Frage zu Kolben vom VW Crafter 2.5 CR TDI 163 PS | Posts 16+

slow-moe wrote:

Fab176 wrote: What are the 2 variants of injection oil cooling? There is an older version where the nozzle is angled, causing the oil jet to perform a wiping motion across the piston head during the stroke. This design was used in engines without a water jacket, such as the AHF, AJM, and some AUY models, among others. The new version uses spray nozzles that direct the oil jet into the cooling channel opening, regardless of the piston position, similar to almost all cooling channel pistons. Piston skirts require recesses in both, and the nozzle attachment is the same.

Wrong. The piston with the central oil cooling is from the AJM (79L53), and I just double-checked the part number with Mahle, and it's right here in front of me!

Regarding the channel... is it possible to insert a thin wire and see if you can rotate it in both directions?

dieselschrauber wrote:

Wrong. The piston with the central oil cooling is from the AJM (79L53), and I just checked the part number with Mahle, and it's right here in front of me!

I am familiar with the AJM, both with and without a cooling channel. Here is an ALCAN from an early model without a cooling channel.

Here is a Mahle piston with a channel.

In both models, the injection nozzle is located on the side, and there are recesses in the cylinder liner.

Hello,

Regarding the question of whether the cooling channel runs completely around: yes, it does. A hole is the inlet, the other is the outlet; somewhere the oil has to come out again, and the better and more it flows, the better the cooling effect.

"Pure injection cooling is suitable for high specific..." Power/torque insufficient.

Best regards,

I also expected the cooling channel to be like that; I've also already practiced pushing the wire through - so it's a complete cycle . However, the pistons are no longer at my house; they were sent away for rework (making the taper in the Omega cavity PD-compatible, deepening the valve recesses by 0.5mm, re-milling the oil channels/openings, and closing the old injection openings); therefore, I can't check it live right now.

I have only ever seen oil spray nozzles in the "vertical" configuration. I somehow trust them more than the version from AJM .

Regards,

Fabian.