Notices
Series I Tech Garage The place to discuss anything technical about the RX-8 that doesn't fit into any of the categories below.

Oil metering pump elimination

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 10-05-2011, 09:59 AM
  #26  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts
Originally Posted by maskedferret
To drive you completely away from this pre-mix only idea, realize that this is a drive by wire system. What happens to fuel input when you let off the gas around 9k rpm while in gear? Where is your lubrication now?

I have a throttle cable convertion lol and pre mix would mean having to buy specific 2 cycle oil right, the OMP Squirt's 4 cycle Motor Oil from your engine which is how the 8's "Consume" oil ... right.. .?

So the OMP shouldn't, can't be eliminated or replaced really..
But the stock ecu in my case could be, the fans aren't even working properly currently.

Last edited by VICEdOUT; 10-05-2011 at 10:01 AM.
Old 10-05-2011, 10:05 AM
  #27  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes on 110 Posts
Shouldn't be replaced at all.

Yes, the OEM OMP injects dirty 4-stroke oil from the oil pan and is the source of the "oil consumption of rotaries. Mazda likely did not have it pull from a separate oil source as a consession to the consumer-hassle factor (i.e. lazy Americans that can't be bothered to remember to refill one oil container, much less TWO)

dirty 4-stroke is very clearly inferior to clean 2-stroke on a number of levels, which is where the SOHN OMP adapter has popularity (blocks off OEM 4-stroke oil and uses whatever oil you supply it from somewhere else, whereever you put the 2-stroke tank)
Old 10-05-2011, 10:17 AM
  #28  
Registered
 
PhillipM's Avatar
 
Join Date: Dec 2007
Location: UK
Posts: 863
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by maskedferret
To drive you completely away from this pre-mix only idea, realize that this is a drive by wire system. What happens to fuel input when you let off the gas around 9k rpm while in gear? Where is your lubrication now?
If it's on a Haltech, it'll be just like mine on a DTA, and pouring the bloody stuff in as soon as you lift off to cool the chambers with fuel, and with the injection angles timed to direct the oil/fuel flow injection to right before the seals sweep over the ports.

Does mean 4-6ft long flames on occasion mind.
Old 10-05-2011, 10:21 AM
  #29  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes on 110 Posts
Sorry PhillipM, forgot that you have dealt with non-OEM ECUs as well.

My bad
Old 10-05-2011, 10:24 AM
  #30  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts
Originally Posted by PhillipM
If it's on a Haltech, it'll be just like mine on a DTA, and pouring the bloody stuff in as soon as you lift off to cool the chambers with fuel, and with the injection angles timed to direct the oil/fuel flow injection to right before the seals sweep over the ports.

Does mean 4-6ft long flames on occasion mind.

How is your OMP controlled then, a DPO ?





Originally Posted by RIWWP
Shouldn't be replaced at all.

Yes, the OEM OMP injects dirty 4-stroke oil from the oil pan and is the source of the "oil consumption of rotaries. Mazda likely did not have it pull from a separate oil source as a consession to the consumer-hassle factor (i.e. lazy Americans that can't be bothered to remember to refill one oil container, much less TWO)

dirty 4-stroke is very clearly inferior to clean 2-stroke on a number of levels, which is where the SOHN OMP adapter has popularity (blocks off OEM 4-stroke oil and uses whatever oil you supply it from somewhere else, whereever you put the 2-stroke tank)

That SOHN Adapter and separate oil tank, does it inject electronically or at a regulated free flow at all times?
Old 10-05-2011, 10:25 AM
  #31  
Registered
 
PhillipM's Avatar
 
Join Date: Dec 2007
Location: UK
Posts: 863
Likes: 0
Received 0 Likes on 0 Posts
My OMP? It's sat on the shelf looking sad.
Old 10-05-2011, 10:40 AM
  #32  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes on 110 Posts
Originally Posted by VICEdOUT
That SOHN Adapter and separate oil tank, does it inject electronically or at a regulated free flow at all times?
It's just a flow redirection bit of hardware, no electronics to it. The OMP is still the part doing the work, it's basically the equivalent of capping off public water supply line to your house and running a line over to a well instead.

Same system, same functions, different liquid source.
Old 10-05-2011, 10:44 AM
  #33  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts
Originally Posted by PhillipM
My OMP? It's sat on the shelf looking sad.
So you are NOT using one then ?
Old 10-05-2011, 10:54 AM
  #34  
Registered
 
PhillipM's Avatar
 
Join Date: Dec 2007
Location: UK
Posts: 863
Likes: 0
Received 0 Likes on 0 Posts
Don't use one, just pre-mix.
Old 10-05-2011, 10:56 AM
  #35  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts
Originally Posted by PhillipM
Don't use one, just pre-mix.

See I LIKE that idea but people say it does not lubricate the side seals and damages the springs as well..
Old 10-05-2011, 11:00 AM
  #36  
Modulated Moderator
iTrader: (3)
 
dannobre's Avatar
 
Join Date: Feb 2004
Location: Smallville
Posts: 13,718
Received 334 Likes on 289 Posts
If you are full standalone without using the stock DBW throttle you can ditch the OMP....if you are using the stock ECU to run the throftle then you need the OMP to make the throttle work.....
Old 10-05-2011, 11:02 AM
  #37  
Registered
 
WhiteDealershipRice's Avatar
 
Join Date: Apr 2005
Location: I am a leaf in the wind...
Posts: 405
Likes: 0
Received 1 Like on 1 Post
SOHN (Single OverHead Nozzle)?

Wouldn't this negate the benefits of having the nozzles spraying directly on teh apex seals inside the combustion chamber?

If it just puts a separate oil reservoir to feed the OMP, then how is the pump generating pressure? (I understood the OMP to be a valve, & not a pump per-se)

I like the Idea of being able to route 2-stroke through the OEM nozzles though.

Last edited by WhiteDealershipRice; 10-05-2011 at 11:08 AM. Reason: Found further info
Old 10-05-2011, 11:10 AM
  #38  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes on 110 Posts
SOHN is the inventor's last name I believe.

It doesn't change anything about the OEM system except where the oil is coming from. It's basically a block of metal with machined oil passages and added oil hose nipple/bung that blocks off the OEM source and allow you to run a line from the adapter to a 2-stroke container.
Old 10-05-2011, 11:17 AM
  #39  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts
Originally Posted by RIWWP
SOHN is the inventor's last name I believe.

It doesn't change anything about the OEM system except where the oil is coming from. It's basically a block of metal with machined oil passages and added oil hose nipple/bung that blocks off the OEM source and allow you to run a line from the adapter to a 2-stroke container.
And this adapter free flows oil at the same force/level at all times?
Old 10-05-2011, 11:29 AM
  #40  
Registered
 
WhiteDealershipRice's Avatar
 
Join Date: Apr 2005
Location: I am a leaf in the wind...
Posts: 405
Likes: 0
Received 1 Like on 1 Post
Originally Posted by RIWWP
SOHN is the inventor's last name I believe.

It doesn't change anything about the OEM system except where the oil is coming from. It's basically a block of metal with machined oil passages and added oil hose nipple/bung that blocks off the OEM source and allow you to run a line from the adapter to a 2-stroke container.
And that's what's got me confused. How does the OMP "pull" the oil from an alternate source?

Is the OMP an electric pump, or just a solenoid valve (I thought/had read somwehere here before that it was the later)

If you remove the engine oil source, you are also removing the oil pressure that comes with it

Unless the OMP "pulls" oil from the unpressurized crankcase, and is timed to open during the intake section of the 4-stroke cycle, using the engine's vacum to "pull" the oil, it seems to me changing the OMP's source would reduce the oil output from being a "pressurized system" to being a "gravity fed" system.
Old 10-05-2011, 11:30 AM
  #41  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes on 110 Posts
No, the adapter only changes WHERE the oil is coming from.

It works with the OEM OMP, and the OMP and ECU still make the decision on how much oil to flow when. The adapter only changes what oil is being used.
Old 10-05-2011, 11:34 AM
  #42  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes on 110 Posts
Originally Posted by WhiteDealershipRice
And that's what's got me confused. How does the OMP "pull" the oil from an alternate source?

Is the OMP an electric pump, or just a solenoid valve (I thought/had read somwehere here before that it was the later)

If you remove the engine oil source, you are also removing the oil pressure that comes with it

Unless the OMP "pulls" oil from the unpressurized crankcase, and is timed to open during the intake section of the 4-stroke cycle, using the engine's vacum to "pull" the oil, it seems to me changing the OMP's source would reduce the oil output from being a "pressurized system" to being a "gravity fed" system.
Agreed, it's more complex than this. I just keep breaking it down further to basics to try to clear the mis-interpretations that it changes anything about the oil delivery decisions and rate. It doesn't. It just changes the source that the oil is pulled from.

I don't know the details of how it still uses the engine's oil pressure (or not, or even if that is needed). I'm sure these details are what keeps people from making their own adapters, as simply a different source with no further complication would be really easy for anyone that can work with metal or whatever. It could be that it 'loop's the engine oil and uses the engine oil pressure through a mechanical means to generate pressure on the 2-stroke alternate oil source.

You would have to ask those more wise than I about those details.
Old 10-05-2011, 11:37 AM
  #43  
Administrator
 
zoom44's Avatar
 
Join Date: Jul 2002
Location: portland oregon
Posts: 21,958
Received 115 Likes on 88 Posts
listen to Phillip might also want to check with Daed https://www.rx8club.com/showthread.p...hlight=renesis

edit: oh right he was using the stock PCM. still thats a nice build to look at

Last edited by zoom44; 10-05-2011 at 11:40 AM.
Old 10-05-2011, 01:05 PM
  #44  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts
I think having the Haltech's power switched wires to a stock ecu relay might be interfering with the Haltech's signal throwing it into loop mode, anyone concurs ?

I just went to walmart and got me 2 16oz bottles of 2 cycle semi synthetic oil for 3.97 each... Mixed about 3 oz''s into a 5 gallon container and am about to pour that in but first I need to fix the Loop mode problem and why the Haltech's control is being affected by it..
Old 10-05-2011, 03:42 PM
  #45  
Registered
 
pistonhater's Avatar
 
Join Date: Nov 2010
Location: Cacti Land, AZ
Posts: 1,061
Likes: 0
Received 1 Like on 1 Post
A well-known rotary builder (whose name I won't mention since I'm not 100% sure of the facts) told me it is possible to modify the ECU so that you can disable the OMP in the RX-8 without going into limp mode. However, this has been done apparently in extremely modified engines for racing.

Perhaps I misunderstood what he said since this happened during a phone conversation about something else (quotes for installing a Sohn adapter), but apparently there are people out there somewhere racing RX-8s without OMPs. I don't know who they are, so the whole thing could be a myth, LOL
Old 10-05-2011, 07:39 PM
  #46  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts
Got 5 gallons with 3 oz's poured into the container before the gas was poured.. Still trying to fix this buzzard with the blinking coolant gauge when the 2 left most plugs are disconnected, there should be no link between the Haltech or the stock ECU therefore limp dilznick mode shouldn't affect this motor...
Old 10-05-2011, 08:00 PM
  #47  
Registered
 
PhillipM's Avatar
 
Join Date: Dec 2007
Location: UK
Posts: 863
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by pistonhater
apparently there are people out there somewhere racing RX-8s without OMPs. I don't know who they are, so the whole thing could be a myth, LOL

Old 10-05-2011, 08:26 PM
  #48  
No respecter of malarkey
iTrader: (25)
 
TeamRX8's Avatar
 
Join Date: Apr 2005
Posts: 26,720
Received 2,007 Likes on 1,636 Posts
You can run the premix heavy enough with the excess blowing through into the exhaust for a race motor plus real race motors typically don't have a long term durability expectation between rebuilds in mind, but most people wouldn't consider this user friendly for a street car

That Walmart oil will likely result in your car smelling and smoking like a weedwhacker plus I know people who run heavier premix than that with a working MOP
Old 10-05-2011, 09:56 PM
  #49  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts

Running a little better with just a little VE Table Tuning.
Old 10-05-2011, 11:27 PM
  #50  
Registered
Thread Starter
iTrader: (1)
 
VICEdOUT's Avatar
 
Join Date: Mar 2011
Location: ORLANDO, FL
Posts: 170
Likes: 0
Received 4 Likes on 4 Posts
The stock ECU would try and go into limp mode by:
Closing the electronic throttle
Turning off the injectors
Cutting the ignition

The above things are all controlled mechanically or by the Haltech now.

If there is anything else we can do to help, please let me know.

Kind Regards,
Scott Hilzinger
Lead Technical Support


Email:scott@haltech.com
Web:www.haltech.com





So if all these things are controlled by the Haltech now, how come I cant rev up past like 4 to 6 k RPMs? Is it the lack of an OMP or maybe the plugs are fouled?
--Well a little tuning and Staging of the secondary injectors to come on a little later lets the motor combust better and allows it to rev up higher.

Last edited by VICEdOUT; 10-07-2011 at 08:24 AM.


You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Oil metering pump elimination



All times are GMT -5. The time now is 12:19 AM.