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.

Gas/Oil Premix Thread

Old Jun 8, 2012 | 02:09 PM
  #3476  
bse50's Avatar
#50
 
Joined: Nov 2007
Posts: 7,521
Likes: 11
From: Caput Mundi

Since that's how a premixed engine looks when torn down...
...I'll happily keep premixing
Old Jun 8, 2012 | 02:17 PM
  #3477  
9krpmrx8's Avatar
SARX Legend
iTrader: (46)
 
Joined: Jan 2007
Posts: 33,788
Likes: 462
From: San Antonio, Texas
Wanna see pics of my premixed engine and Houstonrx8ers? Different failure reason but both were premixed. I am injecting Idemitsu VIA my SOHN but I' debating on whether to stop premixing or not.
Old Jun 8, 2012 | 02:21 PM
  #3478  
Chris's Avatar
Turbo Member
iTrader: (10)
 
Joined: May 2006
Posts: 2,496
Likes: 29
From: Tampa, FL
if you all remember mysql and his rebuild, he premixed and ran synthetic. his engine was amazing internally.

I personally run synthetic and premix.
Old Jun 8, 2012 | 02:28 PM
  #3479  
hoss -05's Avatar
Lucky #33
iTrader: (4)
 
Joined: Feb 2009
Posts: 2,851
Likes: 5
From: San Antonio, SARX Garage
Originally Posted by Chris
if you all remember mysql and his rebuild, he premixed and ran synthetic. his engine was amazing internally.

I personally run synthetic and premix.

That's what I do as well Chris. Think i need to cut back my pre-mix use just a bit. putting in about 8 oz per fill up and I fill at a quarter tank.
Old Jun 8, 2012 | 02:32 PM
  #3480  
9krpmrx8's Avatar
SARX Legend
iTrader: (46)
 
Joined: Jan 2007
Posts: 33,788
Likes: 462
From: San Antonio, Texas
Yeah I ran synthetic and premixed, and ran the SOHN. It still didn't save my coolant seals

We shall see this round since I'm not starting with a shitty Mazda reman. If this one fails despite all that then the next one is getting 10W-30 GTX and no premix and no SOHN.
Old Jun 9, 2012 | 09:42 AM
  #3481  
Everest^'s Avatar
Registered
iTrader: (1)
 
Joined: Dec 2011
Posts: 54
Likes: 0
what is SOHN?
Old Jun 9, 2012 | 09:46 AM
  #3482  
9krpmrx8's Avatar
SARX Legend
iTrader: (46)
 
Joined: Jan 2007
Posts: 33,788
Likes: 462
From: San Antonio, Texas
TX

Originally Posted by Everest^
what is SOHN?

Search and you will find out No spoon feeding here.
Old Jun 10, 2012 | 03:10 AM
  #3483  
Everest^'s Avatar
Registered
iTrader: (1)
 
Joined: Dec 2011
Posts: 54
Likes: 0
https://www.rx8club.com/series-i-do-yourself-forum-73/diy-sohn-tank-under-air-box-213640/
Old Jun 10, 2012 | 09:14 PM
  #3484  
Nubo's Avatar
Lubricious
 
Joined: Oct 2003
Posts: 3,425
Likes: 4
From: SF Bay Area, California
Originally Posted by SayNoToPistons
... Here are the ingredients of MMO..... Light oil, naphtha and isopropyl alcohol. ...
I know -- perfect!

Seriously, think about the task at hand. You're not trying to lubricate a bearing with thousands of psi needing massive film strength, but a metal housing with seals sweeping by while carbon and all manner of partially burned oil residue is accumulating.

If solvents were an issue you'd be doomed from the start -- the whole chamber is misted with friggin' gasoline.


Whatever lube gets to the housings (omp, mmo...) is short-lived in any case, regardless of viscosity. Does its job briefly, "burns", degrades, and then the residue needs to be gotten rid of. The specific solvents in MMO seem like what's needed.

In any case, my time with the Renesis is done. Didn't manage to kill it in 8 years. Who knows if I hadn't sold it...? At some point I think it's all splitting hairs.

Last edited by Nubo; Jun 10, 2012 at 09:19 PM.
Old Jun 11, 2012 | 07:14 AM
  #3485  
usnidc's Avatar
2008 40th Anniversary
 
Joined: Jun 2008
Posts: 276
Likes: 0
From: Virginia, USA
Originally Posted by Nubo
I know -- perfect!

Seriously, think about the task at hand. You're not trying to lubricate a bearing with thousands of psi needing massive film strength, but a metal housing with seals sweeping by while carbon and all manner of partially burned oil residue is accumulating.

If solvents were an issue you'd be doomed from the start -- the whole chamber is misted with friggin' gasoline.


Whatever lube gets to the housings (omp, mmo...) is short-lived in any case, regardless of viscosity. Does its job briefly, "burns", degrades, and then the residue needs to be gotten rid of. The specific solvents in MMO seem like what's needed.

In any case, my time with the Renesis is done. Didn't manage to kill it in 8 years. Who knows if I hadn't sold it...? At some point I think it's all splitting hairs.
So, do the apex seals need more lubrication or less? why did Mazda increase the omp settings in the S1 and add a third nozzle in the S2's? Why do racing teams pre-mix?

I know it is all anecdotal at this point if it is good to premix or not and what to pre-mix if you decide to. I just use Lucas UCL since I have to keep my cat and it is specifically designed to LUBRICATE in a combustion chamber envinronment and not harm smog equipment. Your results may very.

if I was racing my 8 or running cat-less, I'd probably be using idemitsu.

Last edited by usnidc; Jun 11, 2012 at 07:16 AM.
Old Jun 11, 2012 | 12:05 PM
  #3486  
YUL PHL's Avatar
Registered
iTrader: (1)
 
Joined: Jan 2009
Posts: 162
Likes: 0
From: Plymouth Meeting, PA
i found this old 2oz syringe i had in my kitchen.

i use it like this:

[IMG][/IMG]
[IMG] l][/IMG]

[/url]

6-8oz per tank. however, the plunger does get gummy from the oil and sticks.

looking for an easier solution. turkey baster?
Old Jun 11, 2012 | 12:21 PM
  #3487  
40w8's Avatar
Registered
 
Joined: Apr 2011
Posts: 523
Likes: 7
Hey, I'm clumbsy as hell, and I just pour in 6-8 oz. by looking at the clear measuring marks on the side. You're already guessing how much you need, since the gas you need varies.

Anyone can easily do it without over thinking it.
Old Jun 11, 2012 | 12:30 PM
  #3488  
Nubo's Avatar
Lubricious
 
Joined: Oct 2003
Posts: 3,425
Likes: 4
From: SF Bay Area, California
Originally Posted by usnidc
So, do the apex seals need more lubrication or less?
They need more volume of lubricating fluid.
why did Mazda increase the omp settings in the S1 and add a third nozzle in the S2's?
because the rate and coverage were inadequate
Why do racing teams pre-mix?
all of the above, also more fluid improves sealing/compression at the risk of increased emissions, and catalytic converter fouling (though of course racers don't worry about that sort of thing).

But, none of this implies what specific viscosity range is best for premix in general driving. It's incorrect to say that MMO does not lubricate. It does contain light oil, and one has to keep in mind that it is additive to the existing omp input. You are trying to float the seals and keep deposits from forming.

I've used MMO as premix in weed-eaters with decent results. And I use it for bicycle chains. It's a fantastic cleaner/lube. Once clean I usually add a small amount of heavier oil, actuate the links and then let the solvents evaporate -- very similar to what I was trying to achieve in the rotary.
Old Jun 11, 2012 | 01:21 PM
  #3489  
YUL PHL's Avatar
Registered
iTrader: (1)
 
Joined: Jan 2009
Posts: 162
Likes: 0
From: Plymouth Meeting, PA
Originally Posted by 40w8
Hey, I'm clumbsy as hell, and I just pour in 6-8 oz. by looking at the clear measuring marks on the side. You're already guessing how much you need, since the gas you need varies.

Anyone can easily do it without over thinking it.
lol yea. thought i was being clever to get it precise but marking a bottle is way easier and less messy
Old Jun 14, 2012 | 01:17 AM
  #3490  
PeteInLongBeach's Avatar
Registered
 
Joined: Nov 2008
Posts: 603
Likes: 2
From: Long Beach, CA
Originally Posted by 40w8
Hey, I'm clumbsy as hell, and I just pour in 6-8 oz. by looking at the clear measuring marks on the side. You're already guessing how much you need, since the gas you need varies.

Anyone can easily do it without over thinking it.
THIS. I can't believe how much unnecessary thought and effort is put into measuring out premix. The Idemitsu bottles have 4 oz graduations on them. I just pour in the amount I want. Takes all of about 10 seconds...
Old Jun 14, 2012 | 07:17 AM
  #3491  
maxchao's Avatar
Registered
iTrader: (2)
 
Joined: Apr 2011
Posts: 211
Likes: 1
From: SF Bay Area
Yea I just buy some Idemitsu and dump it in when I fuel up. Let it be 4 oz 6 oz 8 oz whatever...Since there has never been a scientific proof on the amount to be used I figure I can't be right or wrong anyway. Sometimes I am lazy and I just not use it at all, and following the same reason above it leads to be same conclusion. The worst case is that I have to spend that $4k to replace the motor a few thousands miles earllier..
Old Jun 30, 2012 | 12:33 AM
  #3492  
gorgin92's Avatar
Registered User
 
Joined: Jun 2012
Posts: 1
Likes: 0
New to Rotorys

I have a ? about the oil everyone is saying use royal purple synthetic oil but my manual says DO NOT USE SYNTHETIC OIL What is the deal should i use synthetic or non????

I am driving a 09 sires 2 rx-8 by the way
Old Jun 30, 2012 | 12:58 AM
  #3493  
RX8Soldier's Avatar
Time for boost...
iTrader: (24)
 
Joined: Jun 2010
Posts: 5,414
Likes: 17
From: Canada
Some say yay. Others say nay.
Read the threads, and make up your own mind.
Old Aug 5, 2012 | 07:11 PM
  #3494  
kevinande's Avatar
Day Walker
 
Joined: Oct 2011
Posts: 585
Likes: 18
I have read a lot of this thread, but not all of it. 3500 posts and many of them are not very informative. I have a question that maybe one of you would be so kind to answer or at least just give me the post number(s)

I found a post where someone had put up a photo of a rotor that had been premixed with no OMP and the other was just the OMP and no premix, if I remember correctly, Pretty dramatic difference. At any rate, I was wondering if somewhere in this vast accumulation of posts was there any photos of any rotors that had been premixed with a functioning OMP?

Also while on the subject if someone with pretty in depth knowledge of how these motors operate can help me understand something I am not quite wrapping my mind around. I can see the benefits of premixing, as I understand the process. As it enters through the fuel injectors , it it atomized and contributes to the lubrication of the seals, aiding in maintaining compression and perhaps some cooling effect as well. In the compression cycle, the oil obviously still present is still performing it's intended purpose. Once ignited in the fuel mixture, (my question) is it all burnt off? If so is there any protection of the rotor and seals during the exhaust phase? Or does it matter since during the next rotation it is just going to get re-oiled (lack of a better term). I apologize if this has already been covered, but I was not ble to find it. Again links are welcome I don't mind the read. Thanks in advance for any help
Old Aug 5, 2012 | 08:58 PM
  #3495  
Nubo's Avatar
Lubricious
 
Joined: Oct 2003
Posts: 3,425
Likes: 4
From: SF Bay Area, California
Originally Posted by kevinande
I have read a lot of this thread, but not all of it. 3500 posts and many of them are not very informative. I have a question that maybe one of you would be so kind to answer or at least just give me the post number(s)

I found a post where someone had put up a photo of a rotor that had been premixed with no OMP and the other was just the OMP and no premix, if I remember correctly, Pretty dramatic difference. At any rate, I was wondering if somewhere in this vast accumulation of posts was there any photos of any rotors that had been premixed with a functioning OMP?

Also while on the subject if someone with pretty in depth knowledge of how these motors operate can help me understand something I am not quite wrapping my mind around. I can see the benefits of premixing, as I understand the process. As it enters through the fuel injectors , it it atomized and contributes to the lubrication of the seals, aiding in maintaining compression and perhaps some cooling effect as well. In the compression cycle, the oil obviously still present is still performing it's intended purpose. Once ignited in the fuel mixture, (my question) is it all burnt off? If so is there any protection of the rotor and seals during the exhaust phase? Or does it matter since during the next rotation it is just going to get re-oiled (lack of a better term). I apologize if this has already been covered, but I was not ble to find it. Again links are welcome I don't mind the read. Thanks in advance for any help
What I recall reading somewhere is that as the air/fuel mixture is ignited, the shockwave causes droplets of the oil to condense and coat the surfaces. Ignition consumes the air/fuel mixture but at a small scale next to the metal surfaces, not everything is burned and some of the lubrication survives. Iirc...
Old Aug 6, 2012 | 02:30 PM
  #3496  
Rudolph's Avatar
Registered
 
Joined: Jul 2009
Posts: 227
Likes: 10
From: Utrecht, Netherlands
EU

Originally Posted by Nubo
What I recall reading somewhere is that as the air/fuel mixture is ignited, the shockwave causes droplets of the oil to condense and coat the surfaces. Ignition consumes the air/fuel mixture but at a small scale next to the metal surfaces, not everything is burned and some of the lubrication survives. Iirc...
Indeed.........and with heavy premixing (1:120) plus operating OMP the 2-stroke oil sometimes is partly dissolved/added to the 4-stroke engine oil, even raising the oil level in the carter.
I have that personal experience with my RX-8.
This aspect is also experienced/reported by wankelpilots, premixing 1:85 conform manufacturers specification.
Old Aug 6, 2012 | 09:21 PM
  #3497  
Nekko92's Avatar
Registered User
 
Joined: May 2012
Posts: 16
Likes: 0
Wait you need oil in the gas mixed together?
Old Aug 10, 2012 | 01:47 PM
  #3498  
Nubo's Avatar
Lubricious
 
Joined: Oct 2003
Posts: 3,425
Likes: 4
From: SF Bay Area, California
Originally Posted by Nekko92
Wait you need oil in the gas mixed together?
Old Aug 10, 2012 | 02:08 PM
  #3499  
RX8Soldier's Avatar
Time for boost...
iTrader: (24)
 
Joined: Jun 2010
Posts: 5,414
Likes: 17
From: Canada
Old Aug 10, 2012 | 02:37 PM
  #3500  
xexok's Avatar
Registered
 
Joined: Dec 2009
Posts: 2,100
Likes: 7
From: Aurora, CO
Originally Posted by Nekko92
Wait you need oil in the gas mixed together?
Read the thread or at least some of it. You don't *need* it but many people do like to do it for some extra protection. Also make sure you understand you do not want to premix with engine oil, people are talking about 2 cycle oil. Don't just buy some random 2 cycle and start using it read and make sure you get the right one. I use lucas semi-synthetic 2 cycle but that is the best I can get locally. If you are willing to order some then you can buy premix specifically made for a rotary by idemitsu.

Thread Tools
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 6 votes, 5.00 average.


All times are GMT -5. The time now is 10:14 PM.