Oil Pressure levels for K20 - need for baffled sump?

[plAythiNG]

Hey All,

Didnt see much info in the Technical section regarding oil pressure discussion on the k series engine.

After having my Defi Guages for a few months now and also one track day. Looking at the Peak data from the track day, I noticed that the left hander after the kink at Wakefield Park, my Defi's showed 0.0 PSI oil pressure at approx 8100rpm. This has been on my mind for awhile now and did some googling around. Cant locate the link/thread of the forum anymore but it was in a Lotus Elise forum. One Elise owner experienced a high speed left hand sweeper and he had no oil pressure also.

Over the weekend, I decided to do some testing on a private road where I would redline 1st gear. I peformed this test 3 times. From a standstill, would release clutch at around 4K rpm and rev to redline, grab second and repeat.

Results of oil pressure at its highest peak;

1. 7800rpm - 0.0 x100kPa / 0.0PSI
2. 8100rpm - 1.4 x 100kPa / 20PSI
3. 8400rpm - 1.7 x 100kPa / 27PSI

From this, my next mod is going to be a baffled sump. What I'd like to know or discuss in this thread is;

1. At what PSI is too low for the K20?

2. What is the optimum amount of PSI for the k20 at track conditions (110deg C Oil Temp / in Vtec)

Extra Info:

Upon driving my car yesterday, was paying much much more attention to the oil pressure. my usual driving see's the engine revs anywhere from 2000-3500RPM. From yesterdays commute to work, the oil pressure was at anywhere from 450-600KPA / 65PSI - 87PSI.

[tinkerbell]

1. At what PSI is too low for the K20?

under 50 PSI

2. What is the optimum amount of PSI for the k20 at track conditions (110deg C Oil Temp / in Vtec)

over 70 PSI

[tinkerbell]

btw - that left hander is where i blew up my first engine, lol!

you are lucky to be posting up "what PSI is too low?" instead of "i need a new bottom-end!"

[ChargeR]

Are you sure those numbers are correct? If you were getting pressure that low at full load and high RPM consistently your motor would have spun a bearing long ago. For how long a period was the pressure that low?

The fish hook is definitely the corner to be afraid of though, the oil will end up getting forced up the timing chain casing on that side of the motor, away from the oil pickup.

My thoughts on your questions:

1. Any significant drop from the normal oil pressure is bad, I don't have a gauge so I can't say what is normal but if you are losing 20% of your oil pressure I think you have problems.

2. Whatever pressure a stock motor, warmed up to operating temperature with the recommended oil viscosity from Honda in it has. The workshop manual says 44psi at minimum at 3000 RPM with the oil at 80°C.

[plAythiNG]

under 50 PSI



over 70 PSI

Thanks Tink, ever since I've had the gauges, I have been able to record this data. I am going to install a Baffle for sure but not until I do my clutch upgrade (hopefully soem time in the middle of 2013) - what are the implications of a few track days of the engine sitting at redline with PSi under 50PSI throughout the day?

btw - that left hander is where i blew up my first engine, lol!

you are lucky to be posting up "what PSI is too low?" instead of "i need a new bottom-end!"

Haha, so since you have experienced this, what measures did you put in place to overcome this - just a baffle?

Are you sure those numbers are correct? If you were getting pressure that low at full load and high RPM consistently your motor would have spun a bearing long ago. For how long a period was the pressure that low?

The fish hook is definitely the corner to be afraid of though, the oil will end up getting forced up the timing chain casing on that side of the motor, away from the oil pickup.

My thoughts on your questions:

1. Any significant drop from the normal oil pressure is bad, I don't have a gauge so I can't say what is normal but if you are losing 20% of your oil pressure I think you have problems.

2. Whatever pressure a stock motor, warmed up to operating temperature with the recommended oil viscosity from Honda in it has. The workshop manual says 44psi at minimum at 3000 RPM with the oil at 80°C.

Well its ever since the trackday in Janaury 2012 I have been able to actually monitor my oil pressure levels. the car drives normal, dont have any issues at all. The defi gauges were installed by Top One and I have utmost confidence in their servicing. Regarding holding higher oil pressures, is there any other modification that can help increase oil pressure?

[fatboyz39]

You havnt ruled out defi unit are inaccurate? Or faulty? 0.0PSI @ 7800rpm you would of blown your motor.

I would install a mechanical oil pressure gauge and check oil pressure to cross reference with the defi unit.

Does vtec kick in and out going around fish hook?

@ 110 degree oil temp depending on which oil weight your using it'll drop around 10psi from normal oil pressure.

[tinkerbell]

1. baffled sum (Moroso)
2. overfill oil a few mm above top dot
3. oil pressure warning buzzer (set at 50 psi)
4. uprated oil pump (80psi at >3000rpm)


(i also do not understand your oil 'recordings')

[tinkerbell]

You havnt ruled out defi unit are inaccurate? Or faulty? 0.0PSI @ 7800rpm you would of blown your motor.

was my 1st thought.

where is the sensor installed?

[plAythiNG]

1. baffled sum (Moroso)
2. overfill oil a few mm above top dot
3. oil pressure warning buzzer (set at 50 psi)
4. uprated oil pump (80psi at >3000rpm)


(i also do not understand your oil 'recordings')

the trackday in Janaury, I didnt overfill it that time. warning buzzer is set to 1.5 x100 kPa / 22PSI, will look at increasing it. Regarding the oil recordings, on the Defi unit, it shows it as X.X x 100kPa. In this thread, im giving both units converted already so its easier for people to interpret.

was my 1st thought.

where is the sensor installed?

Installed from a Greddy sandwich plate. Where else can you tap for oil pressure? or is the filter the best place to read oil pressure?

[plAythiNG]

You havnt ruled out defi unit are inaccurate? Or faulty? 0.0PSI @ 7800rpm you would of blown your motor.

I would install a mechanical oil pressure gauge and check oil pressure to cross reference with the defi unit.

Does vtec kick in and out going around fish hook?

@ 110 degree oil temp depending on which oil weight your using it'll drop around 10psi from normal oil pressure.

Jimmy, where can I get a mechanical oil pressure from - suggestions?

Im in 3rd gear at approx 3-4K rpm to out of vtec but accelerating into VTEC.

[tinkerbell]

Installed from a Greddy sandwich plate. Where else can you tap for oil pressure? or is the filter the best place to read oil pressure?

you need to be more specific.

please use more details in your replies, this is a very specific topic, and you are not providing enough information.

--

so you had the warning set to 22psi and you would have been hearing it the whole way around the fish-hook? and kept accelerating???

[tinkerbell]

which side of the sandwich plate is the oil pressure sensor on?

is the plate a thermostat one?

[plAythiNG]

http://perfectrun.jp/src/detail.php?...d=104014_10405

^^ Thats the one I have.

Going by the description, I dont think it has a builtin thermostat.

I noticed the warning comming out of fish hook.

[tinkerbell]

well if you have that one and no oil cooler (i thought you had oil cooler)

then your readings are very disturbing and mean you have a very serious issue and should not be driving the car until:

1. you verify the Defi readings are erroneous (mechanical gauge - google it)
2. you fix your oil pressure problem

[plAythiNG]

I see, because you say they are very disturbing, what conditions should I feel when driving the car? The car feels no different to how it has been in the 2 years of ownership.