An idea for more high-RPM power

[2446]

The bottom of the fist cut is radiused along the length for a smooth gas flow out of the swirl chamber. The second cut is straight. The top and bottom side edges are all straight. Basically it is just like what is described and drawn in the patent paper.
Good luck, when it's done report back and tell us what kind of real-world difference it makes.  :wink:

[TDIMeister]

TTT.  I love this thread!

[745 turbogreasel]

some (ok, a lot) interesting reading here:
http://www.somender-singh.com/

[Mark(The Miser)UK]

:oops: I wonder if a vortex creating swirl could be machined in to the piston? H'mm maybe it would need a corresponding but tapered 'male' ridge in the head... taper pointing towards exhaust valve to direct exit gases when valve open? A bit too complex perhaps...
What about a couple of ridge and sockets squirting the gasses towards the middle :?:

[RabbitJockey]

thats what i was told in the power stroke course i took, it makes the engine less noisey and rough

I don't know if that's accurate... it doesn't jibe with what I remember reading in the TDI SAE papers.  (I don't recall anything about pilot injection increasing efficiency, but it did cause a more gradual pressure rise during combustion.  By starting a "little fire" burning early in the combustion chamber before the main injection happens, the ignition delay time main fuel injection is reduced (it atomizes and begins burning quicker), and this reduces the otherwise sharp pressure rise and noise of the burning of the main injection, so pilot injection thereby "tames" the more efficient DI combustion process enough to make it suitable for use in passenger cars.)

I'll dig up that SAE paper (based on development of VW's first TDI engine...) and see what it says.

[mike71ghia]

Before you machine a slot, find out how thick the pison is from face to underside in this area. This can be done on the cheap with a regular 6 inch dial caliper and two trimmings of coat hanger cut to a known length in even inches/mm..deep enough on one end to clear the skirt,and the depth you want to probe on the fixed end Take the coat hanger ya have a caliper just cut and file to size, then hot glue or epoxy to the caliper jaws... close the now extended jaws to touch, zero the dial, and subtract your total extension rod lengths to find the actual thickness at any point you touch, sharpen the one on the fixed end and use it on the piston face...
I've got a mill and lathe if anyone wants to experiment I'll be more than willing to chuck and cut!
The hot glue or epoxy should pop right off the caliper if not degreased first. Poster tack will stick probes wherever you want to put them if you prefer...
mike71ghia<AT>yahoo.com
Google "techline coatings" for bake at home ceramic/metalic low friction coatings... anyone considered nikasil cylinder liners?
Never used their stuff but intrigued
http://www.techlinecoatings.com/

[foxracer1]

Very interesting. It seems we need a test mule.  :twisted:

[jtanguay]

nikasil was big like 20 years ago... porsche used it, but the sulphur in fuel broke the liner down and caused engine damage.

even with ultra low sulphur diesel, the chances of the liner breaking down are pretty good.

very interesting thread indeed!

[2mAn]

i think im going to try this

has anyone tried it yet? are you still even around   :roll:

[DA-BRT]

here's a picture with some rough measurments.
The piston top is just like described in the patent paper.

@2446: Can you please put the picture online again?

[2mAn]

here's a picture with some rough measurments.
The piston top is just like described in the patent paper.

@2446: Can you please put the picture online again?

i was checking out my pistons today and im most likely going to have this done.  im glad i saw this pic with the depths

[DA-BRT]

Thanks for putting it online again!

[2446]

you're welcome :mrgreen:

[worf81rab]

nikasil was big like 20 years ago... porsche used it, but the sulphur in fuel broke the liner down and caused engine damage.

even with ultra low sulphur diesel, the chances of the liner breaking down are pretty good.


  Most of the top level sportbikes currently use nikasil to line cylider walls. I know they don't burn diesel but though it was worth mentioning.

  This is a sweet thread though.

[2mAn]

  This is a sweet thread though.

im pretty surprised more people arent currently interested, maybe its an old thing i just found, haha
  but i want to do it now and i know that our pistons arent the same size as the toyotas in the picture, which would affect the size that we would need for our pistons.

why is jake MIA when i need him!!