Author Topic: Bugatti Typ 50 1/4 Scale model  (Read 78025 times)

Online sco

  • Full Member
  • ****
  • Posts: 1694
  • Location: Northants UK
Re: Bugatti Typ 50 1/4 Scale model
« Reply #285 on: December 06, 2018, 12:56:41 PM »
Great work Michael.  The tool post grinder - any more pictures of that, what you use it for etc.

Simon.
Ars longa, vita brevis.

Online Vixen

  • Full Member
  • *****
  • Posts: 3335
  • Hampshire UK
Re: Bugatti Typ 50 1/4 Scale model
« Reply #286 on: December 06, 2018, 01:50:21 PM »
Michael,

The new one piece Corian spark plugs look great.   :ThumbsUp: :ThumbsUp:

What type of coil are you now using? Do you know the output voltage? Some auto coils produce too high a voltage for our miniature spark plugs, which can make the plugs fail prematurely.

Please post the results of your tests and any developments

Mike
« Last Edit: December 06, 2018, 02:28:58 PM by Vixen »
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline steamer

  • Global Moderator
  • Full Member
  • *****
  • Posts: 12787
  • Central Massachusetts, USA
Re: Bugatti Typ 50 1/4 Scale model
« Reply #287 on: December 06, 2018, 05:21:30 PM »
I listened to a talk from Rollie Gaucher,  ...of Rollies Dads lathe alignment method fame.   He talked about making spark plugs using corian but its expensive    his comment was to bring a couple of models to the countertp shops, and theyll usually get so excited that theyll give you some off cuts for free.
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline michelko

  • Full Member
  • ****
  • Posts: 333
Re: Bugatti Typ 50 1/4 Scale model
« Reply #288 on: December 07, 2018, 09:15:14 AM »
Mike,
at the end i was using an old Bosch Coil i had on the shelf. No idea what voltage it delivers.


In germany Corian is not realy expensive. On Ebay you can get rest pieces for a couple of euros.


Michael


Offline michelko

  • Full Member
  • ****
  • Posts: 333
Re: Bugatti Typ 50 1/4 Scale model
« Reply #289 on: December 10, 2018, 03:01:33 PM »
So i did some calculations and the actual CR should be 5,95:1.
What do you guys think, is this to high? Will the engine run with CR 5:1?. This is Maybe better for the Sparkplugs.


What CR do you guys run with your working engines.

Michael
« Last Edit: December 10, 2018, 05:12:51 PM by michelko »

Offline michelko

  • Full Member
  • ****
  • Posts: 333
Re: Bugatti Typ 50 1/4 Scale model
« Reply #290 on: December 10, 2018, 05:16:03 PM »
All parts ready machined, still have to cut the Center electrode to length and glue them together.



Online Roger B

  • Global Moderator
  • Full Member
  • *****
  • Posts: 6394
  • Switzerland
Re: Bugatti Typ 50 1/4 Scale model
« Reply #291 on: December 10, 2018, 05:18:49 PM »
I have tended to design around 8-1, but this does not include the volume in the sparking plug or it's thread.
Best regards

Roger

Offline michelko

  • Full Member
  • ****
  • Posts: 333
Re: Bugatti Typ 50 1/4 Scale model
« Reply #292 on: February 04, 2019, 08:54:45 AM »
Hi guys,
Little update on the Bugatti. I started to diassemble the engine.
I bought a cheap chinese pressure loosing tester to check for leaks.
Made an Adapter to fit the plug threads.

I found three leaking exhaust valves. Not realy bad but noticeable against the others.
All Inlet valves are leakfree :cheers:

The tool Shows realy low pressure loss on all cylinder (around 5 %).
But i think this tool is made for automotive engines with greater Dimensions so the numbers  it doesn´t mean anything.

I will then tear it apart and shorten the pistontops to reduce the cr.


Thinking so mutch about this problem i believe it is a combination between high compressionand high voltage from automotive coils.
So another step would be to reduce the high tension of the coils by shorten the dwelltime.

Michael



Online Vixen

  • Full Member
  • *****
  • Posts: 3335
  • Hampshire UK
Re: Bugatti Typ 50 1/4 Scale model
« Reply #293 on: February 04, 2019, 09:37:38 AM »
Hello Michael,

I am sure your methodical approach with tests and measurements will help you get the Bugatti to run sweetly. :ThumbsUp: :ThumbsUp:

Do you have drawings of the cam profile and cam timing? It may be helpful if we can help you check the overlap and open durations.

Cheers

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline michelko

  • Full Member
  • ****
  • Posts: 333
Re: Bugatti Typ 50 1/4 Scale model
« Reply #294 on: September 27, 2020, 11:51:47 AM »
Hi Guys,
some time past since the last post about the bugatti.
I just found some motivation to complete it after the valve job.
While it was aoppart i redid some pieces.
The oilpump got new gears, the valve train aolso got three new gears to eliminate some backlash.
Also altered the exhaust a bit.
Next step will be cutting a gasket for the intake manifold with my cnc machine and a drag knife.

Here is a video while testing the oilpump, you can also notice the compression while cranking with the drill.
<a href="https://www.youtube.com/watch?v=a4nP-svwNLo" target="_blank">http://www.youtube.com/watch?v=a4nP-svwNLo</a>

Regards Michael

Offline nj111

  • Full Member
  • ****
  • Posts: 146
Re: Bugatti Typ 50 1/4 Scale model
« Reply #295 on: September 27, 2020, 02:33:48 PM »
Fabulous and sounds great spinning over!  Thank you for the update
Nick

Offline michelko

  • Full Member
  • ****
  • Posts: 333
Re: Bugatti Typ 50 1/4 Scale model
« Reply #296 on: September 27, 2020, 02:56:10 PM »
so here are some pictures from the intake and the new gasket. Made one spare while i was in there.
This is made from 0,5mm Gasketpaper, i also used this stuff as head gasket.

Regards Michael

Offline michelko

  • Full Member
  • ****
  • Posts: 333
Re: Bugatti Typ 50 1/4 Scale model
« Reply #297 on: September 29, 2020, 12:23:46 PM »
Hi guys,
it runs again, better than ever. The rework on the valves did the job i believe.

Not already tuneed in but runs nice. smoking from the last cylinders because of the oil bypass.
When that oilline is hokked up on its normal place i think it will stop smoking.

<a href="https://www.youtube.com/watch?v=v2F0rTHp8aM" target="_blank">http://www.youtube.com/watch?v=v2F0rTHp8aM</a>

Regards Michael

Online Vixen

  • Full Member
  • *****
  • Posts: 3335
  • Hampshire UK
Re: Bugatti Typ 50 1/4 Scale model
« Reply #298 on: September 29, 2020, 12:34:44 PM »
Now that sounds sweet. The engine burbles away like only a straight eight can. Well done :ThumbsUp: :ThumbsUp:

Whats next, are you thinking about a simple blower like the original?

Stay safe

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline michelko

  • Full Member
  • ****
  • Posts: 333
Re: Bugatti Typ 50 1/4 Scale model
« Reply #299 on: September 29, 2020, 01:03:45 PM »
i started to machine a dummy blower, just for appearance. Needs some more love and work.

Next step iwill be machining two cover plates on top of the crankcase.
Those will be made from plates 275x20x3mm. Still thinking about how to mount them on the mill.
Thought about gluing them on a larger plate, but how to loosen them after machining without bending??
Any sugestions?

Another project will be the Flywheel housing and the starter motor.

So plenty of worl to do before i can start another project (maybe a holt 75)

Regards Michael

 

SimplePortal 2.3.5 © 2008-2012, SimplePortal