V-twin engine from scratch - yet another interpretation of how (not) to build a

[Stilldrillin]

Very pleased you`re back Sorveltaja!

Hope you can now find everything...... 

David D

[cidrontmg]

Welcome back, hope the apartment is more to your liking now. Expecting continuation with the adventure, and of course the first puffs of exhaust
Everyone else except Sorveltaja, ignore the following:
Suomalainen minakin olen, vaikka Portugalissa asunkin, jo yli 20 vuotta. Enka taida koskaan takaisin tulla.

[sorveltaja]

Head gaskets almost finished:


Material is 0.1mm(0.00393") copper sheet, that was annealed first. Nothing fancy, I just carved the combustion chamber -shaped holes with knife.

Making gaskets has never been my favorite thing, probably because I don't have the right tools for that (yet). I think, that some simple punching tool would make it much easier. But then again, it would be a side project on its own.

Laser cutter is almost on the top on my shopping list, just in case, that I win the lottery .

[Bernd]

Laser cutter is almost on the top on my shopping list, just in case, that I win the lottery .

As they say here in New York, A dollar and a dream.

I've had several night mares that no amount of money could tak care of.

Bernd

[dsquire]

You are doing a fine job there sorveltaja. Glad to see you back at it after the renovations. I missed my daily dose of catching up on your build.

I've had several night mares that no amount of money could tak care of.

Bernd

  Bernd, What the ?ell are you dreaming about??

Cheers 

Don

[Bernd]

Not going there Don.        

Bernd

[sorveltaja]

Spark plugs at progress:

Plugs have 3mm(0.118") holes through them, and 3.5mm(0.137") drilled for buttons at the business end. Above pic shows one button in place, that still has copper layer on one side. Some might guess already, that the material used for 'buttons' is fiberglass-based circuit board.

It stands heat, at least short periods at a time. I'm not sure, how porous it is under compression, but there is one way to find out .
One might wonder, why fiberglass; I have it already, it feels more solid, than ptfe, at the working end of the spark plug. It also has dielectric(insulativity) properties, that are needed at this stage.

Spark plug body, and center electrode, with one button, that has no more copper in it. White rod is ptfe, that is to be used to fill the rest of the spark plug's hole:


Center electrode is 1.4mm(0.055") steel, that will have an M1.4 thread at the end of it.

I'll make only one spark plug, to see if it works. Purely experimental, and not to be tried at home .

[sorveltaja]

Spark plug parts before assembly:


Finished, after some super glue and grunt:


Ptfe insulator lost some of it's shape, when I pushed it in place. As usually, it behaved like a cooked noodle.

Anyways, it's done now, and brass terminal was added.

To start the testing phase, I'll do some basic spark testings.

[sorveltaja]

I tested the new spark plug on the previously made engine, and it ran for a short time, then refused to start. Reason was the fiberglass button, that absorbed some fuel, causing almost short circuit -state.

Well not exactly short circuit, but the ethanol, that I used as a fuel, is conductive enough, to cause a non-sparking situation in that case.

So I removed the 'button', leaving bare ptfe for insulation. I also filed the center electrode's working end from round to t-shape:


Now the new plug is almost like one, that I had used on the test engine before. Appearance of the plug(s) is rather frivolous, but somehow it stands bit of flooding, though.

Anyways, what comes to that fiberglass button -thing, it should have been sealed with some hard, easily poured, dielectric material.

[madjackghengis]

Hi Sorveltaja, it's good to see your posts up to date again, we missed you.  Nice expose on the spark plug, as to a pourable insulator, I can only think of ceramics as having any long term life and pourable.  You might pack chopped glass fiber into the space and then use a torch to melt it so it takes the heat, and allows the ptfe to work without melting, behind it.  I've looked at half a dozen or so methods of plug making, and they all seem very temporary because of the insulator material.  Remember sparks like to leave sharp pointy places and arrive at sharp pointy places best and you will need the lowest voltage for a spark.  I don't particularly want to use ready made spark plugs for my radial engine, but reliability is more important than being able to say I made them myself, so I will try the make it myself route, but if necessary, use a set of ready made plugs.  Your success in this may make the choice for me.  I'm watching closely for your success. mad jack

[sorveltaja]

Madjack, I've done some research, of what pourable ceramic materials could possibly be used for insulator.

Some of the bonding pairs, that are possible candidates:

Porcelain/metal - Porcelain seems to require a long term heat treatment on its own, using a high temperature oven.

Glass/metal      - Very unstable, and may well require some special techniques to achieve, as I have experienced, during the past Lamina -engine phase.
I destroyed a whole lot of test tubes, while trying that.

Enamel            - I guess, that it's basically glass, and coloured one contain some metals.

One non-ceramic substance could be a high-temperature paint. Not sure about the dielectricity of those.

   

[sorveltaja]

Intake adapters in place:


Both will have two holes drilled and tapped for an M2 screws. What comes to carburetor, I think I'll use the test engine's one, as it works to some extent.

Next thing to do, is to make a manifold. It will most probably contain two brass tubes.

Anyways, I also got the second spark plug finished.

[sorveltaja]

Intake adapters drilled and tapped. Two parts on lower side after silver soldering:


Those two part's tubes need to be morphed somehow together, to form a manifold.

They need some bending first, and if any success, they are fastened in place, and final fitting can take a place.

This an unknown territory for me, as this is my first more-than-one-cylinder -engine, that's in progress.

Anyways, I'm prepared to boldly go where no man has gone before that, and lengthy filing session(s).

[madjackghengis]

Hi Sorveltaja, if I end up making plugs, I will probably try to duplicate comercial ones, with a ceramic center tube, with shoulders, fired around the center electrode, steel ends much as you've made, and a copper o-ring to seal between the ceramic, and the steel, with the seal formed by rolling over the edge of the steel compressing the copper o-ring.  I've taken apart a couple dozen plugs, and that is essentially how they are all made with minor differences.  With regard to your intake manifold, having dealt with many of the shape you need on Harleys, I would suggest filling the tubes with cerrro-safe, or some similar low temp melting metal, bend each tube while bolted in place without the other, so you can get the centerline of each tube basically centered, then melt out the supporting metal, do your last little pushing and the like, and cut the two tubes so they meet each other, cut a bit large, and file down to a good match, tack solder them in place, and finish soldering them off the engine, so the heat expansion doesn't leave you with too short between the cylinders.  That's how I've done it with custom manifolds for Harleys, with about an inch and three quarters port diameter, and tigging up aluminum parts.  I hope this helps, if not, I expect you'll figure out a way that works.    mad jack

[sorveltaja]

Mad jack, thanks for the tips .

Ceramic-based materials are undoubtedly best for the spark plug insulator, but machinable ones seem to be rather expensive.

Then again, more traditional porcelain would require a 'glazing', to give it a glass-like surface, similar to that of coffee cups.


Inlet tubes formed so far:


I'm not sure yet, what the next step is, but I guess that I'll find that out before long .

[sorveltaja]

One thing, that popped to my mind, after writing the previous message, was about using ceramics/glass as an insulator, that nowadays small glass/ceramics quantities can be heat-treated on microwave oven(+800 watts), using a 'micro capsule'(freely translated).

At least here in Finland, those are available in three sizes (diameters 70mm(2.75"), 110mm(4.33"), and 160mm(6.29")). Prices are from 99€ to 240€.

Anyone else heard about similar things/devices?

Microwave ovens do not accept the use of metallic materials, that are an essential part of spark plugs, but how about graphite?

It would be an ideal mold material, and mold for center electrode hole could be made of 0.5mm(0.019") re-fillable pencil -rod.

Lil' bit of mindstorm to lighten the thread.

[madjackghengis]

One thing, that popped to my mind, after writing the previous message, was about using ceramics/glass as an insulator, that nowadays small glass/ceramics quantities can be heat-treated on microwave oven(+800 watts), using a 'micro capsule'(freely translated).

At least here in Finland, those are available in three sizes (diameters 70mm(2.75"), 110mm(4.33"), and 160mm(6.29")). Prices are from 99€ to 240€.

Anyone else heard about similar things/devices?

Microwave ovens do not accept the use of metallic materials, that are an essential part of spark plugs, but how about graphite?

It would be an ideal mold material, and mold for center electrode hole could be made of 0.5mm(0.019") re-fillable pencil -rod.

Lil' bit of mindstorm to lighten the thread.

Hi sorveltaja, now you're thinking along the lines I am!  I haven't heard of what you're talking about, however the issue of metal in a microwave is primarily about the life of the oven.  I've been the recipient of more than one which was done for, as far as food, and a gift, so I've experimented in more than one with metal without Mrs. jack coming after me with implements of destruction.  I was considering using "slip", which is ceramic slurry, used to pour castings, in plaster molds, the process basically filling the mold, letting it set for a bit, then pouring our the liquid, to form a hollow casting.  My Mom makes ceramic dolls this way, which is how I know it.  I was thinking of making a plaster mold say a quarter size of the insulator of a conventional plug, a two part split mold, putting the center electrode in, pouring in the slip, with a riser as one would do with aluminum casting, as the insulator needs to be solid, and once it is "green", meaning essentially dry, but not fired, and then perhaps hanging each by a wire on the electrode to keep it from losing its shape while firing, and doing a soft firing, then glazing it, and doing a final hard firing.  That is the the process with the dolls, the soft firing leaving a porous ceramic, the glaze and hard firing leaving it glassy and totally non-porous.  The steel "shell" it goes in typically has a packing of very fine powder I believe is ceramic, to cushion the contact of the insulator with the shell, near the thread end, and at the outer end, a shoulder on the insulator for the copper o-ring to seat against, and rolling the edge of the shell, which is probably twenty thousandths thick, over the copper o-ring and crimped down against the powder packing.  I haven't tried it yet only because I haven't gotten to that stage yet.  What do you think about that?  mad jack

[sorveltaja]

Madjack, definitely worth trying . To me, even the ceramic-making terms are a new thing, and would greatly appreciate your attempt.
I'm sure there is a whole bunch of people(well, at least me ), that would prefer using ceramics instead of plastics.

I did some searching, and found this: http://www.microwavekiln.com/KILNINSTRUCTIONS.HTM
They look somewhat similar to those, that I mentioned earlier.

Some have even done small metal castings using microwave oven http://home.c2i.net/metaphor/mvpage.html

[sorveltaja]

Two Y-pieces made. One for inlet and other for exhaust.


I'm going to test a vapor carb, before making an adapter for conventional one.

Somehow I feel, that the Y-piece should be as close as possible to the engine, to make sure, that both cylinders inhale the fuel mix, instead of each others inlet tube's content.

Gasoline/oil mixture would be an ideal fuel to test the engine, but if the ignition, or timing aren't right, it makes the engine's combustion chamber very dirty, even after short runs. No matter, how small amount of oil is used in the fuel mix. That's what I have experienced during my previous project.

Gasoline-based fuel seems to work better on vapor carb, than an ethanol, though. At least on colder winter months.

But at the moment, the environmental temperature has rapidly risen to a summery level, so the ethanol just might evaporate bit easier

[madjackghengis]

Hi sorveltaja, what little I know about ceramics comes from watching mom and sisters casting dolls, using plaster molds, and they have made their own molds as well, so I've got some "look see" experience to start with.  I figure the plug companies have tried everything, so starting with how they do it is probably the best place to start and attempt to copy.  I should be able to turn a pattern with the electrode as a core essentially, and make a two part mold from plaster around that, and with it being a small tubular piece without much volume, let it dry to the point of being able to break off the "sprue", and then fire it with the electrode in place and fire it a second time for the glazing.  I'll ask my mom tonight, she knows almost everything.
you're looking good on the engine, you should be about going, now, gas has naptha as a primary ingredient, which is far easier to vaporize than alcohol, but the heavier elements in it produce more goo when it doesn't burn completely, and alcohol leaves little but soot and carbon.  I used to use lighter fluid, such as for a Zippo, when I was young and had a hard to start engine, it's pure naptha, and a few drops in the intake will usually at least pop off.  If you know there's oil on the bearings and on the pistons and rings, a couple drops in the intake won't hurt, but if the engine is dry without oil, it can leave you with scored bearings and cylinders, as will "starting fluid".  Good luck on getting the carburetion set up, it seems to be one of the trickiest parts with these small engines.  Looking good, and I'm ready to hear it run mad jack

[sorveltaja]

Today, I took the cam housing apart, disassembled it, and drilled oiling holes to the top of it. That was just one of those things, that I had forgot to do.

At this stage, the engine has an 'open column' crankcase, so no shared oil splashing lubrication available for cams.

But if(when) I manage to get the engine to run, then I'll make an aluminum or brass cover for crankcase, enabling the use of an oil sump.

Anyways, after I assembled the engine, it felt quite stiff again, so I gave it about half an hour spin on the lathe, with plenty of wd-40.

There is still some work to be done though, to get it to testing condition, such as the base, where to attach it, and valve adjustments.

Mad jack, it's good to hear, that you have guides to follow on that ceramics-thing .

[madjackghengis]

Today, I took the cam housing apart, disassembled it, and drilled oiling holes to the top of it. That was just one of those things, that I had forgot to do.

At this stage, the engine has an 'open column' crankcase, so no shared oil splashing lubrication available for cams.

But if(when) I manage to get the engine to run, then I'll make an aluminum or brass cover for crankcase, enabling the use of an oil sump.

Anyways, after I assembled the engine, it felt quite stiff again, so I gave it about half an hour spin on the lathe, with plenty of wd-40.

There is still some work to be done though, to get it to testing condition, such as the base, where to attach it, and valve adjustments.

Mad jack, it's good to hear, that you have guides to follow on that ceramics-thing .  I tell you, I don't much like the idea of regular sized plugs in a model engine, or model plugs that don't work but for a short time.  If we can make models of the engines, we ought to be able to make working models of the plugs.  If I don't get success on the plugs soon enough, there's a guy named Bob Shores who makes model engines and pieces and parts for them, and he has proper model plugs as well as other ignition accessories, he's got a web site which should be easily found, although I don't know it offhand.  Don't ever say "if" about an engine, they always get to run, even if you have to make every single part all over again, it's always "when I get this engine to run", got to think positive.  Of course sometimes in the middle of things, an engine can turn majically into a flying projectile weapon, and kill a window, or some offensive weeds right outside the shop.  Then it has become an engine of destruction, but still an engine, and it did "go". mad jack

[Dean W]

Sorveltaja and Jack, if you fellows are having trouble making spark plugs, have a look at a gent who knows how it's done.  George Britnell is a member here, and has been nice enough to share his considerable experience with us.  His plugs look good, and as evidenced by his many running engines, they work well, too.

The "How To" post is at the following link:
http://madmodder.net/index.php?topic=2439.0

Happy pluggin'.

Dean

[sorveltaja]

Mad jack, take your time, if you intend to try the ceramics. No deadlines here .

What comes to the engine project, it will unfortunately be interrupted for some time.

At the moment, I have some serious official matters to take care of, so not much progress on the project.

But I'll be back as soon as possible.

[Brass_Machine]

...
At the moment, I have some serious official matters to take care of, so not much progress on the project.
...

Hope all is OK. Looking forward to seeing this go on.

Eric