If you look at the .eng file for any car, there is a line in there that tells you the life span of the engine in seconds.
There is also a line that tells you what RPM you cannot exceded safely. If you exceed it, the time that you RPMs are above it counts double(I think) against the engine life.

I am at work, so I cannot tell you what the exact lines say, but I think you will know them if u see them.

So, lower your RPMs.

Do you think that maybe you are changing down through the gears too quickly or too early and putting too much pressure on the engine under braking? I've certainly known that to cause blow ups.

Shift up earlier and shift down later. Do not only count on the rev limiter, as obviously it doesn't help at all on downshifts.

I don't think it is the downshifts, I'm good about that -- I have to be because I don't use auto clutch.

Ok, did a search on *.eng and found ListerFactory_V12.eng (this is the one I'm interested in). I see entries:

RevLimitRange=(6200.0, 100.0, 7)
RevLimitSetting=2
RevLimitLogic=150.0

LifetimeEngineRPM=(6100.0, 95.0)
LifetimeOilTemp=(100.00, 3.00)
LifetimeAvg=10800
LifetimeVar=2250

So for the Lister, 6100 should be the rev limit? Is the 95 the number of seconds above before she blows?

When ever you are at over 6100 rpm, damage starts to accumulate. The more you are over it, the more damage build-up.

If you are careful with your downshifts, you can get through a three-hour (100%) race without engine trouble so that 6100 is no hard limit by any means.

From RSC:

This section quantifies the ways in which heat is removed from the engine.

LifetimeEngineRPM=(17730.0,344.0) // (base engine speed for lifetime, range where lifetime is halved)
LifetimeOilTemp=(125.4,2.90) // (base oil temp for lifetime, range where lifetime is halved)
LifetimeAvg=8105 // average lifetime in seconds
LifetimeVar=2940 // lifetime random variance
This section calculates the engine life dependant on rpm, oil temperature relative to optimum, and statistical treatment of average life. The following is from ISI, courtesy of Maxsilver. I have edited the original to fit with the numbers in this file -

"The LifetimeAvg and LifetimeVar are ... the mean and variance of a normal distribution.

The lifetime of the engine is continually reduced based on the current RPM and temperature. If you were able to drive around perfectly maintaining an RPM of 17730.0 and oil temp of 125.4 deg C, the lifetime would reduce by 1 every second. So on average, you'd have 8105 seconds before your engine exploded.

Now obviously you can't maintain that exact RPM & temp, so the lifetime reduction happens faster if you're above the RPM & temp and slower if you're below. It's an exponential curve - at 17730.0 + 344.0 RPM and 125.4 + 2.90 deg C, the lifetime reduces by 2 every second. At 17730.0 + (2 * 344) and 125.4 + ( 2 * 2.90) deg C, the lifetime reduces by 4 every second, etc. The RPM and temperature each contribute half to the calculated lifetime reduction."

Wow, great info - thanks guys.

You could always practice being real slow like me and never have a blowup! Lol

Well, maybe only one in the 2+ years I've been racing Tim's various leagues (the vette, with 5 minutes left!)

Just slow Dan