New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

premix question

Thread Tools
 
Search this Thread
 
Old Feb 4, 2013 | 08:47 AM
  #51  
RogueFab's Avatar
Full Member
iTrader: (2)
 
Joined: Feb 2013
Posts: 158
Likes: 0
From: Pacific Northwest
Talking

Originally Posted by fbse7en
Ummm, How does 1oz of premix to 1gal of gas = 100:1?!?!?! 1gal = 128oz, you are NOT mixing 100:1. 200:1 for racing?!?! Sooo...you premix LESS when putting MORE strain on your engine....hmmmm....don't make any sense. Rotary Tech Tips: Oil Filters & Metering Oil Pump

Also hows the R50 treatin' ya? I was using Blendzall Racing Castor (only cost $40 for 1gal)...bad idea, now my apex seals are stuck solid w/castor gum/varnish/carbon...
Don't forget, the ECU puts in a controlled volume of fuel (and oil if you premix) with each injector pulse. With an O2 sensor feedback loop this is less of a problem, but more oil in your gas = lass gas in the combusinon chamber. All else equal, this will make you run lean with more oil in your gas. With a good tune and feedback system working, it sould rebalance with the higher oil content and give you the same stoichiometry, i.e. the same quantity of fuel as your other mix ratio. But your gas is still a higher dilution, and that may make your car run different still.

I would recommend checking your AFRs and EGTs on a dyno if you are going to mess with it at all. Taking a system designed by a TEAM of engineers and trashing it without having any sort of professional assist you with adjustments sounds like a gambler's move to me.

What affect will having your engine run with oil in the fuel for the entire compression cycle have? Will it burn with the same flame progression? Are combustion chamber pressures going to be maintained? I know the pressures are hosed when you start cranking up the boost (and I will on my car), but the farther you depart from stock with your input pressures and running conditions, the more risk you take unless you have a way to mitigate it with the help of someone with experience (which isn't me, I'm just playing devil's advocate!).

Reply
Old Feb 4, 2013 | 03:29 PM
  #52  
my89turboII's Avatar
Full Member
 
Joined: Dec 2012
Posts: 70
Likes: 0
From: Utah
Originally Posted by fbse7en
Ummm, How does 1oz of premix to 1gal of gas = 100:1?!?!?! 1gal = 128oz, you are NOT mixing 100:1. 200:1 for racing?!?! Sooo...you premix LESS when putting MORE strain on your engine....hmmmm....don't make any sense. Rotary Tech Tips: Oil Filters & Metering Oil Pump

Also hows the R50 treatin' ya? I was using Blendzall Racing Castor (only cost $40 for 1gal)...bad idea, now my apex seals are stuck solid w/castor gum/varnish/carbon...
If you read it I said 100:1 daily driving or 8oz a full tank. The 100:1 ratio is if you don't fill it up. And obviously when I'm racing my 200:1 ratio I'm not filling my tank full

Also klotz r50 is great but smokes a lot. I use that more for racing and maxima for daily made to mot smoke
Reply
Old Feb 4, 2013 | 07:32 PM
  #53  
fbse7en's Avatar
Senior Member
Tenured Member 15 Years
 
Joined: Apr 2007
Posts: 308
Likes: 4
From: WA state
Originally Posted by RogueFab
Don't forget, the ECU puts in a controlled volume of fuel (and oil if you premix) with each injector pulse. With an O2 sensor feedback loop this is less of a problem, but more oil in your gas = lass gas in the combusinon chamber. All else equal, this will make you run lean with more oil in your gas. With a good tune and feedback system working, it sould rebalance with the higher oil content and give you the same stoichiometry, i.e. the same quantity of fuel as your other mix ratio. But your gas is still a higher dilution, and that may make your car run different still.

I would recommend checking your AFRs and EGTs on a dyno if you are going to mess with it at all. Taking a system designed by a TEAM of engineers and trashing it without having any sort of professional assist you with adjustments sounds like a gambler's move to me.

What affect will having your engine run with oil in the fuel for the entire compression cycle have? Will it burn with the same flame progression? Are combustion chamber pressures going to be maintained? I know the pressures are hosed when you start cranking up the boost (and I will on my car), but the farther you depart from stock with your input pressures and running conditions, the more risk you take unless you have a way to mitigate it with the help of someone with experience (which isn't me, I'm just playing devil's advocate!).

I'm curious as to WHY you quoted my post...I never once "trashed" the OMP (it functions fine, and I won't be deleting it either), also I can't "crank-up the boost" on my NA, also I CAN'T check AFR + EGT with a NON-running engine- due apex seals that are STUCK in rotors because of CASTOR oil gum/varnish (NOT casTROL, tho it got its original name from castor oil, lol) therefore causing a lack of compression to get it started in the first place! I was asking about the R50 cuz I know it also contains castor oil.
Reply
Old Feb 4, 2013 | 07:48 PM
  #54  
fbse7en's Avatar
Senior Member
Tenured Member 15 Years
 
Joined: Apr 2007
Posts: 308
Likes: 4
From: WA state
Originally Posted by my89turboII
If you read it I said 100:1 daily driving or 8oz a full tank. The 100:1 ratio is if you don't fill it up. And obviously when I'm racing my 200:1 ratio I'm not filling my tank full
UMMMM, HOW?! Stay w/me here, a FULL tank in a FC is 16.2 gallons which = 2,073.6 oz of gas. So, if u only put in 8oz when u fill up you are actually mixing 259.2:1 (which = 1oz of premix for every 2.025 gallons!) So, again neither of your statements are accurate.

Here's the break down:
1 gallon (128oz)
128oz x 16.2 gal (Full FC tank) = 2,073.6oz divided by 8oz (the amount u say u add, when u fill up) = 259.2oz (2.025gal) = a ratio of 259.2:1!!! NOT the ratio you claim.

Glad to hear the R50 is workn out for you, but next time you change plugs I'd recommend u take a peak inside w/a mirror or bore-scope like/type device. And this:
http://www.rotaryresurrection.com/2n...injection.html
I did that^ once, should've done it every couple months I think...
Reply
Old Feb 5, 2013 | 10:07 AM
  #55  
RogueFab's Avatar
Full Member
iTrader: (2)
 
Joined: Feb 2013
Posts: 158
Likes: 0
From: Pacific Northwest
Originally Posted by fbse7en
I'm curious as to WHY you quoted my post...I never once "trashed" the OMP (it functions fine, and I won't be deleting it either), also I can't "crank-up the boost" on my NA, also I CAN'T check AFR + EGT with a NON-running engine- due apex seals that are STUCK in rotors because of CASTOR oil gum/varnish (NOT casTROL, tho it got its original name from castor oil, lol) therefore causing a lack of compression to get it started in the first place! I was asking about the R50 cuz I know it also contains castor oil.
I don't know why I quoted you now... I will edit that out of the post. I was going to talk about ratios and the effect on fuel an running lean with oil displacing the fuel... and agree that you called BS on some ratio BS... but then I mentioned the whole "trashing" thing and the post kinda went a little "ranty".

Sorry. My mistake. Good luck with your car.

EDIT: Can't edit posts after a certain amount of time. Oh well. I guess the apology will have to suffice. Cheers.

Last edited by RogueFab; Feb 5, 2013 at 10:09 AM.
Reply
Old Feb 5, 2013 | 11:18 AM
  #56  
livevil904's Avatar
Full Member
 
Joined: Aug 2011
Posts: 67
Likes: 0
From: Oregon
Originally Posted by my89turboII
If you read it I said 100:1 daily driving or 8oz a full tank. The 100:1 ratio is if you don't fill it up. And obviously when I'm racing my 200:1 ratio I'm not filling my tank full

Also klotz r50 is great but smokes a lot. I use that more for racing and maxima for daily made to mot smoke
Yah, this doesn't make sense.

Funny thing about ratio's... it doesnt matter how much. 200:1 is 200:1. It doesn't matter how much fuel you have in the tank.

It's amazing how many people tell me every day that math is useless and they're never going to use it (I work at a math help desk at my college). I'll have to remember this to tell the car people when they try to say that.

fbse7en has it right.


I personally just put in a few oz (2-4) at fill up (with a working OMP).

Last edited by livevil904; Feb 5, 2013 at 11:22 AM.
Reply
Old Feb 5, 2013 | 12:08 PM
  #57  
Sgtblue's Avatar
Urban Combat Vet
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (16)
 
Joined: Oct 2003
Posts: 12,159
Likes: 982
From: Mid-west
Originally Posted by fbse7en
... And this:
Rotary Resurrection home of the budget rebuild.
I did that^ once, should've done it every couple months I think...
For those who aren't N/A, a simple boost-activated AI system makes water injestion is redundant. Carbon shouldn't be an issue no matter what rate you pre-mix, with or without an OMP. It also carries way less danger IMO than injestion, and has other benefits of cooling and knock control.
Reply
Old Feb 5, 2013 | 01:55 PM
  #58  
my89turboII's Avatar
Full Member
 
Joined: Dec 2012
Posts: 70
Likes: 0
From: Utah
Originally Posted by fbse7en
UMMMM, HOW?! Stay w/me here, a FULL tank in a FC is 16.2 gallons which = 2,073.6 oz of gas. So, if u only put in 8oz when u fill up you are actually mixing 259.2:1 (which = 1oz of premix for every 2.025 gallons!) So, again neither of your statements are accurate.

Here's the break down:
1 gallon (128oz)
128oz x 16.2 gal (Full FC tank) = 2,073.6oz divided by 8oz (the amount u say u add, when u fill up) = 259.2oz (2.025gal) = a ratio of 259.2:1!!! NOT the ratio you claim.

Glad to hear the R50 is workn out for you, but next time you change plugs I'd recommend u take a peak inside w/a mirror or bore-scope like/type device. And this:
http://www.rotaryresurrection.com/2n...injection.html
I did that^ once, should've done it every couple months I think...
Im just going.off what I was told 1oz per gallon or 8oz for a full tank. Never had a.problem with it plus all the research says the same. And if I am correct I have a 18.5 gal tank. Not trying to argue just saying
Reply
Old Feb 6, 2013 | 01:14 AM
  #59  
fbse7en's Avatar
Senior Member
Tenured Member 15 Years
 
Joined: Apr 2007
Posts: 308
Likes: 4
From: WA state
Originally Posted by RogueFab
I don't know why I quoted you now... I will edit that out of the post. I was going to talk about ratios and the effect on fuel an running lean with oil displacing the fuel... and agree that you called BS on some ratio BS... but then I mentioned the whole "trashing" thing and the post kinda went a little "ranty".

Sorry. My mistake. Good luck with your car.

EDIT: Can't edit posts after a certain amount of time. Oh well. I guess the apology will have to suffice. Cheers.
Hey, man its cool
Reply
Old Feb 6, 2013 | 10:11 AM
  #60  
RogueFab's Avatar
Full Member
iTrader: (2)
 
Joined: Feb 2013
Posts: 158
Likes: 0
From: Pacific Northwest
Originally Posted by my89turboII
Im just going.off what I was told 1oz per gallon or 8oz for a full tank. Never had a.problem with it plus all the research says the same. And if I am correct I have a 18.5 gal tank. Not trying to argue just saying
This is a huge variation. FDs have a 16 gallon tank, I'm not sure on other 7s. Unless your car has an 8 gallon tank, 8oz per tank won't match 1oz per gallon.

Pick one. Run 1oz per gallon (what everyone else runs) or run 1/2oz per gallon (your 8oz per tank). Switching between the two is not a good idea, you won't even learn anything if you harm your engine (like learning that your mix ratio was bad). Can't have a test without control
Reply
Old Feb 7, 2013 | 08:00 PM
  #61  
kidS4's Avatar
Thread Starter
Full Member
 
Joined: May 2012
Posts: 153
Likes: 0
From: douglasville ga
didnt know this would spark so much debate
Reply
Old Feb 8, 2013 | 12:01 PM
  #62  
RogueFab's Avatar
Full Member
iTrader: (2)
 
Joined: Feb 2013
Posts: 158
Likes: 0
From: Pacific Northwest
Originally Posted by kidS4
didnt know this would spark so much debate
Yeah I guess the debate departed from your original question too... Oops.
Reply
Old Feb 8, 2013 | 03:35 PM
  #63  
davexd's Avatar
Junior Member
 
Joined: Apr 2011
Posts: 5
Likes: 0
From: South Bay
been curious about doing premix with my s4 this has been helpful
Reply
Old Feb 12, 2013 | 06:22 PM
  #64  
fbse7en's Avatar
Senior Member
Tenured Member 15 Years
 
Joined: Apr 2007
Posts: 308
Likes: 4
From: WA state
Originally Posted by RogueFab
Pick one. Run 1oz per gallon (what everyone else runs) or run 1/2oz per gallon (your 8oz per tank). Switching between the two is not a good idea, you won't even learn anything if you harm your engine (like learning that your mix ratio was bad). Can't have a test without control
Yeup, and obviously 1oz per 1gal would be: 128:1
**Might also notice that RB uses as much as 22oz of premix oil for EVERY 5gal of fuel in its turbo rotaries! (hi-output, track-use) thats: 29.09:1!
Reply
Old Feb 20, 2013 | 12:18 PM
  #65  
RogueFab's Avatar
Full Member
iTrader: (2)
 
Joined: Feb 2013
Posts: 158
Likes: 0
From: Pacific Northwest
Fuel tank size came up in this thread... I don't know why it is wrong in some other threads. Us FD capacity is 20 GAL. Not 16/18. Just wanted to prevent the spread of misinformation.
Reply
Old Feb 24, 2013 | 03:56 AM
  #66  
Tj_saxon's Avatar
Junior Member
 
Joined: Feb 2013
Posts: 7
Likes: 0
From: Georgia
Just curious is this why RX7s smoke? Doesn't burning oil cause smoke. Sorry brand new to the rotor scene. None of my car friends like RX7s and I am just now finally really getting into it. All the RX7s I have actually scene in person smoked and when I asked why everyone always answered "Because they are about to blow up" and I figured this might be true due to the fact that the motors need to be rebuilt often. But this thread has me wondering if the cars were smoking due to just burning oil.
Reply
Old Feb 24, 2013 | 05:28 AM
  #67  
Sgtblue's Avatar
Urban Combat Vet
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (16)
 
Joined: Oct 2003
Posts: 12,159
Likes: 982
From: Mid-west
^We can only speculate as to why the RX7s you've seen smoked. My educated guess is because they were all 20+ years old, with abused high-mileage engines and young drivers.
A properly running rotary engine does not noticibly smoke at idle. Maybe just a hint at hard throttle...maybe.
Oil control rings will get worn, just like rings or valve guides in a piston engine. On turbocharged models, old worn turbos, (a consumable) will also cause smoking.
FWIW, there's an 4 or 5 yr old RSX in my neighborhood that's smokes. It's the only one around. Why do the Acuras always smoke?
Reply
Old Feb 24, 2013 | 11:59 AM
  #68  
Tj_saxon's Avatar
Junior Member
 
Joined: Feb 2013
Posts: 7
Likes: 0
From: Georgia
Originally Posted by Sgtblue
^We can only speculate as to why the RX7s you've seen smoked. My educated guess is because they were all 20+ years old, with abused high-mileage engines and young drivers.
A properly running rotary engine does not noticibly smoke at idle. Maybe just a hint at hard throttle...maybe.
Oil control rings will get worn, just like rings or valve guides in a piston engine. On turbocharged models, old worn turbos, (a consumable) will also cause smoking.
FWIW, there's an 4 or 5 yr old RSX in my neighborhood that's smokes. It's the only one around. Why do the Acuras always smoke?
Thanks =D they usually smoked when they would go from a dead stop or when the driver ( all were young) would randomly floor it. Also that is a good statement/question.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
stickmantijuana
20B Forum
21
Mar 22, 2022 01:00 PM
_Tones_
Adaptronic Engine Mgmt - AUS
10
May 25, 2021 05:37 AM
stickmantijuana
3rd Generation Specific (1993-2002)
13
Jan 9, 2018 11:19 AM
Frox
New Member RX-7 Technical
72
Oct 22, 2015 04:54 PM




All times are GMT -5. The time now is 12:24 AM.