# Porsche 917  flat 12 engine



## Foketry (Mar 4, 2021)

Introduction
Porsche 917 is a race car developed by German manufacturer Porsche
The 917 gave Porsche its first overall wins at the 24 Hours of Le Mans in 1970and 1971. 
Powered by flat 12 engine, air cooled ,  of 4.5, 4.9, or 5 liters, 
The Can-Am variant twin turbo  was capable of 1100-1540 Hp


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## Foketry (Mar 4, 2021)

Some pictures of the engine found on the web :


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## petertha (Mar 4, 2021)

I approve of your proposed next model project. Please proceed on design & construction!
HaHa, just kidding. What an ambitious but fantastic engine this would be.


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## EngyB (Mar 5, 2021)

Several years ago there was a chap in the States who was looking to build one for his 917 replica since original engines are like rocking horse poo and if up for sale carry the attendant price tag.......


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## leerkracht (Mar 5, 2021)

Just like this 
gr


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## davidyat (Mar 5, 2021)

The Porsche 917 is close to my heart. I saw it race in the 1970 Sebring 12 Hour. I also build plastic and die cast models. I'm currently building the 1969 Ford GT40 in 1/8 scale:





						DeAgostini - Welcome to DeAgostini
					

Discover all DeAgostini collectibles: models, miniatures or figures of your favorite themes. Enter now!



					www.model-space.com
				



I have been waiting for someone to come out with a 1/8 scale 917 model, but so far I've been teased but no model yet.
Grasshopper


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## a41capt (Mar 5, 2021)

Foketry said:


> Some pictures of the engine found on the web :
> 
> View attachment 123557
> 
> ...


Fantastic!  I’ve been a fan of the 917 ever since the Steve McQueen movie “Le Mans” came out in the early 70s.  If you can pull this off, you’re one hell of a model engineer!

I look forward to seeing your progress, and anyone that hasn’t looked into this exquisite piece of flat twelve cylinder, air cooled engineering is REALLY missing out!

John W


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## Foketry (Mar 5, 2021)

leerkracht said:


> Just like this
> gr




Great, nice engine, really captivating sound
are the connecting rod lubricated by an oil pump? 
I don't see the distributor. It is a glow engine with only one carburetor ?


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## Foketry (Mar 5, 2021)

Here are the drawings found on the internet that I will use as a starting point to design the engine


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## Foketry (Mar 5, 2021)

Compared to the engines that I have already built , this one has a complication, a central gear to the crankshaft to connect the 4 camshafts, the 7 oil pumps , 2 distributors and the cooling fan
 I am thinking of designing a multi-part crankshaft with a central gear
I also have dozens of photos of the disassembled engine, most of them from  Porsche museum


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## a41capt (Mar 5, 2021)

Not sure what scale you’re building, but I’m sure throttle body injection is out of the question. What sort of fuel system will you incorporate?

John W


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## davidyat (Mar 5, 2021)

Foketry,
   Is the avatar picture in your postings a LaFerrari. If it is, I just got a 1/8 scale die cast model of a LaFerrari that I'm just starting to build.
Grasshopper


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## petertha (Mar 5, 2021)

you probably did lots of searching already but this link has some good engine pics








						Building 917 Engine, Click on image to see more by Carl Thompson
					





					www.pbase.com


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## mrehmus (Mar 5, 2021)

a41capt said:


> Not sure what scale you’re building, but I’m sure throttle body injection is out of the question. What sort of fuel system will you incorporate?
> 
> John W


Actually, throttle body injection is possible. Lee Root had a 4-banger running with injection way back at the PRIME shows. That engine is currently in the Sherline museum but they are respecting Lee's desire not to share his designs so the information is not available. Robert Washburn (Strictly IC editor) was working on a prototype TBI when he died. He and a friend from Europe (forgot his name) had used a small injector from Bosch if I remember correctly. Sato has or had an injector for one of their engines. I don't see it listed by Tower Hobbies.


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## DiegoVV (Mar 5, 2021)

I've been working in the plans of this engine for some time. Currently I am analyzing the Kugelfischer mechanical injection to check if something can be done in the model, although it seems to be extremely complex. If anyone is interested, we can make this as a group project. Currently I am working in a Edwards Radial 5, but I can work on the design.


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## Foketry (Mar 6, 2021)

davidyat said:


> The Porsche 917 is close to my heart. I saw it race in the 1970 Sebring 12 Hour. I also build plastic and die cast models. I'm currently building the 1969 Ford GT40 in 1/8 scale:
> 
> 
> 
> ...


the scale I will use will be 1: 3,3 because the piston rings I can buy are 26mm, the 917 bore is 86mm , 1/8 scale is very small, it means 10mm pistons (0.39 inch)


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## Foketry (Mar 6, 2021)

davidyat said:


> Foketry,
> Is the avatar picture in your postings a LaFerrari. If it is, I just got a 1/8 scale die cast model of a LaFerrari that I'm just starting to build.
> Grasshopper



Yes it's La  Ferrari, I live a few kilometers from the Ferrari factory, in this area there are the factories of many sports car manufacturers, Ferrari, Lamborghinini, Maserati, Pagani and Ducati motorcycles

This is the link of La Ferrari, if you want to buy one, there is the online configurator, but only a few hundred cars will be produced, you have to order it quickly........
LaFerrari (2013) - Ferrari.com


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## The_reach (Mar 6, 2021)

Foketry said:


> Yes it's La  Ferrari, I live a few kilometers from the Ferrari factory, in this area there are the factories of many sports car manufacturers, Ferrari, Lamborghinini, Maserati, Pagani and Ducati motorcycles
> 
> This is the link of La Ferrari, if you want to buy one, there is the online configurator, but only a few hundred cars will be produced, you have to order it quickly........
> LaFerrari (2013) - Ferrari.com


I have a load of mates from the UK that worked for the Ferarri F1 team there, night part of the world


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## Foketry (Mar 6, 2021)

petertha said:


> you probably did lots of searching already but this link has some good engine pics
> 
> 
> 
> ...



this is a perfect replica of the original engine, thanks for the link


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## Foketry (Mar 6, 2021)

a41capt said:


> Not sure what scale you’re building, but I’m sure throttle body injection is out of the question. What sort of fuel system will you incorporate?
> 
> John W


I will put 2 carburetors, one every 6 cylinders, but i saw on youtube a model of a 10 cylinder engine with injection, very very nice
I think it is possible to apply Speeduino,  a managing  system for injection and ignition engine, but I'm not an expert in this


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## Foketry (Mar 6, 2021)

DiegoVV said:


> I've been working in the plans of this engine for some time. Currently I am analyzing the Kugelfischer mechanical injection to check if something can be done in the model, although it seems to be extremely complex. If anyone is interested, we can make this as a group project. Currently I am working in a Edwards Radial 5, but I can work on the design.



it would be an interesting but extremely complicated project, very precise mechanical machining is required, we are talking about microns of mm
about the injection I saw on Youtube that someone uses Speeduino to manage the injection, it would be possible to use a small commercial injector, built by Marelli for the Fiat engine
Anyone have information about this?


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## Foketry (Mar 6, 2021)

mrehmus said:


> Actually, throttle body injection is possible. Lee Root had a 4-banger running with injection way back at the PRIME shows. That engine is currently in the Sherline museum but they are respecting Lee's desire not to share his designs so the information is not available. Robert Washburn (Strictly IC editor) was working on a prototype TBI when he died. He and a friend from Europe (forgot his name) had used a small injector from Bosch if I remember correctly. Sato has or had an injector for one of their engines. I don't see it listed by Tower Hobbies.



it's a pity it's not possible to have information about this project, it would be really interesting, I don't understand why not to share experiences, in our hobby, shared experiences are necessary to grow


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## Foketry (Mar 6, 2021)

The_reach said:


> I have a load of mates from the UK that worked for the Ferarri F1 team there, night part of the world



Currently Mercedes F1 is unbeatable, this year Ferrari will have a new more powerful engine  with an innovative injection system. I hope it will be a better season for Ferrari, at least not to make it to the bottom of the standings like 2020


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## sniffipn (Mar 6, 2021)

davidyat said:


> The Porsche 917 is close to my heart. I saw it race in the 1970 Sebring 12 Hour. I also build plastic and die cast models. I'm currently building the 1969 Ford GT40 in 1/8 scale:
> 
> 
> 
> ...


$1400. sounds expensive, but is it typical for an 1/8 scale kit?


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## The_reach (Mar 6, 2021)

Foketry said:


> Currently Mercedes F1 is unbeatable, this year Ferrari will have a new more powerful engine  with an innovative injection system. I hope it will be a better season for Ferrari, at least not to make it to the bottom of the standings like 2020


I worked for amg Petronas in 2014 and 2018-2019 too, they're still way ahead with the electrics and I would like to see them beaten to restore some competition to the sport  hopefully this is the case


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## Jan Dressler (Mar 7, 2021)

Wow, what a great project again!

Seems like there was an 1:4 version of this engine (the later turbocharged one) made back in the '80ies, including mechanical fuel injection... 


			https://www.hemmings.com/stories/2015/10/30/kinetic-sculpture-internal-combustion-style-modeling-the-porsche-904-and-917-engines


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## Foketry (Mar 8, 2021)

Jan Dressler said:


> Wow, what a great project again!
> 
> Seems like there was an 1:4 version of this engine (the later turbocharged one) made back in the '80ies, including mechanical fuel injection...
> 
> ...



The mechanical injection and the double turbo are very very  interesting but not very nice aesthetics, the big pipes are not proportionate to the model
Thanks for sharing  link , there is always something to learn


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## Vietti (Mar 8, 2021)

Ron Bemment had working mechanical fuel injectors on his Offy.  He's gone and don't know the fate of the engine.  It ran extremely well.


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## Vietti (Mar 8, 2021)

If you are looking at premade rings and perhaps pistons, take a look at Honda's small four stroke engines like their mini rorotiller.  Forget the size but pretty small, perhaps even 26 mm!  Bought one and very nicely made esp the oil control ring.


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## Foketry (Mar 10, 2021)

My project is taking shape

Here is the crankshaft half box
The crankshaft has a gear in center that transmits the rotation to 2 secondary shafts, one for the 2 distributors and the cooling fan, the other for scavenge pump and lubrication pump
The gear on the crankshaft also transmits rotation through a gear train to the 4 camshafts


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## Foketry (Mar 10, 2021)

The gearbox that connects the crankshaft with the camshafts


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## Foketry (Mar 12, 2021)

Composite crankshaft

I decided to make the crankshaft divided into several parts to introduce a gear in the center  and to bring the oil in all points, 6 connecting rods and 8 main bushings.
The low thickness bushings are commercial and easy to find , each pin is perforated in the center to bring oil where it is needed .
The holes are subsequently closed with grub screws


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## Foketry (Mar 13, 2021)

The complete drawing of the crankshaft


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## ajoeiam (Mar 13, 2021)

Fascinating - - - the very big Wartzila Sulzer diesel starts as a 5 cylinder and not only the block but the crank use bolt on extensions to go all the way to 9 cylinders. 

Thinking something similar to what you have here is done on the big boy.

(What are you drawing this in?)

Good on you, mate!!


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## Foketry (Mar 15, 2021)

The turned and drilled pieces to compose the crankshaft








The pins with the lubrication holes and the gear, the 2 central holes of the pins are for lubricating the 2 connecting rods , the 2 external holes for the main bushings


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## Foketry (Mar 15, 2021)

I will use commercial low thickness bushings , i have never used this type, i hope they work well


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## michelko (Mar 16, 2021)

Wow, very clever design on the crank
Will follow your build thread for sure.

P.S.i finished the cylinder liners and the cam shaft for the holt. Will send you some pics soon.
Regards Michael


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## Foketry (Mar 17, 2021)

The crankshaft assembled provisionally , I'll have to take it apart to harden the pins and gear


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## Foketry (Mar 17, 2021)

the hardened pins


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## jetstuff (Mar 17, 2021)

Should be  'a piece of cake' compared to Normans....


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## Foketry (Mar 17, 2021)

jetstuff said:


> Should be  'a piece of cake' compared to Normans....



Napier dagger , it's an amazing engine, they look like 2 Porsche 917 engines stacked on top of each other ...


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## Foketry (Mar 20, 2021)

When assembling crank pin with flywheel  under press, I discovered this error, the hardened material is too brittle, the pins break !  Diameter is 12mm (.43 inc)
This material is tool steel, used for reamers and taps: 115CrV3 ( European standard) , L2    Aisi/SAE standard (USA), easy to harden in water or oil, but after quenching at 790 degrees C ,  tempering at 250 degrees is required to reduce fragility.

this break is also favored by the sharp edge of the groove for oil distribution and the hole.
it would be appropriate to make a radius  at the bottom of the groove, but now all the pieces are done

I'll do  tempering at 250 C°


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## Foketry (Mar 25, 2021)

I assembled the crankshaft : connecting rod , flywheels , internal bushings and gear.
To ensure perfect alignment of the flywheels I made a final turning on external diameter, I left an allowance of 0.5 mm
The space between one flywheel and the other has been filled with glued wood to avoid distortions between  the tailstocks
















The original Porsche crankshaft


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## Alec Ryals (Mar 26, 2021)

Foketry said:


> When assembling crank pin with flywheel  under press, I discovered this error, the hardened material is too brittle, the pins break !  Diameter is 12mm (.43 inc)
> This material is tool steel, used for reamers and taps: 115CrV3 ( European standard) , L2    Aisi/SAE standard (USA), easy to harden in water or oil, but after quenching at 790 degrees C ,  tempering at 250 degrees is required to reduce fragility.
> 
> this break is also favored by the sharp edge of the groove for oil distribution and the hole.
> ...


Higher temper temp


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## SPOTTER (Mar 27, 2021)

Fantastic work, it's a pleasure for the eyes


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## Foketry (Mar 27, 2021)

Before final turning I checked if all the internal oil passages were open, the oil from a hole at the beginning of the crankshaft must flow to the last hole of the connecting rod and last flywheel.
I used WD40 for this test , a small gerotor pump and a cordless drill
before final turning


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## Foketry (Mar 29, 2021)

Engine block  from Porsche museum


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## Foketry (Mar 29, 2021)

My 3D drawing of the engine block
they are 2 half crankcases almost equal, the difference is that the 6 cylinders on the right are displaced by 9 mm compared to the 6 cylinders on the left (the thickness of the connecting rod + 1 mm)
There are 2 slots for 2 distributors, one on one half crankcase, the other on the other half crankcase
The top transmission shaft drives 2 distributors and the fan, the bottom shaft drives the oil pumps and the large central seat houses the crankshaft.


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## Foketry (Mar 29, 2021)

for a whole night the printer created the foundry mold , compared to the finished engine block I had to foresee the machining allowances and the 2% shrinkage of aluminum.
I had to print the 2 engine casings in 4 pieces (2 + 2) because the dimensions of my printer are small
Then  I glued the pieces together


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## The_reach (Mar 29, 2021)

Seriously impressive progress on this, looking forward to seeing how the castings turn out


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## Alec Ryals (Mar 29, 2021)

Foketry said:


> I assembled the crankshaft : connecting rod , flywheels , internal bushings and gear.
> To ensure perfect alignment of the flywheels I made a final turning on external diameter, I left an allowance of 0.5 mm
> The space between one flywheel and the other has been filled with glued wood to avoid distortions between  the tailstocks
> 
> ...


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## jetstuff (Mar 30, 2021)

T


Foketry said:


> Napier dagger , it's an amazing engine, they look like 2 Porsche 917 engines stacked on top of each other ...


Your work is looking great, hope you get to complete it.  Normans Dagger was manually machined from solid, No castings /No CNC .


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## Foketry (Apr 6, 2021)

Today the first aluminum casting, half engine block for 6 cylinders

the pattern in petrobond sand ,internal side










Front side


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## FTX (Apr 6, 2021)

I

Great job.

Ftx


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## michelko (Apr 7, 2021)

Foketry said:


> Today the first aluminum casting, half engine block for 6 cylinders
> 
> the pattern in petrobond sand ,internal side
> 
> ...


All i can say is   WOW !  I wish i could visit you in your shop and watch you doing that magic stuff.
Can you show a pic with an outside view of the case half?


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## Foketry (Apr 7, 2021)

Today the other aluminum casting , the printer has worked all night for second mold


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## Foketry (Apr 7, 2021)

michelko said:


> All i can say is   WOW !  I wish i could visit you in your shop and watch you doing that magic stuff.
> Can you show a pic with an outside view of the case half?



Hi Michael , you can see the other side in this photo


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## aarggh (Apr 8, 2021)

Fantastic work! The castings came out brilliantly!

Do you use any type of compounds to degas/flux when casting to get such a good result?


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## Foketry (Apr 8, 2021)

aarggh said:


> Fantastic work! The castings came out brilliantly!
> 
> Do you use any type of compounds to degas/flux when casting to get such a good result?



I have used sodium carbonate in the past, I also tried degassing flux tablets with not always good results
Now I use quality aluminum of a single type (AlSi9Cu) without degassers or fluxes, no porosity, no internal defects
I'm not very experienced but I realized that using aluminum scraps of unknown quality does not always lead to good castings


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## Foketry (Apr 13, 2021)

Outside milling of the engine block, cylinder housing and drilling
the rectangular window in the center is for the camshaft drive gears


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## Foketry (Apr 13, 2021)

After completing the external milling and drilling of the 2 engine half-blocks , I had to bore the crankshaft seat
The motor block is 320 mm long (12,6 inch), it is not possible to do the boring with my milling machine.

I therefore made a jig for lathe , with a boring tool between spindle and tailstock


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## Foketry (Apr 13, 2021)

I aligned the jig by a bar between the spindle and tailstock


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## Foketry (Apr 13, 2021)

here's the boring bar while boring the seats


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## FTX (Apr 14, 2021)

Very acurate job. Loock perfect.

Ftx


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## Foketry (Apr 14, 2021)

roughing the seats for pump shaft and distributor shaft with ball nose end mill


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## Foketry (Apr 14, 2021)




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## Foketry (Apr 14, 2021)

now the 2 engine half-blocks are ready for reaming  shaft seats , I extended a commercial reamer to go through the whole block


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## Foketry (Apr 14, 2021)

gear assembly test


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## michelko (Apr 14, 2021)

Man do you sleep some times?
Just a couple of weeks and it will run.


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## a41capt (Apr 14, 2021)

Wow!


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## dnalot (Apr 14, 2021)

Nice. I will  be following your build.

Mark T


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## Foketry (Apr 14, 2021)

michelko said:


> Man do you sleep some times?
> Just a couple of weeks and it will run.



it is the lockdown that makes me work in my shop, we are not allowed anything else but it will soon end , i hope


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## Willyb (Apr 14, 2021)

Great project. Looking forward to seeing and hearing it run.
Cheers
Willy


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## ajoeiam (Apr 15, 2021)

Foketry said:


> it is the lockdown that makes me work in my shop, we are not allowed anything else but it will soon end , i hope



Good luck with covid ending soon - - - - dunno where Italy is at but here we are starting the 3rd round. 
My guess is that there is at least one if not a few more. 

Wonder what our societies are going to look like when this is done?
(Our economies are already is real trouble and more - - - - well - - - - I' stopping there!)


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## Foketry (Apr 19, 2021)

ajoeiam said:


> Good luck with covid ending soon - - - - dunno where Italy is at but here we are starting the 3rd round.
> My guess is that there is at least one if not a few more.
> 
> Wonder what our societies are going to look like when this is done?
> (Our economies are already is real trouble and more - - - - well - - - - I' stopping there!)



Next week we will be free again, restaurants, bars, cinemas, museums open until 10pm, but respecting all safety regulations, distancing, masks and limited number of people
I hope this is the last time, we are proceeding with vaccinations..


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## Foketry (Apr 19, 2021)

in these days I finished the connecting rods ,12+1
material: 7075 aluminum, end mill 4 mm


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## Foketry (Apr 22, 2021)

My cylinders: bore 26 mm, stroke 21.4 mm, displacement 11.35 cc, total displacement for 12 cylinders :136 cc
Material: cast iron G25
The original cylinders: Bore 86 mm (3.4 in), Stroke 70.4 mm ( 2.8 in), compression 10.5:1 , displacement 4907 cc , 299.4 cu in
Note that the stroke is much less than the bore, it is a competition engine







my drawing , the seal whit the head is guaranteed by a viton o-ring


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## Foketry (Apr 24, 2021)

12 + 2 machined cylinders


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## Foketry (Apr 24, 2021)

the first phase of turning, 2 cylinders joined together to save some material


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## jack620 (Apr 24, 2021)

I just found this thread. Very impressive work! I drove through Modena on my way to Bologna. I visited the Ducati factory which was excellent.

Enjoy your freedom next week.


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## Foketry (Apr 24, 2021)

drilling, internal turning and lapping to obtain the same internal dimension for all cylinders








Lapping with DIY lap


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## Foketry (Apr 24, 2021)

jack620 said:


> I just found this thread. Very impressive work! I drove through Modena on my way to Bologna. I visited the Ducati factory which was excellent.
> 
> Enjoy your freedom next week.



Great !  in Modena and Bologna you can also visit Ferrari, Lamborghini and Pagani car factories as well as some car museums
Thanks , from Monday I will finally be able to enjoy my freedom


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## Foketry (Apr 24, 2021)

drilling and milling


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## Foketry (May 3, 2021)

*Gear box for overhead camshafts*
there are 4 camshafts, 2 for the 6 cylinders on the right, 2 for the cylinders on the left
From the center of the crankshaft a central gear transmits the rotation: under the oil pump shaft, above the 2 distributors and the fan, right to the 2 camshafts (ratio 1: 2), left to the other 2 camshafts (ratio 1: 2)


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## Foketry (May 3, 2021)




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## Foketry (May 3, 2021)

my project ,


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## a41capt (May 3, 2021)

Beautiful looking work.  Really looking forward to seeing the final assembly and run.  Thanks for posting!

John W


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## CFLBob (May 3, 2021)

Beautiful.  It's awesome simply watching this go together.


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## Foketry (May 4, 2021)

The gearbox molds, 3D printed







gearbox and cover just melted, still warm


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## Foketry (May 4, 2021)

Finished machining, assembly of flanged bearings and gears
This is the first of 2, now I have to do the other one the same

T














This is the first of 2, now I have to do the other one the same


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## michelko (May 4, 2021)

Foketry said:


> Finished machining, assembly of flanged bearings and gears
> This is the first of 2, now I have to do the other one the same
> 
> TView attachment 125127
> ...


very nice. Love to see the progress


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## Brian Lawrence (May 6, 2021)

Your castings look fantastic and would love know a little more about your process for casting. what materials you used for the metal (clean store bought Aluminum?? Your formula for the sand mixture, and what grit of sand you used.
I will definitely be following this  article and discussion.
What type of plastic do you use with your 3D printer to achieve such beautiful results, maybe a few setting on your printer (if it's outside of the default settings) might help me.

Brian


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## Foketry (May 7, 2021)

Brian Lawrence said:


> Your castings look fantastic and would love know a little more about your process for casting. what materials you used for the metal (clean store bought Aluminum?? Your formula for the sand mixture, and what grit of sand you used.
> I will definitely be following this  article and discussion.
> What type of plastic do you use with your 3D printer to achieve such beautiful results, maybe a few setting on your printer (if it's outside of the default settings) might help me.
> 
> Brian



In my garden foundry I now only use one type of aluminum (AlSi9Cu1 ) without any additives such as salt, baking soda or degassing tablets.
This type of aluminum also allows to be hardened in water to increase workability and mechanical strength.
In the past I tried to melt aluminum scraps of unknown provenance, with poor results, low mechanical strength and a lot of porosity.
About sand I use a first layer of Petrobond (expensive) in contact with the mold and filling with green sand( cheap)
The printer I used for  molds  is a resin SLA printer, default settings, the molds is very defined because the layers are 0.05 mm instead of 0.2 / 0.3 mm of an FDM printer.
I can recommend you this youtube video of this english guy, expert in foundry and printers, his videos have taught me many things


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## Foketry (May 7, 2021)

The 2 timing gearboxes for  camshafts are completed


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## a41capt (May 7, 2021)

Wow, this is some fantastic work!  I loved the Porsche 917, and your bringing one to life in scale is nothing short of amazing.  Thanks for sharing each step along the way!

John W


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## gbritnell (May 8, 2021)

Outstanding work!


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## Foketry (May 13, 2021)

*The heads , *there are twelve, one for each cylinder, I initially thought of making them through aluminum casting but the cooling fins are very thin and my low foundry technique does not allow me to make these small thicknesses.
I bought a rectangular aluminum bar and cut 12+1 slices


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## Foketry (May 13, 2021)

my draw


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## a41capt (May 13, 2021)

Foketry said:


> *The heads , *there are twelve, one for each cylinder, I initially thought of making them through aluminum casting but the cooling fins are very thin and my low foundry technique does not allow me to make these small thicknesses.
> I bought a rectangular aluminum bar and cut 12+1 slices
> 
> View attachment 125419
> ...


I like how you said “cut 12 +1”


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## a41capt (May 13, 2021)

I just noticed how incredibly thin the valve seat is on the original head.  That contact area can’t be but 1 or 2 millimeters!  Amazing technology, I wonder what that insert is made of to withstand the heat and not burn out?  Unless that’s a 2 step seat, I can’t believe the thin aspect of the outer seating ring surface.


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## Foketry (May 13, 2021)

To obtain the heads many processing steps are required
the first is to mill at least 2 reference planes, perpendicular to each other , the second was to drill 4 reference holes for the subsequent operations (they are the same for fixing to the cylinders), the combustion chamber and the spark plug hole.




Your browser is not able to display this video.


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## Foketry (May 13, 2021)

12+1 milled and drilled heads


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## Foketry (May 13, 2021)

the third step, contouring of the external profile










Your browser is not able to display this video.


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## Foketry (May 13, 2021)

fourth step, drilling and reaming valve cage


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## Foketry (May 13, 2021)

a41capt said:


> I just noticed how incredibly thin the valve seat is on the original head.  That contact area can’t be but 1 or 2 millimeters!  Amazing technology, I wonder what that insert is made of to withstand the heat and not burn out?  Unless that’s a 2 step seat, I can’t believe the thin aspect of the outer seating ring surface.



It is true  , the valves are very thin and certainly heat resistant, this engine has won the 24 hour race of Le mans several times !


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## a41capt (May 13, 2021)

Foketry said:


> It is true  , the valves are very thin and certainly heat resistant, this engine has won the 24 hour race of Le mans several times !


Those engines were a true example of German reliability and toughness.  I’m pretty sure the Porsche 917 still holds the top speed record for LeMans (before they added additional chicanes on Mullsanne to slow things up a bit).


----------



## Foketry (May 17, 2021)

Fifth step
Milling of the intake flange


----------



## Foketry (May 17, 2021)

Sixth step
exhaust flange milling










Your browser is not able to display this video.


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## michelko (May 18, 2021)

Foketry said:


> Sixth step
> exhaust flange milling
> 
> View attachment 125543
> ...


Those chips are flying nice.
Can you say something about the machine and the cutting parameters?
Michael


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## Foketry (May 18, 2021)

michelko said:


> Those chips are flying nice.
> Can you say something about the machine and the cutting parameters?
> Michael




Hi Michael
I normally use these parameters on aluminum, 2 flutes end mill 6mm, spindle speed 9000 rpm, cutting feedrate 200 mm / min, stepover 0.5 mm and also some spray of WD40
I applied a double spindle to my Chinese milling machine, 2.2 Kw, 24.000 rpm, air cooled
I use this spindle on aluminum, original spindle for cast iron and steel


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## Foketry (May 18, 2021)

I wanted mill the fins on the heads, but I broke the saw blade milling at the first fin, by my mistake , now I have to wait for new saw to arrive.
I did an assembly test, with the 3D printed camshaft box, everything looks correct













original engine


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## CFLBob (May 18, 2021)

Foketry said:


> Hi Michael
> I normally use these parameters on aluminum, 2 flutes end mill 6mm, spindle speed 9000 rpm, cutting feedrate 200 mm / min, stepover 0.5 mm and also some spray of WD40
> I applied a double spindle to my Chinese milling machine, 2.2 Kw, 24.000 rpm, air cooled
> I use this spindle on aluminum, original spindle for cast iron and steel
> View attachment 125601



I'm suspecting your Chinese mill is bigger than my Chinese mill but I've thought about doing the same thing with a second spindle.  How big is the work area, and how much do you give up by mounting that second spindle?  Looks like about 15cm?

Mine is a Grizzly G0704 - which is often known as a BF20L.  The spindle won't do over about 2250 RPM so I don't get high feed rates on Aluminum.  I use a Fogbuster on mine for cooling, which works well.


----------



## Foketry (May 18, 2021)

CFLBob said:


> I'm suspecting your Chinese mill is bigger than my Chinese mill but I've thought about doing the same thing with a second spindle.  How big is the work area, and how much do you give up by mounting that second spindle?  Looks like about 15cm?
> 
> Mine is a Grizzly G0704 - which is often known as a BF20L.  The spindle won't do over about 2250 RPM so I don't get high feed rates on Aluminum.  I use a Fogbuster on mine for cooling, which works well.



The distance between one spindle and the other is 150 mm but the working area is reduced by about 50 mm in X, I can move the vice to the right up to 100 mm
my milling machine is similar to Rong Fu RF40, i did it myself 4 axis CNC


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## CFLBob (May 18, 2021)

Foketry said:


> The distance between one spindle and the other is 150 mm but the working area is reduced by about 50 mm in X, I can move the vice to the right up to 100 mm
> my milling machine is similar to Rong Fu RF40, i did it myself 4 axis CNC



Interesting development to me - your mill is very close in size to mine, according to the Rong Fu website.  That's encouraging.

I built the CNC conversion on mine, full 4 axis like yours, but used some popular plans I bought online.


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## a41capt (May 18, 2021)

Loving it!  Will the exhaust manifold be cast or built from tubing?  I’m really enjoying this build, and now considering what my world would look like with CAD/CAM and CNC.

John W


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## Foketry (May 18, 2021)

a41capt said:


> Loving it!  Will the exhaust manifold be cast or built from tubing?  I’m really enjoying this build, and now considering what my world would look like with CAD/CAM and CNC.
> 
> John W


exhaust manifold will be made of welded pipes as the original engine


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## a41capt (May 18, 2021)

I was a pipe fitter and welder in the US Navy, and THAT piece of work looks like it’ll be lots of fun!


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## Jan Dressler (May 18, 2021)

I don't know, something at work yesterday reminded me of this thread... 

(Though this is from a 908 I guess, not 917)


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## a41capt (May 18, 2021)

Foketry said:


> exhaust manifold will be made of welded pipes as the original engine
> View attachment 125609


I was also going to add that it’ll require quite a target deck to make that match up.  Interesting how they’ve balanced the exhaust through the expanded first collected system pipe into a common collector to equalize the back pressure.


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## Willyb (May 19, 2021)

Really enjoying watching this build.  Wonder why they dump the collector for the front three cylinders on the right side into one leg of the three rear cylinders and on the left side the front three collector connects into the secondary collector?  Maybe there is something in the way?


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## Foketry (May 20, 2021)

Willyb said:


> Really enjoying watching this build.  Wonder why they dump the collector for the front three cylinders on the right side into one leg of the three rear cylinders and on the left side the front three collector connects into the secondary collector?  Maybe there is something in the way?



I don't know the reason for this choice, I know that the exhaust manifolds must have the same length for each cylinder to have the same efficiency , example Ferrari and Honda 12V


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## a41capt (May 20, 2021)

Really interesting exhaust system all the way around.  Back in the 60s, while racing two-stroke motorcycles as a teenager, I experimented (trial and error of course) with exhaust gas flow and back pressure.  Of course the piston-ported two stroke engines of the time required that timed back pressure to ensure a proper cylinder charge and still enhance the flow of exhaust, I wasted a lot of sheetmetal building, cutting apart, rewelding, and testing for the best configuration to fit my re-porting and carburetion.  As a 16 year old kid, I was pretty proud of my accomplishments, but those pale in comparison to the advances in modern exhaust design.

I’m sure the Porsche engineers had a whole lot more knowledge and computer tools than I did, and their strange collector system must’ve been well engineered for performance, and yet compromised some efficiency around structural components as needed.


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## ddmckee54 (May 21, 2021)

The problem with a tuned exhaust system is just that, it's tuned.  It will work well at its' dedsigned RPM range, outside that RPM range - not so much.  I would imagine that there were some rather "heated" discussions between drivers, engineers, and mechanics, regarding what RPM range to tune the exhaust for.

Don


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## Jan Dressler (May 22, 2021)

Willyb said:


> Really enjoying watching this build.  Wonder why they dump the collector for the front three cylinders on the right side into one leg of the three rear cylinders and on the left side the front three collector connects into the secondary collector?  Maybe there is something in the way?


Yes, the clutch / gearbox housing is wider on that side because of the starter motor which is located there.


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## Foketry (May 23, 2021)

12 pistons, diameter 26 mm (1.02 in) , material: 7075  (Ergal)
Before making all 12 pistons I built 1, assembled on a cylinder, rotated the crankshaft to the TDC and checked the compression ratio via a graduated syringe and oil in the head.
The real value obtained is similar to the calculated value, I have slightly moved the wrist pin hole down to increase the compression a little
Now it is 7: 1  , I don't want to exceed this value because a very high torque would be needed to start the engine. My cordless drill does not have the necessary strength
Compression ratio of the real Porsche 917 engine is 10: 1






first and second turning step













Milled, drilled and threaded pistons


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## CFLBob (May 23, 2021)

Do you tap under power on your mill?  Using a tapping head or something like it, as opposed to manually with a tap wrench?

Just curious.


----------



## Foketry (May 23, 2021)

CFLBob said:


> Do you tap under power on your mill?  Using a tapping head or something like it, as opposed to manually with a tap wrench?
> 
> Just curious.


being very small threaded holes I use 2 cordless drills,  first one  with roughing tap, the second with  finishing tap , both with  torque set to the minimum.


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## petertha (May 23, 2021)

That's an interesting solution. So will your wrist pins have a slight flat or notch for the set screw to clamp against?


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## Foketry (May 24, 2021)

petertha said:


> That's an interesting solution. So will your wrist pins have a slight flat or notch for the set screw to clamp against?



my wrist pins are made from hardened commercial pins, I will make a slight ground flat


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## Willyb (May 24, 2021)

Jan Dressler said:


> Yes, the clutch / gearbox housing is wider on that side because of the starter motor which is located there.



Thanks Jan. I figured there must have been something to make the one side different for the other.  
Cheers
Willy


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## Foketry (Jun 9, 2021)

Finally ,after 2 broken tungsten  saw blade , I finished  milling the cooling fins of the heads


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## Foketry (Jun 9, 2021)

12 finned heads


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## CFLBob (Jun 9, 2021)

You know, with 12 heads, each with 12 slots, 9 of which appear to be around their entire perimeter, breaking two blades just doesn't seem that bad a price.


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## Peter Twissell (Jun 10, 2021)

What was the cause of blade failure?


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## Foketry (Jun 10, 2021)

Peter Twissell said:


> What was the cause of blade failure?



both cases it was my mistake, once I moved the blade up still inside the cut, the second break I didn't fix properly the head to the jig , tungsten blade are very fast but very fragile, then I used HSS disc .


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## michelko (Jun 11, 2021)

Those are beautyfull parts.

Michael


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## Foketry (Jun 16, 2021)

Head assembly test  , after threaded spark plug hole and counterbore 4 fixing holes


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## Foketry (Jun 16, 2021)

The original Porsche engine


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## Foketry (Jun 21, 2021)

The valves
I used a lead steel bar 36SMnPb14 dia 12 mm
It is a steel with medium carbon, moderate hardenability, high manganese, sulfur and lead content for good machinability.
Normally I use stainless steel, but in this case, given the large quantity of valves to be turned, I tried this material, already used on the Bugatti model engine
Several processing steps were required , cutting, centering, turning, grooving, sanding , parting.








first and second processing step





24 valves + 5


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## michelko (Jun 22, 2021)

do you machine them conventional or with an cnc lathe?

Regards Michael


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## Foketry (Jun 22, 2021)

michelko said:


> do you machine them conventional or with an cnc lathe?
> 
> Regards Michael


Hi Michael 
I bought a small Italian lathe from a school a year ago that I converted CNC, it is suitable for pistons, valves, small parts.
If I have to build a few pieces I use the manual Chinese lathe, over 2/3 pieces I use the CNC

And about your Holt 75 ?


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## davidyat (Jun 23, 2021)

When machining the two valves, how do you control "tool push"? Do you use a steady rest on the middle of the part?


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## Foketry (Jun 23, 2021)

davidyat said:


> When machining the two valves, how do you control "tool push"? Do you use a steady rest on the middle of the part?



I work a single valve with collet chuck  and tailstock, the second valve is hidden inside chuck , 1600 rpm, stepover 0.2mm
Perhaps this short video clarifies the procedure




Your browser is not able to display this video.


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## davidyat (Jun 23, 2021)

Great video. Maybe at some time in the future, I'll figure out and get a CNC machine.
Grasshopper


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## JonnyC (Jun 23, 2021)

Hi, love the posts, this is a major undertaking and made to look so easy. I'm watching with interest on how the various issues are approached regarding scaling a real engine.

It looks like (from the bore in the cylinder head as though you are going to use some sort of valve/seat/spring catridge, is that right?

Jon


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## michelko (Jun 24, 2021)

realy nice swarfs.
what tolerances / free play are you aiming for the valvestem to guide.
I did some test with cnc on my lathe but i had a little problems to get the numbers constant. 
Jules:
the holt is on hold ;-) because of the other hobbies, children, building a pool etc.
the case is ready, the cam also, the cylinder jackets are cnc turned(see above).
here is a video from my first cnc turning work. 
I think i will go on with the project in fall.
You are doing awesome work. Can´t wait to se the updates.

Regards Michael


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## Foketry (Jun 24, 2021)

JonnyC said:


> Hi, love the posts, this is a major undertaking and made to look so easy. I'm watching with interest on how the various issues are approached regarding scaling a real engine.
> 
> It looks like (from the bore in the cylinder head as though you are going to use some sort of valve/seat/spring catridge, is that right?
> 
> Jon



this is my design for valves: bronze cage , oil seal , spring . 2 spring retainer , upper and  under, Seeger, tappet.
 The camshaft pushes directly on the bronze tappet 
The valve on the right has a different solution, instead Seeger I thought of a spring ring to save space in height. I opted for a traditional  seeger solution, easier to make, but keeping the solution of cages on right which reduces the overall dimensions in height and more spring stroke.


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## Foketry (Jun 24, 2021)

michelko said:


> realy nice swarfs.
> what tolerances / free play are you aiming for the valvestem to guide.
> I did some test with cnc on my lathe but i had a little problems to get the numbers constant.
> Jules:
> ...




Hi MIchael
I partially solved the problem of the diameter dimension variation by mounting on the X axis a Heidenhain encoder found at no cost by a friend of mine who repairs CNC motors
In addition to this I always do 2 or 3 passes of the finish, the last at zero stepover. I got a repeatability of +/- 0.01 mm once I optimized rpm and feed.
Jules


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## DiegoVV (Jun 24, 2021)

michelko said:


> realy nice swarfs.
> what tolerances / free play are you aiming for the valvestem to guide.
> I did some test with cnc on my lathe but i had a little problems to get the numbers constant.
> Jules:
> ...



I machine my valves outnof 316ss in a manual lathe. Before making the valves, I make the valve guides reaming the inner bore, then I machine the valves leaving them 0.03 mm oversize in diameter to allow for lapping them to get a perfect fit on the guides. Very important to check consistency in diameter in all the stem length during the lapping process  to ensure consistency in the fit along all the valve movement.


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## JonnyC (Jun 25, 2021)

Foketry said:


> this is my design for valves: bronze cage , oil seal , spring . 2 spring retainer , upper and  under, Seeger, tappet.
> The camshaft pushes directly on the bronze tappet
> The valve on the right has a different solution, instead Seeger I thought of a spring ring to save space in height. I opted for a traditional  seeger solution, easier to make, but keeping the solution of cages on right which reduces the overall dimensions in height and more spring stroke.
> 
> View attachment 126744


Two nice layouts. How will the bronze cages be locked into the heads? Also, why the need for space saving on the right hand valve arrangement? When I looked back at the engine drawing I thought it was because the exhaust side sits lower than the inlet side but then realised that its the angle of the valves that is different from the centre line of the bore.


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## Foketry (Jun 25, 2021)

JonnyC said:


> Two nice layouts. How will the bronze cages be locked into the heads? Also, why the need for space saving on the right hand valve arrangement? When I looked back at the engine drawing I thought it was because the exhaust side sits lower than the inlet side but then realised that its the angle of the valves that is different from the centre line of the bore.



I'll make the diameter of the cages fit a slight pressure in the head and use Loctite 620 high temperatures
I need to reduce the height of heads because this engine has compact dimensions and I would like respect the exact scale.


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## Foketry (Jun 27, 2021)

michelko said:


> realy nice swarfs.
> what tolerances / free play are you aiming for the valvestem to guide.
> I did some test with cnc on my lathe but i had a little problems *to get the numbers constant.*
> Jules:
> ...




Hi Michael , if you want to get constant and repeatable dimensions, I suggest buying the best lathe in the world for hobbyists: SCHAUBLIN, made in Switzerland, watch the final part of  video ...


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## Foketry (Jun 28, 2021)

The cages, 24 + 2, bronze B12 -CuSn12, partially turned on the manual lathe and on the CNC lathe
I had to build a special tool for internal front groove

















a short video, turning seal ring seat


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## Foketry (Jul 1, 2021)

Valve lapping
I make a pre-lapping of valves and cages before assembly in the heads
I know that a final lapping will be required because there may be deformations during the assembly and drilling of the exhaust  and intake  holes
I did a manual lapping with these tools, I glue a small round on the valve head, I put it in the flexible hose of the wooden handle and then I lap for about 1 minute


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## Foketry (Jul 1, 2021)

Then I do a vacuum  test
Lapping is OK if the gauge from 25 to 5 takes more than a minute
In this case valve has an insignificant leak (note: the oil seal is not installed)


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## GreenTwin (Jul 4, 2021)

I was able to get time today to read through this entire thread.
Very nice and impressive work for sure.
.


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## Foketry (Jul 13, 2021)

Lost PLA : overhead camshaft housing
To make this cast aluminum housing I used the lost PLA technique ,pattern has angled angles that do not allow an open casting, cores are required ,i chose lost PLa instead of cores






PLA pattern spilt into 2 pieces, my 3D printer has dimensions that do not allow to print a single piece
the pattern is hollow inside to burn easily and quickly when drowned in plaster, you can see the internal honeycomb in transparency , thickness of the outer skin is very small






pattern inside plaster before burning , 550° C  4/5 hours in electric oven






After burning







after pouring aluminum






removing plaster








after some roughing operations








camshaft housing temporarily screwed to the heads


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## 926wolf (Jul 14, 2021)

So tell us more about the 3d printing. What wall thickness skin and %of infill used because that is a fantastic casting


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## Foketry (Jul 14, 2021)

926wolf said:


> So tell us more about the 3d printing. What wall thickness skin and %of infill used because that is a fantastic casting



this is my setting , Ultimaker Cura , Infil 10%, all other settings are Basic, not high quality


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## 926wolf (Jul 14, 2021)

Thank you i will give that a try


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## propclock (Jul 14, 2021)

Very impressive. Perhaps this old dog really needs to learn new tricks. Thanks for sharing/motivating.


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## Foketry (Jul 17, 2021)

Both camshaft housings  are installed and the holes for spark plugs and valves are made in correspondence with the valve head holes .
Next step: cages assembly in the heads,  valves assembly , tappets , 4 camshafts whit gears ,  camshafts housing final machining , sandblasting.


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## Foketry (Jul 22, 2021)

All 24 cages are assembled with Loctite 620 and I milled the intake and exhaust holes
I preferred to mill rather than drill the holes to avoid deformation of the cages
This, I hope, it will save me a long lapping of the valves of which I have already done an initial lapping before assembling on the heads 
















Your browser is not able to display this video.


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## michelko (Jul 22, 2021)

I wish i could Visite your shop and watch you doing the magic.
Awesome work!!


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## Logan200 (Jul 23, 2021)

Fantastic! Keep on


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## Foketry (Jul 23, 2021)

michelko said:


> I wish i could Visite your shop and watch you doing the magic.
> Awesome work!!


While you come to the sea in Italy, my shop (ex garage, my cars sleep outdoors) is always open to all visitors
I'm waiting for you....


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## Logan200 (Jul 23, 2021)




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## ajoeiam (Jul 23, 2021)

Foketry said:


> While you come to the sea in Italy, my shop (ex garage, my cars sleep outdoors) is always open to all visitors
> I'm waiting for you....



Hmmmmmm - - - - If you would develop some good connection(s) with some reasonable bed and breakfast places I would bet that my wife would love that beach too (I prefer snorkeling on a reef but that water looks great!!!). Your shop would be the draw for me! (grin - - - wacky - - - I know!!)


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## Foketry (Jul 25, 2021)

Valve assembly
After a final lapping I assembled the valves with oil seal, spring, 2 spring retainer, seeger . The second lapping was fast, there was no deformation of the cages when pressing into the holes of the heads.
I put the oil seal because being an engine with double overhead camshaft, where the cam pushes on the tappet it is necessary to lubricate. When the piston sucks fuel through the valve, it could also sucks oil from above.


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## a41capt (Jul 26, 2021)

Amazing work!


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## JonnyC (Jul 26, 2021)

Hi a41capt, whats the old trials bike?


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## a41capt (Jul 26, 2021)

JonnyC said:


> Hi a41capt, whats the old trials bike?


1976 Bultaco Sherpa T 350


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## Foketry (Aug 9, 2021)

Cams
I designed 2 different cams, one for intake and the other for exhaust as the duration of the intake and exhaust phases is different , 14 degrees greater the exhaust . I used hardenable steel, the tempering will have after having assembled everything with the correct timing and fixed in position through a hole made simultaneously on the shaft and cam. They will be disassembled , hardened and then reassembled


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## Foketry (Aug 9, 2021)

the pre-turned steel round ready for milling











milling with a 6 mm end mill





Your browser is not able to display this video.


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## Foketry (Aug 10, 2021)

The camshaft design
Camshaft will rotate on 6x12x4 2Z ball bearings, 8 each shaft , the gear in the center of the shaft will have a phase adjustment by means of 3 slots and 3 M3 screws.
This will allow me to adjust the opening between the 2 camshafts, about 110/120 degrees,  once the cams have been phased one by one
In the original engine there are a series of holes on the gear to find perfect timing


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## a41capt (Aug 10, 2021)

Foketry said:


> The camshaft design
> Camshaft will rotate on 6x12x4 2Z ball bearings, 8 each shaft , the gear in the center of the shaft will have a phase adjustment by means of 3 slots and 3 M3 screws.
> This will allow me to adjust the opening between the 2 camshafts, about 110/120 degrees,  once the cams have been phased one by one
> In the original engine there are a series of holes on the gear to find perfect timing
> ...


I know I’m quite the new kid on the block, I had a hard enough time setting the valve timing on my “Kitchen Sink” engine, but that valve timing looks absolutely overwhelming!!!

Once again, spectacular work and I so look forward to hearing it run. Thanks for keeping me wondering how the hell I’d EVER reach that level of craftsmanship…

John W


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## CFLBob (Aug 10, 2021)

I can't wait to see how it will be assembled and aligned.  I can see all the cam sections have setscrews to hold them on the shaft, but aren't all the bearings press fits?  Built from the middle out toward the ends?  

And same sentiment as @a41capt - thanks for keeping _me_ wondering...


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## ddmckee54 (Aug 11, 2021)

Got a couple of questions about the cam sections.
1) I can see how the setscrews will allow you to adjust each cam section's position on the shaft to get the correct timing,  but will the setscrews be enough to hold that position on the shaft?  It would seem to me that the side forces applied to the cam section each time the valve is actuated would want to twist the section on the shaft. 
2) Once you've got the sections timed where you want them. are you going to pin them in place?
3) Are you going to harden the cam sections?  Or, since this is a model engine that doesn't have to run for thousands of hours - just leave them soft.

Don


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## Foketry (Aug 11, 2021)

CFLBob said:


> I can't wait to see how it will be assembled and aligned.  I can see all the cam sections have setscrews to hold them on the shaft, but aren't all the bearings press fits?  Built from the middle out toward the ends?
> 
> And same sentiment as @a41capt - thanks for keeping _me_ wondering...



the cams will be fixed to the shaft initially with a screw, when the timing is ok, they will be locked in position with a spring pin
The bearings will be held in position by bearing caps and spacers between the end of the cam and bearing .
I will do this assembly in a few weeks, I am waiting for bearings, August in Italy is month of 1- 2 week of holidays.


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## Foketry (Aug 11, 2021)

ddmckee54 said:


> Got a couple of questions about the cam sections.
> 1) I can see how the setscrews will allow you to adjust each cam section's position on the shaft to get the correct timing,  but will the setscrews be enough to hold that position on the shaft?  It would seem to me that the side forces applied to the cam section each time the valve is actuated would want to twist the section on the shaft.
> 2) Once you've got the sections timed where you want them. are you going to pin them in place?
> 3) Are you going to harden the cam sections?  Or, since this is a model engine that doesn't have to run for thousands of hours - just leave them soft.
> ...



the fixing screws are only for timing, the engine cannot work, I will put sprig pins to prevent the cam rotating on the shaft.
In the cam drawing you can see the hole for screw and 2 pin holes
All the cams, once the timing has been carried out, will be take apart and hardened.
This engine, if I can get it to work, will rotate for a few hours in its life, perhaps hardening is not necessary, but I prefer to do it in a workmanlike manner .


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## ddmckee54 (Aug 12, 2021)

My mistake, I didn't look at the drawings close enough.

I saw one threaded hole and at first glance it looked like the other hole was threaded too.  Now that I go back and take a closer look at the drawings I can see that one hole in each cam section is threaded and the other hole is for the pin.

Don


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## Foketry (Aug 21, 2021)

The 4 gears for  4 camshafts, each gear has 3 timing slots , each cam can be adjusted independently


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## ajoeiam (Aug 21, 2021)

I only did a little bit of searching and couldn't find any such  - - - - wondering - - - have you described how you're cutting all this gears?
(Just curious about how you're succeeding at this - - - great looking stuff!!)


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## Foketry (Aug 21, 2021)

ajoeiam said:


> I only did a little bit of searching and couldn't find any such  - - - - wondering - - - have you described how you're cutting all this gears?
> (Just curious about how you're succeeding at this - - - great looking stuff!!)


Are commercial gears, available at any bearing shop. Module 1,   32 teeth
Involute gear cutters is much more expensive than commercial gears, some different sets would be needed depending on the number of teeth.


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## ajoeiam (Aug 22, 2021)

Foketry said:


> Are commercial gears, available at any bearing shop. Module 1,   32 teeth
> Involute gear cutters is much more expensive than commercial gears, some different sets would be needed depending on the number of teeth.



That was what I was wondering - - - sorta hoping that you had cut them - - - - would love to follow such!!


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## Foketry (Aug 28, 2021)

Valve tappets , qty 24
Are made of bronze and kept in axis by an external steel bushing.
The ratio between tappet diameter and bushing length is greater than 1.5 to ensure linear sliding without jamming , everything will be lubricated with good quality permanent grease.
Steel bushings are fixed with Loctite 620
After the final assembly it will be necessary to find the right thickness of the tappet of each valve with respect to the base of the cam , valve clearance must be between 0.05 mm and 0.1 mm
Now I have made tappets increased by 0.5 mm then the internal part will be turned up to the correct thickness.


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## a41capt (Aug 28, 2021)

Terry,

The camhead version of the BMW R1200 models (as well as several other motorcycle manufacturers) utilize a tappet “bucket” of different thicknesses to adjust valve clearance.  These fit inside the tappet and over the head of the valve stem and allow for wear to the tappet face as well as valve seat wear.

Perhaps this type of system would allow you to fine tune each valve as the engine wears in without having to make all new tappets later?

Thanks again for the detailed build thread.  I’m loving the hell out of your work and looking forward to hearing the snarl of a horizontally opposed, air cooled 12!

John W


----------



## Foketry (Aug 28, 2021)

a41capt said:


> Terry,
> 
> The camhead version of the BMW R1200 models (as well as several other motorcycle manufacturers) utilize a tappet “bucket” of different thicknesses to adjust valve clearance.  These fit inside the tappet and over the head of the valve stem and allow for wear to the tappet face as well as valve seat wear.
> 
> ...



In general, all engines with overhead camshafts have shims under the tappets, in my case since this engine will work a few hours in its life and therefore will not need to be adjusted due to wear, I prefer to lower the thickness by turning, one by one , do shims means have at least 24 pieces in addition, a further complication...

I also hope to hear this engine roar , thanks for the encouragement


----------



## a41capt (Aug 29, 2021)

Foketry said:


> In general, all engines with overhead camshafts have shims under the tappets, in my case since this engine will work a few hours in its life and therefore will not need to be adjusted due to wear, I prefer to lower the thickness by turning, one by one , do shims means have at least 24 pieces in addition, a further complication...
> 
> I also hope to hear this engine roar , thanks for the encouragement


Understood!  But I am a bit disappointed that you’re not building it to fit a scale 917 to fit it and shrinking yourself to drive it!!! 

John W


----------



## Peter Twissell (Aug 29, 2021)

I've probably missed it on the pictures, do you have a means to vent the volume under the tappet, so it can't become hydraulically locked with oil?


----------



## Foketry (Aug 30, 2021)

Peter Twissell said:


> I've probably missed it on the pictures, do you have a means to vent the volume under the tappet, so it can't become hydraulically locked with oil?



yes, I will make a small hole in center to relieve  pressure, when all  tappet thicknesses will be fine-tuned


----------



## Foketry (Sep 7, 2021)

Bearing caps for camshafts
As  the original Porsche engine I made 8 supports for each camshaft, the camshaft slides directly into the hardened and lubricated aluminum seats.
My poor technology does not allow me to harden the aluminum, so I put 8 small bearings on each camshaft
Each bearing will have its own cap, total 32 caps


----------



## Foketry (Sep 7, 2021)

To avoid complex machining I made 5 aluminum castings, each with 7 joined pieces, I made  patterns with  3D printer











the shape patterns on sand, the shapes below are for other pieces to make a modification in my CNC milling machine






The furnace with molten aluminum


----------



## a41capt (Sep 7, 2021)

Well, I REALLY need to become educated in 3D CAD.  What a tool, and I guess I’ll have to sit down at my desk and take the plunge.  I experimented with a student version of SolidWorks several years ago and was making headway when I just went back to paper.  SolidWorks has a program for Veterans, so I guess I’ll bite the bullet and get back to it.  The downside?  Next will be CNC/CAM… one more hobby expenditure! 
Thanks for taking us along for this ride,
John W


----------



## Foketry (Sep 7, 2021)

The casting caps






first machining, 3 mm hole and counterbore






second machining, roughing of the bearing seat and face milling





third machining, separation of the caps with 4 mm end mill , the caps are locked with a jig


----------



## Foketry (Sep 7, 2021)

Milling of  bearing seats  and the surface for cover on the camshaft housing
the planes to be milled are inclined, I built a simple equipment to clamp the camshaft housing in the correct position , at the right angle
Note the holes closed with brass screws, I corrected an error


----------



## Foketry (Sep 7, 2021)

To finish the caps, with the correct size so as not to deform the bearings or, on the contrary, leave gap, I measured the seats one by one to mill the cap 






the finishing milling of the caps


----------



## Foketry (Sep 9, 2021)

Bearing alignment test
to be sure that all bearings rotate well, therefore well aligned and not deformed by the caps I did this test , without gears and cams


----------



## Foketry (Sep 9, 2021)

A further test: transmission gears between crankshaft and camshafts, 15 gears in total :7 gears on the left, 7 on the right, one in the crankshaft













Your browser is not able to display this video.


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## michelko (Sep 9, 2021)

What a beauty !!!!


----------



## propclock (Sep 9, 2021)

Fantastic  !  this motivates me to finally get into casting?  Thanks for the great posts.


----------



## a41capt (Sep 9, 2021)

Getting close!


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## Thommo (Sep 10, 2021)

Magnificent


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## Foketry (Sep 17, 2021)

Another step forward for camshaft
I have temporarily installed the camshafts complete with bearings, aluminum spacers , gear ,intake and exhaust cams  , now  are locked in position by M3 grub screw .
Still to be done: timing, drilling hole for spring pins to lock cams on the camshaft, complete disassembly, cam hardening, final reassembly.


----------



## Thommo (Sep 17, 2021)

I can’t wait to this engine running


----------



## FTX (Sep 18, 2021)

What a wonderfull job


----------



## Foketry (Sep 29, 2021)

Gearbox, lost PLA
To make the gearbox castings I used the lost PLA system. I therefore designed the gearbox in 2 parts , + 2 covers and a connecting flange with engine
Gearbox has a smaller scale than the engine, it would get too long.
I will hide the ignition system in here and perhaps the oil pump if the one provided inside the engine block will not be able to pump all the necessary oil
No internal gears , differential  and clutch, it will be a fake...


----------



## Foketry (Sep 29, 2021)

Printed PLa , note some corrections with cyan wax






PLA molds embedded in plaster






inside the oven to PLA burn, 550 degrees approximately 4 hours


----------



## Foketry (Sep 29, 2021)

The 4 pieces of  gearbox, cleaned of plaster and sandblasted


----------



## Foketry (Sep 29, 2021)

Provisional assembly test with engine


----------



## a41capt (Sep 29, 2021)

Wow, just WOW!!!


----------



## Weldsol (Sep 30, 2021)

Absolutely stunning work

Paul


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## ddmckee54 (Sep 30, 2021)

Foketry:

Those castings look great.  You should post some of your castings on thehomefoundry.org.  They have a Lost PLA forum and I'm sure the guys there would be interested in this work.

I've got a couple of questions:
1) What do you use for an investment?  You say plaster but it almost looks too grainy for plain plaster, sand added maybe?  Is this something you bought, or is it a home-brew?
2) How do you pour into the molds?  In your picture of just the molds, it looks like the molds are open topped.  But in your picture with the molds in the burn-out oven it looks like there's been something added to the top of the molds.  Did you add some type of a pouring basin?
3) You show approximately 4 hours at 550, I'm assuming 550°C?  Any ramp up time, or ramp down time, or is that your entire burn-out schedule?  
4) Do you pour immediately after burn-out with the mold hot, or do you cool the mold?  
5) Do you use a vacuum assist during the pour?
6) How many attempts did it take to get the castings shown?  If you are able to do this in one shot then thehomefoundry.org will definitely want to hear from you.  They'll be jealous and want to know what you do to get such results.

Don


----------



## Foketry (Sep 30, 2021)

ddmckee54 said:


> Foketry:
> 
> Those castings look great.  You should post some of your castings on thehomefoundry.org.  They have a Lost PLA forum and I'm sure the guys there would be interested in this work.
> 
> ...


the aluminum castings you see in the photos are obtained after the second attempt, the blue PLA mold  are those of the first attempt, the castings were not of good quality, I had 2 types of problem, cracks in the plaster and the aluminum did not fill all cavities.  In some areas the thickness is about 2.5 mm and if the temperatures of aluminum and plaster are not correct, the aluminum does not penetrate uniformly.  I repeated the whole process turning the models upside down for slower cooling and more pressure.
I created a containment lip in the plaster to generate more pressure.
In the first attempt i used special foundry plaster, but i had cracks.  In the second attempt I used a first layer of ceramic powder, using a brush to fill in all the small cavities, about 4-6 mm thick.  I let the ceramic dry for 1 hour, I put each piece in a metal container (in case of cracks, the liquid aluminum remains inside the container and does not go on the feet).  I then filled each container with inexpensive plaster, the one that bricklayers use.
I let it dry overnight, put the containers in the oven, 220 degrees C for 2 hours to evaporate the water, then 550 degrees for about 4 hours, this time depends on how much PLA has to melt and burn.
It is important in this second temperature step to turn the containers down to release the liquid PLA.  When no more smoke comes out of the oven, the process is finished, the cavities in the ceramic return perfectly white and clean.
A blow with compressed air to remove powder and you can pour the aluminum.  Very important, the plaster must remain very hot, so when you remove it from the oven you must have the molten aluminum ready. Once poured into plaster , it will take several minutes before solidifying.
Each container is housed in a bucket of sand, safety is important !
I did several tests with foundry plaster of different brands, I also bought plaster in England but I always had cracks problems , with ceramic powder I solved this problem.
I don't use vacuum pumps, a first layer with the brush avoids air bubbles but it could be useful.
I hope my tips are useful to you, but I am not a professional and surely someone else knows the subject better than me.
Needless to say that molten aluminum is very hot and dangerous, always use protective devices , on Youtube you see Indian foundries where very experienced men working without shoes and gloves, we are not so experienced and our skin is very delicate.....
I will visit the site you suggested to me, thanks


----------



## Foketry (Sep 30, 2021)

I


----------



## ddmckee54 (Oct 1, 2021)

A vacuum table would probably help the thin sections fill.  But getting those results on your only your second attempt with these parts is no small achievement - it's a pretty big deal.

It sounds like you're using a combination of the ceramic shell method and the investment block method, to take advantage of the best of both worlds.  

What ceramic power do you use?  The slurries used for ceramic shell sound like they are much thinner than what you are using.  It takes several coats of sand and slurry with them to achieve the 4-6mm thickness you mentioned.  Usually with a substantial drying period between each coat.

How difficult is it to de-mold the part when it's cast?  I know the plaster will pretty much dissolve in a bucket of water, but how hard is it to remove your ceramic shell?

I'm not doing any casting yet, but I've got several projects in mind where cast parts would be almost a requirement.  I've got a 3D printer, and I'm getting better at 3D CAD,  With Lost PLA increasing as a casting method I'm slowly picking up some of the required skills.

I agree with you regarding personal safety, common sense rules - liquid metal is UNFORGIVING.  There'll be no "What happens when you pour molten salt into an aquarium filled with water?" type of experiments for me.   I like my skin the way it is.  In relatively one piece, and not boiled, broiled or baked.

Don


----------



## CFLBob (Oct 1, 2021)

ddmckee54 said:


> A vacuum table would probably help the thin sections fill.  But getting those results on your only your second attempt with these parts is no small achievement - it's a pretty big deal.
> 
> It sounds like you're using a combination of the ceramic shell method and the investment block method, to take advantage of the best of both worlds.
> 
> ...



I don't want to derail this thread because it's one of the best on the HMEM, but I'd like to learn more about this side of things.  I have a small vacuum caster and kiln from doing some silversmithing.  Nothing is big enough to cast any of these models, but I'm at least a little familiar with the process.  

I went to go look around at the Home Foundry, but I'm getting a browser error, which seems to be one of those security certificate date things.  The "advanced" tab in Firefox says, "The certificate for thehomefoundry.org expired on 2/15/2018."  It seems that with being expired over three years, I shouldn't be the only person getting that, so do you know anything about that?  Have you been there lately?  Is there another URL or something?



Bob


----------



## G54AUST (Oct 2, 2021)

G'day Bob.

I've just come from there,  and returned after reading your post above,  and have no probs with the site.

Have you tried a different search engine ???

Did you hold your tongue to the left when pressing the "enter" button ???


Regards,

Trevor,
Melbourne,  AU.


----------



## Foketry (Oct 2, 2021)

ddmckee54 said:


> A vacuum table would probably help the thin sections fill.  But getting those results on your only your second attempt with these parts is no small achievement - it's a pretty big deal.
> 
> It sounds like you're using a combination of the ceramic shell method and the investment block method, to take advantage of the best of both worlds.
> 
> ...



this is the ceramic powder I use such as investment casting :





						Rayher 3410602 Polvere di Ceramica Raysin 100, Polvere di Gesso 25 Kg da Colare, Asciuga All’Aria, Inodore, per Uso Hobbistico e Progetti Creativi, Bianco : Amazon.it: Casa e cucina
					

Rayher 3410602 Polvere di Ceramica Raysin 100, Polvere di Gesso 25 Kg da Colare, Asciuga All’Aria, Inodore, per Uso Hobbistico e Progetti Creativi, Bianco : Amazon.it: Casa e cucina



					www.amazon.it
				




This ceramic powder has the advantage, compared to plaster, it becomes much harder and heat resistant, but very difficult to remove from the piece of aluminum,  water has no effect, you have to remove it in small pieces with a chisel and hammer.


----------



## Foketry (Oct 2, 2021)

CFLBob said:


> I don't want to derail this thread because it's one of the best on the HMEM, but I'd like to learn more about this side of things.  I have a small vacuum caster and kiln from doing some silversmithing.  Nothing is big enough to cast any of these models, but I'm at least a little familiar with the process.
> 
> I went to go look around at the Home Foundry, but I'm getting a browser error, which seems to be one of those security certificate date things.  The "advanced" tab in Firefox says, "The certificate for thehomefoundry.org expired on 2/15/2018."  It seems that with being expired over three years, I shouldn't be the only person getting that, so do you know anything about that?  Have you been there lately?  Is there another URL or something?
> 
> ...


I also had the same problem with Chrome and also with Microsoft Edge, it would be interesting to log in, but there seems to be a problem, a security and invalid certificates


----------



## CFLBob (Oct 2, 2021)

Foketry said:


> I also had the same problem with Chrome and also with Microsoft Edge, it would be interesting to log in, but there seems to be a problem, a security and invalid certificates



I've ignored those warnings in the past and never had an issue with it, but I'm being a bit more cautious when I keep reading about big name companies being compromised all the time.  If everyone else is going there and it's not an issue, it's probably OK.  The fact that you're seeing the same warnings with Edge and Chrome (both of which are on this machine but that I rarely use), but Trevor doesn't get the warning is odd.


----------



## Foketry (Oct 4, 2021)

Cover camshaft, from design to finished cover via SLA resin 3D printer
I split the cover into 2 parts to use my  printer (200x140x200 mm )













Phase of curing with infrared rays to polymerize and harden the pieces after printing







matt black paint






logo painting with rubber roller


----------



## Foketry (Oct 11, 2021)

Transmission from crankshaft to fan and distributors
Through a series of  spur gears, bevel gears and 45 degree gears, a gear in the center of the crankshaft rotates  fan and  2 distributors with different ratios.


----------



## Foketry (Oct 11, 2021)

I designed and 3D printed the fan flange mold , made the aluminum casting and machined


----------



## Foketry (Oct 11, 2021)

Looked for correct position of the hole for 2 distributors gear, a long time was required to align the engine block to the axis of milling spindle
The 2 gears must have as little backlash as possible


----------



## Foketry (Oct 11, 2021)

The assembled transmission


----------



## michelko (Oct 12, 2021)

looking realy nice. is the ventilator scale? it looks a little big in relation to the block.

Michael


----------



## johnmcc69 (Oct 12, 2021)

Amazing work! Bravo!
 I really like how those covers turned out!

 John


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## Foketry (Oct 13, 2021)

michelko said:


> looking realy nice. is the ventilator scale? it looks a little big in relation to the block.
> 
> Michael


Hi Michael
maybe my fan is slightly bigger but it fits inside the intake cones as shown in the photo of  real engine
my photo, being taken closely, makes the fan bigger, but  it is inside the cones


----------



## michelko (Oct 13, 2021)

Jules,
how long do ou estimate for completing the build?
I realy like to hear and see it running.

Michael


----------



## michelko (Oct 13, 2021)

by the way now that the summer is gone i will go on working on the Holt.


----------



## Foketry (Oct 13, 2021)

michelko said:


> Jules,
> how long do ou estimate for completing the build?
> I realy like to hear and see it running.
> 
> Michael



Hopefully, I hope to hear the first pops within the year.
After  first pops I would like to try to build a mechanical injection system but the insuperable problem is the diameter of the injector holes which, according to my calculations for a piston of 26 mm it must be max 0.06 mm.


----------



## Foketry (Oct 13, 2021)

michelko said:


> by the way now that the summer is gone i will go on working on the Holt.


Holt 75, good memories, the first pops of mine


----------



## Alec Ryals (Oct 13, 2021)

Beautiful Work !!!  did You cut the gears


----------



## Basil (Oct 14, 2021)

Foketry said:


> Hi Michael
> maybe my fan is slightly bigger but it fits inside the intake cones as shown in the photo of  real engine
> my photo, being taken closely, makes the fan bigger, but  it is inside the cones
> 
> ...


Nice! Looks like a slide throttle plate.


----------



## michelko (Oct 15, 2021)

Foketry said:


> Holt 75, good memories, the first pops of mine


Wow that slow running is awesome. you can nearly count each single ignition.


----------



## Thommo (Oct 15, 2021)

Hi Foketry. Do you have the holt video in another format? I can’t open this one unfortunately.


----------



## Foketry (Oct 16, 2021)

Thommo said:


> Hi Foketry. Do you have the holt video in another format? I can’t open this one unfortunately.



Hi Thommo
 I also have  Iphone format (.MOV ), but it is too big ,  it is not possible to share it in this forum, which format would you like?


----------



## Foketry (Oct 16, 2021)

Distributors
 This engine has 2 distributors, each for all 12 cylinders, there are 2 spark plugs per cylinder
I built 2 distributors, one for 6 cylinders on the right, the other for 6 cylinders on the left, in my heads there is no space for 2 spark plugs 1 / 4-32 each cylinder , I also made cost savings.
Instead of making 2 tabs and 2 screws to hold the distributor cap in place I put an Oring, this allows the timing by rotating the cap
The magnets and the Hall sensor will be positioned directly on the crankshaft , any backlash on the gears does not affect the timing.
The central electrode is obtained from an electric motor brush by turning


----------



## Foketry (Oct 16, 2021)




----------



## Foketry (Oct 16, 2021)

Transmission gears test


----------



## michelko (Oct 16, 2021)

Foketry said:


> Transmission gears test


Thats realy impressive. You are doing magic.


----------



## Foketry (Nov 1, 2021)

Dry sump oil pump and filter
This racing engine has 7 pumps, 4 scavenge  and 3 for pressure ,I am trying to do everything with one pump, not sure if everything will work, but I would like to try it.
My crankshaft is internally drilled, a 4 mm hole goes through the whole shaft to lubricate all the bushings, 20 positions where oil comes out (i hope) , my 4 camshafts are grease lubricated

Original engine wiht External pump










3-stage internal pump, 2 scavenge 1 pressure


----------



## Foketry (Nov 1, 2021)

The hydraulic circuit of a Porsche 917 dry sump engine , but I have simplified the scheme a lot, no oil tank , non oil cooler ,I don't have to do race.


----------



## a41capt (Nov 1, 2021)

Foketry said:


> The hydraulic circuit of a Porsche 917 dry sump engine , but I have simplified the scheme a lot, no oil tank , non oil cooler ,I don't have to do race.
> 
> View attachment 130508


I’m thinking that you’re not going to run the 24 hours of LeMans, so redundancy on oil pumps (even though that may have been a secondary consideration/benefit of the original design) probably is unnecessary. Chances are you’ll see what the end of circuit oil pressure looks like before it becomes critical.

Beautiful work so far, looking forward to the first “pop”!

John W


----------



## Foketry (Nov 1, 2021)

My first problem to solve was  : what kind of pump ? gear pump or gerotor pump ?

The square pump is Volkswagen automatic transmission pump , more than 100 bar, up to 4000 rpm
the triangular pump is a gerotor pump for moped , the technical characteristics are unknown, cost : few euros












I did a bench test for both, the Wolkswagen gear pump only works with low viscosity hydraulic oil, the motor oil is too hard and the pump has cavitation due to inadequate flow. the oil inlet hole could be enlarged, but there is little space.

The gerotor pump has a low pressure, a sufficient flow rate and the oil passes through the entire crankshaft and also exits through the furthest bearing hole.
I therefore use this small pump.


----------



## Foketry (Nov 1, 2021)

Oil filter: I looked for a small oil filter whose dimensions were compatible with my engine model , I found a very small filter in Italy, it is a Piaggio Vespa replacement


----------



## Foketry (Nov 1, 2021)

I place  pump in the side cover, the oil that comes out of the crankshaft holes falls into the crankcase, from here by gravity reaches the pump intake hole and is pumped under pressure through the filter and then on one side of the crankshaft.
Here an oil seal with a lip facing outwards allows the oil to exit only through the inlet hole of the crankshaft.

in this old design the pump was inside  crankcase, but is now external


----------



## Foketry (Nov 1, 2021)

Pump cover: drawing, 3D model pattern , aluminum casting


----------



## ddmckee54 (Nov 1, 2021)

I see very few layer lines on the casting.  Do you just sand the patterns, sand and fill them, or something else?  How big is the casting?  Judging from the fingers in the picture, I'm guessing it's about 4 inches long?

Don


----------



## Foketry (Nov 2, 2021)

ddmckee54 said:


> I see very few layer lines on the casting.  Do you just sand the patterns, sand and fill them, or something else?  How big is the casting?  Judging from the fingers in the picture, I'm guessing it's about 4 inches long?
> 
> Don



Pattern is painted with polyester filler and sanded , the length is 5.3 inches
Casting is not perfect, there was a shrinkage in the upper part where the thicknesses are large, due to the lack of aluminum supply during cooling, I should have placed  vent or feeder in that area . It's a lesson learned for next time.


----------



## ddmckee54 (Nov 2, 2021)

So is this casting still usable, or will you re-cast it?


----------



## Foketry (Nov 2, 2021)

ddmckee54 said:


> So is this casting still usable, or will you re-cast it?



it is a cosmetic defect that can be solved, I can use it after a little file work


----------



## Foketry (Nov 3, 2021)

covers with installed pump


----------



## Foketry (Nov 3, 2021)




----------



## Foketry (Nov 3, 2021)

some machining, cover and seal ring seat


----------



## michelko (Nov 3, 2021)

Man thats a real clever design on the oiling system


----------



## ddmckee54 (Nov 3, 2021)

Foketry:

I get it that the oil seal stops leaks around the crankshaft as it's rotating, allowing the crank to be pressurized by the oil chamber.  But what seals the oil chamber to the crankcase?  Is there a gasket that is yet to be installed?  Leaving it out for now would be understandable if you're just checking the fit of the parts.

Don


----------



## michelko (Nov 3, 2021)

I used Curil with good results for this


----------



## Foketry (Nov 3, 2021)

ddmckee54 said:


> Foketry:
> 
> I get it that the oil seal stops leaks around the crankshaft as it's rotating, allowing the crank to be pressurized by the oil chamber.  But what seals the oil chamber to the crankcase?  Is there a gasket that is yet to be installed?  Leaving it out for now would be understandable if you're just checking the fit of the parts.
> 
> Don



I normally use this Loctite product for all gaskets below 200 degrees centigrade : 
Here you can see  data sheet
LOCTITE SI 5940


----------



## ddmckee54 (Nov 4, 2021)

That looks like some good stuff, I'll have to get some.  I've got a couple of Cub Cadets with leaking differential covers that it should work wonders on.  When I looked at the data sheet it listed a working temperature range of -50° to 200° C.  I didn't see a recommended application temperature range, do you happen to know what that is?

Don


----------



## Foketry (Nov 4, 2021)

ddmckee54 said:


> That looks like some good stuff, I'll have to get some.  I've got a couple of Cub Cadets with leaking differential covers that it should work wonders on.  When I looked at the data sheet it listed a working temperature range of -50° to 200° C.  I didn't see a recommended application temperaturfe range, do you happen to know what that is?
> 
> Don


An application temperature is not foreseen because a particular temperature is not required, the ambient temperature is always good


----------



## Foketry (Nov 16, 2021)

Oil filter

I chose to build  filter components by scratching from solid instead of casting , the filter receives oil via pump through internal holes and sends clean oil to the crankshaft via holes in the cover.


----------



## Foketry (Nov 16, 2021)

filter temporarily fixed to the pump cover


----------



## a41capt (Nov 16, 2021)

I am curious, what weight oil will you run?  With your tight tolerances (unlike my shoddy and sloppy fits!), is this a concern?

More excellent work, thanks for taking us along on the ride!

John W


----------



## Foketry (Nov 16, 2021)

a41capt said:


> I am curious, what weight oil will you run?  With your tight tolerances (unlike my shoddy and sloppy fits!), is this a concern?
> 
> More excellent work, thanks for taking us along on the ride!
> 
> John W



I have not made any calculations for amount of oil, I will establish it with practical tests. it is a dry sump engine, I have never built an engine without oil in  oil pan, I will have to do dozens of tests, when the engine may work .....


----------



## ddmckee54 (Nov 17, 2021)

Foketry:

What's your filter cartridge from?  I like the idea of a working oil filter on a model engine.

Don


----------



## Foketry (Nov 17, 2021)

ddmckee54 said:


> Foketry:
> 
> What's your filter cartridge from?  I like the idea of a working oil filter on a model engine.
> 
> Don


yes it's a cartridge , it is a Piaggio Vespa replacement
In a previous post 247 you can understand the real size


----------



## ddmckee54 (Nov 19, 2021)

I must have missed that post.  It's hard to believe that Vespa used an oil filter that small.  I thought maybe is was a fuel filter cartridge that you were using for an oil filter.  How did you find out about that filter?

Don


----------



## Foketry (Nov 20, 2021)

ddmckee54 said:


> I must have missed that post.  It's hard to believe that Vespa used an oil filter that small.  I thought maybe is was a fuel filter cartridge that you were using for an oil filter.  How did you find out about that filter?
> 
> Don


i found that filter on ebay :
FILTRO OLIO OIL FILTER POLINI HYOSUNG RT Karion 125 2004>2009  | eBay


----------



## Foketry (Nov 28, 2021)

Intake manifold

Real engine has a mechanical injection system and injectors spray directly into the 12 intake bellmouth

I will put a carburetor on the right for 6 cylinders and one on the left for other 6 cylinders, making a small-scale injection pump is very complicated, for example the injector hole that atomises  petrol should have a diameter of 0.06 mm in my engine. 
 I think it is not possible, perhaps only with  laser can such small holes be made.


----------



## Foketry (Nov 28, 2021)




----------



## Foketry (Nov 28, 2021)

I used brass to build manifold to weld very easily  flanges , oval tube and carburetor flange.
Deforming a round tube with the vice I obtained an oval tube , the 12 fixing flanges to the heads were made by brass casting


----------



## Foketry (Nov 28, 2021)

before welding


----------



## Foketry (Nov 28, 2021)

2 finished intake manifolds after water leakage test






leakage test


----------



## Foketry (Nov 28, 2021)

The manifolds screwed to the engine, each head has an OR


----------



## davidyat (Nov 29, 2021)

*Foketry, there are time when someone is TOO good. You're one of them. Absolutely beautiful superb work.
Grasshopper*


----------



## CFLBob (Nov 29, 2021)

davidyat said:


> *Foketry, there are time when someone is TOO good. You're one of them. Absolutely beautiful superb work.
> Grasshopper*



Absolutely.  Honestly, this deserves to be in a museum!


----------



## a41capt (Nov 29, 2021)

Engineering ingenuity at its finest!  Amazing workaround Pard, can’t begin to understand how you develop and implement your planning and work.
John W


----------



## ddmckee54 (Dec 3, 2021)

Foketry:

Back around Post #213 we were discussing thehomefoundry.org and the security issues with that web-site.  I mentioned those issues on that web-site this morning and got this reply from DavidF, one of the site's administrators.

"That's because of the https not showing on all the web pages. There is nothing " unsafe " its just I need to pay for a blanket ssl to keep the computer gods happy.  Tell him ignore it and continue to site..."

I've tried both Chrome and Edge, and they will both puke over the site being "un-secure".  However, the browser that came loaded on this Windows10 machine has NO problem with the site.  I regularly visit that site and none of my machines has crashed and burned - yet.

Don


----------



## Foketry (Dec 8, 2021)

*Hoop fan housing and bellmouth mounts*

I made the cones by deforming an aluminum tube with a conical mold, the first one I made is cracked, I solved the problem by annealing the tube and keeping the flame even during pressing.
Of course  cones are fake, there will be a carburetor every 6 cylinders, instead of injection.

The colored pieces in the photos are 3D printed, painted with primer and yellow final top coat.


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## Basil (Dec 8, 2021)

That does look awesome. Amazing build!!   Cant wait to see it run. I have an interested to see how the large diameter mains work. I have previously thought many times on this approach but never had the courage to try it. Theory of course says that drag will be on the high side but these engines we build are for the most part not being used for any power producing purposes. I very much hope too see it run brilliantly.


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## a41capt (Dec 8, 2021)

Truly beautiful engineering Foketry!  I too cannot wait to hear it come to life, it’ll be an amazing event!

John W


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## propclock (Dec 8, 2021)

Fantastic.  Thanks for all your posts.


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## Thommo (Dec 9, 2021)

Foketry said:


> *Hoop fan housing and bellmouth mounts*
> 
> I made the cones by deforming an aluminum tube with a conical mold, the first one I made is cracked, I solved the problem by annealing the tube and keeping the flame even during pressing.
> Of course  cones are fake, there will be a carburetor every 6 cylinders, instead of injection.
> ...


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## Foketry (Dec 18, 2021)

*Fan conveyor*

In  original engine, a system of aluminum sheets conveys the air flow from fan towards  cylinders and heads.
This ensures  proper cooling of the engine, remember that this engine won the Le Mans 24 hours race for many years.
In order not to hide all the work done, I preferred to use a Makrolon sheet (similar to Plexiglass) to make this conveyor.
MaKrolon can resist temperatures up to 160 degrees C






my draw







milling, end mill 4 mm, 9000 rpm


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## Foketry (Dec 18, 2021)

After milling, the 4 edges had to be bent , I used this method seen on Youtube recovering the resistance from an old hair dryer


----------



## Foketry (Dec 18, 2021)




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## Foketry (Dec 29, 2021)

*Exhaust pipes and gearbox*

After countless attempts and scraps , I assembled the exhaust pipes
I used 12 pipes with external diameter of 12 mm (about half an inch), internal 10 mm and 4 pipes with 20 mm external diameter. I filled the pipes with sand  , I screwed  2 caps at the ends, heated the pipes until they reached red color and bent. The internal sand does not allow the pipe to get crushed.
All the tubes were silver brazing with a welding jig to keep them in correct position. I painted everything with 800 C paint for mufflers.

Porsche engine










My Engine
The original Porsche exhausts have a strange shape, 6 in one, I was willing to copy this geometry but then I decided to make 4 main exhaust pipes instead of just 2.


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## Foketry (Dec 29, 2021)

To connect the 3 pipes together I made a brass casting , each tube is fixed to the head with a brass flange, 3 screws and a Viton oring.












some scraps


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## michelko (Dec 29, 2021)

Sweet.
Greetings from italy.


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## Basil (Dec 29, 2021)

Very impressive!


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## a41capt (Dec 29, 2021)

Nice bit of “plumbing”!  Did you use your heads as the target block, or make a special form?

John W


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## ddmckee54 (Dec 29, 2021)

At the job I had many years ago - I used to have to bend up replacement hydraulic lines for machine tools.  We also had plenty of "rejects" in the scrap barrel, and we always checked the scrap barrel first to see if we could make a reject work for the line we wanted.

It doesn't take much of a boo-boo to turn a good part into a bad part does it?  Not a problem for you with the exhaust headers, but putting the nut on backwards before you make the final flare in a tube is SOOOO easy to do. 

Don


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## Foketry (Dec 29, 2021)

a41capt said:


> Nice bit of “plumbing”!  Did you use your heads as the target block, or make a special form?
> 
> John W


As you can see in the second to last photo, I clamped in a vice a rectangular aluminum tube with  center distance of holes equal to the distance between heads.
On this tool I also fixed the brass flanges with 3 screws during silver brazing.


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## Foketry (Dec 29, 2021)

michelko said:


> Sweet.
> Greetings from italy.



Are you in Italy now ?


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## michelko (Dec 29, 2021)

Foketry said:


> Are you in Italy now ?


Yes we are skiing in obereggen/predazo/pampeago.


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## Steamchick (Dec 30, 2021)

I think that is an expert job! When it looks so simple - and right - there is an expert at work. Thanks for the insights into your work. It sets a standard I (or "many of us"?) don't even dream of achieving!
Well done!
K2


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## Thommo (Dec 30, 2021)

I just cannot wait to hear this beast run!!!


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## a41capt (Dec 30, 2021)

Foketry said:


> As you can see in the second to last photo, I clamped in a vice a rectangular aluminum tube with  center distance of holes equal to the distance between heads.
> On this tool I also fixed the brass flanges with 3 screws during silver brazing.
> 
> View attachment 132305


Sorry, I completely overlooked the picture you mention!  While in the US Navy, my rating was Shipfitter which included all different forms of ship’s repair duties.  From heavy plate, sheetmetal, high pressure hull and pipe welding, and fitting new pipes.  As you can imagine, removing formed pipes that were damaged back to my Tender ship to rebuild, we would be faced with alignment issues with flanges, and also need to replicate obstructions and precise bends.  That is where the “Target Deck” came in handy as we were able to bolt the original piping to flanges welded to stands, and additional marker pieces as obstructions/bend points.

Your aluminum plate in a vise approximates our old target deck perfectly. Thanks for the clarification.

John W


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## Foketry (Jan 4, 2022)

*Engine mounting bracket*

To support the engine the time has come to abandon pieces of wood, so I designed some aluminum brackets. The brackets are made by casting aluminum, so I printed the foundry mold .










undergoing 3D printing






2-piece mold






aluminum castings





sandblasted and drilled





assembled with motor


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## ddmckee54 (Jan 4, 2022)

Foketry:

I know that you printed the molds for these parts, but when you cast these parts, were they sand-cast or was it lost PLA like some of your other parts?

Don


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## Foketry (Jan 4, 2022)

ddmckee54 said:


> Foketry:
> 
> I know that you printed the molds for these parts, but when you cast these parts, were they sand-cast or was it lost PLA like some of your other parts?
> 
> Don



these pieces are sand cast (Petrobond first layer in contact with the mold , green sand all the rest .
I use lost PLA when the pieces are complex and need some cores.
Lost PLA is expensive, takes many hours in the oven, plaster and electricity cost a lot. If I make a mistake, I have to redo everything from the beginning.
 Sand casting , the whole process is simple, visible and more controllable.


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## Steamchick (Jan 6, 2022)

I am simply impressed....
Enjoying your endeavours!
Well done!
K2


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## Foketry (Jan 15, 2022)

*Ignition, first step*

For this engine model I prefer to put 2 ignitions, one for the six cylinders on the right, one for the 6 cylinders on the left. If this engine does 3000 rpm (I hope) 36,000 sparks per minute will be needed.
I think that dividing the necessary sparks by 2 ignitions will give me less problems to solve.
Place the pick ups directly on the crankshaft instead of on the camshafts, it will give me a more precise timing, not affected by gear backlash.
Each of the 4 camshafts is driven by 6 gears and backlash is inevitable.

I chose 2 GY6 CDI ignitions normally used on small motorcycles, reliable and very cheap
Pick ups can be  Trigger or Hall type , in this post  tests with Hall sensor





						Model engine CDI easy and cheap
					

It works  :p Thanks for all




					www.homemodelenginemachinist.com
				



Inside the gearbox I have the useful space to hide 2 pickups, I chose this solution























the pick ups can be rotated to find the correct timing


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## Foketry (Jan 15, 2022)

2 distributors






CDI ignition





Hall sensor circuit


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## ajoeiam (Jan 16, 2022)

Foketry said:


> 2 distributors
> 
> CDI ignition
> 
> ...



I can't wait to see this thing when its all done.
Then a short video to hear it - - - - that's going to be wonderful!!!!!!!!!!!

Great work by the way!!!!!!!!


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## michelko (Jan 17, 2022)

Hi have you thought about some sealing around the dizzy shaft? I made the experience that after some time oil made its way into the cap and the engine stoped running.
I made an return screw onto the shaft. Why do you use ballbearings there? I had good results with just bronce or brass buschings in the dizzy.
Can you say something about that hall circuit?
Somewhere i saw a thread about those chinese cdi having trouble be triggered with a hall.
As allways fantastic work !!!!!

Michael


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## Foketry (Jan 17, 2022)

michelko said:


> Hi have you thought about some sealing around the dizzy shaft? I made the experience that after some time oil made its way into the cap and the engine stoped running.
> I made an return screw onto the shaft. Why do you use ballbearings there? I had good results with just bronce or brass buschings in the dizzy.
> Can you say something about that hall circuit?
> Somewhere i saw a thread about those chinese cdi having trouble be triggered with a hall.
> ...


Hi Michael
The crankshaft has 2 oil seals at the ends, has 1 axial stop on each side and rotates on bronze bushings, but the bearings should work too, I have already built the Bugatti engine on bearings.
About the Hall sensor applied on the CDI, I did some tests on the lathe and it works well, the final test I will do it on this engine, but I am confident,  there is a very long thread on this forum about this, you can find it in my previous post.


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## michelko (Jan 17, 2022)

Hi Lules,
maybee a little misunderstanding
the question was not directed to the crank or camshaft bearings. The drawing of the dizzy showes also two bearings. i am affraid that through these bearings oil will creep up into the Cap. I noticed this on my bugatti and also on the W.T. Seal.

Michael


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## Foketry (Jan 17, 2022)

michelko said:


> Hi Lules,
> maybee a little misunderstanding
> the question was not directed to the crank or camshaft bearings. The drawing of the dizzy showes also two bearings. i am affraid that through these bearings oil will creep up into the Cap. I noticed this on my bugatti and also on the W.T. Seal.
> 
> Michael


ok, I understand, you refer to the distributor, in this engine the oil level is very low, the pump sends it through the crankshaft, I don't think it will arrive inside the distributor, if the first tests highlight this problem I will put a small oil seal.


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## Foketry (Jan 23, 2022)

*Check for piston and valve leaks ,tappet thickness adjustment, valve timing, engine painting*

Before timing all the cams I checked the air leaks once again with this instrument, it is composed of 2 pressure gauges that measure the difference in pressure between the air inlet and leaks through valves and ring. Air inlet through the spark plug hole.
I adjusted the thickness of  tappets, measuring, reducing the thickness on lathe, checking the backlsh, again lathe, again checking,  etc etc , 2 days only for the tappets












*Valve timing*

I adjusted the opening and closing of the valves using a digital angle measuring instrument, all the cams are independent of each other and then I adjusted 24 cams. For now they are temporarily locked by grub screws , then I will put a spring pin. I chosen to make 24 single cams instead of 4 camshafts because it is easier to mill them .
To find the opening and closing point I put compressed air in the cylinder and rotated the single cam, when I hear blowing air, the noise is very audible, that is the precise point.


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## a41capt (Jan 24, 2022)

I love the precision of your build.  Valve timing on 24 valves for 12 cylinders!  I’m glad it’s you and not me, I’m damn sure I’d never be able to get it right.  I had a hard enough time getting my Ford Kitchen Sink engine running. 

John W


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## Foketry (Jan 30, 2022)

*Ignition  , distributor caps with cables and 12 spark plugs*

I screwed the spark plugs on an aluminum plate, I mounted the distributor caps on the engine and by rotating it with the cordless drill I checked the firing order  1-9-5-12-3-8-6-10-2-7-4-11


*
















Ignition test*




Your browser is not able to display this video.


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## michelko (Jan 30, 2022)

Those are some nice boots on the dizzy cap.
From where do you get them?

Michael


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## Foketry (Jan 30, 2022)

michelko said:


> Those are some nice boots on the dizzy cap.
> From where do you get them?
> 
> Michael


They are spare parts for Dellorto carburetors








						Kit 4 cappucci cavi per carburatori VHBT- PHBH - PHM per Moto Guzzi da 350 a 750 - www.motogiovane.com
					





					www.motogiovane.com


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## Foketry (Feb 21, 2022)

I spent several days doing the tests, ignition and carburetors.

Regarding the carburetors I have tried many different sizes, from Venturi 14 mm to Venturi 7.6 mm
I thought that for a 26 mm diameter piston and 9 mm valves a large carburetor was needed, at least 11 -14 mm, in fact I learned that 8 mm venturi bore is optimal for this 12 cylinder engine.
This is because through a small Venturi the speed of the gases is greater and therefore there is a better mixing between air and petrol. in addition to this, a higher speed reaches bettere the cylinders far from the carburetor.

Also one of the 2 electronic ignitions gave me problems, the timing was not constant, it jumped back and forth.
I discovered after several tests that the pick up for cylinders 1-6 lost its pulses and delayed them, but not always.
I waited 10 days for a new pick up and now everything seems to work.

It is very complicated to fine-tune the timing and carburetion of an engine with 2 carburettors, 2 ignitions, 2 distributors. 
I did all the tests on only 6 cylinders on the left (1-6), removing the spark plugs in the other 6 cylinders. The 2 carburettors must also be synchronized with each other, the valve must open at the same time and by the same quantity

The engine is not perfect yet, but I hope to optimize everything to the fullest


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## Foketry (Feb 21, 2022)

*Display base with electronic ignitions












*

after painting, primer and top coat


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## petertha (Feb 21, 2022)

Foketry said:


> Regarding the carburetors I have tried many different sizes, from Venturi 14 mm to Venturi 7.6 mm
> I thought that for a 26 mm diameter piston and 9 mm valves a large carburetor was needed, at least 11 -14 mm, in fact I learned that 8 mm venturi bore is optimal for this 12 cylinder engine.
> This is because through a small Venturi the speed of the gases is greater and therefore there is a better mixing between air and petrol. in addition to this, a higher speed reaches bettere the cylinders far from the carburetor.



I know its more complicated than this, but FWIW the carb orifice size you eventually selected lands like so on these cross plots I made of various 4-stroke OS brand (methanol glow) engines.


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## mayhugh1 (Feb 21, 2022)

What coil are you using? Also, could you say bit more about how you're using the electronic protractor to set valve timing? Is there a remote sensor or is the whole protractor attached to a degree wheel?   Thanks - Terry


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## Foketry (Feb 22, 2022)

petertha said:


> I know its more complicated than this, but FWIW the carb orifice size you eventually selected lands like so on these cross plots I made of various 4-stroke OS brand (methanol glow) engines.



Very interesting your analysis, I will take note .
in my engine, 2 out of 6 cylinders are in the intake phase at the same time. Let me explain better: one cylinder starts the intake phase while another cylinder is completing the intake phase, this roughly means that 1.3 cylinders are sucking simultaneously from 1 carburetor. So I thought that a large diameter Venturi was needed, instead small is better


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## Foketry (Feb 22, 2022)

mayhugh1 said:


> What coil are you using? Also, could you say bit more about how you're using the electronic protractor to set valve timing? Is there a remote sensor or is the whole protractor attached to a degree wheel?   Thanks - Terry



The coil I am using is for motorcycle, I think it can only work in conjunction with the GY6 electronic ignition
Regarding the electronic goniometer it is composed of 2 parts, a rotation sensor and a display
I use it for camshaft timing with this procedure: I fix the protractor the protractor to the camshaft (or to the crankshaft) to indicate the TDC of each cylinder, through the spark plug hole I introduce compressed air into the cylinder with both valves closed (each cam can rotate individually on the shaft )
I rotate the cam until I hear a flow of air coming out of the intake duct,
I rotate the exhaust cam until I feel that the flow of air stops , this is the exact valve crossover point, without overlap at TDC
If I want to overlap I advance the intake valve and delay the exhaust valve. In my case I look for the regularity of the engine rather than the performance, therefore little or zero overlap.
Are you using overlap?

Coil link








						7.91US $ 20% di SCONTO|Candela a 6pin Racing Performance CDI candela accensione per Gy6 150cc 125cc 50cc WEQ candela accensione|Accensione moto|   - AliExpress
					

Smarter Shopping, Better Living!  Aliexpress.com




					it.aliexpress.com
				




There is an interesting series of posts about this kind of ignitions on this forum, PaulC  replaced the big pick up with a Hall sensor ,  works well !

I bought the electronic protractor in England, if necessary I provide the link to you

Greetings and congratulations for your splendid engine, you are a reference for me, I am learning a lot from you


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## propclock (Feb 22, 2022)

I may be late to reply on this. But I have found CDI ignitions
make a LOT of electronic / rf noise. I suggest you try running
1 system and see if  you get any sparks from the powered up
but hall removed from the distributor of the disabled system. Often the cdi #1 will trigger system #2.  I worked on an engine with 2 distributors on a v8 made to look like a dragster.  I finally had to go to Kettering to maintain the 2 distributors . Also beware of cdi units that have automatic spark advance .
 Hard learned lessons. 
Just for what it is worth. 
 You might try a resistor on the HV
coil output lead, 2k??? carbon composition if you have this problem.

Your engine is absolutely fabulous.


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## Foketry (Feb 22, 2022)

propclock said:


> I may be late to reply on this. But I have found CDI ignitions
> make a LOT of electronic / rf noise. I suggest you try running
> 1 system and see if  you get any sparks from the powered up
> but hall removed from the distributor of the disabled system. Often the cdi #1 will trigger system #2.  I worked on an engine with 2 distributors on a v8 made to look like a dragster.  I finally had to go to Kettering to maintain the 2 distributors . Also beware of cdi units that have automatic spark advance .
> ...



I confirm that electronic ignitions make a lot of electrical noise, not only the GY6 but generally all those for engine models.
For example I had a bad experience with the 3D printer, it was printing for over 12 hours, I started my little Demon V8, the printer froze and I had to completely redo the part.
These 2 ignitions also generate rf noise but don't disturb each other and don't give problems to the distributors.
Strangely they don't have automatic advance, I don't know why
In any case, the ignition receives 3 impulses from the pick up for each revolution of the crankshaft, my engine model does not go below 1000 rpm, it means 3000 impulses, (6 cylinders ) , the automatic advance is already exceeded.
I am still in the testing phase, some surprises could happen, I take into account your suggestions, a 1 or 2 K resistance could be necessary
Thanks


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## Rdean33422 (Feb 24, 2022)

Does anyone know of a carb that has a venturi size of 4.5mm or about.  I am finding it hard to find any specs on RC carbs.  Any help will be appreciated.

Ray


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## Foketry (Feb 24, 2022)

Rdean33422 said:


> Does anyone know of a carb that has a venturi size of 4.5mm or about.  I am finding it hard to find any specs on RC carbs.  Any help will be appreciated.
> 
> Ray








						Porsche 917  flat 12 engine
					

Engine mounting bracket  To support the engine the time has come to abandon pieces of wood, so I designed some aluminum brackets. The brackets are made by casting aluminum, so I printed the foundry mold .    undergoing 3D printing    2-piece mold    aluminum castings   sandblasted and drilled...




					www.homemodelenginemachinist.com
				




here Petertha has published 3 tables that can help you


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## petertha (Feb 24, 2022)

Rdean33422 said:


> Does anyone know of a carb that has a venturi size of 4.5mm or about.  I am finding it hard to find any specs on RC carbs.  Any help will be appreciated.
> Ray



Yes, this web site is a good repository of legacy engine articles, but you have to kind of data mine the information.


			Sceptre Flight
		


If you happen to know the orifice size of a commercial engine, you can sometimes get good deals on used carbs... with engines included LOL. There are a couple of RC forums out there to peruse or write a wanted ad. Sometimes Ebay too. They generally don't wear out, just get abused or gummed up. Tiny O-rings used to be hard to source but I just got a kit of tiny silicone metric ones off AliExpress for cheap.





						Aircraft - Fuel - Engines and Accessories (FS/W) - RC Groups
					

Aircraft engines and accessories.




					www.rcgroups.com
				




Regarding new, Conley took over the Perry line & has progressive carb sizes & spare parts. Maybe not quite as appealing as die cast say an OS or Saito, but functionally probably do the same job & lower cost.


			Perry Pumps - Carbs
		


In that range you might find something in RC car carbs, but I'm on uncharted waters there. I think many are slide valves. And some of the lower displacement engines like 0.15-0.21 CI actually have big openings as a function of their rpm/application.

I would also add - pay attention to needle valve & throttle arm position if your engine application is somewhat constrained. Also the throat body diameter varies quite a bit between carbs, so it pays to have some adaptability in your manifold design if you want to try different ones.


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## Rdean33422 (Feb 24, 2022)

Thank you both very much your suggestions will put me on the right track.

Ray


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## Foketry (Mar 11, 2022)

*The first pops*
The engine works, but some improvements are needed
Ignition system: the pick ups are not stable
It is necessary to redo the supports, now they are 3D printed in plastic (PLA), I redo them with aluminum
The intake manifold ducts are too large, I had designed them for a 12-14 mm Venturi diameter carburetor, while a 6 or 8 mm carburetor gave the better results
Speed of air / petrol flow is higher with a 6 mm carburetor, the pulverization is better and therefore the cylinders furthest from the carburetor can be reached more efficiently. In fact cylinders 1 and 6 and 7 and 12 are colder than all the other 8 central cylinders because they are less efficient, poorer air / petrol mixture


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## a41capt (Mar 11, 2022)

Congratulations!!!


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## mayhugh1 (Mar 11, 2022)

Foketry said:


> *The first pops*
> The engine works, but some improvements are needed
> Ignition system: the pick ups are not stable
> It is necessary to redo the supports, now they are 3D printed in plastic (PLA), I redo them with aluminum
> ...


One of the best projects ever on this forum ...


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## a41capt (Mar 11, 2022)

mayhugh1 said:


> One of the best projects ever on this forum ...


Agreed!  I only wish I had the tiniest bit of talent exhibited in this build.  Beautiful!

John W


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## Makin chips (Mar 11, 2022)

Excellent!!


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## FTX (Mar 12, 2022)

Perfect sound. Congratulation.
Ftx


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## stevehuckss396 (Mar 12, 2022)

All of the above! Nice project and thanks for posting progress


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## Eccentric (Mar 12, 2022)

Fantastic, a great looking and sounding engine. Amazing undertaking, I especially liked watching your casting techniques.  Thank you for posting your progress, I thourghly enjoyed following along.


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## michelko (Mar 13, 2022)

awesome build


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## natalefr (Mar 13, 2022)

Wow !


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## propclock (Mar 13, 2022)

Well other than the great feeling you already feel
all I can say is, enjoy.!!
 Nothing like the first run. 
Fantastic. 
You just might have pushed this guy over into pouring metal, 
Great post, I have always followed ,  Just congratulations. 
Paul


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## jetstuff (Mar 14, 2022)

How amazing, congratulations, and just 1 year to produce.


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## Foketry (Mar 14, 2022)

Here are the improvements I have planned to make the engine less rough, with a more constant progression from idle to max
1)Aluminum ignition pick up supports with 2 bearings instead of plastic and a single bearing


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## Foketry (Mar 14, 2022)

2) Flywheel connected with crankshaft and adjusting screw for adjustable advance , the pick up support can rotate through the two bearings even while the engine is running


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## Foketry (Mar 14, 2022)

3) Intake manifolds with different geometry

this is the old manifold, inlet hole for carburetor 12 mm






the new manifold, tin-welded and sandblasted brass tubes , inlet hole for carburetors 6 or 8 mm


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## stanstocker (Mar 15, 2022)

There have been many nice, good projects over the years, even done a few myself.  Then there are those projects you always remember, because they are so complex, so well executed, and just so impressive.  The sort of project that inspires a person to learn more, do better, try new things, even with the knowledge that they will probably never reach the level of the project that is inspiring them.  This is one of those gaze in awe projects.  

Folks like you, Mayhugh1, Lou Chenot, and the others who do such fine work inspire me to keep learning and trying new things.

Reading each new post has been like the old westerns, wondering what our hero will do next or how he'll get out of this pickle.

Congratulations on your magnificent achievement.  
Stan


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## Ken1 (Mar 16, 2022)

Nice engine !!!!


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## Foketry (Mar 16, 2022)

*Some photos of the engine being completed .*
I installed the new intake manifolds and improved the pick up supports , the engine works better ,in a few days the new video


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## Arild (Mar 17, 2022)

Very nice work! I'm really impressed! Did this engine originally have carburattor, or only injection? If carb, your next move must be to buy/make 12 model r/c carburattor and have those venturi to do some real work!


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## Foketry (Mar 17, 2022)

Final video: the engine smokes a bit because I put oil in the petrol and the oil level is high, the engine is still running in


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## Foketry (Mar 20, 2022)

Ferrari F1, first and second place in the Bahrain race, finally a good engine from Motor valley


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## Vixen (Mar 20, 2022)

Complimenti Ferrari, una vittoria meritata


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## Jan Dressler (Mar 20, 2022)

Being a fan of the team since I watched Prost vs Senna in 1990 at 10 years of age... Since then, following every season with interest. 

Have been at the test track in Fiorano in 2007 with my Formula Student team back then (we had to sign various contracts before, quite literally saying that if any team member would be run over by a Ferrari test car there, their relatives would have to pay the damage to the car).

Was an incredible event, including Luca di Montezemolo driving the Turin car through a crowd, after it finished the race... Utterly impossible elsewhere. 

If I remember right, we were third in the final endurance event... With a car hanging in 2nd gear, the pneumatic shifter had failed. Having developed the dry sump system, I was dying every time our car went out on the straight at 13000 rpm, in the rev limiter.. Memories  

Whatever... Forza Ferrari


----------

