Anyone using the rotary aviation MOP adaptor?
If you have the PFC, you can control the amount injected via OMP. The stock system injects depending on load, rpm, etc and varies the amount so it's not a fixed amount across the rpm/load range. The problem with the stock system, like we've known about since they went with an electronic O.M. system is that it's not enough and over time, the engine loses it's ability to idle due to seal wear. That's threads where someone says it dies as they pull up to a red light or turning at slow speeds. Unless you have some way of controlling the amount the stock OMP injects, then you still need to premix since it's still using the stock programming even if you have the RA tank attached.
Tim
Tim
Tim
Good info! I agree that exactly about what you said, but I haven't read it the way you put it. I just rebuilt my engine a few months back. I didn't find any blatant evidence to why my compression was low. This was my first rebuild and I went to great lengths to study the issue. Bought more than one rebuild video, read everything I could find. I came to the realization that my seals must have been worn or I had weak springs somewhere, apex or side seals. My engine had low carbon build up so I felt it wasn't a sticking side seal. I will be much more able to notice things on my next rebuild, but I hope it is a long time down the road. My question is I now run a modified pump with a tank. I run premium Mercury outboard injector oil. I have a quart tank that goes down to around half after three full tanks of gas. I don't feel like its under oiled. In fact for a while I felt it might be over oiled. I started to wonder how much the oil weight might be a factor going from motor oil to 2 stroke injector oil, which seems lighter, but I have no scientific way to tell. If it is a lighter weight wouldn’t it pass though the injection system with more flow than 10W 40? Bottom line I think the injector oil is better, burns better lubes better. I feel this will out way the short comings of the MOP. Time will tell! Your thoughts?
Good info! I agree that exactly about what you said, but I haven't read it the way you put it. I just rebuilt my engine a few months back. I didn't find any blatant evidence to why my compression was low. This was my first rebuild and I went to great lengths to study the issue. Bought more than one rebuild video, read everything I could find. I came to the realization that my seals must have been worn or I had weak springs somewhere, apex or side seals. My engine had low carbon build up so I felt it wasn't a sticking side seal. I will be much more able to notice things on my next rebuild, but I hope it is a long time down the road. My question is I now run a modified pump with a tank. I run premium Mercury outboard injector oil. I have a quart tank that goes down to around half after three full tanks of gas. I don't feel like its under oiled. In fact for a while I felt it might be over oiled. I started to wonder how much the oil weight might be a factor going from motor oil to 2 stroke injector oil, which seems lighter, but I have no scientific way to tell. If it is a lighter weight wouldn’t it pass though the injection system with more flow than 10W 40? Bottom line I think the injector oil is better, burns better lubes better. I feel this will out way the short comings of the MOP. Time will tell! Your thoughts?
Originally Posted by Tim Benton
If you have the PFC, you can control the amount injected via OMP. The stock system injects depending on load, rpm, etc and varies the amount so it's not a fixed amount across the rpm/load range. The problem with the stock system, like we've known about since they went with an electronic O.M. system is that it's not enough and over time, the engine loses it's ability to idle due to seal wear. That's threads where someone says it dies as they pull up to a red light or turning at slow speeds. Unless you have some way of controlling the amount the stock OMP injects, then you still need to premix since it's still using the stock programming even if you have the RA tank attached.
Tim
Tim
It's the same conditions that caused the RX-8 to have the engine recall going on now...not enough oil being mixed via the OMP into the chambers to properly lubricate the seals, leading to increased wear and lower vacuum at idle...that's why they have the vacuum idle test for the 8. Luckliy for the 8, they can reflash the ecu. The PFC/datalogit combo allows you too for the FD.
Alex, in reply, surely you've seen all the posts regarding premixing 2 stroke oil at fill up. Those many threads and posts, and even further back, the "big list" day (when we really only had the rechipped ecu's and PFS PMC) weren't premixing to be safe at the track, it was to be safe all the time. The stock system wasn't injecting enough which lead to engines over time losing compression and had low idle vacuum. You can check with so called rotary experts that have been in business for the past 5 to 6 years, big deal...go to a shop that has worked on the rotaries from their inception and ask their opinion. The shop (I've been going to with my FC's, FD's and rx-8 since 96) that told me about it has been working on mazda's and rotaries in general for over 25 years, racing them as well. Alot of the knowledge base the forum only goes back 5 or 6 years and those that post often are taken as gospel when really their knowledge isn't sufficent to trust on something as finicky as the rotary.
More than likely, if your modifing the OMP, then you've modified a lot more on the car and will probably lose your engine due to something else, rather than insufficient oiling from the OMP which might take 60 to 80K to wear to thepoint of low vacuum at idle. But if you can increase the OMP's amount it injects, do so or atleast continue premixing at each fill up.
Tim
Alex, in reply, surely you've seen all the posts regarding premixing 2 stroke oil at fill up. Those many threads and posts, and even further back, the "big list" day (when we really only had the rechipped ecu's and PFS PMC) weren't premixing to be safe at the track, it was to be safe all the time. The stock system wasn't injecting enough which lead to engines over time losing compression and had low idle vacuum. You can check with so called rotary experts that have been in business for the past 5 to 6 years, big deal...go to a shop that has worked on the rotaries from their inception and ask their opinion. The shop (I've been going to with my FC's, FD's and rx-8 since 96) that told me about it has been working on mazda's and rotaries in general for over 25 years, racing them as well. Alot of the knowledge base the forum only goes back 5 or 6 years and those that post often are taken as gospel when really their knowledge isn't sufficent to trust on something as finicky as the rotary.
More than likely, if your modifing the OMP, then you've modified a lot more on the car and will probably lose your engine due to something else, rather than insufficient oiling from the OMP which might take 60 to 80K to wear to thepoint of low vacuum at idle. But if you can increase the OMP's amount it injects, do so or atleast continue premixing at each fill up.
Tim
Originally Posted by Tim Benton
It's the same conditions that caused the RX-8 to have the engine recall going on now...not enough oil being mixed via the OMP into the chambers to properly lubricate the seals, leading to increased wear and lower vacuum at idle...that's why they have the vacuum idle test for the 8. Luckliy for the 8, they can reflash the ecu. The PFC/datalogit combo allows you too for the FD.
Alex, in reply, surely you've seen all the posts regarding premixing 2 stroke oil at fill up. Those many threads and posts, and even further back, the "big list" day (when we really only had the rechipped ecu's and PFS PMC) weren't premixing to be safe at the track, it was to be safe all the time. The stock system wasn't injecting enough which lead to engines over time losing compression and had low idle vacuum. You can check with so called rotary experts that have been in business for the past 5 to 6 years, big deal...go to a shop that has worked on the rotaries from their inception and ask their opinion. The shop (I've been going to with my FC's, FD's and rx-8 since 96) that told me about it has been working on mazda's and rotaries in general for over 25 years, racing them as well. Alot of the knowledge base the forum only goes back 5 or 6 years and those that post often are taken as gospel when really their knowledge isn't sufficent to trust on something as finicky as the rotary.
More than likely, if your modifing the OMP, then you've modified a lot more on the car and will probably lose your engine due to something else, rather than insufficient oiling from the OMP which might take 60 to 80K to wear to thepoint of low vacuum at idle. But if you can increase the OMP's amount it injects, do so or atleast continue premixing at each fill up.
Tim
Alex, in reply, surely you've seen all the posts regarding premixing 2 stroke oil at fill up. Those many threads and posts, and even further back, the "big list" day (when we really only had the rechipped ecu's and PFS PMC) weren't premixing to be safe at the track, it was to be safe all the time. The stock system wasn't injecting enough which lead to engines over time losing compression and had low idle vacuum. You can check with so called rotary experts that have been in business for the past 5 to 6 years, big deal...go to a shop that has worked on the rotaries from their inception and ask their opinion. The shop (I've been going to with my FC's, FD's and rx-8 since 96) that told me about it has been working on mazda's and rotaries in general for over 25 years, racing them as well. Alot of the knowledge base the forum only goes back 5 or 6 years and those that post often are taken as gospel when really their knowledge isn't sufficent to trust on something as finicky as the rotary.
More than likely, if your modifing the OMP, then you've modified a lot more on the car and will probably lose your engine due to something else, rather than insufficient oiling from the OMP which might take 60 to 80K to wear to thepoint of low vacuum at idle. But if you can increase the OMP's amount it injects, do so or atleast continue premixing at each fill up.
Tim
How much does the OMP inject stock? What is the ideal amount to inject if you are using 2-cycle oil (RA adapter)?
I'll be using the RA oil adapter on my new REW block (near stock) in the hope that it will increase reliability. I think i'll run a bit of tcw-3 on top until i get a PFC after hearing that... it'd be a shame to wear out some nice cermet housings
Can't put my fingers on the OMP injection ratio right now, but I have read it. Its all controlled by the ECU seeing it knows the boost, engine load, and RPMs etc.
The RA adapter has no adjustment that I am aware of. It just blocks the engine oil off and provides a bung for the two stroke oil sorce.
I modded my own OMP and posted a thread about it. All to hopefully enjoy a longer engine life and get my moneys worth out of the rebuild! I like to say I have a mod that most people don't and can say I did it myself too.
Terry
The RA adapter has no adjustment that I am aware of. It just blocks the engine oil off and provides a bung for the two stroke oil sorce.
I modded my own OMP and posted a thread about it. All to hopefully enjoy a longer engine life and get my moneys worth out of the rebuild! I like to say I have a mod that most people don't and can say I did it myself too.
Terry
Originally Posted by Marcel Burkett
Anyone try pressurizind their reservoir with boost for more delivery volume ?
Only a certain amount will enter the plunger each revolution of the OMP regardless of pressure assuming there is sufficient supply and assuming oil is a incompressible.
Tim:
Can you lead us to any threads dealing with OMP oil consumption and the correct increase for a desired loading condition, something with a little content rather than just stating the point?
I would love to read up on this, but cant for the life of me remember any that actually did a synopsis on the topic with any data or empirical facts by an established member?
Junior Member
Joined: Apr 2005
Posts: 25
Likes: 0
From: Australia
Originally Posted by Tim Benton
If you have the PFC, you can control the amount injected via OMP. The stock system injects depending on load, rpm, etc and varies the amount so it's not a fixed amount across the rpm/load range. The problem with the stock system, like we've known about since they went with an electronic O.M. system is that it's not enough and over time, the engine loses it's ability to idle due to seal wear. That's threads where someone says it dies as they pull up to a red light or turning at slow speeds. Unless you have some way of controlling the amount the stock OMP injects, then you still need to premix since it's still using the stock programming even if you have the RA tank attached.
Tim
Tim
I should have clarified a bit better, yes you'll need the PFC and datalogit to control the OMP and the amount it injects. I'll see if I can find any graphs of the OMP, voltage, etc in the service manual and other sources. As far as actual amount pumped in at various rpm and load points, I doubt anyone will have that detail of information available.
Tim
Tim
Rotary Freak
Joined: Nov 2001
Posts: 2,715
Likes: 1
From: trinidad and tobago
Originally Posted by Scrub
I have the RA MOP and I am using a OBX catch can I bought from Car Version 2. You can give them a call...the number is on their site www.carversion2.com . I'd be interested to see the resivoir that holds three quarts, I may be interested in one for my new car if you have extras.
-Dan
Here is a pic of the setup
and it installed in the car. It's not custom made, but it works. You need to install some sort of breather valve on the top so it will flow.
-Dan
Here is a pic of the setup
and it installed in the car. It's not custom made, but it works. You need to install some sort of breather valve on the top so it will flow.
How much does this catch can hold ?
Originally Posted by Tim Benton
I should have clarified a bit better, yes you'll need the PFC and datalogit to control the OMP and the amount it injects. I'll see if I can find any graphs of the OMP, voltage, etc in the service manual and other sources. As far as actual amount pumped in at various rpm and load points, I doubt anyone will have that detail of information available.
Tim
Tim
Thanks for the response Tim.
What specifically is driving your opinion on this point?
Clearly if the engine is asked to go above and beyond its stock power levels then it would probably be a logical precaution to increase OMP consumption.
So I guess the million dollar question is how much is a reasonable increase?
Are there any reputable testimonials that have shaped this opinion?
How much did mazda add to the rx8s OMP consumption with the reflash, or is this a quantifiable amount since it is the stock ECU?
As far as what's driving my opinion, it's the shop I go to that stressed it to me way back in 1996. He had seen plenty of S5 RX-7's with higher mileage that couldn't hold idle. No blown seals but worn out side seals if I remember correctly. I can ask him again to be certain. As the FD's started creeping up in mileage in the Atlanta area, it was happening to those as well. Much like what's happening with the RX-8's now. I can ask him if he's talked to other shops, mazda tech, etc that help him formulate that opinion.
Tim
Tim
There is a manual "ADJUSTER" listed on the RA site which is supposed to let you control the injection rate. It replaces the stepper motor completely and is a manual valve with adjustment. This seems like it would be hard to tune and find a sweet spot, but it is possible to increase the injection rate without an aftermarket tuneable ecu.
"The RX7 OMP is controlled using a position stepper motor. The stepper motor may be replaced with an ADJUSTER to set the control shaft to a fixed position. In this way, the OMP is fully functional, giving an oil amount comparable to mixing the oil in the fuel. If the use of two stroke oil is desired"
http://rotaryaviation.com/oil_inject...p_adaptors.htm
"The RX7 OMP is controlled using a position stepper motor. The stepper motor may be replaced with an ADJUSTER to set the control shaft to a fixed position. In this way, the OMP is fully functional, giving an oil amount comparable to mixing the oil in the fuel. If the use of two stroke oil is desired"
http://rotaryaviation.com/oil_inject...p_adaptors.htm
That's neat, I didn't see they had an adjuster before. Must be relatively new. I just made my own block off plate and moded my own OMP. Working great so far and still control by the ECU. Cost was less than 3 bucks$
Terry7
Terry7
I have a s4 rx7. So basically I just take this ra adapter and bolt it onto my omp then I run a small tank. You use "an ADJUSTER to set the control shaft to a fixed position."
as someone said before how do you know if you are getting a 100"1 ratio?
as someone said before how do you know if you are getting a 100"1 ratio?
Originally Posted by lupin
as someone said before how do you know if you are getting a 100"1 ratio?
Because the pump runs off the engine and therefore spins at a specific rate, then the stepper motor can also change the amount of oil pumped per cycle based on loading conditions.
The S4 are the mechanical oil metering pump and don't seem to have a problem with not injecting enough oil into the chambers. I haven't had a chance to talk to the guys at the shop to get their view point on it again, but I'll try to call before they close for Christmas.
Tim
Tim