ViperEater

Would, like to implement something like this into my FD running a HALTECH. Right now my OMP is there but only running 50% so I premix a bit. Would like a seperate tank. Guees I would have to get a 2nf gen OMP?

patman

iTrader: (3)

probably

Aviator 902S

Mine wasn't "eaten up" so much as made brittle and cracked by the oil. The first thing I noticed was that the plasic cap fit very loose and began allowing oil to slop out around its edges during maneuvers. Then the translucent white plastic began to take on the same greenish hue of the oil. Finally, the leaking and cracking began at the base of the container.

BTW, my container at that time was formerly a stock washer fluid reservior from an '82 RX7. I'm wondering if yours is either a different, an/or newer container with thicker plastic walls (?).

Aviator 902S

Hey Patman,

Good to see this thread brought back from the dead because I'd completely forgotten who it was that first recommended modifying the metering pump itself to deliver 2-cycle oil to the intakes. I also forgot that you'd posted a "how to" on the matter.

As a result, I'd gone ahead and posted another "how to" in the 1st gen forum on the same subject, albiet, specific to the 12A-style omp. This was after I'd done the same mod (with a couple of variances) on mine.

I have a question though:

It looks in your pictures like the hole drilled into the top rear area of your 2nd gen omp is drrilled so that it delivers oil into the metering cam area of the omp rather than into the same passage as where the stock oil inlet hole is. Am I correct in this assumption? If I am, that means that your oil then seeps into the rest of the omp via the metering cam area and if so, it should also work on the 12A-style pumps.

I drilled my supply hole into the edge of the front lower portion of the mounting flange and then custom-made an attachment nipple since there was insufficient room in that area to install a bleeder screw. I'd much rather have had the option of going the route you took.

patman

iTrader: (3)

well, i havent taken apart a 12A version, and i just gave away my last 12A box of ****, so i dont know how they are, but on the s4 version, there is a little chamber right at the intake of the pump ( you can see it in the 4th picture, on the 2nd post, its circled in red.) I tapped my nipple right into that chamber, which is where the stock system gets it anyway.

pat

ps i'll post a pic of my new tank as soon as i get the lid cut out with the waterjet

flubyux2

Im very interested in this project for my GTUs, but of course, its an S5 w/ the electric OMP.

are there any other detours or deviations or special points of interest that i should know of when trying to apply this to the S5 OMP?

according to the S5 oil flow diagram, the OMP is fed through a galley in the front cover which is just branched off a main oil galley that supplies the E-shaft bearings in the front iron. the E-shaft bearings in the front iron and OMP are the LAST items to be supplied via the oil galley system. if i simply install a block-off plate between the stock electric OMP and front iron, the pressure/volume will just back up and apply more pressure to the E-shaft bearings in the front iron... at least, thats how it seems to work in the Lubrication Diagram shown here; http://208.62.166.66:82/guest/shop_m...ion_system.pdf


now if this Lubrication flow chart is 100% accurate, then this means there is No return for the oil supply going to the OMP, which means there is no pressure bleed-off in the stock configureation. the stock OMP sees whatever is left of the oil pressure/volume after all the other oil gallies, bearings and take-offs are fed. i should be able to stop the oil flow from the front iron and tap in a bleeder valve/nipple into the S5 OMP as shown above regarding the S4 OMP.

im just not sure if a gravity fed OMP oil supply is Enough volume for the S5 Electric OMP on an engine revving at 8000rpm. i dont want to do this mod and experience oil starvation at high rpm and oil flooding at low RPM.

will an S5 resivoir-fed OMP setup require a fluid transfer pump to maintain a higher rate of oil flow or would gravity-fed be sufficient?

Aviator 902S

My set-up is for a 12A, but when I disconnect the reservior supply line from the metering pump end (to drain the reservior) it takes all of about 30 seconds for all of the oil to drain out of the reservior. (the fitting at the end of the hose through which the oil drains is about 1/8" diameter). Even if you run your car hard it will take an entire tank of gas to use up 8 fluid ounces of oil from the reservior.

The above would indicate to me that gravity feed would provide plenty of flow for your S5. There had been some earlier concern about the gravity feed possibly siphoning into the engine while parked, but I have never seen this. When the omp isn't being driven the oil isn't being metered but rather, blocked by the pump itself.

The best thing about a system like this for the S5 is that it allows you to use 2-cycle oil without having the computer force the engine into limp mode due to "pump failure" (or "pump missing" if using a block-off plate and pre-mixing) since the stock pump is still being used.

rotarygod

iTrader: (1)

I have the rotary aviation bypass on my S5 n/a. No problems whatsoever. Even at 9000 rpms (you're not there very long) there isn't much oil flow into the engine. Oil flow is much slower than most think it is. You won't have any starvation issues.

patman

iTrader: (3)

i have my revlimiter on the microtech set at 9250, i have had no lubrication issues, even when i hit that speed.

since i made the Al tank, i have had no issues whatsoever, except for minor leakage thru the vent hole in the top of my tank.

i'm still waiting on the shop cnc guy to make me a cap b4 i post a pic, but he has a lot of **** to do, and i am not allowed to run the cnc machines, esp since the boss doesnt know that i can do CAD and CNC maps and programs.

i'll try to vet him to cut/ etch it out asap so y'all can see

anyway, glad you guys like my idea,

Pat

flubyux2

thats very reassuring to know guys. i dont have a charcoal canister or sub-zero assist tank anymore, so the whole area behind the passenger strut tower is completely vacant all the way to the firewall. i think maybe ill build a 1-gallon tank w/ a sumped bottom and run a silicone or teflon hose along the frame rail to the OMP.

i just want to make sure i understand the mechanics behind this so i can grasp the operation. the height of the oil tank, length and diameter of the oil feed hose dictates the flow rate of the oil supply to the omp. once it reaches the OMP, it is then pumped upward thru the 4- oil injector lines, correct? i dont know how the OMP system works 100% yet. the oil injectors/lines arent pressurized by the engine oil pump but rather by the OMP/MOP itself, right?

i have a nagging suspision that the oil injectors/lines are only pressurized due to the oil galley pressure that is created by th engine oil sump pump in the front cover. but if the OMP serves as a pump itself, then ill understand how the oil can gravity feed downward to the OMP and then back upward to the oil injectors which are at almost the same height as the oil tank in any given application.

basically, i dont know the operation of the S5 OMP/MOP. does it simply Meter/regulate the oil flow from the engine oil galley and deliver it to the 4 injectors? Or, does it Meter/regulate the oil flow from an oil gally supply by a secondary pump in the OMP housing itself?

sorry for my ignorance, but i havent yet found a thorough explanation of the intricacies of the S5 OMP/MOP.

thanks alot Pat and R-god

patman

iTrader: (3)

the MOP is a real pump, the stock supply for it has no pressure at all, it makes all of its own pressure.

do NOT use a silicone hose, as oil eats silicone, and it will not last long at all.

also a level sensor is really a must, as it will not only tell you when youre low, but if theres a problem with your system, chances are all the oil will leak out, so you'll still know.

pat

Aviator 902S

[QUOTE=flubyux2]


i just want to make sure i understand the mechanics behind this so i can grasp the operation. the height of the oil tank, length and diameter of the oil feed hose dictates the flow rate of the oil supply to the omp. once it reaches the OMP, it is then pumped upward thru the 4- oil injector lines, correct? i dont know how the OMP system works 100% yet. the oil injectors/lines arent pressurized by the engine oil pump but rather by the OMP/MOP itself, right?

i have a nagging suspision that the oil injectors/lines are only pressurized due to the oil galley pressure that is created by th engine oil sump pump in the front cover. but if the OMP serves as a pump itself, then ill understand how the oil can gravity feed downward to the OMP and then back upward to the oil injectors which are at almost the same height as the oil tank in any given application.

basically, i dont know the operation of the S5 OMP/MOP. does it simply Meter/regulate the oil flow from the engine oil galley and deliver it to the 4 injectors? Or, does it Meter/regulate the oil flow from an oil gally supply by a secondary pump in the OMP housing itself?


You're on the right track for the most part. While it is important to have a large enough internal diameter supply hose that's impervious to oil (fuel hose is ideal), this diameter doesn't need to be excessive. 1/8" to 1/4" is ideal.

The oil from the oil galley has a small amount of pressure to insure that the metering pump receives enough oil to feed into the intakes as required for a given rpm. But the reservoir system uses gravity feed to do exactly the same thing, and does so very effectively as long as the lowest oil level in the reservoir is at an elevation that's at least 6 inches above the metering pump itself. There is also a small amount of vacuum created by the intakes to assist drawing the oil out of the metering lines, even though the system would work on gravity feed alone.

Actually, the term "pump" is not really an accurate description of the metering pump, since pressure produced by the omp is very little if any. What this omp does is meter the volume of incoming oil via a varying orfice that is modulated opened or closed depending on throttle position. This is done as follows:

A "cam" of sorts inside the rear of the omp is rotated by a lever from the throttle linkage as the throttle is opened or closed. As the throttle is opened farther, this cam pushes the internals of the pump end-wise to align orfices thus increasing flow. As the omp rotates, a "barrel" inside the omp containing a "window" of sorts ratates. When the outlet orfice is aligned with the one in the barrel, pressurized oil (via the engine or gravity feed) is allowed to exit the omp and be fed to the intakes.

Aviator 902S

Are you sure about this? I'm asking because when I've had these things apart it appears that the oil exiting the omp is not "squeezed" or expelled out in pump fashion (as is the case with a fuel pump) but rather, relies on just enough pressure coming into the pump to force the oil out of the omp when the orfices align with each rotation. There is no impeller or vanes involved, just a gear that rotates the "barrel."

Dave Atkins (from Atkins Rotary near Seattle) explained this to me way back when I had yet to dis-assemble my first omp, and what I discovered inside seems to bear his explanation out. Are the electric omps different in operating principle than those used on the 12A and pre-1989 13B engines?

flubyux2

well, i wouldnt say that there is NO oil pressure feeding the OMP. the lubrication system diagram shows the OMP being the LAST orifice on the oil gally system, right after the front e-shaft bearing.

but, i ordered an actual 2-stroke oil tank that came out of a Jet ski, a 96 SeaDoo Xp actually. its got 2 pickups in the sump, an oil fill, low oil level sensor and vents in the top. its holds more than 1 gallon, i dont remember exactly how much. it might be 1.1 gallons. if anyone is interested, i can get a couple more of these tanks. the nice thing is all the stuff thats included in them. im going to mount mine where the AWS and vapor canister originally mounted. it should fit snugly, after i make a bracket for it from 1/2" angle iron and flat stock. there are no mounting tabs on the tanks. the tanks are held in place by 2 rubber straps on the skis, just like the batteries and fuel tank.

introVert

Awesome idea- and I love the idea of a bigger container with a warning light- even though I will still check the oil level in the engine and the 2str container at every fillup-

it's all about insurance

How much do these jetski tanks cost, anyhow?

flubyux2

the guy told me that they usually sell for about $40 shipped. seems fair enough to me, considering its a purpose built tank to hold oil... so its blatantly oil resistant. not tomention, its got pickups already plumbed and a low oil sensor integrated.

DamonB

Yep.

https://www.rx7club.com/showpost.php...1&postcount=55

HAILERS

I read this thread by Patman a couple of weeks ago and I decided to make one for something to do.

FIRST and foremost, the omp is a PUMP. Right this minute I have the feed hose stuck in a oil can BENEATH the car and it is pumping (sucking) oil up the line into the pump and then the oil injectors. I can lift the hose out of the can, let a air bubble form and then put the line back in the oil. Then watch the bubble crawl its happy way UP to the OMP. So there IS NO DOUBT that the pump is sucking the oil out of the can BELOW the engine.

I varied from Patman though. He cut a groove b/t the oil feed on the FRONT COVER to the drain hole. This is NOT required, and if you do that you've disabled the front cover if you ever want to go back to a normal OMP.

What NEEDS to be realized is how the front cover oil feed line works. It enters the left side of the cover and follows a internal passage in the cover til that passage meets the Drive Shaft for the OMP. Now if you have a cover off the engine, and blow shop air in the small feed hole on the left side of the cover, you find that the air exits the ROLL PIN that holds the OMP drive shaft in place.

The drive shaft is defined as the shaft that is spum off the drive gear on the eccentric shat on one end and the other end drives the OMP.

So if you block off the area b/t the OMP and the front cover, the oil will all exit the roll pin that holds the drive shaft in place.

I also deviated from Patman in that I drilled a .285 hole just where he did, but I pressed in a piece of hard vac line (sometimes referred to as rats nest) into the hole. It was a press fit and I used some four minute EPOXY and let it dry overnight. It's end protrudes into the OPM cavity apporx 1/32 (plus the thickness of the material I drilled through).

Some OMP pictures attached. I havn't made a reservoir yet. Thanksgiving day and shops are on the whole closed.

I mainly wrote this to dispell the idea the OMP has to be fed by gravity or pressure. It's a pump and sucks. That said I'll not be putting my reservoir under the engine. Done

HAILERS

more

20bfd3s

why noone said about oiling quality with using OMP?
I think premix is much better in this way since just one oil injector in the rotor housing works well just in the middle of it...
i`ve seen many used rotor housings with increasing wear closer to sides.

patman

iTrader: (3)

looks good HAILERS, i didnt take the front cover off when i did this, so i didnt get to investigate the roll pin thing, but i will definately do it that way from now on. i thought about doing a press fit thing like that, but i was afraid it might vibrate out and this is way too important for that, hence drill/tap. plus i dunno if i have the right size drill bit for that. living in two places is killing my tool collection.

also, im gonna try to send one of the nutzo shoppers in the family to get me a good deal on a digicam tomorrow, so if that happens i can post up some pics of the tank and the various other changes i've made.

mmmmm, turkey
pat

HAILERS

Personally I thing the stock OMP is just fine and dandy for any stock or close to stock RX-7. If I had a car like J-RAT whos runs the quarter in 12.3 sec or so, I'd be inclined to premix the thing.

There are other opinions. More than one person on the face of the earth type of thing.

I just did this OMP modification for the exercise and to finally determine one way or the other if the OMP is really a pump, and it is indeed since it's sucking oil from a can under the engine into the injectors.

By the way, the very first picture is of the blocking plate b/t the OMP and the front cover. It's made out of roofing *flashing* material of about .020" thickness. It has RTV b/t it and the OMP and upon installation of the pump, I put a thin film of oil on the front cover attach area and the RTV on the blocking plate mating side. That's so if I remove the pump the RTV will stick to the blockoff plate instead of the front cover. Easier to clean things up that way.

I used a Dremel motor, drill and a scribe to make the blocking plate plus a pair of sheet metal shears. Dremel could have sub'd for the shears.

In the second picture you can see the new pipe end inside the oval cavity area. Another thing I did is take some clear five minute EPOXY to fill a passage in the lower part of that cavity. That passage was to let the original oil pass from the cover to the cavity area. I clean the begeeezes out of the area before filling that area. I did that so there would be NO possibility of oil coming from the front cover and entering the cavity area. Sort of a extra measure that maybe did not have to be done.

The line I'm using is made for small gasoline engines. 1/4 OD and 1/8" ID. The same type line I use to replace the original lines B/t the OMP and the injectors. Secured in this one case with stripped electrical wire twisted around the line end. Sort of like copper safety wire.

The o'rings on the lever had to be replaced. It was leaking. I replaced it with TWO o'rings of a MIL- STD. Bought them from a aviation supply company at Mecham air field. Forgot the number. If you need to replace them try the auto store. Usually behind the counter they have a mix of small o'rings.

Aviator 902S

All good Hailers. The fact that you were able to have the pump "suck" oil out of a container below the pump's elevation confirms your point. (I'll have to go and cuff Dave Atkins upside the head for that one ).

This also means that gravity feed is un-necessary. However, as you also stated, it's better to mount the reservior above the omp. This would of course be for insurance purposes, and I'm pretty sure that's what Richard Sohn (the manufacturer of the metering pump adapters sold through rotaryaviation.com) had in mind when he included in his installation instructions the need for a gravity-fed oil supply.

patman

iTrader: (3)

i dunno...im planning to be running a MUCH faster 1/4 than that (dyno coming soon, 500 whp or bust) and this has been working just fine for me for 20k miles or so.

pat

flubyux2

very good to hear Hailers... so there is some leniancy when mounting the oil resivoir. i still have yet to figure out a way to mount my Sea-Doo oil tank and wire up the low-level sensor to my exisiting Low Engine Oil light on the idiot cluster. some day i will do the full conversion. but, as it stands, the Rotary Aviation plate is still the only thing i need to facilitate my conversion.