3cc Diesel - My first ICE

[Paolo]

Congrat's Bob a very top class work !! Well documented as ever ! Thanks for sharing with us..
Best regards
Paolo

 

[Maryak]

Paolo,

Thanks for your kind words. :bow:

Best Regards
Bob

 

[Maryak]

YOU ARE NOW ENTERING THE TWEAK ZONE​

After reading and digesting the advise from Gail and Seagar.

I decided to make a new Contra Piston.

This time I used the David Owen method as recommended by George, (Serceflyer).

Let me tell you this is the absolute best way to make the contra piston, so without further ado here's my interpretation of the method.

A lump of spun cast iron for the new cp. The piston is turned down to 0.015" oversize.

End milling the cp to give a thin wall piston (1/32")

The cp ready for parting off

Brass for the cp mandrel.

The cp glued to the madrel with super glue.

After facing the cp, the compound slide is set over 1/2 deg.

The cp is now turned down with this slight taper, using the compound slide, until about 1/4 of its' length will enter the cylinder. At this point fine 440 grit emery lubricated with oil and a flat bar are used to further reduce the dia of the cp until about half of its' length will enter the cylinder.

BELIEVE IT OR NOT - THAT'S IT

NO LAPPING

The finished Contra Piston.

A little heat and a wooden clamp removed the piston from the mandrel.

The engine was re-assembled the new contra piston was tapped into place with a brass dolly.

Below is the result - the rev counter showed 7000rpm.



What's left ???, another turn of thread on the compression screw.

Best Regards
Bob

 

[GailInNM]

Looking and sounding good Bob. I think you are sneaking up on it.

It looks like it is starting easy enough so you have plenty of good ether. After you get some time on it, you can probably cut the fuel with a little more kero to reduce the kero to oil/ether ratio and get a little more RPM.

Just don't go below about 27 percent oil with a sleeve bearing and you should be safe. I would not change anything until you get about 30 minutes on the engine. If you start reducing the oil, start checking the front bearing temperature with your hand and if it starts to get hotter, then go back up a little bit on the oil.

Gail in NM,USA

 

[Maryak]

Thanks Gail,

I will play with the compression screw next and see where that leads. I feel just a touch more compression will take out the miss and give a few more rpm. Fuel consumption has improved by about 30% with the new CP.

Best Regards
Bob

 

[rake60]

I have never build an IC engine myself.

I sure am enjoying watching this thread Bob! :bow:
Beautiful works indeed!

Rick

 

[Maryak]

Thanks Rick, :bow:

One more tweak on the screw and then it's thinking time for what's next ??? ???

Best Regards
Bob

 

[kustomkb]

Sounds great!

The view from Tweak Mountain must be sweet! 8)

Kevin.

 

[Maryak]

Sounds great!

The view from Tweak Mountain must be sweet! 8)

Kevin.

Thanks Kevin, :bow:

Yes I'm pretty chuffed at having a runner

Best Regards
Bob

 

[jack404]

It a little ripper Bob

well done

as to whats next

please doco it like this one for the lesser mortals here

cheers and well done eh

jack

 

[Philjoe5]

Great video Bob. Looks like you'll need to pass on your seat in the Tweak Zone:bow: :bow:

Cheers,
Phil

 

[Maryak]

Phil,

After I've screwed the compression screw and unscrewed my butt, the seat will be vacated for the next Tweaker, adjustments "All for your safety and comfort my dear!!" occupant.

Best Regards
Bob

 

[SERCEFLYER]

Bob,

What can I say-- brilliant stuff here!!!! You really should contact your fellow Oz resident, Ron Chernich and tell him about this thread. I think he'd love to display your work on his webbsite, www.modelenginenews.org.

This has been a great instruction on building a traditional engine from the 40's.

Thanks for taking us along for the ride. I have a 3-month-old boy at home, so "armchair machining" is the best I can do at the moment.

Best,
George

 

[Maryak]

George,

Thanks for your kind words and help along the way. The darning needle and the contra piston advise were especially helpful

:bow: :bow:

Best Regards
Bob

 

[Maryak]

I've been pretty well flat out with the new house and tanks

But Yes dare I say it - ICB is finished

Here is my swansong on this topic and a HUGE thank you to all who participated. :bow:



Best Regards
Bob

 

[SandyC]

;D

Hi Bob,

A truly great piece of model engineering, my most sincere congratulations to you.

This whole build series, warts and all, has demonstrated just how dedication, perseverance and willingness to remake necessary components WILL lead to a just reward.
It has been a great pleasure to follow your progress over the past few months.

Not only have you built a wonderfull example of a VINTAGE 40's aero engine, you have also shown the way with your skills in movie making.
That, my friend, is one of the best video's I have watched on model engines and I consider it a great honour to be included in the credits given to all who contributed.

What's next?..... tough act to follow.

Congratulations again Bob.

I wish you all the best with your new home and hope you and your good lady manage to have a great Christmas and a peacefull New year.

SandyC. ;D ;D

 

[Cliff]

I would like to congratulate you on a fantastic build it has inspired me to try to built a engine and put my almost forty years of machining experience to work. I thoroughly enjoyed following the build from the start thanks for the experience. Cliff

 

[Philjoe5]

Bob, the video was great. Sounds like you've got the tuning down. It seems to run smoothly, congratulations. And hats off for sharing the build process with us.

Cheers,
Phil

 

[malcolmt]

:big: :bow: :big: :bow: :big: :bow: :big: :bow: :big: :bow: :big: :bow: :big: :bow:

BOB
Heartfelt congratulations on a super job, I am sure we all learned something from your generous serialising of this build.
Many thanks for the video finale.
Kind regards

Malcolmt

 

[joe d]

Bob

Happy for you that the tuning has worked out to a really nicely running engine. Thanks again for bringing us all along for the ride. Now that you've gone and put my name in the credits I'll have to shell out for membership in the actor's union :big:

Cheers, Joe