Rings? Are the 2000+ gt-s rings teflon coated?

[zphoria]

Just talking to my friend about new engine break in periods, mentioned his rsx has teflon coated engine rings so seating during breakin period is not a issue. Thus u don't really have to worry about rpm limits for breakin. Anybody know what the rings on the GT-S are coated with? My old SHO had chrome coated rings but they chippend or scratched over time. Just curious, got a new engine in my this week, bought it used previously so I have no idea about breakin limits.


thanks

[chris1zz]

never heard of teflon ptfe on rings. i think it would wear off very quickly. the cylinders in the gt-s engine are lined with what toyota calls a MMC, some type of metal/ceramic composite.

[Griffin]

MMC = Metal Matrix Composite. - Theres also a coating on the pistons which are a high silicone aluminum alloy if I remember. But the rings are pretty plain.

Griffin

[GTS LAID]

i believe they're not must lined with MMC but they're entirely made of it right?

[marcus_GTS]

GTS Laid, I think you're right. MMC is more appropriate as a thick section than as a thin coating. I have heard though that there's also an additional coating (nikasil?) on the cylinders on top of the MMC. I know this isn't mentionned in the SAE paper on the Toyota MMC, so maybe this was a last minute design addition to improve wear resistance?

[t2000gts]

Originally posted by marcus_GTS
GTS Laid, I think you're right. MMC is more appropriate as a thick section than as a thin coating. I have heard though that there's also an additional coating (nikasil?) on the cylinders on top of the MMC. I know this isn't mentionned in the SAE paper on the Toyota MMC, so maybe this was a last minute design addition to improve wear resistance?

i think the yamaha guys were mostly responsible for the nikasil.

and from what i gathered from that paper, the MMC isn't a thin layer or coating, but spread out through the entire thing, resulting in MMC comprising a significant % of the final piece.

[zphoria]

What all did Yamaha tune on this engine, seems like they have quite a rep for making high specific output numbers. The Yamaha motor in my 89 sho is the only thing in it that still works, a testament to there build quality IMHO. It made close to 75hp per litre back then and I think that was about the best production NA number around. I heard the new version of the celica engine in the corola hatch sport edition is 106hp per litre! Not sure if that is US spec, but WOW!

[GTS LAID]

ya yamaha does a good job designing their engines... hayabusa... 1.3 liter .... 175 hp... thats an insane number...


oh and did i mention if can do 200mph... try doing that on two wheels with air rushing past you at that speed

[Griffin]

Yamaha builds the cylinder heads and takes part in head design.

I double checked and the aluminum pistons are iron & tin coated - I don't find any mention of a material besides MMC in the cylinder walls but I do remember hearing somethign about Nikasil or something like that but I dont see substantiation. Perhaps thats the proper name of the MMC material.

Griffin