25-08-2014, 05:11 PM
(25-08-2014, 04:20 PM)japie Wrote:(25-08-2014, 11:55 AM)Ruan Wrote: Absolutely love it!!! Massive tractor pulling fan - this is right up my street!
With regards to the problem with the oil film before 45BTDC - I'm surprised you're having as many problems, although cylinder pressures will be much higher, the ignition delay of Diesel surely isn't really starting to generate high cylinder pressures until a few degrees later?
You may want to look into DLC (Diamond-Like Carbon) coatings for the bearing surfaces which may allow you to get the fuel in a little bit earlier. Though as far as I'm aware, the XUD11 cranks are no better in terms of oiling holes, not to mention your rods wouldn't work with the crank since they're a wider crank journal width.
I'd be very interested to see what you've done with the valvetrain to hold it together at 500kPa and 7000+rpm!
We can see the hole is a problem since it leaves a ferm impression on the bearing, how, what or why is not clear but the damage is there after one 10 second run, if other types use the same place we have to look for a way to plug the original one and drill another. (and thereby making it weaker)
The wider journal width is only 2mm (4mm stroke) so I can grind that away from the casting, no problem. (4mm for a DW12 would be more problematic)
The valve train is completely stock however I do have a dry sump turbo oil system so al of the pump capacity is used for the engine.
We use the ultimate road cam from piper cams, to our knowledge the fastest thing there is for these engines, if some of you know a more cruel cam please let me know!
Coatings do scare me, never seen wonders from it, only damage if it gets loose.
I think the translation has gone wrong on the journal width - the stroke shouldn't be a problem as you say as you can deck the block - by the crank journal width I mean:
This measurement is wider than the DW10 crank - it is the same on the XUD9/DW10 engines - on the larger XUD11/DW12 engines it's larger.
I also think the rod is located on the little end in DW10 but on the big end in DW12 - don't quote me on that, that may be a rumour.
I do agree with you with regards to coatings - maybe if you needed to make the engine survive at 46*BTDC, the coating may help, but you will want to push for 50*+++ SOI and more power - you'll probably cause damage and wreck the coating rendering it useless.