krazik

hmm. I do have my accusump in the trunk, but that shouldn't affect the pressure I would think.

How many 90's do you guys have in the lines? Does he run a remote filler and which cooler?

He mentioned you guys used AN-10, I'm all AN-12.

davepk

You can see the relief spring sitting in its bore but without the cap holding it in place. The green outline shows the extent of the bore. The yellow outline is of the relief piston that sits at the end of the bore. The relief spring pushes against this piston and keeps the end of the bore plugged by the piston. As the pressure rises in the high pressure chamber eventually it gets high enough the push the piston and compress the relief spring. An opening from the high pressure side to the low pressure side is created when the spring is compressed enough by the oil pressure acting on the piston.

With the cap installed the spring is compressed and preloaded against the piston. This preload represents a certain required pressure be present to open up the relief pathway. This regulated pressure can be increased by increasing the preload on the spring. Simply placing a washer or stack of washers of the same diameter as the spring between the spring and the cap would be sufficient. The only question needed to be answered is how thick should this stack be.

ultimate lurker

I'd have to go back and check, but I believe there is only one, maybe two 90's in the whole system. Accusump is in the passenger footwell though, so there is a lot less oil line to deal with. About 36" total under the hood between oil filter, block and cooler, and then another 36" or so for the Accusump. Filter is a Canton cartridge type and the cooler is a Setrab or Mocal (6 x 10" or thereabouts).

I checked the pressure again last night and we're above 100 psi with any sort of revs when cold. When warm above 3k rpm it stabilizes in the 90s. Its pretty clear when the relief valve opens up too. Gauge is a Autometer and it matches up with the gauge on the Accusump perfectly, so I assume its reading correct.

You may want to contact Joe Alaniz about shimming the relief valve as I believe he did that on Karner's original race motor (the non-Honda Challenge legal engine )

UL

Greenlight

Regarding shimming the spring. If you shim it too much the spring will coil bind and the relief valve will never open, causing the oil pressure to go to the moon (or at least low earth orbit).

A rough estimate on shimming the spring is as follows:

The valve diameter is 0.707"

Therefore, the valve area is 0.393 inches squared

The spring must be compressed ~ 1.25 inches from its free length of ~ 3.835 inches in order for the valve to bypass.

85 psi x 0.393 in^2 = 33.4 lbs.

At 85 psi this requires a spring force of ~ 33.4 lbs

The spring constant (k) can be calculated from the equation F = k x

This gives k = 26.7 lb per in


95 psi x 0.393 in^2 = 37.3 lbs.

To increase the oil pressure by 10 psi to 95 psi the spring force must be ~ 37.3 lbs.


Again, from F = k x

37.3 / 26.7 = 1.4"


The new value for the spring compression distance (x) is ~ 1.4 inches

So, 1.4 - 1.25 = 0.150 inches

This is the thickness of the washer/spacer that must be added either between the spring and the nut or the spring and the valve in order to increase the pressure by 10 psi..

The spring wire diameter is 0.090" and there are 26 total coils of which 24 are active coils. The stacked length (coil bind) of the spring is 25 x 0.090" = 2.25"

Subtracting the free length (3.835") from the stacked length (2.25") equals 1.585"

Adding the 0.150" shim only compresses the spring 1.4" which leaves a safety margin of 0.185"

I hope this helps.

Greenlight

davepk

Thank you much GreenLight, its much appreciated.

Spoolin

I'm using the UR oil filter relocator kit with -10 braided lines, two 90 deg., and two 45 deg. fittings and at idle(with engine at normal temp), my oil pressure is around 20 to 25 Psi. At normal driving it's around 75-80 Psi and it drops in VTEC to about 60 Psi and holds there all the way to redline. Is this normal because of the oil being supplied to the turbo and rerouted to the relocator kit with longer lines? Is 60 Psi enough pressure at 9000 RPM? Also, I have DEFI gauges so I think the calibration should be good since these are pretty expensive and well made. But I could be wrong. Thanks

Tinker219

http://www.we-todd-did-racing.com/wetoddim...kZmQzMXk1NDE%3D
You can see the oil pressure guage a little bit in this video. Stock oil cooler/filter setup, just feeding a turbo. Dont know if it helps, but this is what I experience!
15w50 oil btw...I will be heavily tracking the car this spring

Spoolin

It's hard to tell what your oil pressure is but it doesn't look like it moves at all until after you let off the throttle. Is this the way the pressure should be? Mine is nothing like that at all.

Tinker219

Im not sure. Driving and on the dyno it was around 75psi most of the time. You can see it "tick" when Vtec kicks in, like it drops a few PSI, then raises again with RPM to close to 100psi. Im thinking my 15w/50 has something to do with the high oil pressures. Im all for it, as I think Im less likely to have an engine failure with these pressures.

Spoolin

I may switch to 15w50 oil and see what happens. With the turbo, I'm sure using 10w40 can get a litle too thin under the extra heat.