FA20 Engine Oiling, Bearings, and Starvation

[celek]

Originally Posted by D K

Hey guys


My Reimax gears arrived a few days ago and should be going in today or tomorrow.

We didnt do any spring or shimming mods, hopefully it will hold up.

Originally Posted by Spartarus

Got a tracking number! It's arriving Monday AM! So you should have it by Tuesday AM @Element Tuning. PM sent.

I'll buy another set once you receive mine. I'm planning on getting "stock" and then "mild turbo" data for now. I've got my fingers crossed for this. In a perfect world, if this pump provides the boost we need, I'd like to run a scavenge only dry sump and rely on the engine pump for pressure. That would massively simplify the dry sump development. That's a next year kind of thing though. I have other projects too, and once I'm finshed with the the turbo and all associated mods, I'd like to put development on the back burner until at least winter.
Have to take a break to actually enjoy the damn thing once in a while.

I'm eyeing the battery area for the dry sump tank for a few reasons, and it sits right next to that cam plate that loves to leak. I know AVO runs that dinky-ass scavenge pump off of the camshaft at the plate location, but does anyone know what that camshaft accessory drive looks like? Or how strong it is? Could it turn a 2 stage scavenge-only pump? If so, there's your magic solution. That, plus a dry sump pan with two fittings for scavenge ports and one fitting for the engine driven pump inlet. Then, plumb the 2 PCV lines and the 2 crankcase vent lines to baffled chambers on opposite sides of the dry sump reservoir (at the top), add some condensing media and some drain holes to the resivoir, relocate the PCV check valve to the res->intake manifold line, and voila... Catch cans eliminated as well.

Hold on, I'm on a roll here... Now you can add capacity to the reservoir and keep that Texas-sized accusump for extreme RPM pump cavitation or pressure drop (If it's still even necessary)... Without overflowing the crankcase or jamming oil into the intake, or running a big silly catch can. Also, having the reservoir above the pump will provide a pressure head that should help to eliminate pump cavitation if it's even happening.

EDIT: I suppose you could eliminate one of the lines in that equation and connect the res and crankcase via only the single PCV hose, and block off the front crankcase vent. It wouldn't really matter. It takes time to visualize these things... But i have plenty of time to look out the window at the clouds and contemplate these things.

Let us know ASAP on now the new gears perform. I am a ways off on my build but would like a concrete solution to add to the never ending list of parts

[grant]

Originally Posted by LS1M

If you don't mind my asking, what kind of oil were you running?

amsoil signature series 5w30, other than assembly oil from dealership till 1000km, and ran cheap conventional oil for 2-4min as dump oil after having my oil pan welded for drain pipe for the turbo, it was thoroughly cleaned by myself after getting it done, so highly doubt it was from metal from there. I can't see it being the oil IMO, and its been changed every 4000km (or less) since new

with the turbo on the new engine I'm likely going to 10w30 amsoil signature series after reading this thread

[Spartarus]

Originally Posted by celek

Let us know ASAP on now the new gears perform. I am a ways off on my build but would like a concrete solution to add to the never ending list of parts

I've had some delays, but I'm making progress. Finally got a proper oil pressure gauge in. Been waiting a while for that. Now just waiting for the replacement Reimax gears. First set is with Element.

Took quite a while to get this little bastard

[rice_classic]

Originally Posted by Element Tuning

Lee is correct in this application. Shimming the pressure relief only increases pressure where there is excess volume such as colder oil temps and at medium RPM ranges.

That part needs to be bolded to clarify for the audience following along, because in general terms and for most cars, Lee is not correct. On most cars the pump, at high rpm with hot oil, will produce enough pressure to cause damage without a PRV to regulate it. This car is a very rare exception.

It's a damn sad thing that the The FRS pump is so pathetic that it can't produce 70 psi @ 7krpm with 7cSt oil when relief from a PRV is @ 0.

[EAGLE5]

This simply reflects good engineering from a mass production and efficiency standpoint. The engine is designed for stock power, including the pump. A higher pressure pump would take more power to run, hurting fuel economy. It's certainly a PITA for those seeking big power and high rpm at the track, but it's not a design flaw.

[cdrazic93]

Originally Posted by jsimon7777

This simply reflects good engineering from a mass production and efficiency standpoint. The engine is designed for stock power, including the pump. A higher pressure pump would take more power to run, hurting fuel economy. It's certainly a PITA for those seeking big power and high rpm at the track, but it's not a design flaw.

you can still over engineer the parts without hurting fuel economy. Although the price would creep into the $$ of the car.

Larger/higher pressure pump would require more parasitic power, unless you use low inertia materials for the pump, resulting in a higher psi achieved much easier; but at the cost of materials.

[Element Tuning]

Originally Posted by rice_classic

That part needs to be bolded to clarify for the audience following along, because in general terms and for most cars, Lee is not correct. On most cars the pump, at high rpm with hot oil, will produce enough pressure to cause damage without a PRV to regulate it. This car is a very rare exception.

It's a damn sad thing that the The FRS pump is so pathetic that it can't produce 70 psi @ 7krpm with 7cSt oil when relief from a PRV is @ 0.

I don't agree with you at all. Pretty much any engine I've ever dealt with concerning a performance build (more power and more rpm), and most of the racers I talk to at the track, dropping oil pressure is the one commonality we all share.

[Element Tuning]

Originally Posted by jsimon7777

This simply reflects good engineering from a mass production and efficiency standpoint. The engine is designed for stock power, including the pump. A higher pressure pump would take more power to run, hurting fuel economy. It's certainly a PITA for those seeking big power and high rpm at the track, but it's not a design flaw.

Yeah this is unfortunately what we face in this day and age as the engineers don't build in a significant amount of excess. Just enough to get the job done safely, within reasonable use, and in the end saves money and increases efficiency.

[Spartarus]

Originally Posted by Element Tuning

Yeah this is unfortunately what we face in this day and age as the engineers don't build in a significant amount of excess. Just enough to get the job done safely, within reasonable use, and in the end saves money and increases efficiency.

Really makes you hate new cars, doesn't it? Really makes me wish I could buy the shell with no goddamn engine, and put an appropriately over-engineered piece of machinery in there. Still considering that option - more to come soon.

Originally Posted by Element Tuning

Lee is correct in this application. Shimming the pressure relief only increases pressure where there is excess volume such as colder oil temps and at medium RPM ranges.

I'd just like to reiterate what I said on the last page and clarify for everyone, because the statement Lee made is correct in this application by pure coincidence, and his statement is conceptually incorrect. He made a 4-part statement, and it's wrong to call it correct.

Originally Posted by Lee

shimming the PRV wont help up the oil pressure at high rpm at all. Thats not how a PRV works. It only opens when there is too much pressure, its a relief valve.

At high rpm and temperature with dropping oil pressure the PRV will be closed.

I color coded it by factual accuracy.
Green = Correct
Red = Wrong
Orange = Correct in this application, by coincidence, but USUALLY wrong. And will likely become incorrect in this application if pump discharge volume is increased at any given viscosity.

Hope that helps people understand a bit better. Read post #489 for further clarification

[rice_classic]

Originally Posted by Element Tuning

I don't agree with you at all. Pretty much any engine I've ever dealt with concerning a performance build (more power and more rpm), and most of the racers I talk to at the track, dropping oil pressure is the one commonality we all share.

BMW's, Honda's, VWs... Yes at the track we all see a drop in pressure because hot oil is thinner and many folks combat this with increased viscosity oil, shimming their PRV or both.

I installed an oil cooler, lost 10psi. Added shim: gained 10psi.

I increased operating temp from 220 to 240 (ignition timing), lost 10 psi. Added 2nd shim, gained another 10 psi.

Finally settled in on 260F and then jumped from 0w-30 to 0w-40 to finish off the equation.

The PRV spring is like any other spring, the greater distance it is required to move, the more pressure is required. That's why people who think the PRV would regulate pressure at the same pressure all the time are doing it wrong. It's not a trap door, it's spring and will vary pressure differently depending on the viscosity of the fluid trying to escape past it. To think it does nothing in a hot engine at high RPMs is a bit myopic because only very rarely is that the case and if indeed so in the FA20 it's a goddamn shame. In damn near ever engine, the PRV is always part of the equation.. always.

The degree to which it's part of the equation is the question because some engines respond radically with a shim, while others only minor with rapidly diminishing returns. You are confident that 2 things are true in the FA20: 1) the PRV is closed in a hot engine at high rpm and 2) with an entirely closed PRV (no relief), at max RPM, the FA20 pump cannot produce enough volume with hot oil such that adequate system pressure is maintained.

Element: I'll be on board with what you're cooking if you can show how you came to this conclusion that proves it to be true because on so many other production based race engines, a shim in the PRV (or increased spring tension of some method) is almost standard operating procedure.

[D K]

Originally Posted by jsimon7777

This simply reflects good engineering from a mass production and efficiency standpoint. The engine is designed for stock power, including the pump. A higher pressure pump would take more power to run, hurting fuel economy. It's certainly a PITA for those seeking big power and high rpm at the track, but it's not a design flaw.

WTF???

[cdrazic93]

Originally Posted by rice_classic

It's not a trap door, it's spring and will vary pressure differently depending on the viscosity of the fluid trying to escape past it.

are they usually linear or progressive? or does the viscosity of the fluid make a linear spring act like a progressive spring?

[rice_classic]

Originally Posted by cdrazic93

are they usually linear or progressive?

I don't know. It could be either depending on engine. Considering how little they move, however, I'm not sure how significant the difference would be or how it would affect the outcome. The dual spring design in the FA20 is somewhat unique.

Originally Posted by cdrazic93

or does the viscosity of the fluid make a linear spring act like a progressive spring?

This would stand to reason. Imagine using a plunger to push a fluid through a tube and on the other side of the tube the door is held closed by a spring just like how a PRV works.

Let's say the tube is 1" in diameter and 10 inches long. There's 2 tiny holes in this tube just before the relief door that replicate your engine's bearing orifices.

Now, let's say I push the plunger at the same rate (speed) for two different fluids: Molasses and water. Let's say 1 inch per second. So same speed with each fluid.

What will happen is that relief valve will open for both but the tube pressure for the molasses will be higher and distance the spring on the relief door will travel (the opening) will be greater. Let's say the molasses test peaked at 50 psi and the water peaked at 5 psi during this 1 in/sec plunge. What's funny is that with the water having much less pressure, it has much more flow so the fluid squirting out the 2 escape holes will be greater.

Without changing the fluid viscosity of water, the size of the 2 holes or the rate of the plunger; the only way to increase pressure is to increase the tension of the spring behind the relief door up until the door will no longer open. At this point system pressure cannot be increased without then changing: Viscosity, rate of plunger (oil pump) or size of the 2 holes.

Element tuning has made the case that this is what's occurring in the FA20 that at a certain point of very thin viscosity, at peak RPM the oil pump isn't producing enough volume to enact any movement on the PRV spring and the door remains entirely shut and therefore the system pressure is entirely based on the sum total of the bearings orifices and that the system pressure is still inadequate. This would represent a rather under engineered oil pump IMHO and is unfortunate but if it is indeed the truth..

Then the logical conclusion is a larger pump is required. But if you put in a much more efficient pump but only see a 5 psi bump then logic would dictate that now the PRV is part of the equation and will need to be stiffened.

[cdrazic93]

awesome! im glad i just had a crash course about PRV's now lol