Relief for Exhaust Valves

[SubLGT]

Thats' what Federal-Mogul is offering.

http://articles.sae.org/15575/

Quote:
...At the 2017 IAA motor show in Frankfurt, Federal-Mogul Powertrain plans to reveal advances aimed at cooling the valves of downsized boosted engines via significant heat transfer. For exhaust valve head alloys, every 20°C reduction in temperature negates the need for an upgrade to the next, more expensive alloy specification….

...Gian Maria Olivetti, Chief Technology Officer, explained ... “The extreme valve temperatures experienced on today’s highly boosted downsized engines can lead to reduced valve fatigue life and critical valve guide and stem seal temperatures, resulting in the need for expensive valve steel alloys. If late ignition timing is used to reduce knock and enrichment is protecting components from critical temperatures, CO2 emissions are increased."…

...tests involving “highly rated turbocharged gasoline engines” using a combination of HTC and TIM technologies are stated by Federal-Mogul to have reduced peak inlet valve head temperatures by between 26ºC and 32°C. The improvement in exhaust valve head temperatures was even greater; on a solid valve the peak was reduced by up to 70°C and on a hollow, sodium-filled valve, by up to 67°C…

...HTC (High Thermal Conductivity) materials and TIM (Thermal Interface Material) coating to reduce valve head temperatures by up to 70°C, allowing improved combustion and lower emissions. HTC can also contribute to obtaining a more even circumferential temperature distribution on the valve seat insert and surrounding cylinder head material. By doing so, local hot spots can be avoided, so reducing wear reduction and temperature-related distortion….

 

[Trav]

We found a way to reduce cyl head temps so we can use cheaper materials that will probably fail sooner than later but hey we can use the public as a test mule and as long as its out of warranty who cares we will blame it on them.

 

[supton]

True, but most people don't want to own outside of warranty anyhow. They might have unexpected repairs, like needing tires or something really expensive like spark plugs.

 

[Lolvoguy]

Originally Posted By: supton
True, but most people don't want to own outside of warranty anyhow. They might have unexpected repairs, like needing tires or something really expensive like spark plugs.


...or "break" pads

 

[PeterPolyol]

What
Originally Posted By: Trav
We found a way to reduce cyl head temps so we can use cheaper materials that will probably fail sooner than later but hey we can use the public as a test mule and as long as its out of warranty who cares we will blame it on them.

Ding ding ding

 

[Chris142]

Originally Posted By: supton
True, but most people don't want to own outside of warranty anyhow. .
huh? The motoring public is clueless when it comes to choosing good and bad cars. At least around here they are. If gm found a bunch of vegas or 80s cadillacs the public would buy them up without ever checking the cars past history.

 

[philipp10]

Huh? Not sure how you all came to such a negative reaction to an article on the engineering of valve.....jeeez