mtunreal

Isn't oil pressure the expression of the amount of pressure required to move the oil. As a liquid it under goes no compression but the viscosity will change with respects to its temperature. The density would remain the same unless a phase change occurs (degradation or sheered). A colder oil has a higher viscosity and therefore experiences an increased pressure. Higher viscosity means that more pressure is required to move the oil, hence increased resistance. An increase in resistance is comparable to reduced lubrication and increased friction. This may lead to increased wear or less movement. Correct me if this is wrong?

A difference is evident between the oils.

Ultra_Nexus

This engine doesn't burn oil but I still think it is a case of vapour that is causing this. Removing the PCV and venting to atmosphere would eliminate this.

I also want to try this on a 2004 engine.

Density and viscosity are independent variables and share no correlation.

The rest of what you say is correct, but the JDMs don't have an oil pressure sensor for VTEC and the affect is over 20% of the rev range.

This simply shouldn't be happening, but it is so where do you go from here?

mtunreal

Certainly dude, singing from the same hymn sheet.

markforrester99

Oil pressure shouldn't be the issue. In testing i get 20psi at 800rpm when warm and 85psi by 3000rpm. It would have to be some sort of restriction to cause a drop in oil pressure to cause the dip on the graph.

I have always been of the mindset that the big oil companies that advertise on tv are normally the ones that have the worst oil! For the last 5 years ive used motul 8100 with no problems at all and £40 for 5 litres is reasonable. Doesn't burn a drop of oil

Si2k

That was only an idea. As Ron has said though, it's a JDM so no pressure switch.

Maybe the JDM and higher compression means the Ecu is doing something different? Although do JDMs have knock sensors?

Ultra_Nexus

Yes they do and I think you have hit the nail on the head here.

Seems that the knock sensors are quite aggressive.

Whatever sound the engine gives with edge in it, seems that the knock sensor doesn't like it and is winding it all back.

s2konroids

Is Petronas fully synthetic?

Typically he Honda knock control is only designed to compensate for different qualities fuel, it wont quickly advance/retard as quick as other makes of vehicles do. You could knock retard without any knock,or vice versa. Obviosuly the engine can/will knock pretty much anywhere in the rev range and whenyou switch the car off it resets. The knock sensor is a bit over zealous and taps like exhaust heathsield can cause phantom knock - most bloody annoying!

The dip appears to be linked to vtec engagement, but odd its over such a large rev range.

I've used petronas and was good for the money as said in the past, the car did use more of it - thats the only thing i can bring to the debate.

s2k_Nut

The one tested here is SEMI I think.

I could be wrong on that though

s2konroids

Ah okay, so a slight difference in the test we are comparing a fully synthetic to a semi synthetic.

I just don't want to run a semi in my car, i know you do but think I'd more comfortable running a fully synthetic.

I'll throw this in...

What i will say was my car did 176k miles predominantly on castrol edge 5w40 and it was supercharged for 50k of that and i sold the car a couple of weeks ago and it was running sweet as a nut.

I'm all for saying overpriced mugen is shit compared to other LOL, so i give an unbiased opinion.

s2k_Nut

Its FULLY synthetic Aj, read the link I posted