cp-e™ MagnumDI™ MZR 2.3 DISI Stage2 Pistons

[www.cp-e.com]

Precision CNC machined to cp-e™ spec, Stage 2 pistons have specifically designed valve pockets and a dome with unique features to optimize fuel distribution within the cylinder. The extra pocket in the dome design sends fuel up towards the spark plug, optimizing the mix with oxygen and in turn making the burn process more efficient.

...more here

[kmac]

These look like the pistons I would like to use in my build.

[SgtP]

sexy

[www.cp-e.com]

indeed

[bertrand_CX_7]

Originally Posted by www.cp-e.com indeed

Sorry my english is very bad, but indeed means you'll get it for free or something like that?

lol

[08.5MS3]

Originally Posted by bertrand_CX_7 Sorry my english is very bad, but indeed means you'll get it for free or something like that? lol

That would be nice!

He was agreeing with SgtP and possibly with kmac.

[Haltech]

The pricing actually seems fair on these.

[JumpingJackson]

What testing have you guys done on these pistons?

[Enki]

Originally Posted by JumpingJackson What testing have you guys done on these pistons?

Knowing CPE, they've probably been in someones car for the past two years.

Also, 2 weeks.

[www.cp-e.com]

Haha we have these in a few motors. There is endurance and long term durability testing going on for past few months.

[Lex]

Are there any differences seen with these pistons at idle, low load, and throttle transitions?

[www.cp-e.com]

no - a tune was neccessary as fueling characteristics changed.. but otherwise - wouldnt really know.

They are low noise due to special geometry and a few other features.

[mason]

i think ill be going with these when the time comes!

[06Speed6]

I like these pistons, but I have a few questions:

1. What has been done to the top ring area to prevent coking? On DI type engines the higher cylinder temps seem to lead to the top ring coking, which reduces its ability to properly seal the chamber which leads to a drop in compression. All of the other aftermarket pistons that I am aware of have aproached this engine as if it were a port injection engine, and they have not addressed this issue since most seem to think that you would have to move the pin down and reduce rod length.

2. I see the intake valve reliefs, but how much lift can we run with this pistons, intake and exhaust?

3. What is the pin diameter?

4. Generally speaking, what tuning changes were made for these pistons?

5. Why was a 4 ring design chosen over a 3 ring design? Im not knocking it, im just curious.

6. What compression ratios are available, and is it possible to custom order a specific ratio?

7. What company manufactures these?

[www.cp-e.com]

Originally Posted by 06Speed6 I like these pistons, but I have a few questions: 1. What has been done to the top ring area to prevent coking? On DI type engines the higher cylinder temps seem to lead to the top ring coking, which reduces its ability to properly seal the chamber which leads to a drop in compression. All of the other aftermarket pistons that I am aware of have aproached this engine as if it were a port injection engine, and they have not addressed this issue since most seem to think that you would have to move the pin down and reduce rod length. 2. I see the intake valve reliefs, but how much lift can we run with this pistons, intake and exhaust? 3. What is the pin diameter? 4. Generally speaking, what tuning changes were made for these pistons? 5. Why was a 4 ring design chosen over a 3 ring design? Im not knocking it, im just curious. 6. What compression ratios are available, and is it possible to custom order a specific ratio? 7. What company manufactures these?

Excellent questions.. please give me abit of time and let me compile some data and respond all in one post to these

Thanks!

[www.cp-e.com]

Originally Posted by 06Speed6 I like these pistons, but I have a few questions: 1. What has been done to the top ring area to prevent coking? On DI type engines the higher cylinder temps seem to lead to the top ring coking, which reduces its ability to properly seal the chamber which leads to a drop in compression. All of the other aftermarket pistons that I am aware of have aproached this engine as if it were a port injection engine, and they have not addressed this issue since most seem to think that you would have to move the pin down and reduce rod length. 2. I see the intake valve reliefs, but how much lift can we run with this pistons, intake and exhaust? 3. What is the pin diameter? 4. Generally speaking, what tuning changes were made for these pistons? 5. Why was a 4 ring design chosen over a 3 ring design? Im not knocking it, im just curious. 6. What compression ratios are available, and is it possible to custom order a specific ratio? 7. What company manufactures these?

I'll try and address these questions as best as I can.

1) There really isn't much different with these as compared to the stock piston ring geometry. We would like to continue research concerning ring wear, however we didn't feel it was completely necessary to move the ring placement on these. After some time we may change the design if we feel it is necessary.

2) I don't have the available P/V clearances with these pistons in front of me. They are a little deeper than stock, however there aren't really any popular camshafts on the market yet so this wasn't so much a concern straight away. I can look these up when I get back to the office if you would like.

3) Stock pin OD. There really isn't a need for an oversized pin until you get in the 200 hp / cyl range or higher (from my own personal experience). Again, if the cylinder head development for these engines progresses, and it is within the possibility to make that kind of power with the MZR then we may make a model with an oversized pin in the future.

4) This is the cool part with these pistons, we've set up and modeled the injector spray pattern with regards to the piston. So the dish in the piston is used to "cup" the fuel and move it toward the spark plug. I think this is cool, and the soon to be released stage 3 is a more dramatic version of this same principal.

5) Technically this is a 5 "ring" design. There are 2 compression rings, 2 oil control rings, and one oil ring spacer. This is how most every piston (that I've ever worked with) is designed. Some people assume that there are only 3 rings because there are only 3 ring grooves, however the oil groove actually consists of 3 separate rings (two omni directional rings, and one spacer)

6) The compression ratio is 9.5:1. You will not be able to order custom comp heights or ratios, We would have a hard time stocking / accommodating these requests, we're a pretty small company, that would be rough on us.

Hope this helps a little (on a plane from UT right now and my battery is dying!). If you have any other questions you can email me smarques@cp-e.com

-Sander

[Realgib3]

So do you guys actually manufacture these or are they Wiseco's? That is the last unanswered question.

[JumpingJackson]

So what testing have you done on the dish design aside from modelling in a computer program? Dynos with a stock piston / stock style piston? Any kind of actual data? +1 on #7. Are you guys manufacturing these your selves or outsourcing to another company?

[www.cp-e.com]

The R&D of the pistons and some of the manufacturing process we handle - castings, coating and etc we outsource as thats outside of what we can do (for the time being).

We have alot of data from modeling the motor on the computer, engine dynos and etc. Research is not finished by any means and there is a bit of proprietary info. We are putting together a paper on these pistons and the research we have done...

at a point we will let the power numbers and reliability speak for themselves along with some proven data... all in due time.

[xcoldricex]

wahhhh cp-e hates our platform and never does anything for us.


interested in seeing the research and data as it comes up!

[Cataphract_40]

You said additional tuning is necessary due to the scoop shape, the way the fuel interacts with the piston/spark plug/etc...is it possible to do this 'tuning' via the AP, or is this something that only SB customers will be able to do?

[Enki]

Of course it will be possible; the question is will CP-E be awesome enough to release this information to everyone, regardless of tuning platform?

[www.cp-e.com]

Originally Posted by Enki Of course it will be possible; the question is will CP-E be awesome enough to release this information to everyone, regardless of tuning platform?

The design of the piston, geometry and such is proprietary.

Tuning to take advantage of the setup is nothing special - we are testing Stage III pistons and we are still learning of what does what and when with fueling and timing.

Just with any build - a tuner will play with the car and see how it reacts - this is exactly what we are doing... You can do this with a Standback, AP or any of the other engine management solutions out there.

[djuosnteisn]

One potential concern that comes to mind, is that with our oem injectors and limited fueling window, most high hp disi's are spraying fuel very close to the spark event. Already we've been having some difficulty with spark blowout from this (regardless of tuning solution).

I would be scared that a dished piston face that directs fuel toward the spark plug would only aggravate this issue.


Have these pistons been installed on a motor already? How much power was made with that motor? And did you have issues with ignition?

I don't need specifics, cause i know you want to guard your IP, i'd just like to see some general thoughts on the idea.

[Lex]

I am also of the belief that if you sell a product that is not just stronger than OEM but redesigned to "improve" combustion, you will have to quantify those improvements to make it credible.