Oil Pressure Relief Valve Spring, Which one to use on a race motor? Options

[GBallantine]

My 4 cylinder race motor is making to much oil pressure. Any of the race guys know if changing to a lighter spring would make a difference? Anyone had such a problem? Any other suggestions or areas to trouble shoot?

GB

[Joe Ricard]

What's too much?
yes putting a stock pressure control valve and spring will bring it down.

What kinda pump you got? Melling High volume pumps REALLY are HIGH VOLUME.
even at 260 degrees I was able to maintain 12-15 PSI at idle.

[GBallantine]

Joe,

I'm using a Schadeck 30mm oil pump in combo with a stock cooler attached to the case location and a big front cooler. At last weekend races at Mosport I blew a small hole in the stock cooler, replaced it and the same thing happened to the second cooler. I'm going to check the spring to determine if it's stock. Is there any identifying marks on the spring? My 911 oil pressure gage messures 2 bar at idle.

Gord B

[Joe Ricard]

30 PSI at idle probably isn'y bad for cold oil. but hot oil seems pretty high.
My VDO gauge goes to 80 I think. Flat out 6200 RPM down the straight oil hotter than hell I am able to reach 50 PSI.

[GBallantine]

Yup, that sounds about right 6200 rpm flat out = 50 -55 psi with oil temps at 210 to 220. How do you identify if the oil relief spring is stock? Any markings?

GB

[Joe Ricard]

How do you identify if the oil relief spring is stock? Any markings?

GB
[/quote]
I have no idea, however I do know that mine is a weltmiester piece. I think the spring is the same (I don't really know) But the piston is actually longer which is what I assume gives you more spring pressure to control/maintain higher oil pressures.

[GBallantine]

I pulled the spring and piston last night. No real identifiable markings on either. Interesting your comment on the piston size vs spring tension. So the longer the piston the greater spring tension which maintains higher oil pressure.

GB

[KenH]

The springs are the same. The piston length is what changes to vary the pressure.

I think something else is wrong. I regularly run 80+ pounds with cold oil and have never had a leak. Others I know have also been OK.
May be somthing restricting the valve or just bad oil coolers.

Ken

[GBallantine]

The springs are the same. The piston length is what changes to vary the pressure.

I think something else is wrong. I regularly run 80+ pounds with cold oil and have never had a leak. Others I know have also been OK.
May be somthing restricting the valve or just bad oil coolers.

Ken

Ken,

Any ideas of what could be restricting the valve? It seems to simple a setup to screw up.When I took it out it moved freely in the bore. It's unlikely that 2 oil coolers would be defective??? However stranger things have happened.

[jhadler]

Does your auxiluary cooler have a thermostat? Cold starts with thick oil can rupture a cooler.

-Josh2

[GBallantine]

No thermostat in the auxilary cooler mounted right up front . Didn't want any restrictions. The problem is with the primary stock oil cooler blowing out.

[Brad Roberts]

I'm surprised that the seals dont blow first.

Dedicated track car? I dont run stock coolers. I use a block off plate and route the oil to a front mounted cooler.

This is interesting. I'm going to have to think on this one.


B

[Brett W]

You need to check the other releif valve and see if it moves OK. Remember lost of oil pressure is not a good sign. You want oil flow, pressure is based on restriction. You need a T-stat in line to your front cooler. There is not much reason to run a stock cooler. Anything you can do to eliminate the stock cooler, filter mount, etc the better off you are.

[GBallantine]

I'm surprised that the seals dont blow first.

Dedicated track car? I dont run stock coolers. I use a block off plate and route the oil to a front mounted cooler.

This is interesting. I'm going to have to think on this one.


B

Brad, interesting observation about the seals not blowing off first before the cooler lets go. At present the stock cooler is removed and a block off plate installed with 2 fittings and a single braided line from the plate and returning back to the plate creating a loop.
I ran one race and the car seemed to run about 10 degrees hotter. You say you don't run the stock cooler on your track car only the front mounted cooler. Do you run a 180 thermostat somewhere in the line? I'm running a 30mm Shadeck oil pump with braided line to a remote oil filter and up to the front mounted cooler and a return line back to the case. How do you run the lines from the oil pump? Is there a more effective routing?

Thanks Gord B