Oil pressure relief valve. Options

[Keith914]

To the "brain trust". Two experienced engineer/mechanics have described the following:
When our Type IV engines are at operating temperature and rpm's exceed about 3,000 the pressure relief valve (ball bearing valve seen in the oil filter bracket) opens up and prevents or reduces oil flow through the filter. Thus, this reduces oil flow through external oil coolers attached via a "pancake" to the engine, greatly reducing there cooling effect when needed most, e.g. at the track. They have altered this valve so that it cannot open, and advised to keep rpm's low until the engine is warmed up -- particularly in cold climates. there are various ways to "plug" this valve, easy when removed from the engine, -- drill and thread a bolt with lock nut to hold the ball bearing closed, press in an aluminum plug, etc.
Two questions: 1) are there other (than too high an oil pressure with cold engine with higher rpm's) unintended consequences, and 2) can this valve be "plugged" and how, without removing the engine to get at it?

[ChrisFoley]

AFAIK, the only downside to disabling the bypass valve occurs if your oil filter becomes clogged somehow.
At that point you will have no oil pressure and will cook the bearings right away.
Personally, I would prefer to increase the cracking pressure of the bypass valve rather than completely disable it.
But I haven't devised a method yet.

[Elliot Cannon]

Doesn't that valve open by oil pressure depressing a spring? Would a stronger spring help?

[N_Jay]

Yes there are heavier springs.

You can go up until you risk popping the oil filter (or cooler).

If you are generating so much heat at high RPM (high oil flow, high airflow) and still have a problem cooling, you either need a bigger cooler, thinner oil, or a dry sump system. (IMHO)

[ChrisFoley]

Doesn't that valve open by oil pressure depressing a spring? Would a stronger spring help?

It isn't designed to be a user serviceable item.
Therefore, changing the spring is complicated.

[ChrisFoley]

You can go up until you risk popping the oil filter (or cooler).

You can totally disable the bypass valve without danger of popping the filter.

[N_Jay]

Doesn't that valve open by oil pressure depressing a spring? Would a stronger spring help?

It isn't designed to be a user serviceable item.
Therefore, changing the spring is complicated.

Am I miss-remembering, or doesn't the spring and ball on in through a easy to access threaded plug on the bottom of the engine.

And didn't some vendor (in the 80's at least) have upgraded springs?


EDIT:
http://www.ephotomotion.com/914engine/page08.html

It is a piston valve not a ball valve.

[ChrisFoley]

Keith called it a relief valve, but he described the bypass valve.
The pressure relief valve is located in the location you described.

[TheCabinetmaker]

Njay they are referring to the filter bypass ball in the oil filter console. The op obviously misstated "relief" valve.

[N_Jay]

Njay they are referring to the filter bypass ball in the oil filter console. The op obviously misstated "relief" valve.

At what pressure does that open?

[ChrisFoley]

a couple psi

[Keith914]

I am referring to the valve that has a ball bearing looking "thingy" one can see when the filter is removed.

[stugray]

I ran my racecar for a whole season with a sandwich adapter to my oil cooler with the bypass valve in stock form.

I didnt have any trouble keeping the car cool.
(I DID get pissed however when I dumped about $40 worth of brand new Brad Penn on the floor of my garage by getting the o-ring pinched during a routine oil change)
One secret is to make the lines to the OC as large as possible to reduce pressure drop across the OC loop.

I used 12 AN to the front & back.

I have since changed to the OC adapter plate mod instead of the sandwich adapter.
(anyone need a sandwich adapter with 12AN fittings?)

[barefoot]

Njay they are referring to the filter bypass ball in the oil filter console. The op obviously misstated "relief" valve.

Haven't started my 2056 build yet, so i looked closely at the pressed in ball seat in the oil filter console & noted that it was somewhat cocked and not pressed in fully.
The ball had very little preload from the spring. I pressed the ball seat down flush and it seemed that the spring preload was now greater. Pull your filter console off and inspect that ball seat !

[stugray]

This is the focus of the OP I believe:

(IMG:http://www.914world.com/bbs2/uploads_offsite/i366.photobucket.com-10819-1474721992.1.jpg)


I considered drilling & tapping the hole for a plug.
Since I run a K&P oil filter, & clean it frequently I didnt see it ever getting clogged enough to trigger that valve.

But if you have a OC loop in between the bracket and the filter and the oil is really cold and the oil doesnt want to flow towards the oil cooler (yet) I thought leaving the ball valve stock was sort of a thermostat.

This might help:
(IMG:http://www.914world.com/bbs2/uploads_offsite/i366.photobucket.com-10819-1474722504.1.jpg)

[Keith914]

Thanks for the input and flow diagrams.

It is clear from the flow diagrams that the filter relief valve has the ability to reduce the flow to an outside in series filter and cooler that is connected directly to the stock oil filter console. This confirms the explains the experienced advice.

Unfortunately it is also clear that while there are several ways to eliminate this by pass valve function, they require removing the engine to either; 1) access the upper oil filter console nut to remove the console for modification, or 2) to connect the external filter/cooler system to the galley plugs next to the oil pump.

[jim_hoyland]

Question: does the oil filter relief valve in effect reduce the flow or pressure to the cooler ?

[stugray]

Question: does the oil filter relief valve in effect reduce the flow or pressure to the cooler ?

ONLY if you are using an oil cooler plumbed via a sandwich adapter from the filter bracket.

[jim_hoyland]

Question: does the oil filter relief valve in effect reduce the flow or pressure to the cooler ?

ONLY if you are using an oil cooler plumbed via a sandwich adapter from the filter bracket.

Mine will fall into that category; should I plug the filter relief valve ? Bring in So Cal where it doesn't get very cold; good ?

[yeahmag]

I've taken to pulling them out and TIGing in a plug. I'll let the oil filter do the bypassing if it needs to...