SOHN vs stock oil pressure for OMP
#27
They should be but they also sometimes get air bubbles in them. Nothing to be alarmed about, though.
#28
Turbo Member
iTrader: (10)
I cant imagine that the oil would change while in the pump so I know that my 2 stroke hasnt been hitting there, bc if so the oil lines would be blue and not the normal color.
I also noticed that one of Kahlens omp lines doesnt even have oil in it.
I also noticed that one of Kahlens omp lines doesnt even have oil in it.
![Scared](https://www.rx8club.com/images/smilies/scared.gif)
Last edited by Chris; 11-24-2010 at 10:30 AM.
#30
Turbo Member
iTrader: (10)
I just read through some other threads and it seems like we should have some kind of flow of somewhere around 1 qt ever 1k miles or so.... Well I am NOT getting anywhere close to that kind of consumption.... I will be taking the car apart this evening to see what is going on.... I have a new gasket for the omp bc I think I am getting a small leak there. Also, I am not seeing the oil in the four lines that go from the pump to the motor.
I am
to say the least.
I drive highway miles to work. about 25-30 miles a day.
I am
![Scared](https://www.rx8club.com/images/smilies/scared.gif)
I drive highway miles to work. about 25-30 miles a day.
#31
SARX Legend
iTrader: (46)
![TX](https://www.rx8club.com/images/icons/tx.jpg)
I just read through some other threads and it seems like we should have some kind of flow of somewhere around 1 qt ever 1k miles or so.... Well I am NOT getting anywhere close to that kind of consumption.... I will be taking the car apart this evening to see what is going on.... I have a new gasket for the omp bc I think I am getting a small leak there. Also, I am not seeing the oil in the four lines that go from the pump to the motor.
I am
to say the least.
I drive highway miles to work. about 25-30 miles a day.
I am
![Scared](https://www.rx8club.com/images/smilies/scared.gif)
I drive highway miles to work. about 25-30 miles a day.
#33
Super Moderator
Here is the best "pic" I can give you for a S1..
Edit: BTW If you have to replace the S1 Specific Nozzles they are $59.00 Each (N3H1-14-631B)
Also the WASHERS between the Banjo/Injectors are Copper ($1.65 each 9956-21-000 by qty 8)
Edit: BTW If you have to replace the S1 Specific Nozzles they are $59.00 Each (N3H1-14-631B)
Also the WASHERS between the Banjo/Injectors are Copper ($1.65 each 9956-21-000 by qty 8)
![](https://www.rx8club.com/attachments/series-i-tech-garage-22/165367d1290629556-sohn-vs-stock-oil-pressure-omp-2.jpg)
Last edited by ASH8; 11-24-2010 at 02:18 PM.
#34
Can someone school me on the difference between utilizing the sohn adapter and premixing? Is it simply 'ecu' controlled metering? I find that the oil injection nozzles seem to be a unreliable part of the lubricating puzzle. I have yet to really test it, but they could theoretically become inoperable and at worst boost leaks for FI applications?
#35
Registered
iTrader: (3)
all the sohn does is to allow a "clean" oil to be supplied to the omp. The omp will not have access to the engine oil--only to a separate tank you install to hold the oil of your choice.
Since I change oil every 2-3 K miles and use a high ZDDP brand--i never have seen the use for one personally. I do wonder if the 2 stroke oils that people use when they add the Sohn has high levels of ZDDP?
Its nice to have but imho it is not life or death. I think it would be better if it could supply a pressurized oil supply to the omp--.
Yall do know the oil "Injectors" can be drilled?
OD
Since I change oil every 2-3 K miles and use a high ZDDP brand--i never have seen the use for one personally. I do wonder if the 2 stroke oils that people use when they add the Sohn has high levels of ZDDP?
Its nice to have but imho it is not life or death. I think it would be better if it could supply a pressurized oil supply to the omp--.
Yall do know the oil "Injectors" can be drilled?
OD
#36
SARX Legend
iTrader: (46)
Thanks ASH, I am wondering if I should just replace them then. I have 118,000 miles and I am assuming these are the same original oil injectors transferred from motor to motor. Or are they new with the rebuilds?
#37
Banned
iTrader: (3)
And for those of you that still have a CAT, uh, yeah. lol
#39
I may be wrong about MM and the Idemitsu....
(oil conversations always invoke much discussion)
Having used all different kinds of 2-stroke in my tank, my own opinion is that it really doesn't matter much what we run in the tank as long as it is dedicated 2-stroke (and I haven't been desperate to need to run crankcase oil in it but I bet that would work, too). Whether or not it is specifically designed for injection hasn't seemed to make a difference.
Then again, I have also accidentally run my OMP tank dry for a few hundred miles and everything is still fine...... my engine runs as good as it ever has.
![Dunno](https://www.rx8club.com/images/smilies/dunno.gif)
Having used all different kinds of 2-stroke in my tank, my own opinion is that it really doesn't matter much what we run in the tank as long as it is dedicated 2-stroke (and I haven't been desperate to need to run crankcase oil in it but I bet that would work, too). Whether or not it is specifically designed for injection hasn't seemed to make a difference.
Then again, I have also accidentally run my OMP tank dry for a few hundred miles and everything is still fine...... my engine runs as good as it ever has.
At the least you want a multipurpose oil but the best choice would be 2-stroke designed for air cooled engines like dirt bikes, snow mobiles and chain saws. The oil is formulated more for how the rotary engine uses it and also is designed to prevent carbon buildup on exhaust ports.
all the sohn does is to allow a "clean" oil to be supplied to the omp. The omp will not have access to the engine oil--only to a separate tank you install to hold the oil of your choice.
Since I change oil every 2-3 K miles and use a high ZDDP brand--i never have seen the use for one personally. I do wonder if the 2 stroke oils that people use when they add the Sohn has high levels of ZDDP?
Its nice to have but imho it is not life or death. I think it would be better if it could supply a pressurized oil supply to the omp--.
Yall do know the oil "Injectors" can be drilled?
OD
Since I change oil every 2-3 K miles and use a high ZDDP brand--i never have seen the use for one personally. I do wonder if the 2 stroke oils that people use when they add the Sohn has high levels of ZDDP?
Its nice to have but imho it is not life or death. I think it would be better if it could supply a pressurized oil supply to the omp--.
Yall do know the oil "Injectors" can be drilled?
OD
First, 4-stroke oil is not designed to burn in a combustion process while 2-stroke is designed for just that purpose.
Second, the aspect of high ZDDP was something that I thought was necessary at one point however as I poured through the physics of lubrication and oil formulation it became apparent that ZDDP is only necessary in situations where metal on metal contact is a guarantee. Flat tappet cams, for example, are that specific situation. The design of the cams would provide so much pressure that it would almost always force oil out when the cams made contact. No modern car has this problem.
If you're choosing your oil based only on the boundary layer lubrication then you're not running the right oil.
Is the sohn adapter necessary? Not exactly since a small minority of RX8 owners use it. However, I do believe that it provides advantages that are well worth the $100 cost. It's one of those mods IMO that sells itself.
#41
Super Moderator
As far as I know they (Mazda Dealer) reuse your original Injectors, and yes I think I would probably replace them.
#43
The Stink w.o The Sause
iTrader: (5)
Jeff and I have not discussed this particular issue in a couple years, and he has not mentioned anything to me since, but my guess is (since the factory OMP system relies on pressure delta between atmosphere and engine vacuum) that he has much better/more predictable OMP flow when his oil canister references his manifold pressures. Much in the same way that fuel injection system pressure should account for rising intake manifold pressures in boosted applications.
Under boosted applications, doesn't engine vacuum turn into positive pressure relative to atmos?
#45
Hint: bypass/blow-off valves moderate this so we can better tune the engine and keep from damaging the turbocharger.
Last edited by Charles R. Hill; 01-11-2011 at 12:42 AM.
#46
#49
BearBlasterExtraordinair!
iTrader: (3)
How would the oil pan be pressurized? I could see on a piston engine, since some exhaust gas can get by the piston rings. With the way a rotary is made, wouldn't everything stay in the irons or go out the exhaust port? I'm not sure how the oil pan connects to the rest of the engine, so forgive me if I'm just being a re re.