hi. im gonna be doing a service on the fc this weekend, i have been thinking about the oil... i dont like the idea of using mineral oil in a turbo car that gets driven hard, just seems like asking for trouble.
so i was thinking... the omp mod, i had a very quick look into it and from what i can work out, you fit a tank somewhere to hold 2 stroke oil, then blank something and bypass something else.
is this mod detrimental in any way?
also, will it be safe to do on a stock engine?
im going to use mineral for now but i want to get started making the tank etc for the mod.
sorry if they are stupid questions haha.
You want an SOHN adaptor.. Check out Rotary Aviation in the USA
Mazda state that mineral oil only be used in a rotary engine.
as far as i understand it they recomend mineral oil as thats better for injection into the combustion chamber to lubricate the rotors than synthetic oils. the idea is to replace the oil fed into the combustion chamber with 2 stroke oil that does a better job lubricating the rotors and does not combust. this allows better synthetic engine oil to be used to prolong the life of the turbo etc and prevent sludging that happens when mineral oil brakes down.
i just found a decent write up. it looks pretty easy to just adapt the omp to inject 2 stroke, making a tank is no problem either.
you will get better lubrication if you just premix into the petrol tank. as the 2 stroke will be mixed with the petrol, rather than just dripping into the engine via the OMP.
also if you just remove the OMP you dont have to worry about it failing. as you wouldnt really be able to tell if the OMP isnt putting out enough 2 stroke.
just something you might want to think about.
i wanted the keep the omp but decided just to pre mix
From what I can see, shifty biscuits consternation is turbo life, this is why he wants to go SOHN and synthetic in the sump.
synthetic oil is better for turbo applications, i want to use synthetic so the omp mod is ideal. there is a way to test its operation by using premix in your tank and letting the omp pump into a container
i would rather use the omp with a level warning sensor on the oil tank, than have to try to pre mix my fuel in correct quantities, to do that i would have to fill then use a full tank each time, not real world viable, motorway journeys where you top up when you can for example, having to measure out enough oil would be a pain in the ass. then what if you forget to add it? much safer my way, and a mechanical pump is more trustworthy than my memory i can assure you.
As far as promising on the fly goes, I do this in my RX8 all the time.
It does not have to be scientifically accurate.
I think you reading far too much in to the cons of premix however I can see your point of going SOHN with 2T and synthetic in the sump.
There are quite a few guys running them on their RX8\'s over on RX8OC with custom tanks that have level sensors built in.
It\'s a mot I may look at when I eventually get round to turbo charging my 8
however do remember while synthetic is better for turbos the vast majority of rx7 owners are using mineral oil in their turbo motors, I dare say the majority would say then have had no issue with mineral oils
Maybe look at Royal purple... It\'s big in the USA and is synthetic that\'s safe for rotaries (according to RP) as it burns with minimal deposits. It\'s also the only oil sold by Racing Beat in the USA
cool. cheers for the info. i just got carlube :censored::censored::censored::censored:ty mineral oil from my auto factors as thats pretty much all they had. i just dont want to be running crap oil like that for ever. i have some decent fully synth i never used in my last skyline i could throw in if i did the mod haha. i can get it at a good price through a contact but he cant get much in the way of mineral, i will ask about royal purple though.
Before you go putting a Rotary aviation 2 stroke omp adaptor on do a bit of research into how the OMP works, That adaptor is for NA engines and requires the compression chamber to be under Vacuum to atomise the Oil and if the engine is on boost your omp uses the Oil pumps pressure to push oil into the motor, so you might find your engine not getting OMP oil on boost ;) so to say there is no issue when i was told by Rotary aviation a good few years back that the kit is not meant to be used on Turbo application is a bit miss leading (so NA good Turbo bad ;))
Stock OMP or pre mix is the way to go on a turbo.
How does the SOHN effect how the oil is delivered, from my understanding it only effects how the OMP is supplies oil
The delivery is taken care is by the injectors.
I tried this and found it to be a pain in the butt, saying that it did work but I still used mineral oil and changed it regularly, I still have the adapter in the garage somewhere it was used on my fc s4 with the mechanical omp, now running a fc s5 turbo and just premix , the best thing to do is just change your oil regularly
The Oil injectors are fed with metered amounts of oil by the OMP - the rate at which this happens is altred by revs and boost on the T2 (the old mechaninal ones were only revs as the lever was attached to the throttle mechanism).
The Injectors themselves have an air blow feed, which comes from the manifold, so the oil is effectively atomised into the chamber. On the T2 there are 2 sets of injectos, one set sit on the rotor housings in the top left quandrant (intake area) and the other 2 are sat on the primary air ports.
I ran the SOHN adapater qutie successfully for 40,000 miles, using High performance marine 2 stroke with detergents in it, the 2 stroke IS meant to burn in the chamber as well as lubricating it, but as it\'s designed to be combusted has very low ash. I used a semi synthetic (Shell Helix) as the main engine oil - but be careful with oil choice - one of the reasons that Mazda say mineral oil is becasuse of seal shrinkage - there are a number of different types of rubber seal in the engine - Viton, Nitrile and straight Rubber - so be careful that your oil additives don\'e attack these.
When the engine was pulled apart recently (due to a slipped bearing on the front), the actual rotor chambers had very little Carbon buildup, the reason for the engine failure was me not replacing the bearings after the previous tear down - and I should have done - it\'s always a good idea to replace what ever looks worn or is close to spec when you get the chance - it\'s much cheaper than a rebuild in the long run ;-)
Oh - and I ran the car as a daily driver and it was driven quite hard - so I would say the 2 stroke mod is an execellent adaptation for the rotory - and it does work on the TII as long as your OMP and injectos are properly serviceable. The Service manual does tell you how to check them - it\'s well worth doing this - as they can get clogged.
One other bonus - one of the reasons for the OMP failing is crap in the engine oil fouling the little OMP pump chamber (I\'ve taken apart about 4 of these now) - which causes the weak stepper motor\'s windings to burn out - often taking the ECU\'s unprotected output transistors with it when it goes. Using clean oil will avoid this problem happening :-)
nice one, i still have some reading up to do but im pretty sure i will go with this mod, good shout about the seals being damaged by oil additives, i will look into that some more to find a suitable semi/fully synth oil.
Quote from: Prof;869153The Oil injectors are fed with metered amounts of oil by the OMP - the rate at which this happens is altred by revs and boost on the T2 (the old mechaninal ones were only revs as the lever was attached to the throttle mechanism).
The Injectors themselves have an air blow feed, which comes from the manifold, so the oil is effectively atomised into the chamber. On the T2 there are 2 sets of injectos, one set sit on the rotor housings in the top left quandrant (intake area) and the other 2 are sat on the primary air ports.
May well be different on an FD but the OMP oiler has a one way valve in it, on inspection air is dragged IN to the engine via the engines Vacuum and shuts when the engine goes into Positive boost, the Pipes on the top of the Oiler are to the breather system and hold no Pressure (just there to supply air to be dragged through the oil to atomize it as it enters the engine)
After many hours of reading up and Inspecting parts i know exactly how it works now, The engine oil pressure feeds a small reservoir of oil which any pressure is bled back to the sump, from this small Reservoir the OMP feeds a small Piston pump in the side of the OMP, that is actuated by a spinning disk driven from the engines front spacer assembly, once the Piston is actuated it pushes a metered amount of oil into the omp line (x amount per rotor bath) so the Oil is force fed into the very small diameter OMP line (its small bore so the Vacuum doesn\'t pull too much oil out of the line and the Volume inside is low), next once that oil finally reaches the oiler there is two scenarios that can happen, either the engine is on Vacuum so the oil is pushed into the Oiler and the vacuum drags air through the oil as its pulled into the engine atomizing it or the motor is on boost so the oiler one way valve shuts and the oil simply carries on being pushed through the oiler into the motor in a steady metered stream. The Only variation on the amount of oil is set by the Stepper motor on the later OMP\'s this acts like a kind of oil Throttle adding more or less as the engine requires, this job on the earlier OMP\'s was done via the linkage to the throttle.
(http://i32.photobucket.com/albums/d26/Grizzly30/FDomp_zps8ec244b2.jpg) (http://s32.photobucket.com/user/Grizzly30/media/FDomp_zps8ec244b2.jpg.html)
So... it looks like the 2 stroke oil method would work fine, but the only question that remains is the Quantity of oil, as the 2 stroke oil cold is thicker than the hot engine oil would that alter the amount used? plus added resistance in the very thin bore omp lines? as it seems to work out of the box no one has tested to see how much is actually being used.
Premiixng is far simpler and superior. 2stroke comes in 500ml bottles. Poor one bottle 50 litres of fuel Simple. Better lubrication of the seals. No more dirty engine oil in the chamber. No risk of oil lines getting clogged up and not deliver oil
Depending on placement of the reservoir the 2 stroke oil should be warmed by the heat radiating from the engine as it warms up.
Remember engine oil is also cold on initial start up too.
I would hazard a guess that cold pure 2T has a lower viscosity than say cold 15w40 (just guessing here)
Quote from: Grant Monkhouse;869849Premiixng is far simpler and superior. 2stroke comes in 500ml bottles. Poor one bottle 50 litres of fuel Simple. Better lubrication of the seals. No more dirty engine oil in the chamber. No risk of oil lines getting clogged up and not deliver oil
Frankly i\'ve used stock omp for over 10 years now running over 450hp on the same engine so i see it all as a waste of time, the only time the stock OMP doesn\'t do its job fine is when the OMP oilers one way valve sticks and there are obvious tell tail signs when that happens (either oil all over the show or Popped off breather pipe on oiler)
I can\'t talk for anyone else but my oil never gets dirty (gets changed every 3k without fail) what it does do is get badly fuel Diluted which makes it thinner (you can tell when it needs changing as the idle oil pressure drops down to a bar on my aftermarket gauge) so "Dirt" or Carbon in the oil is not a problem. Using cheap oil is most people\'s problem, less refined oil - Carbon deposits as its burnt ;)
I keep hearing Pre mix is better than omp too, yes and no...... Pre mix is not for a Road car, its simply too easy to forget if your FD is a second car or a "Weekend warrior" but like the 2 stroke reservoir, its ok if get in the habit of using it and filling it (a tip is use 2 stroke oil that is available at the same place as the fuel you use for example Shell V-power so i used there shell synthetic 2 stroke oil) i only forgot once to put stroke oil in it was 3am and i was tired driving home from London which is one of the reasons i went with omp, its also really messy i found 2 stroke oil in the Throttle body and the LIM was covered in it. Not for me.
Quote from: Arnie_O;869854Depending on placement of the reservoir the 2 stroke oil should be warmed by the heat radiating from the engine as it warms up.
Remember engine oil is also cold on initial start up too.
I would hazard a guess that cold pure 2T has a lower viscosity than say cold 15w40 (just guessing here)
The stock OMP is the benchmark its probably the only setup that has been thoroughly tested and set up correctly by Mazda (so lets say that works fine if all the components are in working order ;))
Don\'t forget that No one opens the car up cold, the engine is designed to get the oil up to operating temps as fast as possible and the OMP is designed to meter the engine oil correctly hot or cold via the stepper motor.
I did play about with some tests, not very scientific, but I wanted to see how the 2 stroke oil compared to engine oil in a spread test, both with the oil cold, warm or hot and the also the metal sheet cold, warm or hot.
It\'s no suprise that in both cases, the warmer the oil and the warmer the plate, the greater the spread was. What was surpsising is that the 2 stroke I used (blue marine stuff), spreads rapidly on the metal if it\'s warm or hot, pretty much regardless of the oil temperature. Even when it\'s only warm (30-40 degrees), the 2 stroke spreads faster than the hot (close to 100 degrees) engine oil.
What buggered my engine was the fact that I didn\'t replace the bearings on the last rebuild, and at some stage the front bearing spun, blocking the oil pathway and resulting in the front bearing disintegrating, taking with it the stack at the front (1 torrington, 2 thrust plates, and some signs of wear on the e-shaft).
The rear rotor looks to have been well lubricated and has very low carbon buildup, and all the seals came out easily.
I will definitely use the OMP / 2 Stoke mod again in the rebuild.
The SOHN adaptor does not delete the OMP It simply redirects where is supplied with oil.