Well.
The racing season is now over and it ended somehow not good.
The valvetrain have been behaving very nice, and engine power was very good.
Last weekend rod bearing on cylinder 2 failed, and the reason might be known....
First one question: The rod bearing on cylinder 2 was completely gone, the rod cap was blackened and the rod bore is not round anymore. How long does it take to make such a damage? Two minutes or 10 minutes of high RPM driving?
Needless to say I need a rod replaced and a crank reground/ checked.
But now to what caused this. There was a modified dual sump on this engine. I HAD BEEN ANXIOUS ALL YEAR because the
oil pressure reading was going down low in the tight ends of LH and especially RH corners at the track. As it was returning to 4 bar in a straight, I didn't take much notice of it. At this very last run, I noticed low pressure for a longer time; at both the start, the ight & the end of bends. After 10 laps it started to make alot of noice....
It was not the bad rod I hear knocking, but the rods hitting the windage tray (customized & welded to the bottom og the
oil sump).
As I did have the dip stick in the front sump, and the
oil level at "max" was at just below rod/ crank - which means about level with the upper floor of the pan, this is the explanation I'd bet for: Oil level in front sump OK, but much too low at the rear- caused by the oil getting trapped in the front, not showing actual oil level. Another piece of the cause might be one of the trap doors had broke loose. (At the bottom of the picture.)
Here's a nice painting:
What I should have done: Made a connection between front and rear sump... Thought of it, but never happened.
Now I'm installing a Canton roadrace pan.
Oh well; the engine lasted 3 years and with 8000 rpm redline & an amature builder, what more can you expect?
RS
How this season ended.
Threaded Mode
