Rumor of having to re-spray the plasma coating on cylinder walls at 60k miles...?

[JeremyBlackwell]

I have heard this rumor from 'Motor Magazine', who recently did a test of the R32-35 models. Someone mentioned that at 100,000 kilometers (60,000 miles), you have to pull the motor, disassemble, and re-spray the plasma coating on the cylinder walls. Does anyone have any more information about this? I'll try to find out what I can from the sources at Nissan I have, but I don't know how much they'll know about service since the car isn't released yet...

If so, cylinder sleeves will be a bit hit, and might as well over-bore and increase the stroke while you are in there ;)

[Ev0H8t3r]

JB,

I'll call Nissan japan this week...hopefully its false but if its true, haha money to be made...LOL...

[JeremyBlackwell]

I have now read that the rumor about the cylinder liners is not true. So, probably just another wild rumor indeed! I was questioning why Nissan would do that instead of just using cylinder sleeves if it were so unreliable...

[Ev0H8t3r]

JB, yeah FASLE...I called my buddy in Japan who is a NISMO certified Machanic...

he was a little confussed at first...My japaense is so rusty...i explained the wrong part at first...

[JeremyBlackwell]

JB, yeah FASLE...I called my buddy in Japan who is a NISMO certified Machanic...

he was a little confussed at first...My japaense is so rusty...i explained the wrong part at first...

Thanks for checking! I guess the guy that made that quote in Motor Magazine doesn't know what the hell he is talking about.

[Ev0H8t3r]

JB,

yeah there are just to many TOOO MANY rumors out there right now...We all just have to wait till it hits our parking lots! hehe!

[Phoenix]

JB,

yeah there are just to many TOOO MANY rumors out there right now...We all just have to wait till it hits our parking lots! hehe!

RE: plasma liner
it is my understanding that the plasma liner has been extensively tested and should pose no problem with most applications; it hasn't been over-engineered necessarily, but it certainly seems to have been designed to operate up to 600 HP using OEM equipment under racetrack conditions.

The following article published by:
Plasma Spraying of Lightweight Engine Blocks
G. Barbezat
Sulzer Metco AG (Switzerland), Wohlen, Switzerland
K.Harrison
Sulzer Metco (UK) Ltd, Risca, Gwent

Coating Performances in Engines-
Systematic friction measurement studies in gasoline and diesel test engines have shown that the plasma sprayed coating can contribute significantly to the reduction of the friction between the piston group and the cylinder liner in comparison to cast iron. Depending of the choice of the piston ring material and of the tangential stress of the ring a 20 to 30% reduction in friction was measured in test engines. The measurements of friction were done in the Institute FEV in Aachen, Germany. The results show that a significant improvement in comparison with cast iron can be achieved.

In particular, the tangential stresses of the third ring can be significantly reduced, the critical limit is located at about 10 N. A value of 20 N can be recommended compared to the standard value of 40 N for cast iron. The geometry of the ring also plays a certain role. With optimization of the piston ring geometry, materials and tangential stresses, a potential of 30% reduction of friction in comparison with cast iron is possible.
Measurement of oil consumption has also shown that a reduction by a factor two in comparison with cast iron is possible. In this case the topography after finishing plays an important role.
The oil consumption is directly dependent on the surface topography after machining. The best results are achieved with a value of Ra 0.2 microns. If the Ra value after machining is Ra 0.6 microns or more no improvement in comparison with cast iron can be expected.
An extremely low wear rate relative to cast iron was measured in engine testing. After 150,000 km the wear on the top ring area was about only 10 microns. Also in a high loaded diesel engine the plasma sprayed coating showed a significantly lower level of wear in comparison with cast iron. In a diesel engine for automotive with a power level of 50 kw/l the measured wear on the rings and on the liner was a factor of two lower than cast iron [11] after 300 hours full power enduration test.
The results from engine testing have been confirmed in series production engines for both gasoline and diesel fuels.
- Formula1 and Formula3 for racing in 1999
- Motorcycle engine in 2000
- Large volume I5, I6 diesel for VW in 2002
Additionally several prototypes of modern gasoline and diesel engines are now involved in long term testing. The test results havw been confirmed in Europe and Japan by several engine manufacturers."

So it seems the technology has been in place for a reasonable period of time, appears to be economical, and have nominal wear rates under most conditions. According to above data, it should have ~ 10 microns of wear over 150,000 km (93,205 miles). The coating applied to the GT-R bore is 150 microns, which is the same as used in this study. That works for me.