When the engine is fired up the piston will get more heat. This will give some permanent grow on the piston due the working of the copper molecules. So when even the pinch is totally gone after running one tank and let it cool down you must feel a pinch again. The amount of effect on it is determed on how much the manufacturer did give it a heat treatment.

We have tested some engines on the shape of the piston after using it for several times. Engines based on an aluminium sleeve did show a tiny expansion on the exhaust side (less than a micron), with brass sleeves we have not seen a measureable expansion.
Also a tight fit in the crankcase will keep the sleeve more round

Then I will not buy you any beer anymore, period!

Hahaha Martin, just joking offcourse. If you buy me a beer maybe you get a discount..

Why, can you explain what you mean and why it will loose compression due to you`re heat cycle theory?

Thanks, could you explain how the machine would influence the front bearing and elaborate what will happen in your opinion?

Can you explain why you think more rpm is needed and what the benefit would be? and what happens to the o-rings in oil?

Can you please tell me how you know this, the last 40 motors we have run in, the piston was just like a mirror. Could you tell me were you found your wishdom?

The biggest advantage is saving time and money, hope you can understand this based on the explanations. If you still don`t get it,shoot me a PM and i will explain it a bit more if you like. In my opinion you can`t say you think the whole pre-run system is BS based on 1 engine you used. Who tells us you are competent enough to tune the engine and you are not one of those many falls idle drivers, running always to lean on the top and to rich at the bottom with a high idle? Just saying..

Dan, did the comments of decelarating with 40k rpm come through, normally we here you a lot. You were pretty sure about your comments, do you understand that the conrod is also subjected to tension stresses? If not, shoot me a PM and i will explain you a bit more. Could you explain to me why you think the service is hugely expensive..? If you want you can send me an engine and i will break it in and send it back for free.

Apology accepted!

Yeah, as you have expected our Pistons are a bit larger in size than the nitro engine pistons. I took a picture for you from one of our smaler ones...
Thank you very much for your commentary of my concerns.
And yes, my Argumentation was based on feelings, I didn't spend the time to go over it in detail.

Oh yes, I definitely agree on that. I have a brand new engine at home and I still use the old becouse I don't take the time for breaking in the new one.

Cool stuff you got there, with open questions there is always room for discussion. That how we engineers come to greater products, working together and beiing open to constructive comments.

Once been in the factory and design department of Stork engines, they also made big diesels, 620mm diameter pistons, really amazing. But only turning a couple of hundred rpm as i recall.

Engines are cool stuff..!

Yes, they are one of our competitors. They belong to Wärtsilä now.
I think they sell only medium speed engines, we are producing mostly high speed engines. I'm working in the "Big engines department" our engine has about 350l displacement. (20 Cylinder)

Sorry for OT...

An interesting approach, but I am curious what you need to do since the oil is incompressible, and a fixed amount in a container.

Is replacing the head button necessary or is removing just the glow plug enough?
What do you do with the crankcase plate, or is the crankcase compression not that significant?

Also, is there much particulate matter in the oil after 1 engine? is the material in suspension or does it settle with gravity(it almost seems like the run-in process is more burnishing than wearing in the surfaces?

Indeed oil is incompressible, the container is not completely filled.
Here a movie where you can see all..!

+ YouTube Video

The particles will sink, the flow in the container is minimal.
After 1 engine i throw away the old oil and use new oil for the next engine and clean the container with brake cleaner, just to be sure.

Offcourse i checked the used oil and filtered it to see the amount of particles, it`s really not much...there is some on the bottom of the container, but really hard to find.

Could you try to explain to me the difference between burnishing and wearing in?

Of course, there are not much partikels. First, there ist not much material to remove and second, the material is removed in very very small steps. I would expect you will have a very fine powder, and no particals.
And I think the oil bath will remove the particals from the contact surfaces faster than a normal operation.
If you think about sharpening a knife on a stone, there is a lot of particals on the stone and on the knife. Now expect what happens, if you do that under water in a sink. Where do you expect more particals between blade and stone.

The piston is made on a lathe, if you have a fresh piston and you zoom in on the surface you will see the lines made by the toolbit on the lathe. This surface is ideal to use for the break-in



Zoom in on this pic:
http://www.euronet.nl/users/tooms/ftp/DSC_0024.jpg
you will see sthe small lines.....

With less oil and high rpm the tips of the rough surface of the piston will burn and snap off, that will create small noticeable particles. With lot of oil, a slow movement and a controled temperature the surface will be polished giving a dirt in the oil that small that it will not create scratches

burnishing is accomplished by rubbing 2 smooth surfaces, a harder surface on a softer one. there are very small amounts of plastic deformation to produce a more smooth surface, as opposed to polishing(or grinding) a surface with small particles which scratch the surface and remove material to improve the surface finish.

this is a good idea all in all except that we here in asia will have to pay to ship the engine to you, pay for the service, then pay for the shipping again back to asia. that could be very costly especially from here philippines to holland and back.

cant we just buy the machine instead so that we can do it here in asia?like, one per country would be more feasible enough.