Speedworks

http://www.rebuildingrotaryengines.c..._Oil_Regulator


Pineapple has a clip on their site for increasing the oil pressure. They say it's both for street and race cars.

has any one done this yet? Is this a must have mod?

Do you need to port the oil chamber for this or just do this and leave the rest alone?

Rx7_Nut13B

iTrader: (1)

I have done this meathod, but used spacers instead of crushing the thing,

I allways say that there is never enuff oil pressure, the only Negative side to increasing your oil pressure is you stress everthing out side the motor (Oil lines aging, Oil coolers)

It will also reduce the life of the oil pump but that is something i have never seen before.

I am running 130-140psi @ redline

t-von

iTrader: (8)

Wow which oil pump are you using to create that much pressure with the spacers? You mind sharing the other things you do as far as pressure upgrades? I'm building a NA 20b for a my fd. I saw a video a while ago showing the oil pressure of a PP and it was as high as yours. I always wondered what they did to achieve that.

cewrx7r1

iTrader: (2)

The stock FD oil pump will normally reach at lease 100psi if all parts are good.
Reworking the inlet and outlets in the front side housing helps to increase flow.
Just doing this my max pressure is about 115psi and over 90psi by 3000 rpm.

You can shim the front regulator in the front housing about 1/16" . This one if for back pressure between the pump and oil filter.

The rear regulator is the one that controls pressure to the engine after the oil filter. This you have to mechanically take apart and shim or replace with a modified early model which screws apart.

Blake

As it says in the video, you have to approach oil modifications as a system. One mod does not make a new or logical system. That said, increasing oil pressure by modifying a stock pre-93 regulator, shimming an old-school screw-together regulator, or swapping in a 93+ regulator is pretty straight forward and beneficial to some degree. Don't forget to shim the front regulator too. Oil pressure does not equal oil flow, so ideally, you would also be porting the oil pump cavity and opening up the galleys a bit (but not too much!). This, along with proper bearing clearances and multi-window bearings, can really make an engine damn near bullet proof on the lubrication side. One step farther is to run a loop line from the rear bearing galley to the front bearing galley, so the main bearings see equal and adequate pressure.

However, this is not what you would do on a race car...at least not a competitive one in a competitive class. Race cars typically run relatively low oil pressure to free up HP. Generally, 5 psi at idle and 10 psi per thousand RPM. But there are a lot of race engines we build for customers who need their engine to last many seasons or that are so far ahead or so far behind the competition that the slight HP loss is not a concern, so we run more of a street pressure profile.

Speedworks

mY plan was to shim the front (thermal pallet) in any case, but to leave everything else alone (no oil pump porting).

Just the shims and the oil pressure regulator mod.

My car is a street driven 300-400hp car which I hope to use many years (on weekends and occasional track days)

Future plans could be other oil coolers but that's not an option right now.

If shimming the front pallet provides bearing lubrification from cold start on, that will make things better. If the oil pressure regulator mod brings no real extra value in my setup, I'll leave it alone.

Blake

The thermal bypass valve (aka thermal pellet) and the front pressure regulator are two different things. The thermal bypass valve is the device that Mazda used to accellerate engine warm-up by bypassing oil that would otherwise cool the rotors. It is located in the snout of the eccentric shaft. If it fails, it is bad news for the motor, so it is a simple tradeoff to accept a longer warm-up for increased reliability. To defeat the valve, you use three 8mm or 5/16 inch lockwashers to shim it closed. The front pressure regulator, which is what I was referring to in my post, is in the bottom of the front cover, under that large cap that protrudes down. That is part of the oil pressure regulatotion system and should be addressed at the same time if you are increasing the pressure by means of modifying the rear regulator. Not a big deal, but I wanted to make sure you understood what I was talking about.

Speedworks

You are right... too much going on my mind I guess...

I understand the balance of the front and rear regulator. Question still is, if this is a must have option for my case.

Blake

FDs already have fairly high oil pressure, so I wouldn't worry too much about that unless you are addressing the rest of the system in terms of improving flow. If this were pre-93, then I would absolutely recommend bumping up the oil pressure even if that's all you were able to do. It cost a little bit of HP, but the added protection is usually worth it.

(the)mouse

Blowing up old lines I agree with, but coolers? When I have my coolers flushed they also pressure test them to 350 psi. That's something I highly recommend even for just a stock rebuild. You clean the oil pan before you put it back on don't you? It only costs me $50 a piece and they even give me back the stuff they get out. Aerospace guys, they do it out of habbit and you just can't talk 'em out of it.

The pumps do wear noticably faster along with the chains. That's why MFR pumps are hardened. Still, if you use new ones when you bebuild instead of reusing old ones it's not a factor.

Rx7_Nut13B

iTrader: (1)

It was more for the lines, but i have heard of some cooler failures, more on the lines of rocks and stuff.

Dick Elliott

Aerospace coolers are cleaned because the FAA requires it. On a motor with so little HP, why would you want to give up 2 or 3 HP? I've run both IT and GT rotarys as low as 35 psi wide open and as low as 10psi idle. Seams to make no difference at all and motors lasted as long as my hi pressure ones. I have run in enduros for hours on end at low pressure with no harm. Heat kills rotarys more often than low oil pressure. My two cents worth.

Dick Elliott

Go to http://www.bacomatic.org/~dw/library/tech/oilpump.htm to read the truth about oil pressure. This web site contains more good stuff than any man ought to know.

RICE RACING

superb article and its nice talking to smart people

I used to work as a engineer for a bearing company and can realte to those topics dicussed 100%

They are the reasons i run internal water injection (cools the oil indirectly through the rotor since 1/3rd of all heat is rejected via the oil system through combustion) i also have a brand new set of Stillway oil coolers for my FD rx7 and also run a 68deg C thermostat with a racing radiator fully sealed in the car to maximize cooling, also have a Xcessive manufacturing high capacity oil pan of fined alloy construction. ]and a totaly stock FD oiling system ! even though the engine can turn to 9k and make 900bhp. The other BIGGEST thing is I ONLY use Mobil 1 fully synthetic 5w-50 motor oil again for reasons well laid out in the link above, its one of the best engine oils you can buy or run in your rotary.

Control the heat loads, use the best oil you can find/afford and forget about the pressure for its a falicy in most cases and not understood by the majority, cooling is the key here.

RICE RACING

you see it alot in FD's where the stationary gear bearings have that break down in the wedge and the bearing materials literaly overheats localy and bubbles through to the copper but you dont see it on the rotor bearings as they run at a lower temperature for various reasons *rotor being geared down relative to stat gear speed and having much larger surface area help greatly to explain why + volumes of oil be spalsh cooled around that area*. not even in racing cars, but streeters that only make 300bhp or so but run stupidly high water temperatures (115deg C) and following oil temps, combined with very low rpm operation (idle of 720rpm), its easy for that *wedge* to break down in the right conditions and its VERY common in FD RX7's so much so that if your not used to seeing it you would think there is major issues happening to cause such stationary gear bearing wear.

run exactly same combination of stuff in a car without the excessive heat loads/retention and making double the power also with an engine ideling at 1100rpm and reving to 9.5k v's 8k for a road going FD and on same engine oil and same ovehaul period by *hand of god* there is no such wear and tear on the bearings .

iceblue

I would say that 5/50 has to high of a sheering rate. In our race cars in FL here we run straight 50w oil and 20/50 in street cars.

either way it is not the pressure many shops that have done the research will all point out that the added oil pressure increases wear as the oil is jetted onto the bearing. Your increasing enemy being heat. Around 40psi properly clearanced and volume efficient is very optimal pressure. The reason we increase the pressure is in very high rpm and high HP motors the rods or rotors are subjected to harsh deflection in the opposite direction of combustion and at each TDC/BDC positions. The added force caused the rods and bearings to touch so we increase pressure to combat the added force. A more proper approach is to increase the journals accordingly with proper clearances. But this may be asking to much from the normal builders around the hood because now we are building motors and not assembling store bought parts. Might I suggest balancing the assembly since they are so far off from factory its amazing these motors run.

Dick Elliott

Make sure you look at the entire web site. http://www.bacomatic.org/~dw/index.htm Much good reading here.

[QUOTE=RICE RACING;7232733]superb article and its nice talking to smart people

iceblue

[QUOTE=Dick Elliott;7233760]Make sure you look at the entire web site. http://www.bacomatic.org/~dw/index.htm Much good reading here.

I read it, it is not bad but you still seem to be missing some stuff.

I like what was said both here and in that email archive however most of the stuff explained or stated in both places are explained in a static nviroment. This being so they are only acuret in a small scope of the aspect of a motor. They no longer hold true as conditions change. because of this variable we must design out system to be capable of covering this variable. However this capability also over does our lower scope of atributes.

Are we familiar with centrifical walk of the crank and rods? As well heat atributes to this have been being neglected. As RPMs rise and heat increases we do ned more oil psi or even a different oil weight. What about when the metal heats up? it expands right? Well it also shrinks. When you have a bore and you heat the metal up the bore has no go it shrinks into itself for it's expansion. As the crank heats and change and rpms ride the wall clearance has changed the crank begins to want to seperate from itself. the crank does this because of cintrifical force at the center. Because of this the motor is always trying to self destruct and pull away from itself and explode from the axis. If there was no neeed for the pressure or the crank supposedly lubing itself we would not have bearing failures. As the motor changes in this way we need to fill the area with oil the only way to do this is to increase the pressure. Pressure can induce velocity it does not directly relate to volume.

Take that article with a grain of salt its not all acuret.

t-von

iTrader: (8)

That's a very good example of the very good engineering of the stationary gears. They support a large percentage of the rotational assembly's weight.

TonyD89

iTrader: (10)

I won a hundred dollar bet with a guy that swore up and down that a hole in a plate would get smaller as the plate was heated. Due to the expansion of the metal. A cylinder under pressure from coolant may be different but I've disproved "the inside of a ring gets smaller and the outside bigger" and the "hole in the plate gets smaller" wives tales. Both using my old electric oven I use for pre-heating parts before welding. It's a simple experiment. Try it. Just make sure your measurements are quick!

Dick Elliott

As a metrology inspector for the past 30 years, who deals with measurements in the .00005 and smaller, every day, I can state your 100% correct!!!! A master set ring will get bigger on both the id and od as the ring heats up. If it wasn't true, a piston engine would shrink the bores as it warm'd up. And we all know thats not true.

atihun

Hey all,

Based on the information above, will I see issues with higher oil pressure?

I am seeing around 115 psi at 3000 RPM cruising at normal temps. Measured using a Defi gauge in the stock location.

At WOT and higher RPMs it goes to around 145 psi.

I built a brand new ported engine, all parts new and correctly tolleranced (at least I think so!) . I've put about 2500 miles on the engine, and am running at 15psi with 385rwhp. The only 4 things I did for the oil were:

1. E-shaft oil thermo pellet replacement with a solid piece.
2. Webber carb jets in the e-shaft.
3. Two new Mocal Oil coolers, Mocal Thermostat, braided lines, and a new RESpeed oil pedestal.
4. Viton oil control rings. (I saw the post too late from Blake regarding using these).

I used Penzoil 20W-50 non synthetic for the first 1200 miles, and then switched to Amsoil TRO 20W-50 synthetic.

I am not seeing any oil being burned as the oil level is not going down. Part of this is also because I use an OMP adapter and two stroke oil from a reservoir.

TIA.