Author Topic: Bugatti Typ 50 1/4 Scale model  (Read 43986 times)

Offline michelko

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #240 on: March 07, 2018, 09:26:13 AM »
Roger
they are wasted spark Coils. One coil fires two plugs.

I tryed connecting the coil housing to the block and the block to battery ground.
Helped nothing.

Michael

Offline michelko

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #241 on: March 23, 2018, 10:24:12 AM »
Hi so here is the Video of the testrun with the new plugs.


Plugs worked fine, just one is faulty the spark jumps outside the engine throug the Isolator  :(

Looks like the macor has imperfection at this place.

Another Problem is again the ECU. Noise on the tach Input makes missfires all the time, not realy bad but noticeable.

I will try the Transistor ignition shown in Modelengineer issue 34. Just ordered the electronic components and the pcb.

These will fire through a Distributor to the plugs.

Michael

Offline Vixen

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #242 on: March 23, 2018, 10:56:12 AM »
Hi Michael

Sweet, straight eight music. Well done

Mike
It is the journey that matters, not the destination

Offline Roger B

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #243 on: March 23, 2018, 05:06:06 PM »
Excellent  :praise2:  :praise2: Did the water pump give enough flow?
Best regards

Roger

Offline Vixen

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #244 on: March 23, 2018, 05:07:50 PM »
Hi Michael

Try cleaning (polishing) the surface the faulty spark plug insulator with fine wet-n-dry abrasive paper followed with a wash in alcohol. There may be some invisible contamination from the manufacturing process.

15000V and a 15 thou gap (oh, thats about 0.38 mm) works well. I find higher voltage can cause trouble with our miniature plugs. A coil-over-plug unit will produce a very high voltage

Mike
« Last Edit: March 23, 2018, 05:14:09 PM by Vixen »
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Online sco

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #245 on: March 23, 2018, 08:45:19 PM »
Awesome Michael - Ettore would be proud to have that on his desk.

Simon.
Ars longa, vita brevis.

Offline michelko

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #246 on: March 28, 2018, 03:00:44 PM »
Hi i started to work on an Transistor Ignition. The template was shown on Modelengineer Issue 34.
Colected parts and the pcb. Soldered the parts together yesterday. Makes i nice Spark so far.
I fittetd the hall sensor into the dizzy and also 8 magnets.

How big should the cap be? How fare should the pins are away from each other? I have o experiences.

Would like to hear youtr thoughts.

Here is a short video:


Michael


Offline Vixen

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #247 on: March 28, 2018, 03:37:16 PM »
Hello Michael

I like your spark plug holder.

I have an eight cylinder distributor cap made by Bruce Satra. I believe S/S Machine & Engineering took over from Bruce. Try http://www.cncengines.com/orderpage.html

The eight plug leads are equispaced on 25.4mm (1 inch) PCD. The individual leads are therefore spaced at 9.7mm

Hope this helps

Mike

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Offline michelko

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #248 on: April 04, 2018, 12:57:36 PM »
Hi Guys,
did the first testrun with the Transistor ignition.
I must say i am realy impressed from this Little electronic Piece.

Here is a Little longer Video running the engine with a Distributor. 

Believe me or not it is just running on 3 cylinders.
Number 1 5678 exhaust pipes are cold.

But it is a rock solid idle.

The Problem is the material of the Cap. as you can see it got Little paths from some Points to another. This is Bakelit with Cotton. I think the Cotton is burned and builds up Carbon the leads to shortcuts between the electrodes. Was a quick and dirty part to try the System.

Will make a new one from pom and with a sligthly different design
« Last Edit: April 04, 2018, 01:06:50 PM by michelko »

Offline Roger B

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #249 on: April 04, 2018, 02:40:21 PM »
Does the rotor make contact with the electrodes or is there an air gap? If it makes contact it may be spreading particles of brass between the electrodes which will promote tracking. Full size distributors usually make contact to the coil electrode (often a carbon brush) and have a small airgap to the sparking plug electrodes.
Best regards

Roger

Offline michelko

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #250 on: April 04, 2018, 03:41:43 PM »
No contact, i think i go with gbrittnel design for the next cap/rotor. This Hobby is a steady learning process.

Michael

Offline michelko

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #251 on: April 16, 2018, 10:53:02 AM »
Hi guys,
herre is a new update on the Project.

I fabricated a new cap and rotor from pom. I made also new wires with brass plugs as Connection to the cap.
This works realy nice. could get the engine running nice and stable with almost all cylinder firing.

The engine is running on 2 stroke mixture 1:50 with literaly no oil in the crankcase. I only filled aprox 20ml of 20w50 into crankcase to save  the oilpump from running dry.

Here are the videos :



With more oil in the case just 2, 3, and 4 are running al other cylinder get oil fouled plugs after some revolutions.
Just have to research the oil control ring story.


Michael


Offline Vixen

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #252 on: April 16, 2018, 12:19:26 PM »
Hello Michael

It's good to see the Bugatti running so well and with the original exhaust headers.

I understand you are still having trouble with oil fouling from the crankcase. I have looked at your engine but cannot see any means of ventallating the crankcase. Is the crankcase pressurising and forcing the oil mist up into the cylinders?

I have these two photos of a full size type 50 engine. You can clearly see 6 (two hidden behind the blower) crankcase breather vents located midway up the crankcase to discharge the gas pressure from any piston blow-by.





This may help

Mike
« Last Edit: April 16, 2018, 12:32:40 PM by Vixen »
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Offline michelko

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #253 on: April 16, 2018, 01:14:54 PM »
Hi Mike,
These are my crankcase breathers. I believe that These are the same in the real engine.
the engine has 6 of it every one is a 6mm hole.

BTW your JUPITER is an awesome fine build  :ThumbsUp:

Michael

Offline Vixen

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Re: Bugatti Typ 50 1/4 Scale model
« Reply #254 on: April 16, 2018, 01:36:16 PM »
Hi Michael

I can now saw the circles on the crankcase top, I did not realise they were drilled through to ventilate the case.

Is there much air blowing out of these vents? I would have expected some blow-by oil as well.

If the problem is not blow-by air/oil, it could also be from bearing oil being sprayed onto the cylinder walls.

I think we both know that oil control rings may be the answer. Steel oil control rings will be easier to fit without breakage than cast iron, but take longer to bed in.

Keep working at it

Mike
It is the journey that matters, not the destination