Custom turbo
Custom turbo
09-02-2020, 09:45 PM
#8
(08-31-2020, 10:55 AM)OM616(08-27-2020, 05:54 PM)Austincarnut(08-11-2020, 09:27 AM)OM616I was running no more than 1100*F going up hill with ac on at full boost on a hot day
What was your average sustained and highest EGT while you were thrashing on it?
Valve seat spring pressure has a lot to do with valve cooling. As boost (for intakes) EMP (for exhaust) pressure increases effective seat pressure decreases.
Additionally, if the spring pressure is not enough, the valve will bounce on the seat which significantly reduces the cooling of the valve which can result in the valve sinking or dishing. As far as I know, the OM61X engines redline is around 4500 ish at only 10/12 PSI of boost which on a stock T3 would generate around 15lbs of EMP. And that is will very little fueling. It sounds like you have increased fueling, boost, EMP, and RPM enough to push the valvetraine beyond its working range.
Valve cooling is all about seat pressure, and in really extreme set ups, seat material. Springs need to matched to suit the cam profile, boost, EMP, and RPM range.
Another thing I have seen is the valve nuts coming loose.
Hence my question. What will you do to your to avoid this? there is little to no room for adjusting spring pressure / valve geometry. I'm going to govern my max RPM for now.
Austincarnut
09-02-2020, 09:45 PM #8(08-31-2020, 10:55 AM)OM616(08-27-2020, 05:54 PM)Austincarnut(08-11-2020, 09:27 AM)OM616I was running no more than 1100*F going up hill with ac on at full boost on a hot day
What was your average sustained and highest EGT while you were thrashing on it?
Valve seat spring pressure has a lot to do with valve cooling. As boost (for intakes) EMP (for exhaust) pressure increases effective seat pressure decreases.
Additionally, if the spring pressure is not enough, the valve will bounce on the seat which significantly reduces the cooling of the valve which can result in the valve sinking or dishing. As far as I know, the OM61X engines redline is around 4500 ish at only 10/12 PSI of boost which on a stock T3 would generate around 15lbs of EMP. And that is will very little fueling. It sounds like you have increased fueling, boost, EMP, and RPM enough to push the valvetraine beyond its working range.
Valve cooling is all about seat pressure, and in really extreme set ups, seat material. Springs need to matched to suit the cam profile, boost, EMP, and RPM range.
Another thing I have seen is the valve nuts coming loose.
Hence my question. What will you do to your to avoid this? there is little to no room for adjusting spring pressure / valve geometry. I'm going to govern my max RPM for now.
Messages In This Thread
Custom turbo - by OM616 - 07-29-2020, 01:46 PM
RE: Custom turbo - by Austincarnut - 07-29-2020, 10:07 PM
RE: Custom turbo - by OM616 - 07-30-2020, 01:27 PM
RE: Custom turbo - by Austincarnut - 08-10-2020, 09:30 PM
RE: Custom turbo - by OM616 - 08-11-2020, 09:27 AM
RE: Custom turbo - by Austincarnut - 08-27-2020, 05:54 PM
RE: Custom turbo - by OM616 - 08-31-2020, 10:55 AM
RE: Custom turbo - by Austincarnut - 09-02-2020, 09:45 PM
RE: Custom turbo - by OM616 - 09-09-2020, 04:27 PM
RE: Custom turbo - by vica153 - 09-30-2020, 11:09 PM
RE: Custom turbo - by OM616 - 10-02-2020, 05:21 PM
RE: Custom turbo - by vica153 - 10-02-2020, 08:29 PM
RE: Custom turbo - by OM616 - 10-03-2020, 04:08 PM
RE: Custom turbo - by vica153 - 10-04-2020, 12:25 AM
RE: Custom turbo - by OM616 - 10-04-2020, 12:08 PM
RE: Custom turbo - by vica153 - 10-04-2020, 02:01 PM
RE: Custom turbo - by OM616 - 10-04-2020, 06:28 PM
RE: Custom turbo - by vica153 - 10-04-2020, 08:40 PM
RE: Custom turbo - by vica153 - 10-04-2020, 08:52 PM
RE: Custom turbo - by 50harleyrider - 10-11-2020, 09:11 PM
RE: Custom turbo - by vica153 - 10-11-2020, 11:39 PM
RE: Custom turbo - by OM616 - 12-06-2020, 02:11 PM
Users browsing this thread:
1 Guest(s)
1 Guest(s)
Users browsing this thread:
1 Guest(s)
1 Guest(s)