18 Cylinders Isotta Fraschini (straight six-cylinder x3 )

[Foketry]

Electronic ignition test with oscilloscope

I asked my friend who builds the ignitions to check how many sparks per minute his ignition can make, if my engine will make 3000 RPM it needs 27000 sparks per minute.
its ignition can reach 120,000 sparks per minute, here are the photos on the oscilloscope

 

[lee webster]

To cut down on the spark jumping all over the place in an Austin Seven distributor cap, we would spray the inside with WD40. It could be worth a try.

 

[stevehuckss396]

Try reducing the spark plug gap. A smaller gap at the plug will give you a higher probability that the arc will be at the plug instead of in the cap. Try a .015 inch gap. I run my v8 at .012 and it helped out tremendously.

 

[Richard Fryer]

Has this fantastic project come to a halt?

 

[Foketry]

Has this fantastic project come to a halt?

Hi Richard , the project is not stopped, I had other commitments so I worked for a short time on the project, but I'm on the home stretch.
I had to redo some pistons and cylinders due to overheating and seizure, but I will be more precise in the next few days.... weeks

 

[Richard Hed]

Wait a minujte, I have only followed this in passing. I thot this build was a 2X9 cylinder. You're saying this is a 6X3? Fantastic.

 

[Richard Hed]

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

View attachment 136674

View attachment 136673

OKf, is see it from the original post--EXTREMELY interesting.

 

[ddmckee54]

If you're replacing pistons/cylinders due to overheating, that means the beast has been running long enough to overheat - right? Don't keep us in suspense, I can't hold my breath for much longer. Enquiring minds want to know, what's it sound like?

 

[Foketry]

If you're replacing pistons/cylinders due to overheating, that means the beast has been running long enough to overheat - right? Don't keep us in suspense, I can't hold my breath for much longer. Enquiring minds want to know, what's it sound like?

The engine has made its first pops and is working, it still needs to be improved and refined, for now it only works at minimum rpm, I have to understand how to improve but all 18 cylinders work. When I accelerate it turns off. Maybe it's a problem with the carburetors, which are too small? too big ? ignition timing too early?

 

[Foketry]

Isotta Fraschini 18 cylinder: problems detected on first starts :

Distributor cap with irregular functioning
Pistons with low compression
Pistons with too much friction in the cylinders
Geometric shape of the pistons with oil accumulation in the spark plug area
Burnt Teflon head gaskets
Intake manifolds with geometry that does not facilitate fuel distribution
Distribution transmission joints weak and with play due to wear

I solved these problems by redesigning and remaking many parts, since it is an 18 cylinder

 

[ajoeiam]

Isotta Fraschini 18 cylinder: problems detected on first starts :

Distributor cap with irregular functioning
Pistons with low compression
Pistons with too much friction in the cylinders
Geometric shape of the pistons with oil accumulation in the spark plug area
Burnt Teflon head gaskets
Intake manifolds with geometry that does not facilitate fuel distribution
Distribution transmission joints weak and with play due to wear

I solved these problems by redesigning and remaking many parts, since it is an 18 cylinder

You had one heck of an impressive build.
Now with your testing, analyzing and modifications - - - you are in process to create a most extraordinary item.

Good on you sir!

 

[Foketry]

Distributor cap
I designed and built the first prototypes with 3 levels in height, each level manages 6 cylinders.
It runs at low rpm but does not distribute the 10,000 volt voltage between 18 cylinders correctly
I went back to the traditional distributor, 18 cables for 18 spark plugs on a single level
In the photo a dozen or more distributor for testing

 

[Steamchick]

Incredible work. Congratulations on everything you achieve! A vee-twin is about the limit of my comprehension... W18 just blows my head apart!
Is the cycle something like a regular straight 6-cylinder (A) 1-5-3-6-2-4, integrated with a second (B) at 20degree delay, then a third (C) at a further 20 degree delay?
So: A1,B1,C1,A5,B5.C5,A3,B3,C3,..etc.?
Or something different to smooth the torsional loading on the crankshaft? e.g. A1,B6,C1,A5,B2.C2,A3,B4,C3,..etc.?

K2

 

[ajoeiam]

Incredible work. Congratulations on everything you achieve! A vee-twin is about the limit of my comprehension... W18 just blows my head apart!
Is the cycle something like a regular straight 6-cylinder (A) 1-5-3-6-2-4, integrated with a second (B) at 20degree delay, then a third (C) at a further 20 degree delay?
So: A1,B1,C1,A5,B5.C5,A3,B3,C3,..etc.?
Or something different to smooth the torsional loading on the crankshaft? e.g. A1,B6,C1,A5,B2.C2,A3,B4,C3,..etc.?

K2

Hmmm - - - - I'm wondering if its 3 rotors inside so that its still that straight six sparking just the banks are set apart (on the different rotors).

Likely make for issues with taming stray sparking. Your candidates all seem like their size is going to help make for grief.
Maybe a larger dia would help?

Dunno - - - - just brainstorming - - - - or is that barn storming!

 

[Nerd1000]

Could you make three separate distributors, one for each bank? This would surely be easier than a single distributor managing all 18 cylinders.

 

[Steamchick]

Sometimes "Modelling" means doing it the way it was originally....? Sometimes that is near impossible, so that is where "engineering", as in problem solving, takes over. See Post #4 - uses 2 distributors! The solution you offer may seem the simple and straightforward solution, treating it as 3 separate 6 cylinder engines, but for some reason (Packaging? Servicing?) the original designers decided on 2 distributors, probably because they could not readily fix the third in the central location/off that camshaft?
Who knows? - Foketry?
K2

 

[Foketry]

The designers had chosen 2 distributors because it was an aircraft engine, therefore double ignition and 2 spark plugs for each cylinder.
By reducing the dimensions everything becomes more complicated due to lack of space, for example: to dismantle the spark plugs of the 6 central cylinders, I have to dismantle the head of the 6 cylinders on the left.
To avoid complicating the gear transmission system, I preferred to place a single distributor, now on a single level.
I moved the magnets for the Hall sensor directly on the flywheel, instead of on the bottom of the distributor, therefore 9 magnets instead of 18

 

[Foketry]

The designers had chosen 2 distributors because it was an aircraft engine, therefore double ignition and 2 spark plugs for each cylinder.
By reducing the dimensions everything becomes more complicated due to lack of space, for example: to dismantle the spark plugs of the 6 central cylinders, I have to dismantle the head of the 6 cylinders on the left.
To avoid complicating the gear transmission system, I preferred to place a single distributor, now on a single level.
I moved the magnets for the Hall sensor directly on the flywheel, instead of on the bottom of the distributor, therefore 9 magnets instead of 18

 

[Foketry]

Could you make three separate distributors, one for each bank? This would surely be easier than a single distributor managing all 18 cylinders.

I had thought about putting 3 distributors, but I tried to design the transmission system with gears, too little space and too complicated, in addition to this 3 ignition control units would have been needed.
Final solution 1 distributor for 18 cylinders and 1 ignition control unit

 

[Foketry]

The first pop of the engine, not yet complete