need help with oil pressure on 2t motor

[2t toyota racer]

Im drivving a 2t toyota motor in my dirt ovaltrack racing car but after the 2nd or 3rd lap of 7 the oil pressure starts to drop and drop even to 0,7 bar I knock a bearing this time the previous 3 races i was just lucky to finisch.

please give me any information u can .

[quick69gto]

"7 bar I knock a bearing this time the previous 3 races i was just lucky to finisch."
I take it this means the engine spun a bearing?
If it did, then I'm sure you know the engine is done. It's time to rebuilt it.
As for the oil pressure loss, your using the engine for racing. The engine will wear out much quicker that using it for normal street use.
Race engines, whether stock of modified, rarely last an entire season without freshening them up (new rings, bearings,etc.).
What happened is that the bearings started to wear, bearing clearances started to get wider, heat caused the bearing clearances to become even wider, heat caused the oil to become thinner, and eventually the oil pressure went to zero.
The result; a spun bearing.
In the future, if the oil pressure drops to zero, shut it down and take it home.
It's usually allot cheaper to rebuild an engine with no oil pressure than it is to rebuild one with no oil pressure and a spun bearing.

Good luck.

[2t toyota racer]

i rebuilt it just before the race day .
i always service it before a race but the last race i blow a head gasket and stuff the rings up dew to overheating.

i change the rings,bearings,full gaskets and seals i`ve skeamed the head and reseeded the valves checked the oil pump and and resized the pushrod lifters and changed all the filters and still running on quit high heat and and stufed up the motor dew to low oil pressure .

on start up i`ve been running on 5.8 -7 bar of oil pressure and after a few rounds on the test day it went up to nearly 8 bar but on race day after 2 - 3 rounds it started to drop ,why?