JKE

no, I do not know of any.

I mentioned 3 types of additives. The fuel additive is not having the effect on the intake except for deposits and corrosion on face and rim. It is the lubrication additives that do this. ALL stem guide seals weep some amount oil. This stuff is in contact with the back of the intake valve. 20% of your heat travels through the fillet area and up the stem to the guide. If you have a bad seal, then the problem is amplified as you mentioned. Intake valve temps are escaping me at the moment. Not nearly as hot as the exhaust of course and that is where we focus most of our attention....even in gassers....
Exhaust is the offender here for FUEL additives. Keep in mind this is long term. over 50 - 75,000 I would say, depending on your engines condition. Exhaust valve temps in fillet are 1000 - 1200 degrees F. and 1200 - 1400 on face center. At these temps, different chemicals cause different prob......stopping this is going to get too long for this dicussion.......

Burn what it is designed to burn with the exception of water and Nitrous. We can't and don't design valves that can withstand the many additives/chemicals in the automotive market. Way too many to account for. We design them to run the fuel only.

Maybe some under estimate the severe conditions in the chamber.

Oh yeah - Water injection will help keep things clean and cool.

FWIW.

Just throwing some info out for you guys to feed on. I am no expert, but I know a little.

John

2manydogs

Granted, all engines develop exhaust valve deposits. The only thing that causes a valve to lose it's clearance and not contact the seat is it's movement towards the rocker arm tip- seat and face erosion, seat coming loose and pounding into the head or the stem physically streching. So, if the valve is never run with out it's ability to lose contact with the seat, and lose it's cooling ability (through proper adjustment) I, personally, don't think valves are a big problem in a Cummins. Any failure from the above problems could be detected ahead of time from routine maintanence. My point of view comes from my engine, after 280,000 miles, has never needed a substantial change in adjustment except for wear (loose). But maybe I'm wrong. I came from the world of air cooled VWs, where the words VALVE PROBLEM were spoken daily Jim

JKE

VW ....

I do not think the cummins has valve issues either

Your explanation is true to a point, but over simplified. One has to consider adiabatic softening, super alloy valve is forged from, valve rotation, superficial hardness and core hardness specifications and on and on and on...no real need to go further. I think the last few posts have just been worhtless information

Have a nice day. It is beautiful outside..... ;D