I have a few questions about oil pressure and oil temperature- in general and in relation to large 4's.

-I realize that increased oil temperature will cause lower oil pressure however will increased oil pressure cause lower oil temperature?

-My oil temps normally run around 210. On a hot day, if I am driving the car very hard then get stuck in stop and go traffic for a while- my temps rest around 220-230 and occ will get up to about 240-250 if I accelerate hard (for just a very small amount of time- then goes right back to 220-230).

-My oil pressure is about 10 psi per 1000 rpm. That seems to be normal from everything I can see. I use a schadek 26mm pump. Would there be any advantage to switching to a 30mm pump for me? I have a large 4 with an external cooler in the rear or the car. I already own the different schadak pumps so I wouldn't need to buy anything- I just want to do what is best for my car.

Frontal air for the cooler

I am planning on installing a front oil cooler in the middle of winter however for now I am trying to figure out if there are any temporary alternatives and if I going to damage my engine?

Easiest would be a bigger cooler and possibly fans.
More area means faster cooling.

I also believe the higher oil pressure would not reduce the heat.
That is a thermodynamics question, but I suspect it won't make a difference if you move the oil around faster, it creates friction and heat by doing just that...plus it needs time to cool.

Not saying that 10 psi is good at 1000 rpm, but a quick fix would be a different cooler location or larger cooler, more air to the cooler (think Trevor Home Depot ducting)

If you are using the sandwich adapter at your oil filter bracket for the external cooler, then some people modify the relief valve that bypasses the filter.

If that valves opens at too low of pressure, then your oil will bypass the filter AND the cooler.

If your pressure is peaking when you drive it hard, then it could bypass when you need the cooling the most.

Stu

Here is a diagram of what I mean:



The red adapter plate will get zero flow if the "Filter bypass valve" opens due to high pressure.

Stu

What is the best way to plug the bypass valve?

Also- any one have any input on the weltmeister oil pressure relief valve modification?

If the pressure is too high, it will open one or another of the bypasses. It can bypass the oil filter media, and it can even bypass the cooler.

I don't know how high "too high" is.

The most common way to disable the oil filter bypass is to pop the cover off of the spring-and-valve hole and put a solid plug in its place.

Sorry, no input on the WM kit. I hear that it's a stronger spring, so it would help some with cooling at higher oil pressures, but I haven't used it.

--DD

Increasing pressure reduces the oil diverted to the factory cooler.

Soooo- interesting story.

First- my plug and jb weld worked very well- too well.

I installed a KN oil filter (which is supposedly high flow). I let the car idle for abotu 5 minutes. Then I drove very gently at low rpm for about 5 minutes then smoke and low oil pressure light. The threaded nub on the intermediate flange snapped off!!! I was surprised that the filter didn't blow out first.

So the pipe nipple that holds the adapter plate onto the intermediate flange broke.
And the oil filter broke away still attached to the oil cooler adapter plate?

My first reaction would be to say that the pipe nipple must have been stressed at some point in its life.
Does any weight from the cooler lines hang on the adapter plate?
Or did the cooler adapter people send you a POS pipe nipple?

Even if the filter was 100% clogged I would assume that the cooler or the cooler lines would blow before snapping off the pipe nipple.
So I dont think oil pressure caused the failure.

However if somehow the oil filter or the oil passage that leads out of the intermediate plate was fully clogged, and the pump could reach 100PSI, then that would be ~450 pounds of pressure pushing on the cooler adapter plate.

Any chance you got JB weld back into the passage that leads out of the intermediate plate?

Stu

And what was your oil pressure gauge saying during all of this?

I was closely looking at the oil pressure gauge the whole time. The readings were between 60 and 70- max 75.

I do not think that the JB weld was the issue. I did not think that I overtightened the oil filter nipple extension at the time however I did purposely tighten the the oil filter nipple extension (for the sandwich plate) more than normal cause last time I installed it I had a slight amount of rotational movement of the sandwich plate. I wanted to make sure the external cooler lines didn't bump into the header pipe. In hindsight- I must have overtightened it and stressed the intermediate flange nipple. I was only about 50 feet from my home when it happened so no big deal- it's in my garage and I will just install a new intermediate plate.
Click to view attachment

If your pressure looked normal, then you had flow through the engine while it was running, so it was not clogged.

If you just over tightened the adapter nipple, then just get another one and try again.
You shouldnt need a new inter-plate.
The broken nipple should come out fairly easily.

Stu

The part that broke off was the threaded nipple that is connected to the intermediate plate so unfortunately I think I have to remove the plate and install a new one. Kind of a pain but not a huge deal.

The threaded nipple broke off from over tightening. Seen it happen.

I think that must be what happened.

New question-

Since I have to remove the engine, fan and stock oil cooler- is there any reason I should change my oil pump? I have a schadek 26mm installed now.

My pressure were ok but could have been a bit higher. I had just installed a weltmeister oil pressure booster piston however I had not been able to see if it brought the pressures up.

I have an external oil cooler via a sandwich plate. I am going to plug the oil bypass on the new intermediate plate I am installing.

I have a Schadek 30mm pump also so it would cost little to nothing to change.

Should I just keep my current pump?

Did you notice Jake's comment above?

raising the oil pressure means that more oil will bypass the stock oil cooler.
It will still be forced through your external though.

Stu

Am I correct in stating that if the intermediate plate bypass is plugged- the engine oil pressure will not be effected (assuming everything else stays the same)? I can see how it would affect the pressure in the eternal oil cooler but not the engine.

Yup. The filter bypass is just that.

Playing with the springs and pistons in the bottom of the case will affect overall oil pressure.

I'm not advocating either course of action here.

Please help guide me-

When the temp is 210- I get about 10 to 1000rpm pressure. The problem is that my oil temps are normally ok however after long drives- if I accelerate hard- my oil temps go up to about 230-250. As expected, when the temps get high, the pressure gets a bit lower. I have a fairly large setrab cooler with fan. It is located in the trunk floor- it pulls cold air from the outside via ducting (A hole is cut in the trunk floor- air comes in via ducting from top and exits down). I was hoping to get more oil to the external cooler (I have a sandwich plate). I have a schadek 26mm pump. I run brad penn 20/50.

So, what should I do. I figure if I keep the temps down, the pressure would be fine however I am not sure if I should increase the pressure just to be safe? My thought was that getting more oil to the external cooler would cool the oil better.

1.- do nothing
2.- Plug Oil filter bypass
3.- install scahdek 30mm pump
4.- install weltmeister oil booster kit
5.- Change oil type
6.- other

What would you do if it were your engine? I can easily do any or all of the options, I have all of the parts so it would be easy and free.

With the sandwich plate installation, pressure drop across the external cooler circuit will cause oil to bypass both the filter and the cooler.
I'm not a fan of blocking the bypass, as it can cause unfiltered oil to be recirculated through the bearings.
Unfortunately the bypass spring operates at too low a pressure differential and it isn't easy to increase the spring pressure.
My recommendation is to switch to lower wt Brad Penn (10/40) and improve the external cooler circuit to reduce pressure drop.
The best choice IMO is to wait for my new cooler take off kit to hit the market. It will eliminate the stock cooler so the external cooler is fed off the exact same circuit through the crankcase. This will allow the bypass to work as originally intended and only operate if the filter is restricted. It will also free up a little bit of engine cooling air to better cool cyls 3 & 4. I believe it will be the best solution to adding an external cooler on any Type 4 engine in a 914.

Your input is greatly valued. Until your new product comes out (which I am very interested in), would a stock oil cooler adapter help? Like this-
http://www.kerryhunterenterprise.com/new_page_5.htm

How would blocking the bypass cause unfiltered oil to get to the bearings? I think you have that backwards. Blocking the bypass port turns it into a 'full-flow' setup where all oil must go through the filter. And if you have a sandwich adapter, all oil must flow through the external cooler. Seems like a quick cheap fix to me.

Yep, same idea.
I didn't know KHE had that product.
My kit will include other components to simplify the change-over, like a sheet metal piece shaped to eliminate all airflow to the stock cooler location.

Very interesting. When will your kit be available?

Oops, you're right - except that I don't think the full flow option makes good sense.
I'd rather have dirty oil than no oil at all.
I've seen a filter clogged to the point that it collapsed when a lifter/cam failed - and the engine was totally starved from lubrication because the bypass was blocked.

So my next question- in numbers- what is considered normal oil pressure in a autocross large 4? What is a safe range?

its deja vu all over again

I know its been covered many times but it doesn't seem like its ever been clearly answered (at least as far as I can tell).

LOL- It was just address- in my own post. Oops- forgot about that.


How about- what is the maximum acceptable oil temp?

230 is red zone. 240-250 is shut it off

So I just got my car back together after replacing the intermediate oil filter plate. Here are the changes I made (unless stated- everything else is the same)-
-plugged intermediate plate bypass (so all oil will be sent to my external oil cooler)
-installed weltmeister oil pressure booster
-changed oil filter types (empi hp1 from KN)
-changed oil to Brad Penn 10w40 from Brad Penn 20w50

Now my oil pressure sucks after warming up and my oil temps are getting even higher!!!! WTF!!!!!

Any ideas why I would now have poor oil pressure and temps after making the above changes? I can see maybe a small decrease in pressure with the oil viscosity change.

Everything seems to run fine, no leaks, no smoke, etc. Oil level is topped off.

I should have mentioned what my oil pressures were (at 210)-

before the changes-
3000rpm- 30psi

Now-
3000rpm- 25psi

I know thats not a huge different however I thought that my pressure would be higher not lower (except the viscosity change). Also my temperatures seem to be a bit higher.

It sounds like a problem with the oil pressure relief piston.

Last night I took the oil pressure relief piston out and reinstalled it. I also changed back to 20w50 brad penn. Now my oil pressure is great. I am now getting about 35 psi at 3000rpm at 210 degrees. I am sure that the big change wasn't just from the oil so clearly the relief piston must have been stuck open.

Thank you to all for your help.

http://www.914world.com/bbs2/index.php?showtopic=210207

He explains how to fix the ridge in the pressure relief bore.

Stu

I made a few changes to my car. I put in a RX7 front oil cooler and I put in a larger oil pump- schadek 30mm from 26mm. I previously had a weltmestier oil pressure relief booster piston installed which I left in.

I drove my car around for the first time since making the changes. I drove for about 40 minute of very hard driving. My temp never got past 185!!!! Is that ok? Also, my oil pressure is high. Now it is about 55psi at 3000 rpm at 185. Should I remove the oil pressure relief piston?

Chris, do you have the new by-pass adapter for the external oil cooler? Don't see it in your catalog yet...

I'm still getting my new machinist up to speed.
Earlier this week I asked one of my suppliers about oil thermostats.
These things take time...