# 18 Cylinders Isotta Fraschini (straight six-cylinder x3 )



## Foketry (May 31, 2022)

I found an old maintenance manual for this interesting engine built in Italy in 1930. 2 versions were made, one aeronautical, aluminum casing, one for naval use, all  cast iron.
It's a very challenging project but I decided to build the airplane version,  1: 5 scaled engine model, I think it is a 6 cylinder engine multiplied 3 times, I hope to be able to make it work.
Technical features:
Bore =140 mm( 5,5 ")
Stroke=170 mm(6,7")
Displacement = 47.100 cc (2874 cubic inch)
Power Hp = 924
Some photos and drawings taken from the manual:


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## Foketry (May 31, 2022)




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## ddmckee54 (May 31, 2022)

I was wondering if they staggered the cylinder alignment between the three banks.  With that connecting rod I guess they didn't.  It's going to be interesting to see what they did with the firing order.


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## Foketry (May 31, 2022)

ddmckee54 said:


> I was wondering if they staggered the cylinder alignment between the three banks.  With that connecting rod I guess they didn't.  It's going to be interesting to see what they did with the firing order.



yes the 3 cylinders are aligned,  the firing  order is also interesting, the number that appears in the diagram is not the cylinder number, but the ignition order, see for example the position  1-2-3 , 4-5-6 etc.


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## G54AUST (May 31, 2022)

G'day Foketry.

This is going to be a _*very*_ interesting build.

18 cylinders,
18 pistons,
36 spark plugs,
72 piston rings,
72 valves ..........
(plus spares)

This project will def keep the grey matter stirred.

If you don't mind,  I'll be watching every step with keen interest.   Bring it on Maestro .....

Kind Regards,

Trevor,
Melbourne,  AU


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## GreenTwin (Jun 1, 2022)

Each group of three firing cylinders creates a triangle, with alternating groups of three in an inverted triangle.

Balances the power strokes out evenly along the crank, or as evenly as possible I guess.

.


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## kvom (Jun 1, 2022)

Just the wiring for the plugs looks to be a challenge, esp. if the wire doesn't scale.


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## ajoeiam (Jun 1, 2022)

Foketry said:


> I found an old maintenance manual for this interesting engine built in Italy in 1930. 2 versions were made, one aeronautical, aluminum casing, one for naval use, all  cast iron.
> It's a very challenging project but I decided to build the airplane version,  1: 5 scaled engine model, I think it is a 6 cylinder engine multiplied 3 times, I hope to be able to make it work.
> Technical features:
> Bore =140 mm( 5,5 ")
> ...



Very interesting - - - - looking forward to your pics and descriptions as you work through the build!!!


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## Foketry (Jun 1, 2022)

G54AUST said:


> G'day Foketry.
> 
> This is going to be a _*very*_ interesting build.
> 
> ...



Hi G54AUST
It is a very demanding projectI  but I will try to simplify this engine, I don't need as many HP as the original Isotta engine  





This old engine is also used for tractor pulling......


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## ddmckee54 (Jun 1, 2022)

Are you planning on casting a lot of the parts, or carving them from billet?  (Or is it too early to tell yet?)


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## Foketry (Jun 1, 2022)

ddmckee54 said:


> Are you planning on casting a lot of the parts, or carving them from billet?  (Or is it too early to tell yet?)



I plan to make the most important parts by casting aluminum with the casting mold made by 3D printer, some parts lost PLA


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## Steamchick (Jun 2, 2022)

Good luck Foketry! I am sure you'll succeed, as (Like the merry few before you who take on huge challenges) I am sure you simply don't feel it is too big a project! (Most of us stick to single cylinders!). The u-tube clip sounded great!
K2


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## SPOTTER (Jun 3, 2022)

It is a very demanding project, good work.
I follow you.


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## Foketry (Jun 4, 2022)

I am working on the project, after having done some calculations on the stroke of the pistons to size the length of the connecting rods, the cylinders and the crankshaft, I have produced some drawings:
The original connecting rods are built with steel, with very thin thicknesses, my connecting rods are 7075 aluminum, I could not make the central connecting rods with the 2 + 2  thin lateral fins, I inverted, I drew the 2 lateral connecting rods with 2 fins rather than integral in the central connecting rod. I think i get more resistance. 2 hardened pins support the 2 lateral connecting rods.


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## Steamchick (Jun 4, 2022)

I think it should work. You are not planning to fly on the aircraft when finished, are you?
K2


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## johnmcc69 (Jun 5, 2022)

This is going to be a good one! What a beast!

 I like your con rod set up, that should work well. 

 John


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## Foketry (Jun 5, 2022)

Steamchick said:


> I think it should work. You are not planning to fly on the aircraft when finished, are you?
> K2


For now I am not planning to fly, but in the near future ....


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## Vixen (Jun 5, 2022)

I had similar deep undercuts to do on my Bristol Mercury master rods. They were also in steel, so I was able to use a small diamond stone mounted on a high speed spindle. The grinder was rotated, by hand, about the axis of the slave rod pin. You can see the extent of the undercut in the drawing.

So, it would be possible for you to make the Isotta Franschini conrods true to scale.


Mike


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## G54AUST (Jun 6, 2022)

Nothing wrong with flying;   just the sudden stop at the bottom when the engine cuts out .....

R...

T...


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## Foketry (Jun 6, 2022)

Vixen said:


> I had similar deep undercuts to do on my Bristol Mercury master rods. They were also in steel, so I was able to use a small stone mounted on a high speed spindle. The grinder was rotated, by hand, about the axis of the slave rod pin. You can see the extent of the undercut in the drawing.
> 
> So, it would be possible for you to make the Isotta Franschini conrods true to scale.
> 
> ...


Very ingenious your solution, I had tried a similar thing, I should have used a 4 mm  ball endmill and then an flat endmill to remove the edges, with poor quality of the lateral conrod housings, I preferred an easier solution.
Even the second solution with T slot endmill  you see below,  doesn't work , only an EDM machine could machining  these parts on a smaller scale.

Really nice and well worked your master conrod.


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## Foketry (Jun 6, 2022)

The crankshaft is identical to the crankshaft of a straight 6-cylinder


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## Foketry (Jun 12, 2022)

The project is taking shape, the main components are designed


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## ajoeiam (Jun 12, 2022)

Foketry said:


> The project is taking shape, the main components are designed
> 
> snip



Hmmmmmmmm - - - what program are you doing your modelling in please?


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## Foketry (Jun 12, 2022)

ajoeiam said:


> Hmmmmmmmm - - - what program are you doing your modelling in please?



Fusion, but I think all 3D programs can do these simple designs..


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## ajoeiam (Jun 13, 2022)

Foketry said:


> Fusion, but I think all 3D programs can do these simple designs..


Thanks - - - - I'll pass on that option - - - - for a number of reasons. 
I 'gave up' (passed) on Microsoft's continuing and ongoing 'security opportunities'.
Autodesk has a history of pulling out the rug from under its low cost (and especially free) offerings. 

AIUI windows is now even setup so that Win11 really doesn't work on even an air gapped machine which is the only way that I would run such. 

Hmmmmmmmmm - - - if you call what you have presented 'simple designs' - - - - dunno what you might call complicated - - - grin. 
You will have at least 40 if not 75 different pieces you'll need to model - - - hmmmmmm likely fall into my definition of 'not simple'. 

Continuing to follow your intriguing thread.


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## metalmangler (Jun 13, 2022)

ajoeiam said:


> Thanks - - - - I'll pass on that option - - - - for a number of reasons.
> I 'gave up' (passed) on Microsoft's continuing and ongoing 'security opportunities'.
> Autodesk has a history of pulling out the rug from under its low cost (and especially free) offerings.


Have a look at a Linux operating system (I use Mint), and Blender for the modelling. Both free.


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## kvom (Jun 13, 2022)

Yellow is a great color for that swiss cheese header.


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## Foketry (Jun 13, 2022)

ajoeiam said:


> Thanks - - - - I'll pass on that option - - - - for a number of reasons.
> I 'gave up' (passed) on Microsoft's continuing and ongoing 'security opportunities'.
> Autodesk has a history of pulling out the rug from under its low cost (and especially free) offerings.
> 
> ...



so far I have 149 drawings and I have not finished.....
many are duplicated with minor modifications to optimize the design


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## ajoeiam (Jun 13, 2022)

metalmangler said:


> Have a look at a Linux operating system (I use Mint), and Blender for the modelling. Both free.


Thank you!
Have been running Debian testing for about the last 14 or 15 years. (Started w Linux somewhat over 20 years ago but as a user so now I get to the point where I need to 'dive under the hood').
In process of setting up a new machine (waiting for a replacement doa psu) that will be on Devuan 'testing' (daedalus (sp?)).

Blender warns of deprecation of gpus but the description and the linked lists don't really make any sense.

Perhaps spinning this off into its own topic might be best but I would like to know more.

TIA


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## Foketry (Jun 14, 2022)

Cylinder and piston: in the original engine the spark plug is directly on the cylinder, the piston is concave and the petrol is ignited correctly. In my engine ,to have a correct compression ratio , I had to make a dome on the piston to leave the spark plug uncovered.
i think it is not a good solution but i have no alternative. I do not know if the ignition of the petrol will take place uniformly and immediately.
Your every suggestion will be appreciated


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## Vietti (Jun 14, 2022)

Maybe the top/side of the piston doesn't have to be some exact geometric shape like a cone.  Maybe a wedge shape like some V8s used or just a pocket for the plug etc.

Look forward to your build!!

John


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## Peter Twissell (Jun 15, 2022)

Remember the spark will occur at some advance, before the piston is at the top of its travel.
If the cylinder head is flat, the piston shape will create a reverse squish band.
I can't guess what effect that might have on the flame front, but if it slows it down a lot, you will just need to use more advance on the ignition.
I am guessing you are not looking for maximum performance from this engine?


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## Foketry (Jun 15, 2022)

Peter Twissell said:


> Remember the spark will occur at some advance, before the piston is at the top of its travel.
> If the cylinder head is flat, the piston shape will create a reverse squish band.
> I can't guess what effect that might have on the flame front, but if it allows it down a lot, you will just need to use more advance on the ignition.
> I am guessing you are not looking for maximum performance from this engine?



It would be a great success if all 18 cylinders worked, no performance is required, I don't have to fly, I just want to hear 18 pop in succession


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## Steamchick (Jun 16, 2022)

Foketry said:


> Cylinder and piston: in the original engine the spark plug is directly on the cylinder, the piston is concave and the petrol is ignited correctly. In my engine ,to have a correct compression ratio , I had to make a dome on the piston to leave the spark plug uncovered.
> i think it is not a good solution but i have no alternative. I do not know if the ignition of the petrol will take place uniformly and immediately.
> Your every suggestion will be appreciated
> 
> View attachment 137158


As I worked with piston and combustion chamber designers on a couple of engines: "modern thinking" - as of the late 1980s~90s. was to simply flatten the piston and head as much as possible. On CAD: Draw a sphere at BOTTOM dead centre and it should touch the cylinder walls, head and piston with very little overlap. That minimises heat loss to the metal when a spherical flame develops as the piston travels down the bore. (This was developed in laboratories with single cylinder "see through" engines, lazers, etc.). 
On Model (seriously small engines, sub-50cc per cylinder) the heat losses to adjacent metal are much worse than your small car engine, and low compression makes things worse.
I would therefore, remembering that the piston does not rotate, simply mill a small pocket for the spark-plug, and a curved bottom groove from there to the middle of the piston, with maybe a SLIGHT dishing of the piston crown). The flame generated by the spark ignition will then progress up the channel to the centre of the piston to meet the remainder of the charge and burn that as the piston travels down the bore.
I have done a quick sketch... - Hope it makes sense?




Ask more questions if you wish...
K2.


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## Foketry (Jun 16, 2022)

Steamchick said:


> As I worked with piston and combustion chamber designers on a couple of engines: "modern thinking" - as of the late 1980s~90s. was to simply flatten the piston and head as much as possible. On CAD: Draw a sphere at BOTTOM dead centre and it should touch the cylinder walls, head and piston with very little overlap. That minimises heat loss to the metal when a spherical flame develops as the piston travels down the bore. (This was developed in laboratories with single cylinder "see through" engines, lazers, etc.).
> On Model (seriously small engines, sub-50cc per cylinder) the heat losses to adjacent metal are much worse than your small car engine, and low compression makes things worse.
> I would therefore, remembering that the piston does not rotate, simply mill a small pocket for the spark-plug, and a curved bottom groove from there to the middle of the piston, with maybe a SLIGHT dishing of the piston crown). The flame generated by the spark ignition will then progress up the channel to the centre of the piston to meet the remainder of the charge and burn that as the piston travels down the bore.
> I have done a quick sketch... - Hope it makes sense?
> ...


I really appreciated your suggestion, even a friend of mine who builds engine models suggested a similar thing to me. “The flame triggered by the spark plug must reach the center of the piston.“
In the next few days I will draw the piston by copying your drawing. It will be a bit complicated to mill 18+2 pistons on the head but I think it is the best solution.  Thank you


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## Steamchick (Jun 17, 2022)

Hi Foketry, I guess a simple jig will hold the piston while machining - repeatable multiple times. - For 26 cylinders, I would make it all on jigs, etc. (But I am not clever enough to design the jigs!).
K2


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## ddmckee54 (Jun 17, 2022)

26 pistons?  You making 8 extras, or did I miss something?


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## Foketry (Jun 17, 2022)

ddmckee54 said:


> 26 pistons?  You making 8 extras, or did I miss something?


sorry for my mistake 18 pistons + 2 extras = 20 not 26


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## leerkracht (Jun 19, 2022)

Hallo Foketry 
The engine must work with your piston design as on -30-    flame travel is short , first runs  on glow fuel wiht glow plugs 
the v 10 engine is the project i am working on (bore and stroke 26mm )my own design and make
gr


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## Steamchick (Jun 19, 2022)

Leerkracht: That looks superb! 
K2


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## Foketry (Jun 19, 2022)

Steamchick said:


> As I worked with piston and combustion chamber designers on a couple of engines: "modern thinking" - as of the late 1980s~90s. was to simply flatten the piston and head as much as possible. On CAD: Draw a sphere at BOTTOM dead centre and it should touch the cylinder walls, head and piston with very little overlap. That minimises heat loss to the metal when a spherical flame develops as the piston travels down the bore. (This was developed in laboratories with single cylinder "see through" engines, lazers, etc.).
> On Model (seriously small engines, sub-50cc per cylinder) the heat losses to adjacent metal are much worse than your small car engine, and low compression makes things worse.
> I would therefore, remembering that the piston does not rotate, simply mill a small pocket for the spark-plug, and a curved bottom groove from there to the middle of the piston, with maybe a SLIGHT dishing of the piston crown). The flame generated by the spark ignition will then progress up the channel to the centre of the piston to meet the remainder of the charge and burn that as the piston travels down the bore.
> I have done a quick sketch... - Hope it makes sense?
> ...


to facilitate the ignition of petrol, through the spark plug, in addition to the first version, I designed 2 other versions, similar to each other, the last one has an inclined plane.
What could be the best solution?
I remind everyone that the spark plug is located on the cylinder, next to the piston, not above as per image post #30


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## Foketry (Jun 19, 2022)

leerkracht said:


> Hallo Foketry
> The engine must work with your piston design as on -30-    flame travel is short , first runs  on glow fuel wiht glow plugs
> the v 10 engine is the project i am working on (bore and stroke 26mm )my own design and make
> gr


Hallo Leerkracht
Beautiful engine, is the glow plug on the head or in the cylinder?


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## leerkracht (Jun 20, 2022)

Hallo Foketry 
the plug is in the hemi shape head 
keep your piston so simpel as possible , the modelengines from the beginning has a baffle (on two stroke engines ) this  work wel , your pistons with a dome  and a plug on the side wil work  , for testing make a simple 1 cilinder 
gr


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## Steamchick (Jun 20, 2022)

Hi Foketry: post#41 - My vote is no 3: the inclined groove, but even as small as 1/8" parallel sided will shoot the flame to the middle of the piston. - Possibly smaller? - and parallel is OK. Or a vee-groove, or round bottomed? Or even a 1/8" hole drilled from the spark plug centre to centre of piston will work. Basically, fill as much of the cylinder as possible up to the crown face, but have the combustion chamber in the middle and across the surface of the crown Of course, the notch on the side of the crown to clear the spark plug must be all the way up the side, so an "open channel" to the crown centre is quite reasonable to ignite the "flat pancake" of gas as it approaches TDC. With any "side positioned" ignition source the flame front will "wrap around" the "pancake" of gas at TDC and pre-ignition will occur opposite the spark plug when flame fronts turn and collide. Ignition advance must be set as early as possible without this pre-ignition (detonation for flame front shock waves colliding) occurring before TDC has passed.
K2


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## leerkracht (Jun 20, 2022)

there is a saying (there is a difference in theory and practice , but in practice the difference is even greater than in theory)
gr


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## Steamchick (Jun 20, 2022)

Leerkracht: I like that one!
Theory is like a map: It is a "human" representation of what we should expect, and where we should go. In fact, "Theory" means it has been proven by some so we tend to believe it is relatively useful (within the scope of the proof). But like all "virtual" information, (Imagination, memory, Maps, Drawings, TV, Internet, etc.) it isn't really there, it is just an impression so we can decide where to go and what to do. And then it becomes real, and is more than likely going to be close to what we expected. But "Life" does have a laugh when reality isn't what we expect! - e.g. Columbus not finding India? Buzz Aldrin finding that the Moon is not made from Cheese? People thinking that the atom was the smallest indivisible particle, or the Earth is the centre of creation?
I do like theory, because if it says something will fail I would rather not waste time trying to prove the theory wrong. (I am not a "Galileo"). Especially if it risks hurting me or my loved ones.
But I do enjoy it when someone succeeds by using theory (Higgs with his Boson?), and also when they succeed despite the theory saying "it will fail" - though I can't think of any examples just now... 
K2


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## Foketry (Jun 21, 2022)

Another piston with V-milling, easier to make.
I will do a test on a single cylinder with at least 2 types of pistons to see if there are any appreciable differences.
Another solution could be to place the spark plug on the head with a recess similar to Holt 75 but it would be different from the original Isotta Fraschini project.


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## Steamchick (Jun 21, 2022)

Better for combustion would be using a ball-ended mill, for a round bottomed groove. - (The V-groove has a small corner at the bottom for cooler gas to not ignite, and a possible stress raiser that could develop a crack in the piston. So I should prefer to avoid that shape.). Or milled with a square-ended milling cutter, from the side, with piston angled, so the groove gets shallower towards the middle of the piston, to virtually run-out at the middle of the piston.
I can do a sketch, if you think this is useful?
K2


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## Foketry (Jun 22, 2022)

Steamchick said:


> Better for combustion would be using a ball-ended mill, for a round bottomed groove. - (The V-groove has a small corner at the bottom for cooler gas to not ignite, and a possible stress raiser that could develop a crack in the piston. So I should prefer to avoid that shape.). Or milled with a square-ended milling cutter, from the side, with piston angled, so the groove gets shallower towards the middle of the piston, to virtually run-out at the middle of the piston.
> I can do a sketch, if you think this is useful?
> K2


I modified the piston using a 6 mm diameter ball end mill, similar to the diameter of the spark plug
Now the compression ratio is 7.4 , I think the piston project is now final but if you have any other suggestions they are welcome


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## Steamchick (Jun 22, 2022)

Seems good!
Needs a real part running to prove it.
Well done Sir!
K2


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## ddmckee54 (Jun 23, 2022)

Foketry:

Are the cylinders going to be keyed somehow so that the spark plug will line up with the groove in the piston?

Don


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## Foketry (Jun 23, 2022)

ddmckee54 said:


> Foketry:
> 
> Are the cylinders going to be keyed somehow so that the spark plug will line up with the groove in the piston?
> 
> Don


sure, they will be aligned with the spark plug


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## Steamchick (Jun 24, 2022)

Hi again, Thinking of "what can possibly go wrong".... I wonder if the combustion when cold will need a choke, to richen the mixture, but the engine will take a relatively long time to fully warm up and temperature to stabilise, during which time you'log need to fiddle the choke to keep it running, before the hot engine runs on the stoichiometric mixture? Purely an operational, not mechanical issue. A feature of the thick piston crown. Perhaps some of the thickness (mass) can be relieved from the underside of the piston? A horse shoe shaped grove?
But only my guess.
K2


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## Foketry (Jun 24, 2022)

Steamchick said:


> Hi again, Thinking of "what can possibly go wrong".... I wonder if the combustion when cold will need a choke, to richen the mixture, but the engine will take a relatively long time to fully warm up and temperature to stabilise, during which time you'log need to fiddle the choke to keep it running, before the hot engine runs on the stoichiometric mixture? Purely an operational, not mechanical issue. A feature of the thick piston crown. Perhaps some of the thickness (mass) can be relieved from the underside of the piston? A horse shoe shaped grove?
> But only my guess.
> K2



My brief experience tells me that it will not be a problem, to enrich the air-petrol mixture. it is sufficient to plug the venturi of the carburetor with a finger, the engine will become hot in a few minutes
There are 18 cylinders that heat, the exhaust temperature will reach 120-140 C degrees  in less than 2 minutes


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## Steamchick (Jun 24, 2022)

OK Foketry, I think (hope) you are right.
Thanks for reply,
K2


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## Foketry (Jun 30, 2022)

I made some changes to the block design, some reliefs and ribs


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## Foketry (Jul 4, 2022)

From drawing to the finished piece : *crankshaft




*

the steel bar with the 2 references at the ends to drill the centers in phase for tail stock











to drag the crankshaft with the spindle I screwed a threaded pin





roughing






finishing before grinding with tool post grinder







glued wood shims to avoid bending and vibrations during turning


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## Foketry (Jul 4, 2022)

I left 0.3 mm in all turned diameters for final grinding









For my grinding tool post I used a washing machine motor with an electronic speed control board and a Poly V belt, now after this test I have to build the safety protections, *very important to avoid accidents.*





The final check to verify the alignment, max error 0.03 mm, means 0.015 error on the rotation axis, more than satisfactory.


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## Foketry (Jul 4, 2022)

The crankshaft almost completely finished, I am waiting to build the engine block and then make the last finishes and adjustments






the final pin with the cone will be fixed in its seat at the end, once the engine block has been made
On this cone which originally was to fix the propeller I will put a flywheel, large when necessary


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## Vixen (Jul 4, 2022)

Beautiful crankshaft and toolpost grinder. Well done.

What was the spindle speed of your home made toolpost grinder?
What was the diameter, width and grit size of the stone?

Mike


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## Foketry (Jul 4, 2022)

Vixen said:


> Beautiful crankshaft and toolpost grinder. Well done.
> 
> What was the spindle speed of your home made toolpost grinder?
> What was the diameter, width and grit size of the stone?
> ...


with pulley ratio in reduction 1: 2 the grinding wheel turns up to 6600 rpm , the engine over 13,000 rpm but i can adjust the revs with the potentiometer
I have several stones, from diameter 90 (pink color) mm to 110 mm , grit 120-220


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## stevehuckss396 (Jul 4, 2022)

Very nice work. I know what a nerve racking experience that can be.


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## Tim1974 (Jul 5, 2022)

hmm yer amazing work well dun


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## SPOTTER (Jul 5, 2022)

Nice and very refined work, while you are doing the grinding you don't use coolant?


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## Foketry (Jul 6, 2022)

SPOTTER said:


> Nice and very refined work, while you are doing the grinding you don't use coolant?



I use cooling water sprayed manually with a sprayer, my little lathe has no pump


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## kvom (Jul 6, 2022)

One down, two more to go.


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## Vixen (Jul 6, 2022)

kvom said:


> One down, two more to go.


Surely ONE crankshaft but SIX camshafts
Mike


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## kvom (Jul 7, 2022)

brain fart


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## Foketry (Jul 8, 2022)

The connecting rods are made up of a central and 2 lateral connecting rods
The lateral connecting rods are fixed by means of a hardened pin derived from a commercial pin, shortened by grinding
I used a cup wheel mounted on a high-speed electrospindle, the same one I use to mill aluminum.









the connecting rods have been sandblasted









the hardened pin is press fit and held in place by a grub screw


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## Foketry (Jul 8, 2022)

some phases of construction

first phase of the lateral connecting rods










second phase






drilling and threading of the 4 screws of the main connecting rod






the small keyboard that controls the milling machine





second phase of the main connecting rod fixed on a reference fixture






the empty skeleton of the lateral connecting rods


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## awake (Jul 8, 2022)

Impressive work!


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## Eccentric (Jul 8, 2022)

Wow,

I am amazed with how quickly and efficiently you work.  It seems one week you are contemplating tackling a new engine and tossing CAD ideas around, then the next week you are cranking out parts.  And so many at the same time.  A mere mortal would be making each part one at a time, but not you.  Well done.


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## minh-thanh (Jul 9, 2022)

Foketry !​ 
I have a question 
Do you use washer in this position ?
 Thanks !


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## Foketry (Jul 9, 2022)

minh-thanh said:


> Foketry !​
> I have a question
> Do you use washer in this position ?
> Thanks !
> View attachment 138039


I do not use bronze shims for 3 reasons: the thickness of the connecting rod decreases and is already quite critical, the rotation movement is small, in this position there is always oil.....


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## Foketry (Jul 9, 2022)

Eccentric said:


> Wow,
> 
> I am amazed with how quickly and efficiently you work.  It seems one week you are contemplating tackling a new engine and tossing CAD ideas around, then the next week you are cranking out parts.  And so many at the same time.  A mere mortal would be making each part one at a time, but not you.  Well done.


I hope I don't have to redo parts, I did some checks on the project, the most important, but there could be some error that forces me to redo parts, they are all prototypes, only the final test will tell me if I have designed everything well.
Only when I cast the aluminum engine block and put the parts together will I discover the mistakes...


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## leerkracht (Jul 10, 2022)

crankshaft V 10 -72° project DOHC
the crankshafts for my multi-cylinder engines (two   12 cilindersOHC  )are of 42CrMo4 steel ( 4140 ) the material has been at home  for over 10 years and most internal stresses have disappeared
The photos are the guideline for the construction, pre-turn , than  milling as much as possible this is to avoid stress  in the workpiece, use sharp hss milling cutters 
 then cylindrical grinding with oversize, this goes remarkably faster than turning and the next step is grinding to size, the clamping is always done with a fixture so that there is no pressure on the workpiece (this is the case when you clamp between centers).dril the center hole and oilholes for the bearings and the connecting rods , eventually  polisch and finaly  Nitrated
TIR no more than 0.02 mm no loads applyd


----------



## leerkracht (Jul 10, 2022)

next foto's


----------



## ajoeiam (Jul 11, 2022)

leerkracht said:


> next foto's


very nice work sir!!!

Some questions - - - -
1. how are you getting the nitriding done?
2. your bearing shells - -  well - - - do you have a thread on here?
    would love to understand your steps?
3. you drilled a lube hole through the center of the crankshaft
    how are you getting the oil into the journals on the crank ends?
    how are you getting the oil to do the circuitous course through the various webs/members/etc?

(hopefully not viewed as questions for frustration - - - just trying to understand the practical outworkings)


----------



## leerkracht (Jul 11, 2022)

1 -gasNitriding  is done by a professionel firm 
2 - bronze ( RG7 )bearing shells have a light press fitting and a silver steel  pin of diameter 4mm prevents rotating (the hole is for the oil )
3- center hole 6mm in the cranckschaft   for the oil > closed on the webs  , feeding from an  oil gallery in the lower crankcase 
oil from the center hole trou the connecting rod journals by a 1.6mm hole , connecting rods are from 7075  riding direct on the Nitrided cranckshaft  (this works just fine on my  2  12 cilinder engines ) 

pressurised filtered oil via oil gallery in the lower crankcase tho the bronze cranckshaft bearings  then to the connecting rods lower end , just like the real ones


----------



## Foketry (Jul 11, 2022)

The phases of construction of the bushings for main rod (Bronze type: CuSn12)






I cut a bar into 2 equal parts and soldered them with tin










the internal and external turning phase, taking care not to separate the 2 welded pieces






To separate the 2 bushing halves it is necessary to heat with a gas flame


----------



## ajoeiam (Jul 12, 2022)

leerkracht said:


> 1 -gasNitriding  is done by a professionel firm
> 2 - bronze ( RG7 )bearing shells have a light press fitting and a silver steel  pin of diameter 4mm prevents rotating (the hole is for the oil )
> 3- center hole 6mm in the cranckschaft   for the oil > closed on the webs  , feeding from an  oil gallery in the lower crankcase
> oil from the center hole trou the connecting rod journals by a 1.6mm hole , connecting rods are from 7075  riding direct on the Nitrided cranckshaft  (this works just fine on my  2  12 cilinder engines )
> ...



Thank you for the information!!!

Are the gas nitriding services very far away from you?


----------



## Foketry (Jul 18, 2022)

cylinder machining :
material: G25 cast iron from centrifuged bar, piston diameter 24mm
the piston in the image has been modified to facilitate the ignition of petrol, see previous posts













first phase on the lathe










internal drilling and boring









21 cylinders, 3 more in case of rejects


cylinder lapping




zero setting ring 24mm for bore gauge


----------



## Foketry (Jul 18, 2022)

drilling and threading 6 holes M3, long and tedious work









22 finished cylinders, centering, drilling, threading with 3 taps, total 660 phases




threaded and countersunk hole for spark plug


----------



## Foketry (Jul 23, 2022)

Like many aircraft engines of those times, this 18-cylinder also has the cylinder liners covered with a thin water jacket which contains a small volume to reduce weight.





Initially I thought of using brass, starting from a thick tube, but I didn't find very thick brass but only solid bars with a prohibitive cost (+ 70% in 2 years). Brass is easily machinable and weldable, but I found only very thick aluminum tube.


----------



## Foketry (Jul 23, 2022)




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## Foketry (Jul 30, 2022)

Cylinder fixing flange to the block
Through this perforated flanges , a retaining ring and 6 M3 screws I fix the cylinders to the block, I could not make the flange integral with the cylinder because otherwise it is not possible to insert the water jacket.


----------



## Foketry (Aug 2, 2022)

Retaining ring for cylinders : are commercial rings, generally used for bearings but my supplier had many sizes available, but not the one I need.
I would have had to buy a whole box, 1000 pieces from another supplier , I therefore decided to build, using a standard Seeger and grinding it on the external diameter via my tool post grinding.


----------



## Foketry (Aug 8, 2022)

*Cams and rocker arms*
This engine has overhead camshaft, it is a DOHC engine.
For simplicity of construction, I have designed a single camshaft for each head with the exhaust and intake cams on the same axis, contiguous to each other, each cam has a rocker arm.






my design


----------



## Foketry (Aug 8, 2022)

I also joined the two exhaust and intake cams in one single piece, the 2 cams are rotated 110 degrees to each other (red is exhaust, blue is  intake) , each cam operates one rocker arm, one left and one right, each rocker arm has a valve clearance adjustment screw









for the milling I used a disc cutter, diameter 26 mm













after a simple turning I got the finished cams







the red dot is the exhaust cam


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## Foketry (Aug 16, 2022)

The camshaft and rocker arms must have a support flange which also supports the bronze bushings.
These support flanges (blue color) are fixed in position with two M3 screws, I created a small enlargement at the base to have a better support* , *
the biggest difficulty is that all the seats for the bushings must be perfectly aligned with each other otherwise the camshaft will not rotate freely











Initially I had thought of building them by casting aluminum or bronze but later I found two recovery aluminum plates in my small warehouse, so I milled a few days to scrape off the aluminum plates.


First step





Second step , a small fixing and reference jig, through 2 pins






third step





Last step, counterbore and sandblasting


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## Foketry (Aug 25, 2022)

I turned the valve with 4 successive steps in order not to deform and bend the stem.
The valves have a 3 mm diameter stem and a 9.6 mm diameter poppet , the diameter of the raw bar is 10 mm
40 valves on my little CNC lathe , I bought this lathe from a school, price 200 euros.
 Is very old but used very few hours. I redid the whole electrical panel, replaced the motors and encoders, the mechanical part is almost new and now it works well.






Second and third turning step





Your browser is not able to display this video.






last step





Your browser is not able to display this video.






The groove for seeger was later turned manually , the CNC lathe only made a small groove to indicate the correct position


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## Steamchick (Aug 26, 2022)

Next you should try and find an old Delapena valve grinder. Then you can put a double angle face on the valve -44.5 degrees and 45 degrees - like the professionals. (I last used on in 1972! Good hunting!)








						Projects - 40's b&d valve grinder restored
					

Hi all - I bought a valve grinder 5 months ago for 80 bucks, it was in pretty poor shape cosmetically, but otherwise very sound..  Here is what it...




					jalopyjournal.com
				











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Find many great new & used options and get the best deals for hall valve refacer machine surface grinder at the best online prices at eBay! Free delivery for many products.



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						Lot 810- Valve Grinder NO RESERVE - Lucky Collector Car Auctions
					






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K2


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## Foketry (Aug 26, 2022)

Steamchick said:


> Next you should try and find an old Delapena valve grinder. Then you can put a double angle face on the valve -44.5 degrees and 45 degrees - like the professionals. (I last used on in 1972! Good hunting!)
> 
> 
> 
> ...


Hi Steamchick , thank you for your suggestion
I turn the valves 44 degrees and the bronze seat 45 degrees, then lapped with silicon carbide and WD40
In case of problems of leaks, I go to the house of a friend of mine who owns a Dekel like this one and I grind the 44 degrees surface.
It is very important that the contact circle between valve and seat is as small as possible, max 0.2-0.3 mm to obtain a good seal.
If this area widens I have to repair the valve with Deckel to remove the contact area and re-lapping


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## Steamchick (Aug 26, 2022)

Good stuff. Glad you know all about this.
It makes a huge difference to success...
Your work looks great from the pictures. 

Cheers. 
K2


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## ddmckee54 (Aug 26, 2022)

Foketry:

Did I miss the memo, or will you be cutting the o-ring groove in the cylinders for the upper water jacket seal at a later time?

Don


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## petertha (Aug 26, 2022)

Very nice work. Maybe I missed it but what material are the valves machined from? I was impressed with the movies showing a tiny amount of shavings coming off each pass. And I didn't see any lapping so the finish was good enough off the lathe to run in the valve guides?


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## Mechanicboy (Aug 26, 2022)

Foketry said:


> It is very important that the contact circle between valve and seat is as small as possible, max 0.2-0.3 mm to obtain a good seal.
> If this area widens I have to repair the valve with Deckel to remove the contact area and re-lapping



Not such a small width of valve/valve seat contact because cooling is needed via the cylinder head so that the valves do not get too hot. The exhaust valves have a wider contact area than the intake valves since the exhaust valves are more exposed to heat and must conduct the heat away from the valves to the cylinder head.

After running in, there is full contact between the valves and the valve seats so that it is no longer 44 degrees versus 45 degrees. Only at the start is there a difference between the two angles before the valves are ground and driven in until the valves are completely sealed.


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## Foketry (Aug 28, 2022)

ddmckee54 said:


> Foketry:
> 
> Did I miss the memo, or will you be cutting the o-ring groove in the cylinders for the upper water jacket seal at a later time?
> 
> Don


Yes, I will do the grooves for OR later, first I have to weld the water inlet and outlet pipes to the water jackets. They are brazing on aluminum, I have never done brazing on aluminum and I don't know if there will be deformations or defects. In this case I will have to put OR with a larger section or find another solution, silicone, Loctite etc.


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## Foketry (Aug 28, 2022)

petertha said:


> Very nice work. Maybe I missed it but what material are the valves machined from? I was impressed with the movies showing a tiny amount of shavings coming off each pass. And I didn't see any lapping so the finish was good enough off the lathe to run in the valve guides?


the material of the valves is 36SMnPb14, an easily machinable steel but which contains Carbon and Manganese which make it resistant and also hardenable in water or oil.
Each roughing stepover is 0.3mm and 0.15mm finishing passes with repeat at zero stock .
I didn't take a photo, but before taking the valve off the lathe I polished the 44 degree cone with 600 sandpaper.


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## Foketry (Aug 28, 2022)

Mechanicboy said:


> Not such a small width of valve/valve seat contact because cooling is needed via the cylinder head so that the valves do not get too hot. The exhaust valves have a wider contact area than the intake valves since the exhaust valves are more exposed to heat and must conduct the heat away from the valves to the cylinder head.
> 
> After running in, there is full contact between the valves and the valve seats so that it is no longer 44 degrees versus 45 degrees. Only at the start is there a difference between the two angles before the valves are ground and driven in until the valves are completely sealed.


yes correct, I don't know after how many hours the engine has be running  the contact area will extend but it will happen


----------



## Foketry (Sep 6, 2022)

*Piston rings*
To build  these rings I did not follow the *Trimble* method because in previous experiences I had a lot of waste , after heating.
I wanted to try the method without heating of which I have seen videos on Youtube and I have read some explanations.
I used Nodular cast iron or Ductile cast iron (EN-GJS-400-15) ,the difference between traditional gray iron and ductile iron is the shape of the graphite. While cast iron has small flakes of graphite, ductile iron contains spherical graphite nodules.
The graphite spheres give it more resistance and elasticity than traditional gray iron which in my opinion is more suitable for making rings.

First step
Starting from a cast iron rod , I turned the OD leaving a 1 mm of stock allowance , the same for the ID


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## Foketry (Sep 6, 2022)

*Second step*
I turned the piston rings leaving a small stock of 0.03mm on the thickness of the rings, necessary to polish the 2 sides with sandpaper and WD40.
I left the rings joined by a thin thickness on the internal diameter, so as not to leave burrs.






Your browser is not able to display this video.


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## Foketry (Sep 6, 2022)

*Third step*
internal turning to separate the rings




*Fourth step*
Rings cut
I slipped the rings on an alignment pin and they were compressed in the vise












*Fifth step*
Finishing turning of the outer diameter
by means of a tool fixed on the spindle, perfectly concentric with the rotation axis, a bushing with a conical hole and a fixing washer that holds the ring closed, with no space in the cut, I turned the outside diameter exactly equal to the honed diameter of the cylinder










*sixth step*
inside diameter finishing turning
I slipped all the rings into a tube that has the same diameter as the cylinder, through many small steps I turned the diameter of the rings up to the desired size.


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## Foketry (Sep 6, 2022)

*Polishing of both sides of the rings and final inspection, more than 50 piston rings*
with the known method of light I checked all the rings, it looks amazing, but zero rejects
The real final test will be the compression test once the pistons and heads are installed.
In the photo only some rings have been polished, it is a very boring job, smooth one side, measure, smooth, measure etc.
 I will do it in the next few days, maybe ...


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## stevehuckss396 (Sep 6, 2022)

Nice way to do it.


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## ajoeiam (Sep 7, 2022)

Foketry said:


> *Polishing of both sides of the rings and final inspection, more than 50 piston rings*
> with the known method of light I checked all the rings, it looks amazing, but zero rejects
> The real final test will be the compression test once the pistons and heads are installed.
> In the photo only some rings have been polished, it is a very boring job, smooth one side, measure, smooth, measure etc.
> I will do it in the next few days, maybe ...



(Wacky beeg grin! ) - - - boring maybe - - - but just imagine if you had even more cylinders? (Chuckling) 

A very nice job by the lookee see and an interesting method of getting things done - - - thanks for sharing!! 

Wondering - - - - could you have turned an internal mandrel and then used a sleeve to compress all the rings onto it followed by the OD finish machining as a way to save time? 

Given the quality of your machining - - - had you considered using a tool nose radius with speeds/feeds so that you would not have to polish the individual rings or is this final polishing quite needed?

TIA


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## ddmckee54 (Sep 7, 2022)

Foketry:

In your Step 5 description you say that the ring is turned to the exact same OD as the honed ID of the cylinder - with no space in the cut.  Does this mean you won't have any ring gap?  If so, what's going to happen as the ring heats up?

Don


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## Foketry (Sep 8, 2022)

ajoeiam said:


> (Wacky beeg grin! ) - - - boring maybe - - - but just imagine if you had even more cylinders? (Chuckling)
> 
> A very nice job by the lookee see and an interesting method of getting things done - - - thanks for sharing!!
> 
> ...


yes , I could have compressed the rings to make them more locked, in reality I have slightly glued them on the outer diameter with cyanoacrylate, after having compressed them with a spacer and tailstock. After the internal turning some heat released the rings.

I believe that the rings must have the support surfaces (at least one of the 2) with a mirror surface. The compression seal takes place on this surface. Therefore a surface roughness and a flatness that only a polishing with 1000/1200 grit sandpaper can obtain.


----------



## Foketry (Sep 8, 2022)

ddmckee54 said:


> Foketry:
> 
> In your Step 5 description you say that the ring is turned to the exact same OD as the honed ID of the cylinder - with no space in the cut.  Does this mean you won't have any ring gap?  If so, what's going to happen as the ring heats up?
> 
> Don


I will get a really small gap with a diamond file, in my humble experience after a few minutes that the motor is running this gap widens. Our cylinders and piston rings are not hardened


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## ddmckee54 (Sep 8, 2022)

Foketry said:


> Our cylinders and piston rings are not hardened


 
No they are not.  But then again, we aren't trying to build engines that will run for thousands of hours either.

Don


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## ajoeiam (Sep 9, 2022)

Foketry said:


> yes , I could have compressed the rings to make them more locked, in reality I have slightly glued them on the outer diameter with cyanoacrylate, after having compressed them with a spacer and tailstock. After the internal turning some heat released the rings.
> 
> I believe that the rings must have the support surfaces (at least one of the 2) with a mirror surface. The compression seal takes place on this surface. Therefore a surface roughness and a flatness that only a polishing with 1000/1200 grit sandpaper can obtain.



That sounds like there is a use for a surface grinder - - - hmmmmmmmmmmm (re: polishing the rings and sizing accurately).


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## Foketry (Sep 10, 2022)

*My surface grinder for piston rings*

I built myself this little surface lapping machine , the rotating disc is a brake disc driven by an electric motor with worm gear , naturally the surface of the disc was made perfectly planar.
I can lap 9 rings at the same time, I put 320 grit silicon carbide powder at the first step then 1000 grit, seasoned with WD40 oil, I measure the thickness of the rings every 2-3 minutes with micrometer. Few minutes on each side is enough to finish the rings













Your browser is not able to display this video.


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## ajoeiam (Sep 10, 2022)

Foketry said:


> *My surface grinder for piston rings*
> 
> I built myself this little surface lapping machine , the rotating disc is a brake disc driven by an electric motor with worm gear , naturally the surface of the disc was made perfectly planar.
> I can lap 9 rings at the same time, I put 320 grit silicon carbide powder at the first step then 1000 grit, seasoned with WD40 oil, I measure the thickness of the rings every 2-3 minutes with micrometer. Few minutes on each side is enough to finish the rings
> ...


Would love to watch the movie but its format is not readable here - - - bummer! 

Looks like you got to make tools to make tools to make the whatsits - - - - good on you!!!!!!!!


----------



## CFLBob (Sep 10, 2022)

ajoeiam said:


> Would love to watch the movie but its format is not readable here - - - bummer!



Works fine for me - for whatever that's worth.


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## Foketry (Sep 12, 2022)

*43 finished piston rings, ready to assemble




*


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## burkLane (Sep 13, 2022)

wow!


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## ddmckee54 (Sep 13, 2022)

Many years ago when I worked at Sundstrand in Ames, I had to rewire the controls on one of the lapping tables in the "Seal Room".  It was a just a *LITTLE* bit bigger than yours but it did the same type of work.

Did you use a new brake disc when you built yours, or just re-surface an old one?

Don


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## Foketry (Sep 13, 2022)

ddmckee54 said:


> Many years ago when I worked at Sundstrand in Ames, I had to rewire the controls on one of the lapping tables in the "Seal Room".  It was a just a *LITTLE* bit bigger than yours but it did the same type of work.
> 
> Did you use a new brake disc when you built yours, or just re-surface an old one?
> 
> Don


Using a new disc would be a waste, I used a worn disc from my car. I got it from the repair shop that does my car maintenance. A friend of mine made it perfectly flat by grinding the surface, at no cost .
Also the electric motor with worm gearbox is used, paid a few euros.


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## CFLBob (Sep 13, 2022)

It's a cool machine, with the three different sub turn tables to lap the rings.  Clever design.

For what it's worth, I've ground mirrors for telescopes and it's a similar machine but we tend to do one at a time.  Depending on what you're doing, lenses or large mirrors the tools change shape.


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## Foketry (Oct 2, 2022)

My garden foundry is open, the first brass casting
To support the shaft that drives the propeller I designed a cone for the ball bearings.
I made the mould with the 3D printer , I made the internal core with sand, sodium silicate and Co2














The core





still hot molten brass


----------



## ajoeiam (Oct 2, 2022)

Foketry said:


> My garden foundry is open, the first brass casting
> To support the shaft that drives the propeller I designed a cone for the ball bearings.
> I made the mould with the 3D printer , I made the internal core with sand, sodium silicate and Co2
> 
> ...




Neato!!!

Next we get to see this cone in its final (read machined) state - - - yes?

Like very much!!!!!!!!


----------



## GreenTwin (Oct 2, 2022)

Nice casting !
.


----------



## Foketry (Oct 3, 2022)

The finished brass cone


----------



## ajoeiam (Oct 3, 2022)

Foketry said:


> The finished brass cone
> 
> 
> View attachment 140346



Hmmmm - - - if you decide to polish and then lacquer this thing - - - - that will look incredible!!!!!!!!!! 

Just beautiful!!!!


----------



## ddmckee54 (Oct 3, 2022)

Foketry:

A couple of questions about your latest casting:
1)  Did you use the same 3D print to make both the core print and the sand mold?
2) What layer thickness did you print this at?

Don


----------



## Foketry (Oct 4, 2022)

ddmckee54 said:


> Foketry:
> 
> A couple of questions about your latest casting:
> 1)  Did you use the same 3D print to make both the core print and the sand mold?
> ...


Yes ,  I used the inside of the 3D printed mold to make the sand core and the outside to make the footprint in the petrobond sand, this was possible because the angle of the internal cone is large , it was not even necessary to paint the mold

The layer thickness was 0.16 mm


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## Foketry (Oct 4, 2022)

ajoeiam said:


> Hmmmm - - - if you decide to polish and then lacquer this thing - - - - that will look incredible!!!!!!!!!!
> 
> Just beautiful!!!!


I am undecided whether to polish or sandblast the cone, I will decide in the final assembly stages to give a good look to the whole engine


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## ddmckee54 (Oct 4, 2022)

Foketry:

In Post #120, in your picture labeled "the core", the sodium silicate core and the 3D printed pattern appear to be the same height.  If they were the same height, how did you keep the core centered in the mold?

Don


----------



## Foketry (Oct 5, 2022)

ddmckee54 said:


> Foketry:
> 
> In Post #120, in your picture labeled "the core", the sodium silicate core and the 3D printed pattern appear to be the same height.  If they were the same height, how did you keep the core centered in the mold?
> 
> Don


It is not seen in the photo but under the core, during the hardening with CO2 I put 3 self-tapping screws.
Through these 3 screws protruding for half of their length ,I fixed the core to the petrobond inside the alluminium cope


----------



## ddmckee54 (Oct 5, 2022)

Foketry said:


> It is not seen in the photo but under the core, during the hardening with CO2 I put 3 self-tapping screws.
> Through these 3 screws protruding for half of their length ,I fixed the core to the petrobond inside the alluminium cope


Neat idea, I'll have to remember that one.

Don


----------



## Foketry (Oct 10, 2022)

*Lost PLA, aluminum engine block*

I 3D printed the 2 parts of the engine block, the upper part that houses the 16 cylinders and the crankshaft and the lower part that holds the crankshaft and oil.


----------



## Foketry (Oct 10, 2022)

I increased the models by 1.3% because of the shrinkage of the aluminum , using PLA
The additional orange parts are the channels for letting out the molten PLA and for pouring the aluminum into the plaster,  once all the PLA has evaporated or burned. Of course the models are almost empty inside, there is only the outer skin


----------



## Foketry (Oct 10, 2022)

Same thing for the lower part of the engine block


----------



## Foketry (Oct 10, 2022)

I coated the 2 PLA models with several layers of ceramic 
I use the ceramic powder, water and with a brush I deposit the ceramic on the model to form a layer of 5-10 mm. This requires at least 4-6 layers, allowing the ceramic to dry and harden for each layer before depositing the next layer.






I then cover everything with a thick layer of plaster mixed with sand, leaving the sprues uncovered


----------



## michelko (Oct 10, 2022)

very informative and outstanding work.. as usual.

Greetings Michael


----------



## Basil (Oct 10, 2022)

Watching and learning. Thank you!


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## ddmckee54 (Oct 10, 2022)

What is the ceramic powder that you use to for the initial ceramic shell?

Waiting to see what the next step will be.  You've either got a VERY steady hand while pouring or you are going to add some sort of pouring basin to make it easier too hit those sprues.


----------



## CFLBob (Oct 10, 2022)

If I may add to what @ddmckee54 is asking, you said you did several coats waiting for each to dry.  Could you estimate the time to dry?  That is more like one hour to two or more like 12 hours or more?


----------



## Foketry (Oct 10, 2022)

ddmckee54 said:


> What is the ceramic powder that you use to for the initial ceramic shell?
> 
> Waiting to see what the next step will be.  You've either got a VERY steady hand while pouring or you are going to add some sort of pouring basin to make it easier too hit those sprues.





			https://amzn.eu/d/3PfYZr6
		



			https://amzn.eu/d/fXZhwKX
		


I have tried both of these powders. The second seems to me to be more resistant to high temperatures, 500 C, with fewer cracks, but for a correct comparison it would be necessary to try both on the same piece with the same temperatures,and v with the same thicknesses .The second is also difficult to detach from the aluminum casting, the first "sticks less" to the piece.
It is not very difficult to center the pouring hole, being plaster I can place the crucible on the edge of the plaster  block and then pour, o course I put the plaster block in a container full of sand, if the liquid aluminum comes out, it remains contained in the sand and my feet do not cook like a roast chicken  

I have tried many times not to use ceramic but only plaster, special plaster for foundry but never got good results, only and always crack , maybe my 500 degree C heating process is incorrect.


----------



## Foketry (Oct 10, 2022)

CFLBob said:


> If I may add to what @ddmckee54 is asking, you said you did several coats waiting for each to dry.  Could you estimate the time to dry?  That is more like one hour to two or more like 12 hours or more?


the ceramic powder solidifies in 20-30 minutes generating heat , after which you can make another layer, it does not need to be perfectly dry, rather it is better that it remains wet, the layers stick better to each other.


----------



## ddmckee54 (Oct 11, 2022)

Foketry:

When you burn-out these parts, could you detail your burn-out procedure?  What do you use for a burn-out oven, temperatures used, ramp-times, burn-out time, do you let the mold cool before you pour, that kind of information?

From the results that you get, with the relatively simple process that you use, it almost seems like you may have found the Holy-Grail of Lost PLA that many people have been looking for.

I've probably already asked this, and you probably already answered it - but when you print your patterns, how many perimeters do you print and how much infill do you use?

Don


----------



## ddmckee54 (Oct 11, 2022)

Foketry:

Another quick question.  You provided 2 links to products, which product did you use when you coated the engine block parts?  The Raysin 200, or the Kera-flott?

Don

P.S. - Pouring with the mold in a container of sand is a good idea, as long as the sand is dry.


----------



## Foketry (Oct 12, 2022)

ddmckee54 said:


> Foketry:
> 
> Another quick question.  You provided 2 links to products, which product did you use when you coated the engine block parts?  The Raysin 200, or the Kera-flott?
> 
> ...


 I prefer Kera flott


----------



## Foketry (Oct 12, 2022)

ddmckee54 said:


> Foketry:
> 
> When you burn-out these parts, could you detail your burn-out procedure?  What do you use for a burn-out oven, temperatures used, ramp-times, burn-out time, do you let the mold cool before you pour, that kind of information?
> 
> ...


I use a ceramic kiln that can reach up to 1,100 degrees C, the plaster-ceramic block must remain 1-2 days at room temperature to dry
when I create the plaster blocks I use aluminum containers for food, of various sizes, also cut and glued together

The plaster- ceramic is heated in 3 stages:
100 degrees C , 1 hour (plus time to reach 100 degrees) to dry the plaster
200 degrees C , 2 hour ( you see the PLA melting)
500 degrees C , 3-4 hour to burn and vaporize the PLA (some black smoke is emitted and if you open the oven door the PLA ignites and burns)

to automate the process I built an electronic Kiln controller, like this one








						Electric Kiln Controller
					

Upgrade old manual kiln to a digital controller with firing schedules (ramp, target, hold) and data logging. By arduinokiln.




					create.arduino.cc


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## Foketry (Oct 12, 2022)

*Lost PLA, my kiln and the burn / vaporization phases*

reading Dragondark's post # 10 post referring to M-5 engine, to automate the process I built an electronic Kiln controller, based on Arduino









						Electric Kiln Controller
					

Upgrade old manual kiln to a digital controller with firing schedules (ramp, target, hold) and data logging. By arduinokiln.




					create.arduino.cc
				




the first tests on the workbench of my shop









everything worked fine on the first try and I installed the controller on the kiln


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## Foketry (Oct 12, 2022)

the kiln at 250 degrees C and  and the PLA is melting


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## ddmckee54 (Oct 12, 2022)

Foketry:

Thanks for the information, keep it coming.

Don


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## timothysielbeck (Oct 13, 2022)

Foketry said:


> I use a ceramic kiln that can reach up to 1,100 degrees C, the plaster-ceramic block must remain 1-2 days at room temperature to dry



My sister was a potery instructor.  She would put the unfired, and sometimes very wet, pieces in the kiln at 200 deg F for a few ours to dry them out before the temp was ramped up to firing temperature.  This technique could save you some time.


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## Foketry (Oct 13, 2022)

timothysielbeck said:


> My sister was a potery instructor.  She would put the unfired, and sometimes very wet, pieces in the kiln at 200 deg F for a few ours to dry them out before the temp was ramped up to firing temperature.  This technique could save you some time.


Next time I try with the plaster blocks still wet , i think it can work, thanks for the advice


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## Foketry (Oct 15, 2022)

*Aluminum castings of the engine block (lost PLA)*

the engine block is made up of 2 parts, the upper one where the cylinders are housed and the lower one that supports the crankshaft
While the plaster was still hot, about 400 degrees C, I poured the molten aluminum, to be safe I put the plaster in a container of sand, in case the aluminum came out, my feet would remain safe.
Notice many cracks in the plaster, where aluminum could come out



























I made some milling operations on the plane of the 6 central cylinders to test the coupling of the 2 semi-blocks

The oil cover was made with Petrobond sand


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## CFLBob (Oct 15, 2022)

I have a completely untrained eye, so I see what looks like pits and areas where the metal doesn't appear smooth, and wonder if all that is usable?  The oil cover looks better but also looks like rough metal in places (left end of its first picture, still in the petrobond).


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## Foketry (Oct 15, 2022)

CFLBob said:


> I have a completely untrained eye, so I see what looks like pits and areas where the metal doesn't appear smooth, and wonder if all that is usable?  The oil cover looks better but also looks like rough metal in places (left end of its first picture, still in the petrobond).


The surface is not perfect but I have foreseen a machining allowance of 2 mm, when everything is milled it should improve and have no problems of leakage or mechanical strength . The oil cover needs a file finish.
If I encounter any quality problems, I will remake these pieces. My work is free of charge....


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## Foketry (Oct 26, 2022)

*Boring of bushing seats for crankshaft*
I have built a boring bar that is more than twice the length of the engine block to carry out this machining on the lathe.
I also had to build a fixing base for the motor block on the lathe carriage, the seats for cylinders at the ends of the engine block were used as a reference to align everything according to the rotation axis of the lathe











usual process, model printed with 3D printer, aluminum casting











alignment by means of 2 vertical pins with respect to a pin between spindle and tailstock






block boring











boring of oil seal  seats


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## michelko (Oct 27, 2022)

Awesome work.

Greetings Michael


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## Foketry (Oct 29, 2022)

Boring of cylinder seats on rotary CNC 4th axis 





Your browser is not able to display this video.


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## Foketry (Nov 1, 2022)

The fixing holes of the remaining 12 cylinders
The holes of the 6 central cylinders had already been made without rotary table, this plane is parallel to the base of the engine block .
Using the CNC rotary table I first milled the 3 planes, again the central one and then the 2 lateral ones at 40 degrees .
It is very important that the crankshaft axis is parallel and aligned with these 3 planes, otherwise each cylinder will have a different compression ratio.
It is also important that the angles at 40 degrees are the same, if they are different, change the timing.
After milling I drilled the 12x6 = 72 holes for M3 screws


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## Foketry (Nov 1, 2022)

First crankshaft and connecting rod assembly test to understand if everything rotates, if all the holes match.


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## ddmckee54 (Nov 1, 2022)

Foketry:

It looks like the casting for the top half of the crankcase cleaned up fairly well when you machined it.  There's a couple of spots that look a little iffy, but some JB Weld would fix them right up.  In that last photo, it almost looks like the right-hand bank of cylinders has sleeves in it, or are my eyes playing tricks on me?

Don


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## stanstocker (Nov 2, 2022)

Hi Folks,

This is one heck of a build, and I'm really interested in seeing the mix of conventional, cnc, casting, and 3d printing all in one thread.  Interesting and exciting times to have such a variety of techniques within our reach!

Sorry to back track a bit, but the two products mentioned for the initial ceramic coating don't quite match up to a product I can find in the US.  The Raysin 100 powder looks like a gypsum type plaster although the packaging matched the provided listing, and I had no luck on the Keraflott product or in fact on searches for "ceramic casting powder".  Is this just a translation disconnect or could some kind person point me to the equivalent or similar products in the US.  Investment casting materials seem the most likely equivalent so far.

Thanks,
Stan


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## ddmckee54 (Nov 2, 2022)

I think both the Raysin and the Keraflott are both molding plasters, and not really formulated for burnout.  I checked with both manufacturers to see if they had any U.S. distributors - no luck.  When I get things set up, I think I'm going to try experimenting using Foketry's Keraflott/plaster-sand method, only using something like Ultavest instead of the Keraflott.

Don


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## Foketry (Nov 2, 2022)

ddmckee54 said:


> Foketry:
> 
> It looks like the casting for the top half of the crankcase cleaned up fairly well when you machined it.  There's a couple of spots that look a little iffy, but some JB Weld would fix them right up.  In that last photo, it almost looks like the right-hand bank of cylinders has sleeves in it, or are my eyes playing tricks on me?
> 
> Don


You have seen correctly, both the right and left banks have sleeves, 7075 aluminum to avoid permanent deformation on the 2 most stressed banks. The length of the coupling between cylinder and cylinder seat is only 9 mm, I could not increase it, the cylinders inclined 40 degrees touch the central cylinder.
Furthermore the cylinders are fixed to the engine block by means of a separate flange and a retaining ring, a not very stable solution, but to assemble the water jacket inserted from underneath I have not found a better solution .


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## Foketry (Nov 8, 2022)

3-way T-fittings for inlet and outlet of cooling water for cylinders
I tried 3 possible alternatives to build 40 of these T : aluminum casting, but when I printed the model with 3D printer I realized that the dimensions are really small, impossible to do these with my poor equipment, a jewelers centrifuge would be needed.
Welding of 2 small tubes 4 mm external diameter, I tried with aluminum tubes, but it is really difficult to weld aluminum of small size, the welding temperature is high and a few more seconds make the tubes melt.
The final solution was to obtain them from a rectangular aluminum bar by milling.









3D printed for casting mold





aluminum welded tubes





milled pieces


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## CFLBob (Nov 8, 2022)

The milled pieces definitely look like the way to make those.  

One question.  How did you do the third tube, the one that gets threaded?  Are they threaded so that the start and end of the thread always leaves them aligned your sample?


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## Foketry (Nov 8, 2022)

CFLBob said:


> The milled pieces definitely look like the way to make those.
> 
> One question.  How did you do the third tube, the one that gets threaded?  Are they threaded so that the start and end of the thread always leaves them aligned your sample?


I milled the T in 4 subsequent steps, in the photo you see the first and second step, deep drilling and contouring milling of the 40 pieces, rotation of the bar by 180 degrees, contouring milling, third step drilling and contouring of the threaded side.  In this third step the pieces are separated from the bar, fourth step manual threading.


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## ajoeiam (Nov 9, 2022)

Foketry said:


> I milled the T in 4 subsequent steps, in the photo you see the first and second step, deep drilling and contouring milling of the 40 pieces, rotation of the bar by 180 degrees, contouring milling, third step drilling and contouring of the threaded side.  In this third step the pieces are separated from the bar, fourth step manual threading.



Hmmmmmmmm - - - you didn't consider thread milling the threads? 
(Not that your parts don't look great - - -grin!!!)


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## Foketry (Nov 13, 2022)

the cylinder cooling water liners are finished and painted black like the original engine







Primer and epoxy paint


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## Foketry (Nov 13, 2022)

cylinder liners assembly test, without water jacket, with Oring
Upper oring is 1.78 mm, lower oring 1mm


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## Foketry (Nov 22, 2022)

The cylinders painted and assembled to the engine block
Now I have to check the compression ratio with the crankshaft, connecting rods and at least 3 pistons assembled. The theoretical calculation was done during the design, but it's better to do a practical check as well .
Then I have to flatten the entire bank of 6 cylinders exactly at the same height as there is a single head for 6 cylinders,3 heads for 18 cylinders.





to check the compression ratio I must also take into account the geometry of the piston with this central niche due to the position of the spark plug


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## petertha (Nov 22, 2022)

Foketry said:


> Now I have to check the compression ratio with the crankshaft, connecting rods and at least 3 pistons assembled. The theoretical calculation was done during the design, but it's better to do a practical check as well .
> Then I have to flatten the entire bank of 6 cylinders exactly at the same height as there is a single head for 6 cylinders,3 heads for 18 cylinders.
> to check the compression ratio I must also take into account the geometry of the piston with this central niche due to the position of the spark plug


Nice work. Silly question, but does the master/link rod assembly deliver the piston to the same height at TDC & are compression ratios therefore equal between center & side cylinder bank? I know on radial engines some parameter needs to be slightly compensated for either equal CR or position, either the link rod assembly or piston/top end. It may not be enough to fret about, but just curious.


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## Foketry (Nov 23, 2022)

petertha said:


> Nice work. Silly question, but does the master/link rod assembly deliver the piston to the same height at TDC & are compression ratios therefore equal between center & side cylinder bank? I know on radial engines some parameter needs to be slightly compensated for either equal CR or position, either the link rod assembly or piston/top end. It may not be enough to fret about, but just curious.


In this engine the axes of all the 3 cylinders that are part of the same master rod converge at the center of the rotation axis of the crankshaft so that the stroke is the same for all 18 cylinders and therefore the compression ratio is the same. All pistons reach TDC at the same height.


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## Peter Twissell (Nov 25, 2022)

I think that's not quite true, Foketry.
Assuming you have compensated for the master rod angle when positioning the slave rod eyes, at bottom centre on either the left or right cylinder, the master rod angle is different, so those cylinders have slightly different stroke to the centre cylinder.
I created a spreadsheet to calculate balance for my large 7 cylinder radial.
The spreadsheet calculates the travel of each piston and has options for compensated or non compensated slave rod eye angles.
I'm happy to share it of anyone is interested.


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## Steamchick (Nov 25, 2022)

I agree with Peter. I once found (somewhere?) on utube an explanation of why longer con-rods produce more power than shorter con-rods (for the same stroke), and a few other things that I had "forgotten" from my education in the Japanese design office back in 1989. Many things have moved on over the decades, but not geometry. I suggest you simply check dimensionally from the top deck to piston at BDC and TDC for 3 pistons connected to the same journal and compare to crank angle. It will give you the information for compression ratio per bank, and you may then decide to develop any variation of other parameters to compensate for anything you deem worthwhile. You can even plot stroke in intervals of 10 degrees of crank and produce some nice curves on a graph - if you feel inclined (Pardon the pun?).
There are many articles on the web about engine design aspects. e.g. The Long and Short of Connecting Rods










						How Rod Lengths and Ratios Affect Performance
					

Changing the length of the rods with respect to the stroke of the crankshaft offers some advantages in certain situations.




					www.enginebuildermag.com
				




But none of these really explains the secondary big-end centre motion of the radial - or 3-bank Vee - engines, as found for the outer cylinders of this engine.
peter, does you model produce a graph of stroke versus crank rotation angle? - That may be interesting for us "observers and hangers-on" to this thread.
Ta,
K2


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## Peter Twissell (Nov 25, 2022)

Hi k2,
Yes, my spreadsheet plots the location of all pistons through a full crack rotation at 1 degree intervals.
It also calculates all the mass moments of the moving parts and the resulting balance of the engine for a given counterweight.

Pete.


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## Steamchick (Nov 25, 2022)

Hi Peter, That sounds like a proper job!
Well done!
K2


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## Peter Twissell (Nov 25, 2022)

Spreadsheet here:





						Radial Engine balance calculator
					

Spreadsheet to calculate balance of a radial engine.  Enter values for your engine in column C. If you select 'corrected' slave rod pin angles, they are calculated automatically. The first graph shows piston displacements from TDC. The second shows the motion of the centre of mass of each of the...




					www.homemodelenginemachinist.com


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## Foketry (Nov 27, 2022)

Peter Twissell said:


> I think that's not quite true, Foketry.
> Assuming you have compensated for the master rod angle when positioning the slave rod eyes, at bottom centre on either the left or right cylinder, the master rod angle is different, so those cylinders have slightly different stroke to the centre cylinder.
> I created a spreadsheet to calculate balance for my large 7 cylinder radial.
> The spreadsheet calculates the travel of each piston and has options for compensated or non compensated slave rod eye angles.
> I'm happy to share it of anyone is interested.


The CAD images below demonstrate that the piston stroke is the same for all 3 cylinders, right, center and left, stroke 30 mm for all 18 cylinders, the piston bore is 24 mm for all and therefore the compression ratio is the same for everyone. Am I doing something wrong?

Central rod BDC




Central rod TDC





Right rod DBC




Central rod TDC


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## petertha (Nov 27, 2022)

I've been meaning to work out some kind of simplified CAD tool to evaluate these sorts of engine kinematic issues anyways. (I've also done something similar in Excel but starts to get a bit complicated). 

Can you provide me more dimensional details of the master rod assembly so it is fully defined? For example layout of the red cross (defines position of link rod bottom ends & crank throw rotation center etc.). Is the vertical rod dimension (pink) exact same as the left/right link rod length (blue). What is the crankshaft throw? What is angle of cylinders viewed from front?






The way I'm trying to solve is: make the master rod a fixed block element, insert into engine layout background, adjust alignment & angular constraints to some position of interest, then evaluate resultant position of link rod wristpin point which is indicative of TDC. We can add pistons in too, but but for purposes of CR evaluation, same thing. Example (with random guess measurements) shows TDC of right cylinder bank.


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## minh-thanh (Nov 27, 2022)

In my opinion, if 3 cylinders are all on a circle and the connecting rods of the left and right cylinders are also on a circle with the center of the connecting rod in the middle, the length of the connecting rod and the compression ratio is same


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## petertha (Nov 28, 2022)

Maybe this sketch will help (assuming I understand the engine layout correctly). I tried to superimpose the snapshot position where the right cylinder link rod is assumed at maximum throw (TDC for right cylinder). But sketch also illustrates the problem viewing the rod assembly in isolation. The master rod (purple) must also be simultaneously constrained by the middle cylinder centerline (dash red line), which it is not. If it were rotated like blue annotation, the link rod would no longer be at maximum reach, aligned to right cylinder. In other words I don't think this layout can exist as shown. The master rod geometry + constraints collectively 'drives' the link rods.






Not to detract form this wonderful post but I asked the question because it reminds me of the top 3 cylinders of a radial engine. The Edwards radial for example has an equal (uncompensated) master rod layout. Each axle is 360/5=72 deg apart. The distance between master rod (crankpin) center to each wristpin are also identical. The cylinders are also 72 deg apart. But similarly, when you superimpose the MR onto the cylinder layout, constrain the wrist pin centers to occur along their cylinder axis & compare resultant distance at TDC to a fixed datum like cylinder top, they measure slightly different. Therefore slightly different CR. So to achieve equal CR, you must either alter the cylinder length (as Edwards specifies) or compensate the angular position of the master rod axles. How much of either depends on the physical dimensions.

I hope this makes sense. I thought it worth questioning because its kind of important aspect of the engine.
Left TDC comparison for #1 & #2 cylinders   Right = identical distances wristpin to master rod center


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## Mechanicboy (Nov 28, 2022)

To understand better why we has difference angles on the master rod connected to other connecting rod..

With 2 different lengths from the crank pin to the piston pin in the connecting rod, the piston does not have the same speed and side pressure in the same stroke length, therefore a specific angle must be set on the master rod in order for the other pistons with short connecting rods to have approximately the same piston speed and side pressure on the cylinder  the wall.


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## Peter Twissell (Nov 28, 2022)

Even with compensated slave rod eye angles or the Edwards cylinder length adjustment, the stroke of each piston is slightly different, because the angle between the master rod and any given slave rod is wider at TDC ( when the pistons are furthest apart at the tops of the bores) and narrower at BDC (when the pistons are closest together at the bottoms of the bores).
It is possible to get equal compression ratios, by adjusting the length of each cylinder to match the combustion chamber volume to each stroke.
On my big radial, with 6:1 compression, it's not worth the bother.
For higher compression ratios the difference will be more significant.
Pete.


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## Foketry (Nov 28, 2022)

petertha said:


> I've been meaning to work out some kind of simplified CAD tool to evaluate these sorts of engine kinematic issues anyways. (I've also done something similar in Excel but starts to get a bit complicated).
> 
> Can you provide me more dimensional details of the master rod assembly so it is fully defined? For example layout of the red cross (defines position of link rod bottom ends & crank throw rotation center etc.). Is the vertical rod dimension (pink) exact same as the left/right link rod length (blue). What is the crankshaft throw? What is angle of cylinders viewed from front?
> 
> ...



here is a drawing with more dimensions, I hope it will be useful for this analysis. Please ask if you need other sizes.
My opinion is that, the axes of the 3 connecting rods converge in a single center, TDC and BDC are the same for all 3 cylinders and therefore the compression ratio is the same. Probably the speeds of the pistons change, but all 3 arrive at the same height.


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## petertha (Nov 28, 2022)

ok, here goes. let me know if I misunderstand any dimensions

definition of MR (master rod) & LR (link rod) and MR+LR assembly with LR aligned to MR center just to confirm your dimensions












layout of cylinders & crankpin throw radius





Now overlay MR & LR to crankpin, align MR to center cylinder which is TDC, take reference dimension






Position MR to find TDC of right cylinder. Here it is not quite straightforward. I initially assumed TDC occurs when LR is aligned to its cylinder, but I realized that is not the case because MR position is also constrained to center cylinder. There may be some unique geometric or mathematical equation solution but the way I approximate in CAD is iteration/convergence. So I specify crankshaft rotation angle, position MR & LR with their constraints, take resultant measurement like example (at 38-deg, throw = 79.8137mm). I vary CS angle across likely range in 1-deg steps. Resultant table & graph. TDC (maximum distance) occurs at peak of curve, somewhere around 79.83mm or 0.17mm less than 80mm reference TDC of center cylinder. So, not very much deviation in practical terms, but it is different! haha. Also note BDC of right/left cylinder is similarly different than center cylinder but I left that for now.

Let me know if you spot errors. First time I did this, always wanted to try. Maybe one of the spreadsheet guys can compare CAD results.


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## Vixen (Nov 30, 2022)

Hello Petertha,

Or in other works, ' The geometric errors are so small, they can safely be ignored in a low compression ratio (6:1) and low revving engine (less than 3000 RPM) such as the 18 cylinder Isotta Fraschini model'.

Mike


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## Peter Twissell (Nov 30, 2022)

Mike, yes - in this case the errors may be so small as to be insignificant, but I would leave that to Foketry to decide. Given his attention to detail in other areas, he may choose to correct for the slight differences in compression.

The princliple is sound - geometry of the master rod does alter stroke in other cylinders and it is worth going through the calculation in order to decide whether to ignore the difference or not.


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## petertha (Nov 30, 2022)

Vixen said:


> Or in other works, ' The geometric errors are so small, they can safely be ignored in a low compression ratio (6:1) and low revving engine (less than 3000 RPM) such as the 18 cylinder Isotta Fraschini model'.


Yes, I'm happy for Foketry the calculations turned out this way, resulting in no extra trimming/shimming work unless he wants to. The kinematics was a bit of morbid curiosity on my part. Now I have a new tool & some added understanding. I suspect the low CR deviation on this engine is a function of the narrower cylinder angles, tighter clustering of LR's & stroke length, either by design or the unique layout. The Edwards 5-cyl radial I mentioned has equal uncompensated LR spacing resulting in significant CR deviation requiring secondary modifications. It's MR-LR assembly is more spread out. Anyways, enough of this business, back to Fraschini 18 cylinders!


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## Foketry (Dec 1, 2022)

petertha said:


> Yes, I'm happy for Foketry the calculations turned out this way, resulting in no extra trimming/shimming work unless he wants to. The kinematics was a bit of morbid curiosity on my part. Now I have a new tool & some added understanding. I suspect the low CR deviation on this engine is a function of the narrower cylinder angles, tighter clustering of LR's & stroke length, either by design or the unique layout. The Edwards 5-cyl radial I mentioned has equal uncompensated LR spacing resulting in significant CR deviation requiring secondary modifications. It's MR-LR assembly is more spread out. Anyways, enough of this business, back to Fraschini 18 cylinders!
> 
> View attachment 142652


Your analysis is very interesting, in fact I hadn't considered the CR deviation. Basically there are no appreciable differences in the compression ratio, but I can take them into account when I drill the piston pin, 0.17 mm displaced per 12 cylinders compared to the central 6 cylinders. Thanks for the work done


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## Foketry (Dec 1, 2022)

*Grinding to make 6 cylinders planar*
As I said in this engine there are 3 heads, one head for 6 cylinders.
This means that the 6 cylinders of each bank must be at the same height, very precise and planar.
I mounted a small cup wheel on the 2.2Kw spindle, 20,000 rpm
The engine block with the 18 cylinders on the divider and tailstock, aligned on the crankshaft via a shaft


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## Basil (Dec 1, 2022)

This is going to be an amazing sounding engine!


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## Foketry (Dec 15, 2022)

All 18+1 pistons are finished (Aluminum 7075)





the radial groove on the piston crown is necessary because the spark plug protrudes horizontally into the cylinder











first step : turning on my little CNC lathe





Your browser is not able to display this video.





second step : drilling






third step: drilling and reaming the wrist pin hole whit a jig











Fourth step: internal milling





fifth step: groove milling on the piston crown , a jig is required to orient the milling with respect to the wrist pin





after an ultrasonic cleaning the pistons are completed , 18+1


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## Foketry (Dec 15, 2022)




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## ajoeiam (Dec 16, 2022)

Foketry said:


> All 18+1 pistons are finished
> 
> 
> 
> ...




Curious - - - there is no obvious orientation for the 'internal milling'. 

How did you keep a consistent setup to keep everything oriented?


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## Foketry (Dec 16, 2022)

ajoeiam said:


> Curious - - - there is no obvious orientation for the 'internal milling'.
> 
> How did you keep a consistent setup to keep everything oriented?


Yes, you are a keen observer , I put a long pin in the piston hole and with a 90 degree angle square I oriented the piston with reference to a plane of the vice , making sure that while I was screwing the ring nut the piston didn't rotate.


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## ajoeiam (Dec 16, 2022)

Foketry said:


> Yes, you are a keen observer , I put a long pin in the piston hole and with a 90 degree angle square I oriented the piston with reference to a plane of the vice , making sure that while I was screwing the ring nut the piston didn't rotate.


Dunno if I'm a 'keen observer' (LOL) - - - - just had to fight a few of these kind of 'not simple' setups in the past and wondered what you had used. 

Experience is a right royal female canine (to not offend any overly prissy ears) and she really doesn't care how much it matters or how much work it was to get to that point!

Always trying to learn and really know that I sure don't have enough years left to make all the mistakes never might all the projects - - - - LOL!!


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## Vietti (Dec 16, 2022)

I now hold the piston blank in a square 5C collet and do the internal machining and most importantly it's quick and easy to locate and drill the wrist pin hole properly.  Pistons over 1" can be turned with a stub to fit the collet.


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## Foketry (Dec 20, 2022)

Cylinder gaskets
I got the gaskets from a 0.25mm thick Teflon sheet by turning, drilling and milling, 18 sealing gaskets


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## Foketry (Jan 2, 2023)

first running-in of the cylinders with pistons, rings, connecting rods and bushings, a couple of hours on the lathe at 120 rpm





Your browser is not able to display this video.


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