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Increase MOP oil injection by changing hoses?

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Old 05-15-2010 | 10:05 AM
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Increase MOP oil injection by changing hoses?

Was just reading this TSB. Its a bout an issue with people experiencing higher oil consumption than they are used to and a "FIX".

http://www.finishlineperformance.com...30-09-2159.pdf

Turns out the issue they are tracking is caused by using a part from 2009+ rx-8s in 04-08s

Some vehicles may experience high oil consumption if the air intake hose was replaced with service parts. The
cause of this is the number of ventilation holes on the hose was changed from three (3) to two (2) for 2009.
However, it appears that the service part hose for 2009 was shipped for 2004-2008 RX-8 by mistake since January
8, 2008. If the hose for a 2009 model is installed on a 2004-2008 RX-8, the barometric pressure, which is
normally applied on a small hose (A) connected to the metering oil nozzle is plugged. Engine vacuum then goes
to the metering oil nozzle instead so that oil is supplied inside the engine is more than the Metering Oil Pump
(MOP) injects, resulting in high oil consumption.

So this might be an easy way for people to inject more oil without tuning. I wonder how much the increase actually is. might be an alternative to pre-mixing for people worried about dirty socks or for the measuring impaired...
Old 05-15-2010 | 10:13 AM
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Interesting.....subscribing.
Old 05-15-2010 | 10:18 AM
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Your ideas intrigue me, I'd like to subscribe to your newsletter.
Old 05-15-2010 | 08:09 PM
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I noticed that TSB months ago.

I rather use premix in my gas ...
Old 05-15-2010 | 08:14 PM
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Originally Posted by newcastle
Interesting.....subscribing.
you have an AccessPORT and Idemitsu premix in your garage, you don't need this.
this is an interesting 'fix' for some guys who want to try and get more oil in there without tuning or pre-mix.

I wonder what mazda considers 'high oil consumption'
Old 05-15-2010 | 08:24 PM
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Originally Posted by Jedi54
you have an AccessPORT and Idemitsu premix in your garage, you don't need this.
this is an interesting 'fix' for some guys who want to try and get more oil in there without tuning or pre-mix.

I wonder what mazda considers 'high oil consumption'
from 0.5 quart to 0.6 quart = "high oil consumption"

Old 05-15-2010 | 08:29 PM
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what a minute--- i thought the mop was a volume delivery system---how can vacuum get by that?
OD
Old 05-15-2010 | 08:34 PM
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Originally Posted by olddragger
what a minute--- i thought the mop was a volume delivery system---how can vacuum get by that?
OD
Since the OMP nozzles are vented to atmosphere, it is a volume-measured/vacuum-delivered system (for the most part, anyway). As the engine vacuum approaches 0 in./hg., manifold, the OMP pressure is more responsible for the delivery.
Old 05-15-2010 | 08:39 PM
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Originally Posted by nycgps
I noticed that TSB months ago.

I rather use premix in my gas ...
I also noticed it a few weeks ago, and was wondering about it, and wondered how much additional it was really adding?
I think I'd still be inclined to premix in the gas as well, but itr is interesting.
Old 05-15-2010 | 09:01 PM
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so in essence, engine vacuum can pull oil through the mop?
Old 05-15-2010 | 11:22 PM
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Yes thats how i read it denny
Old 05-16-2010 | 11:41 AM
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Originally Posted by olddragger
so in essence, engine vacuum can pull oil through the mop?
Engine vacuum is largely responsible fior the delivery. Mazda has a procedure in the service manual for checking the operation of the OMP nozzles' venting system and improper venting can result is low or zero oil flow. This is why we all spent so much time pondering and discussing the issue in F/I applications.
Old 05-16-2010 | 11:43 AM
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wow
This could make for a totally different line of thought
I wonder what amount of volume change occurs?
Anyone?
Kinda makes sense --vacuum occurring on both ends cancel each other out.
OD
Old 05-16-2010 | 11:55 AM
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Originally Posted by olddragger
vacuum occurring on both ends cancel each other out.
OD
Mazda's illustration is rather lacking, as is their explanation (what else is new?), but the way the OMP venting system operates has been discussed and can probably be found in the "Pettit Supercharger Owners" thread (somewhere).
Old 05-17-2010 | 03:09 AM
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Yeah, Interesting...I also noticed this and posted a thread on the PART Difference or Supply Mix Up months ago....correct part number wrong part inside.

But it makes some kind of sense, as the 09's do not need this extra or 3rd connector like the 04-08's as Series 2's have a totally different MOP mechanism (that being fully electric).

Strange Part is the S1 Hose Part Number N3H1-13-221E with the 3 holes is about $144, But if you want the same part for a Series 2 with 2 Holes, according to My EPC it is ONLY available with other Small Vac Hoses and Resonance Chamber (small square Black Box) as a Complete SET.
Part # N3R1-13-22XA at $270...go Figure..

So if you wanted to try the 09 Hose on your Series 1 to increase Oil Use you could order a N3H1-13-221E and hope it has the wrong part (09) inside for $144, or Spend $270 on the 09 Part N3R1-13-22XA...and have a lot of useless Vac Hoses spare.

Crystal Clear?
Old 05-17-2010 | 03:22 AM
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oh thats annoying
Old 05-17-2010 | 03:25 AM
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When I was looking at the relative ambient pressures across the OMP system back in 2007, I had speculated on the effect of deleting this hose or valving it to alter the pressure differential.

In the end, in an N/A application, this change in the vacuum routing only affects oil delivery during very low load situations where increased volume just isn't desired.
Old 05-17-2010 | 06:14 AM
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Originally Posted by ASH8
Yeah, Interesting...I also noticed this and posted a thread on the PART Difference or Supply Mix Up months ago....correct part number wrong part inside.

But it makes some kind of sense, as the 09's do not need this extra or 3rd connector like the 04-08's as Series 2's have a totally different MOP mechanism (that being fully electric).

Strange Part is the S1 Hose Part Number N3H1-13-221E with the 3 holes is about $144, But if you want the same part for a Series 2 with 2 Holes, according to My EPC it is ONLY available with other Small Vac Hoses and Resonance Chamber (small square Black Box) as a Complete SET.
Part # N3R1-13-22XA at $270...go Figure..

So if you wanted to try the 09 Hose on your Series 1 to increase Oil Use you could order a N3H1-13-221E and hope it has the wrong part (09) inside for $144, or Spend $270 on the 09 Part N3R1-13-22XA...and have a lot of useless Vac Hoses spare.

Crystal Clear?
Clear, thanks for the infos!

Anyway I think more simple and cheaper to plug in the third hole and the nozzle's vac hose.
Old 05-17-2010 | 09:08 AM
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who wants more engine oil in there? rather pre mix.
But for those with the sohn i wonder if this is something to play with?
MM low load could also be when you let off the accelerator ---right?
Old 05-17-2010 | 09:28 AM
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For n/a, the "vacuum" will be highest when the throttle is closed and decelerating. This is a good time to supply extra oil when there is nothing coming from the premix (if any) since the fuel is shut off. However, the second-highest vacuum is at idle, so you're getting extra oil when you don't need it. I don't know if the minus is worth the plus.
Old 05-17-2010 | 10:08 AM
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MM and HiFlite; I have been pondering the same thing for the past few days, which is why I haven't posted on that issue, but closing off the OMP vent circuit could deliver more oil during higher manifold vacuum which, as you both allude to, is seemingly counter productive.

Here is what causes me to pause on any conclusions: the Renesis has historically low OMP volumes in the areas where 99% of us do most of our driving..... low-load/high manifold vacuum levels (which is to say cruising and idling). In the higher load/low manifold vacuum ranges, the OMP system seems to be delivering volumes which help longevity (hence the "redline a day" theory).

To further confuse the issue from a philosophical standpoint; I would tend to not want to mess around with anything the presumably "knowledgeable" Mazda engineers designed for the Renesis but, then again, we on this forum have solved plenty of Mazda's problems for them with the RX-8 so I have no idea as to the effectiveness or desirability of this particular line of thought, especially if F/I were to be added to the conversation.
Old 05-17-2010 | 10:53 AM
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Good info. I have been noticing that my SOHN reservoir is not emptying as fast as it would before, i don't have any CEL's for the OMP system but is there a easy way to test it?
Old 05-17-2010 | 11:17 AM
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There is no need for more oil when you let off the gas.
No load, no heat and no need for additional compression.

Remember, the Renesis is, essentially, a dry-seal motor. The parts that need lube all the time (bearings) get oil all the time.
Injected oil is mainly there to cool the seals, not lube them.
Old 05-17-2010 | 12:35 PM
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Originally Posted by MazdaManiac

Remember, the Renesis is, essentially, a dry-seal motor. The parts that need lube all the time (bearings) get oil all the time.
Injected oil is mainly there to cool the seals, not lube them.
Interesting, but I don't see how that would have much effect on cooling at the tiny volumes of oil involved. It takes almost no heat to evaporate the oil itself. Or does it work by wetting the seal and thereby increasing the thermal conductivity to the relatively cool rotor and rotor housing?
Old 05-17-2010 | 12:46 PM
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You would be absolutely amazed at the effect of that tiny bit of oil.


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