External Oil Pressure Regulator

[Anonymous]

Let's assume there is someone strange enuff to want to place the wet sump engines's oil system pressure regulator remotely, outside the engine block.

Are there purpose-built regulators for such a use? Would Moroso or Milodon or someone like that be the source?

Or would a high pressure/high flow fuel pressure regular (some of the EFI regulators have some impressive numbers) adapted to the use be the way to go?

Eddie

 

[Anonymous]

I don't think that would be possible. In order to regulate the flow externally, there would have to be some way of diverting the flow from the pump discharge to an externally mounted port. That just does not seem feasible with a stock pump. Now if you had some specialty aftermarket pump that was configured differently or had an external oil pump, then it may be possible.

I also do not think there would be any reason to have adjustability to a stock type oil pump that is designed for the engine. The only reason I can think of why you would want to regulate the pressure, is if you had a pump that was oversized and was generating too much pressure. Two ways to mount it. One would be an in-line choke that would hold back pressure on a pump and controlling the flow to the engine. The other would way would act as a pressure relief valve, dumping enough excess fluid back to the suction in order to stay under a maximum pressure. The latter is how stock oil pumps are configured.

 

[xctasy]

I concur with you, 66 Fastback 200.

There is a empirical rule when shimming up the pressure release. On stock first gen 350's, fitting the high volume Z28 oil causes the oil to froth up too much on street and strip engines, even with the even with modern anti- frothing agents. Staying with the stock pump, but adding the Z28 spring rasies presure, without causing frothing. Then the oil tends to flow better, without forthing up, without what they call cavitation. If pressure goes up too much, the potential for caviation is reduced, but if the volume of the oil pump changes, then so can cavitation.

Same with Fords 351 Clevelands, the stock oil pump has enormous volume, and flicks oil around like crazy. The priority oiling system results in the oil pump picking up oil, and spining it in an eddy formed by pressure at 7300 rpm.A well oiled Clevo then dies of oil starvation as the heads fill up with oil, then the oil pump stops giving oil. First it drowns, then it dies by starvation. By regulating the pressure, you can change the level of cavitation. What cluey people did when they drag raced those engines in the States in Pro street etc, was restrict oil flow to the heads, and that allowed the oil pump to take more oil and rasie the rpm at which cavitation happend.

How this works exactly, I don't know. There are circuit racing people who do simple oil tempurature testing, and they can pick up cavitation points, and then recommend a change in oil or oil pressure setting. Apparently, oil temperature is controlled best by crank scarpers and windage trays of non spark material closer than 60 thou to the crank and rods. That normally controlls oil temperature, sometimes getting up to a 100 degrees oil temperature drop, while adding up to 12 hp on a 362 hp engine. After that, the oil pressure setting can be changed if needed. Most roundy roundy guys with milder Cleveland or SVO blocks that don't have dry sump lubrication run 100 psi at 6300 rpm cold, or 90 psi hot. They just use stock TRW high volume oil pumps, and a high spring rate competiton spring. Normally, if the main and bearing clearances or, especially the chamfers on the crank oil holes, have been changed, it changes the level of line pressure. NASCAR engineers play around with these sort of things, real deap and meaningfull stuff.

Hope that helps out.

 

[addo]

I'd be happy to do it if truly necessary, using a high flow fuel regulator, and the added insurance of a pressurised accumulator and OP shutoff switch.

 

[Anonymous]

Xecute, the way to control oil going to the top of a clev is to use a plug in the head galley that has a small hole bored through the plug. IIFC, the stock block has a roughly .200" hole feeding oil to each head. The hole is drilled, tapped and a plug with an 80-thou or so hole is locktighted in. This restriction forces more of the oil to go to the main and rod bearings. The clev also suffered from rear mail bearing starvation at sustained high RPM (and even hard street running or casual Friday night drags). The fix is to run a hard line from the galley plug at the front left of the block (just above the fuel pump) back to a tee at the oil pressure sender port, which just happens to lie directly above the rear main bearing. That ensures enough oil gets to the rear bearing.

Eddie, there are two common solutions to your challenge. The first is to hook up an external single stage oil pump, a la a poor-man's dry sump. The pump pulls oil from the pan and then sends it to a special oil filter adapter, where it is filtered and then enters the block. These pumps usually have an external pressure regulator one can adjust with a screw driver. The other solution is a full dry sump system, which are all adjustable. In either case, other changes to the block for oil management are required.

Stan

 

[MustangSix]

One other way to add an adjustable regulator (I'm still not sure why you'd do this) is to remove the pressure bypass spring in the pump and thread it for a bolt to hold the plunger in place.

Then use an external adapter to pick up the oil coming out of the filter. Add an external regulator there and plumb a bypass back into the pan from the regulator. Add a cooler and an external filter.

 

[Anonymous]

The I-6 engine in question (we'll call it a "Ford") has an internal gear-type pump, with an integral oil pressure relief valve in the pump--spring, plunger, all the vintage stuff. That integral relief valve regulates pressure to around 70 psi, verified.

Pressurized oil then exits the block into an external bolted-on oil filter header casting, which contains not just one but three more spring-loaded relief valves--
one a filter bypass;
one a water/oil heat exchanger bypass (there's an OEM block-mounted oil cooler);
one a second-stage pressure regulator, which takes it down to 35 psi or so.

That oil filter header mounts/mates to the block via a flange; there are two drilled passage in that flange, one a "goes-inta" and the other a "goes-outta", A/K/A, "pressure and return". :roll:

Obviously, that oil filter header's gotta go, and a remote full-flow filter and oil-cooler are no-brainers.

My problem, then, is how to regulate that liquid flow back down to 35 psi (or so), which was the point of the question; a collorary question is finding the GPH potential requirement of that pump.

The number 12.6 GPM sticks in my head, but that could easily be the quantity of operable remaining brain cells I possess.

Eddie


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