I finally pulled the engine that gave up in Utah. I started taking it apart and punted. Art has it now. He found the #2 rod bearing is trashed/spun but that the crank is actually fine. He was looking into the intake/exhaust ports and also noticed some bent valves. Nice. I brought him a replacement head today, we'll see what he comes up with.

I don't know if a rod bearing getting trashed can lead to low oil pressure, or if the low oil pressure/high oil temp led to the rod bearing problem. maybe the crank pulley bolt was loose and that led to the whole thing. The bent valves must have been from an over-rev from a missed gear change. I don't think I did that, but who knows. I certainly didn't over-rev in Utah. Oh well.

I wouldn't be too supprized if the valves in #2 are a little bent, I have seen that when a rod bearing goes. As for the other cyl's that is an odd one.

Even through the crank looks good, make sure to measure the ID on the con-rod! We have worked on way too many engines where new bearings are put in without replacing the rod that was out of round. Long story short, the new bearing set lasts about 3-4 hours...

-Nick Miller
Bennington Motorsports
(Midwest Region)

I don't know about the bent valves but I think the rod bearing was probably caused by a combination of factors with the excessive temps being the final straw. These engines normally fail at the #2 rod bearing and your high oil temps would have made for very low viscosity oil. Combine that with a very long time on full throttle at Miller, fast sweeping turns, and you have a recipe for disaster.

After trashing two engines at the #2 rod bearing, I finally spent the money to do all the oil system mods allowed and invested in a good oil cooler and accusump. All in all, it is relatively cheap insurance. Consider the cost of going to Nationals and blowing an engine....

^^ And thats why we will have at least one (maybe two) spare engines for trackside support at Nationals!!

-Nick
Bennington Motorsports

turns out that my bent valves were all the larger diameter ones, i think they are the intake. That means three different cylinders. I don't think they are related to the #2 rod bearing or the oil pressure problem. i suppose i have been running around with bent valves since the over-rev incident.