gears. Four, two smaller crank gears, one large clutch gear and an idler that will more than likely run the water pump and autolube pump. So essentially only one extra small gear over a conventional layout. If you were to add a balance shaft on a conventional layout, my OP engine would have no extra gears at all. Cranks counter rotating balance naturally so clearly no need for a balance shaft.

[lohring]

If I use a piston with a full skirt, I can solve the short transfer vs intake port issue. Neels flooded me with opposed piston engine papers. Several things I noticed so far is that exhaust lead can be produced by offsetting the crankshafts from the piston bore center. This allows synchronized crankshafts, eliminating unequal torques and balance issues. The other is that the OPEC (Eco Motors) engine had two rows of intake ports. The upper row was angled to produce swirl while the lower row is straight in. They run dished pistons. They suggest that two symmetrical intake and exhaust passages give better CFD flows.

All the combustion chamber shapes in the papers are for diesel injection. They use dished piston crowns with squish at the edge. I still think central squish would be better for dual spark ignition. A central squish would probably scavenge best with some ports with both a swirl angle and an up angle. The other ports would be straight in with no swirl. This would scavenge both the central and wall areas. The diesel dished pistons look like they mostly use straight in ports with a swirl angle. I may try these ideas to see what happens. What are your thoughts?

Lohring Miller

[Pursang]

These linear solutions surface every 15 years.The cheated former investors have to be demented or dead first.A very cyclic market.

Better dump your Toyota shares, those scammy pricks are at it too! And claiming 42% thermal efficiency!

http://www.extremetech.com/extreme/185789-toyota-develops-high-efficiency-free-piston-no-crankshaft-combustion-engine-to-power-an-ev

Not an O/P Two Stroke, but at least uniflow. Once again, it's just a demonstration of the linear generator approach.

And, I think I found the group that Frits referred to (DLR):

https://bioage.typepad.com/.a/6a00d8341c4fbe53ef017c36fe7ea7970b-800wi

Cheers, Daryl

[WilDun]

If I use a piston with a full skirt, I can solve the short transfer vs intake port issue. Neels flooded me with opposed piston engine papers. Several things I noticed so far is that exhaust lead can be produced by offsetting the crankshafts from the piston bore center. This allows synchronized crankshafts, eliminating unequal torques and balance issues. The other is that the OPEC (Eco Motors) engine had two rows of intake ports. The upper row was angled to produce swirl while the lower row is straight in. They run dished pistons. They suggest that two symmetrical intake and exhaust passages give better CFD flows.

All the combustion chamber shapes in the papers are for diesel injection. They use dished piston crowns with squish at the edge. I still think central squish would be better for dual spark ignition. A central squish would probably scavenge best with some ports with both a swirl angle and an up angle. The other ports would be straight in with no swirl. This would scavenge both the central and wall areas. The diesel dished pistons look like they mostly use straight in ports with a swirl angle. I may try these ideas to see what happens. What are your thoughts?

Lohring Miller

What is the reason for employing swirl? - ie what does it achieve in our situation? and is squish necessary? - doesn't it cause problems? - I was led to believe that it did! (I perhaps don't read enough - because I'm lazy).

[Niels Abildgaard]

Better dump your Toyota shares, those scammy pricks are at it too! And claiming 42% thermal efficiency!

http://www.extremetech.com/extreme/185789-toyota-develops-high-efficiency-free-piston-no-crankshaft-combustion-engine-to-power-an-ev

Not an O/P Two Stroke, but at least uniflow. Once again, it's just a demonstration of the linear generator approach.

And, I think I found the group that Frits referred to (DLR):

https://bioage.typepad.com/.a/6a00d8341c4fbe53ef017c36fe7ea7970b-800wi

Cheers, Daryl

I have worked on some WW2 Junkers 200 bar compressors 55 years ago made the same way.
They made compresser air for some even older german torpedoes in danish navy and were same idea.
It is not the way You make 200 bar today.

The future way to make electrcity for transport vehicles can be this:

https://i.imgur.com/H0mjML2.jpg

There is some thoughts on air travel that is almost as important as buckets:
https://www.homebuiltairplanes.com/forums/threads/two-cylinder-gear-less-twin-aircraft.33811/

[lohring]

What is the reason for employing swirl? - ie what does it achieve in our situation? and is squish necessary? - doesn't it cause problems? - I was led to believe that it did! (I perhaps don't read enough - because I'm lazy).

Good question. Swirl is necessary for combustion in diesel engines. Except for Fletner's efforts, I'm not aware of spark ignition engines. Swirl scavenges the cylinder walls while colliding flows result in a rising central column. Does swirl past the plugs help ignition? Does a central squish displacing mixture outwards do the same thing? Are either or both needed? I'm probably not going to be able to test all these theories. So far I'm guided by the FOS full circle intake exhaust and transfer designs as well as conventional port layouts. Colliding columns need a small up angle, while swirl ports might need a higher up angle. Below is a picture of the OPEC cylinder with both types of ports.

Lohring Miller

347158

[Flettner]

Found an old photo album, OP uniflow in aviation. Pitty it never flew but it did do a lot of ground running, as I said earlier I didn't have the balls ( or the licence for that matter ) to fly it back then.
A real OP engine doing real work in the real world, not just drawing or speculation. As Lohring is doing, the only real way to find out is build one and see, good on him.

[Flettner]

Lohring, my first uniflow, 100cc twin cylinder, ran domed weedeater pistons with a central squish. With single spark plug needed in the order of 40 degrees advance to run right. With dual plugs back to approx 20 degrees, still not wonderful considering the size of the pistons. Im not sure its a wonderful combustion chamber shape. Although it had only six transfers set up for swirl also not wonderful.

[F5 Dave]

All together now;

Who wears short shorts?
We wear short shorts
They're such short shorts
We like short shorts
Who wears short shorts?
We wear short shorts

[WilDun]

Good question. Swirl is necessary for combustion in diesel engines. Except for Fletner's efforts, Im not aware of spark ignition engines. .....................
Lohring Miller

I guess the swirl in diesel engines aids high pressure direct injection, but (in the case of petrol / HCCI), relatively low pressure injection, carburation or whatever and complete homogenous (if that's a word) mixing earlier on, might also be a solution if used in the right way (that's only how I see it of course!).

[WilDun]

Found an old photo album, OP uniflow in aviation. Pitty it never flew but it did do a lot of ground running, as I said earlier I didn't have the balls ( or the licence for that matter ) to fly it back then.
A real OP engine doing real work in the real world, not just drawing or speculation. As Lohring is doing, the only real way to find out is build one and see, good on him.

Well, that's something which none of us knew before!! and we've got to applaud you for trying it!

So, I guess you have grown the necessary balls and licenced them in order to try again, this time with an improved version? :niceone:

Be careful, - plenty of ground and dyno testing first - we don't want to lose your input here!........ maybe buy yourself a set of airbag type leathers instead of a new pair of shorts! :msn-wink:

BTW, 'speculation' is also my middle name these days and I would dearly love to be able to sort stuff out by trial and error as you do, but some of us just can't - forget about the old "no such thing as can't" rhetoric, sometimes it aint possible because of ' other circumstances'.

[husaberg]

Found an old photo album, OP uniflow in aviation. Pitty it never flew but it did do a lot of ground running, as I said earlier I didn't have the balls ( or the licence for that matter ) to fly it back then.
A real OP engine doing real work in the real world, not just drawing or speculation. As Lohring is doing, the only real way to find out is build one and see, good on him.

Hi Neil, Does the seat also double as the fuel tank?

[Flettner]

You know it, smiley emoji.

[ken seeber]

All together now;

Who wears short shorts?
We wear short shorts
They're such short shorts
We like short shorts
Who wears short shorts?
We wear short shorts

Jeez Dave, you wouldn't even be taking the piss would you ????? :facepalm:

[Condyn]

At this point I have developed an art for hijacking threads. My curiosity always gets the best of me. And I cannot get enough of kiwibiker. I would like to build myself a furnace for melting aluminum like so many of you have before me. I have a good opportunity to grab a formed refractory in a steel enclosure for free. They are used in diesel and natural gas/propane fired boilers here in the states. We use them for mobile ground thawing machines for winter construction projects. Is there any mandatory guidelines for design? Will this work?

I have added a photo of one of the bare refractorys that we stock. The large hole on the front matches up to the steel enclosure box that the refractory sits in. There is a 3 bolt flange where a burner attaches. Also shown is a natural gas burner that I could easily convert to propane. The photos will most likely be any direction except correct. I would make a plate for the top lined with refractory material. I know this is probably 100 steps in reverse for most of you, but I still must ask to avoid wasting time. 347163347164

[Flettner]

freshly cast and machined 440cc uniflow castings although a few years ago now.

[WilDun]

At this point I have developed an art for hijacking threads. My curiosity always gets the best of me. And I cannot get enough of kiwibiker. I would like to build myself a furnace for melting aluminum like so many of you have before me. I have a good opportunity to grab a formed refractory in a steel enclosure for free. They are used in diesel and natural gas/propane fired boilers here in the states. We use them for mobile ground thawing machines for winter construction projects. Is there any mandatory guidelines for design? Will this work? .................................................. .................


Seeing as there is a steel enclosure, I guess it already has insulation between it and the steel? - (ceramic wool makes a good insulator) but if it's ready made for commercial work then it'll probably be fine!

I can't actually tell what size it is, but you'll have to buy a crucible to suit and make some sort of ceramic pedestal for it to sit on, and to get it in the correct relationship with the burner (ie tangentially with the bottom of the crucible) and of course it needs a removable insulated refractory concrete lid. - and there are gaping holes there! and who knows how they are filled, but they'll have to be filled with something!

Anyway, there is a wealth of ideas on the net, you just pick your way through them and figure out for yourself which parts are best - that's what I did and built one from scratch (you've got a head start on me with the ceramic inner and burner ready made!).

Sometimes though, adapting things to suit can be more difficult than scratch building! - it's not the exact science it's made out to be and it can be done a thousand different ways!

You will also need to make foundry tools etc. -(make up or buy all the stuff - whatever) - things like moulding boxes, mouldng sand mixes, tongs and various other tools.

Safety first is the most important thing of course, so take your time and think every move through carefully beforehand and at the pour make sure that every foundry tool is within easy reach! ..... BTW, Water and molten metal do not mix - a no no!!- explosions!!

If you use your head (and You Tube etc.) you'll get there, just persevere - good luck!

[WilDun]

freshly cast and machined 440cc uniflow castings although a few years ago now.

Where is that engine now?

[Flettner]

Where is that engine now?

Out in the wood shed.

The supercharged Honda 100 in its final form.

The OP engine with tuned pipes.

[husaberg]

Out in the wood shed.

The supercharged Honda 100 in its final form.

The OP engine with tuned pipes.

Cool i had never been a photo of the honda, whats on the ignition housing off the cam. An oil pump?
also what happened to it.
Looks injected as well?
347182


https://www.youtube.com/watch?v=bIu5D-6NzLM

[Flettner]

Yes fuel pump on the camshaft, methanol, yes fuel injected.
I think its out in the wood shed as well?

[Flettner]

I know, too many side projects.
Data logging a YZ125 cases, to make a new set, to be able to go out to 175cc. 60 bore, 61 stroke. It will fit, just.

[Flettner]

New cases, nice large dia rotary disc valve.
OP uniflow.

[lohring]

I did a redesign with full skirt pistons. It makes a much better engine. I hope the ports are narrow enough so I don't need to pin the rings, hard for me with 1 mm thick rings. The transfers are straight in with a 5 degree up angle. I can easily adjust them for swirl and various up or down angles depending on the piston design. One thought with central squish is shown, but dished pistons with the squish at the edge could be substituted. They would work with either straight in or down angle transfers. Any thoughts?

Lohring Miller

347285347286347287347288

[lohring]

More Pictures:

347289347290

[WilDun]

More Pictures:............................



Will you be trying 3D Printing and Lost PLA casting?

[lohring]

I'll start with 3D printing the parts and assembling everything to catch the mistakes I expect to find. I then need to decide how to make everything. I could send it out to be 3D printed or print the parts for investment casting. Though I have a kiln and foundry, I have more confidence in others for things like this. I can do the machining. Then comes dyno testing. It will be a long project. I may try a simpler, single cylinder 26 cc engine first.

Lohring Miller

[Niels Abildgaard]

I'll start with 3D printing the parts and assembling everything to catch the mistakes I expect to find. I then need to decide how to make everything. I could send it out to be 3D printed or print the parts for investment casting. Though I have a kiln and foundry, I have more confidence in others for things like this. I can do the machining. Then comes dyno testing. It will be a long project. I may try a simpler, single cylinder 26 cc engine first.

Lohring Miller

Can You enter a Junkers type with two counterrotating propeller shafts in any class based on cubic capacity?

[WilDun]

I'll start with 3D printing the parts and assembling everything to catch the mistakes I expect to find. I then need to decide how to make everything. I could send it out to be 3D printed or print the parts for investment casting. Though I have a kiln and foundry, I have more confidence in others for things like this. I can do the machining. Then comes dyno testing. It will be a long project. I may try a simpler, single cylinder 26 cc engine first.

Lohring Miller

I don't think that 3D printing is the answer to everything of course, but the way you propose to do it would seem to be very good for the purpose of trying everything out before committing to metal! - gets everything well within the ballpark - quickly! ...... and you get to make use of a powerful program like Fusion 360 or Design Spark Mechanical - (both for free!) - that, even 10 years ago would have been just a dream for the average person at home!!
For anything else, I reckon the old style patternmaking is still king though!

[lohring]

Niels, we have a twin class that's limited to 64 cc from either two engines or a twin cylinder engine. People mostly run two engines, but there are a few inline twins.

Amen brother Will. Just to give you an idea of what it takes to 3D model exhaust and transfers in Fusion 360, i wrote this for another engine builder.

Lohring Miller

347307

[ken seeber]

[QUOTE=lohring;1131171998]
Amen brother Will. Just to give you an idea of what it takes to 3D model exhaust and transfers in Fusion 360, i wrote this for another engine builder.

Lohring Miller

Lohring,
Really nice work and detailed paper on your methodology. I just have limited access to Solidworks and can only just do simple stuff, but have recently done a loft. Yippee.
Love the bifurcated inlet. Can see now why you mentioned full skirt pistons. Will you need piston pin bore plugs?

[lohring]

Thanks, I spent several years both learning Fusion and figuring out how to model two strokes. I believe a member here mentioned revolves for transfers. That paper used an older project. Again, someone on this forum suggested that a bifurcated intake would allow a boost port in a piston port engine. I'm interested in the opposed piston concept these days. I need to think of a way to visualize the scavenging flow with 3D printed parts.

Lohring Miller

[WilDun]

Niels, we have a twin class that's limited to 64 cc from either two engines or a twin cylinder engine. People mostly run two engines, but there are a few inline twins.

Amen brother Will. Just to give you an idea of what it takes to 3D model exhaust and transfers in Fusion 360, i wrote this for another engine builder.

Lohring Miller



Lohring,
You're just a "tad" ahead of where I am at the moment! - but thanks, - I'll look at it a little more closely and hope I can get my head around it! - I (like Ken) have been doing relatively simple stuff (successfuly) - I always learn something new each time I do a drawing.
I find that if I have a definite design in mind (other than just exercises), I do learn much more quickly! - but I'm still a long way behind!

Ken,
I see you got a good 'mention' from Alex on You Tube (re: your idea on piston ring design ):niceone: ........ ie when he took his bike to the salt flats. - pity the salt flats had turned into a lake again!
BTW, don't you have similar dry lakes in Aus? (salt flats?).

[TZ350]

Ken, I see you got a good 'mention' from Alex on You Tube (re: your idea on piston ring design ):niceone: ........ ie when he took his bike to the salt flats. - pity the salt flats had turned into a lake again! BTW, don't you have similar dry lakes in Aus? (salt flats?).

Yes, Lake Gairdner. https://www.dlra.org.au/2020.htm

Jim from Team ESE has been taking his bikes there the last few years.

[WilDun]

Yes, Lake Gairdner. https://www.dlra.org.au/2020.htm

Jim from Team ESE has been taking his bikes there the last few years.

Thanks TZ, all very interesting - didn't know all that existed (even though they are right on our doorstep!).

Looks like the dry salt lakes all over have returned temporarily to salt water lakes!

[Flettner]

another house lot of pattern wood, daughters kitchen rebuild. Waste not want not.

[lohring]

I ran my opposed piston design in EngMod with 2 to 8 degree exhaust lead and no other changes. Detonation happens at 6 and 8 degree leads. The power is below. The peaks are very close at 4 to 8 degree leads, but 4 degree lead gives a better low end. The higher leads give better over rev, and the lower leads give better low end. The transfers have huge STA, the exhaust and intake STAs are about right for the power, but the blow down STA is low. Does the exhaust lead help with this?

Lohring Miller

347489

[ken seeber]

Foundry lesson for the day:
Making up some sand moulds for a UHV variant. So, faced the pattern with a virgin sand/sodium silicate mix and gassed it with CO2, all good. Then have to back it up with some bulk sand. What about all the sand from a previous cast. Few hard bits, crush them up and sieved it, no lumps. Gave it the sodium silicate, packed it around the facing sand, hit it with CO2 and nothing. Didn't take, almost no bond at all. Virgin sand after was fine.
Moral of the story: Used CO2 sand is useless.

[Flettner]

yes, set off sand won't stick to new sand. I pack mold segments separately against each other, they will not stick together.
Apparently there is a process to post treat used sand for recycling its use.

[lohring]

We're starting to look at scavenging flow in the opposed piston engine. I can't post the movie here, but it can be found on two stroke tech if you are a member. The most notable things so far are effects of delay from the two different transfer passage lengths and the lack of scavenging of the cylinder walls. The first runs were with straight in transfers with no swirl. Next tries will be with swirl and/or some transfers with higher up angles. Below are the flows just after the transfers open. The first is the pulse from the short transfers. Note where the pulse is in the long transfers. The second is the pulse from the second transfers.

Lohring Miller

347516

347517

[ceci]

We're starting to look at scavenging flow in the opposed piston engine. I can't post the movie here, but it can be found on two stroke tech if you are a member. The most notable things so far are effects of delay from the two different transfer passage lengths and the lack of scavenging of the cylinder walls. The first runs were with straight in transfers with no swirl. Next tries will be with swirl and/or some transfers with higher up angles. Below are the flows just after the transfers open. The first is the pulse from the short transfers. Note where the pulse is in the long transfers. The second is the pulse from the second transfers.

Lohring Miller

347516

347517

Not using EFI led him to think that his project would not be a clean 2-stroke.
The CFD has shown that it can be a clean 2-S, taking advantage of the difference in the transfer pulses to perform a stratified scavenging

[lohring]

I hope. Still the goal is a simple twin with better power than the inline twins it will run against. The packaging is better already with its flat configuration. We'll see.

Lohring Miller

[ceci]

I hope. Still the goal is a simple twin with better power than the inline twins it will run against. The packaging is better already with its flat configuration. We'll see.

Lohring Miller

You know the history of champagne, it was invented by mistake, and look at how successful it is.
I think your engine can be as powerful as it is clean

[Flettner]

Top crankcase on the OP uniflow engine. It will have to be reed after all bugger it, no room in the frame to fit disc valve.

[Flettner]

Ive been out of action for the last week and a half, surgery.

Finally feeling human again, last few days recooperating, in the pattern shed, not much done, but some. Made a core for the reed cavity, now to make a core box from this male shape. Save having to cast it solid and machining it all out, this is much easier.
Background pattern is that Subaru E81 four port head, finally making a start on that as well. Always run two pattern projects at the same time then there is no waiting around for glue or bondi to set, while one sets you are working on the other, back and forth.

[Flettner]

https://youtu.be/hoe5YAlyMwI
This is what Im building, one of these. look similarish?

[Flettner]

reed cavity core box made.

[ken seeber]

https://youtu.be/hoe5YAlyMwI
This is what Im building, one of these. look similarish?

Neil,
Give it a coat of green paint it it'll be "factory"...

[Flettner]

mmm, Kawasaki green.

My happy place, the pattern shed.

Building sand baffles.

My standard four sides, a top and a bottom type CO2 sand mold.

[Flettner]

Co2 sand being packed in. Two of the four sides.

[Flettner]

Reed sand core, x 2 just in case I drop one.
Because my furnace runs on E85 and Gull the barstards have stopped selling it, Ill have take these sand molds to town and get the local guys to pour them.
I see I can get ethanol by the 210 L drum again, I'll have to go that way for the future. I need E85 / E90 for my motorcycles anyway.

[Flettner]

Sand molds are in town, now we wait. Next week apparently.

[husaberg]

Reed sand core, x 2 just in case I drop one.
Because my furnace runs on E85 and Gull the barstards have stopped selling it, Ill have take these sand molds to town and get the local guys to pour them.
I see I can get ethanol by the 210 L drum again, I'll have to go that way for the future. I need E85 / E90 for my motorcycles anyway.

Gull used its stocks of ethanol to use as hand sanitizer.


NO LONGER AVAILABLE
In March 2020, Gull released a total of 340,000 litres of ethanol from its stocks to assist in the production of hand sanitiser to meet the urgent demand for healthcare services, due to the overwhelming shortage brought on by COVID-19. It brought us great joy to see hand sanitiser back on the shelves in the weeks to follow.

In conjunction with the above taking place, our primary ethanol supplier Fonterra notified us in earlier in 2020 that local drought was limiting their production, which therefore affected our ability to blend. We have also most recently been importing ethanol, but this is a drawn-out process and not a viable long-term option. With limited local supply and imports we can only obtain enough ethanol to support one fuel grade and we will continue to blend Gull Force 10 (E10), which remains available at most Gull North Island sites for the foreseeable future. The means the permanent withdrawal of Force Pro from retail sites and sales to our third-party suppliers. There are no plans for Gull to stock Gull Force Pro/E85 again in the future.

We thank all Gull Force Pro enthusiasts for your loyalty and support over the past years of this biofuel. We have loved seeing you run your beasts on the good stuff and have thoroughly enjoyed witnessing communities of motorsport out on the track and gravel, so devoted to their hobbies and passion projects.

The Autostore, suppliers of Gull Force Pro drums in the past, will endeavour to blend their own E85 moving forward, pending ethanol supplies. Please make direct contact with them regarding any drum enquiries. Please note, the Autostore will not be selling Gull Force Pro – they will independently blend their own E85 fuel.

For any tuning enquiries, please contact Carl and Hans at E & H Motors, who specialise in re-tuning and high-quality performance car services.
i have seen it advertised for $3 a liter odd. so well cheaper than Meths i guess.