Oil pressure and (probably) temps--arrgh

[s-zero]

I havent checked oil temps but i've never ran longer than an hour straight lapping session. Should probably install a temp gauge since these cars have been known to overheat the oil during lapping. Oil pressure drop happens about 10-15min into the lapping anyways. I've also tried running 40wt oil and now onto 50wt with minimal difference in pressure, slightly higher (5psi) at redline. Also have the comptech billet gears in a new pump. I'm not as concerned about the oil pressure in the head at redline since the cams are probably only under a few hundred psi of journal load as compared to the several dozens of tonnes on the bottom end bearings which is why i have the gauge on the bottom end of the engine. I've also disconnected vtec and the oil pressure at 7000rpm is about double on the gauge (50psi?). I'm assuming then that vtec causes some of the oil pressure drop but not all of it.

 

[Mac Attack]

...The second valve in the filter bracket is there in case either the filter or cooler is blocked completely, oil by passes and flows directly to the main bearings.

Respectfully, I have to question that.

I guess car manufacturers have to design failsafes for idiots, but if the filter or coolers are completely blocked, there are bigger problems to worry about.

I think the second relief valve is there for cold startups. When the oil is cold and dense, it bypasses the filter (and cooler I guess too), so it can reach the engine at a critical time. It's the same effect when the engine is hot yet we're at 7500RPM's - oil starts to bypass the restrictive filter and cooler where it can be needed where important - the engine bearings and journals.

Of course I don't race around with a cold engine, but tonight I did take it out for a quick spin and when the engine is cold, oil pressure from my stock gauge is ~5.25 @ 2000 RPM's. At 4k RPM's, it's right at 6 kg/cm^2 and doesn't really increase much from there.

I forgot to get some equivalent warm readings....

Dave

 

[menfou]

The second valve in the filter bracket is there in case either the filter or cooler is blocked completely, oil by passes and flows directly to the main bearings.

On my car, I changed the stock oil pressure sender, and I put a VDO 0-10bar with a VDO gauge.
I rebuilt my engine, I changed the 1st valve, spring, oil pump

I have 6-7kg/mm at idle with cold engine on my oil filter adaptor
I have 3kg/mm at idle with cold engine, on the vdo gauge
I have 6-8kg/mm between 2000-8000rpm on the oil filter
I have 3.8kg/mm between 2000-8000rpm on the vdo gauge

Can I have a problem with the second valve ?