Just FYI:

I did a quick check and Slick 50 stopped using molybendum some time ago and now uses PTFE (Teflon). Apparently it was crap when back in the day and is crap now. Even lost some lawsuits concerning their claims. Anyway, if anyone was interested...

Back to the topic at hand.

dude --my dad was a diesel mechanic and i "breathed" the bad air and played beside the dirty roads since 1949. So did a lot of my friends. We breathed in nitro methane, alcohol, kerosene and coal stoves and all the other crap that everyone said would kill you ,make you retarded and destroy the world.
I am not advocating the return of leaded gas. i have been and continue to be in the health care profession x 31 yrs and i understand risk vs benefits.
I also can say with certainty "dont believe a damn thing big business tells you"

All my question was --"is leaded gas better than premix?" Does it work better? I think it is worth discussing. Perhaps some gain may occur.
I can see where leaded gas can be possibly better. Check out the Av gs airplanes use and some of them are using our engine.
olddragger

Yeah, that is cool. As for your good health, congrats. I hope I am as lucky.

As for the question at hand, there are nuances that are interesting to debate, particularly once the specific hypotheses are stated; however, I have doubts on the assumptions underlying the discussion. To wit, pre-mix provides a significant benefit in lubrication to the combustion chamber surfaces within a RENESIS with a properly functioning oil delivery system. Futhermore, I take greater issue with the concept that leaded gas provides any lubrication, period. I dont take much issue with anyone running leaded race gas at the track, if that is what they want to do and they tuned thier engine to that level of octane. If you are running a 16:1 compression or more on a race specific engine, more power to you. I just dont see ANY objective measure that suggests leaded gas would provide any significant benefit to your car. In fact, to the contrary, the downside risks could involve significant teratogenic, embrogenic and developmental defects. Us old dudes could take a significantly higher dose with no ill effects, but some kid could end up way dumberer than they should have.

I just dont see the need. Respectfully

me

maybe you ARE retarded ... who knows .... :rolleyes:

JUST KIDDING ! :evil_laug

The best thing about lead is that its super cheap. I guess.

Denny,
I need to chime in.
I found lead to add to unleaded, it doesn't seem to raise vacuum the way the CD2 stuff does.
It does raise the octane a good bit though....
It stinks more too.

PS: I found some 40% nitromethane RC car methanol fuel......
"White Lightning Competition Fuel"

Let's throw this into the mix:
I seem to remember some older rotary cars were marked "Leaded Fuel Only" on the gas tank cover.

Was there anything else at the time (other than white gas)? Also, those were the days that the apex seals didn't last long.

Just FYI from a 1973 RX3 Owner's Manual I have and my 1972 R100 says the same. Also remember that when it says Premium or Super grade gasoline, it also refers to Leaded Fuel. There was no unleaded gas sold back in the early 70's at your local gas station. Carbureted rotary engines run better with low octane gas. Some people do actually use MOGAS on carbureted rotary race engines. That is why it calls for not to use Premium or Super gasoline. However, the Renesis and specifically a FI (Force Induction) engine do require and benefits from high-octane fuel.

Do u still have the Rx3 ?

interesting read indeed.

nycgps brings up the heart of the matter - that tetra-ethyl-lead is cheaper than dirt.

Well not exactly cheap, it's an expensive chemical, but it's WAAAY cheaper than the alternatives.

If I can refer you to an old thread on gasoline composition
https://www.rx8club.com/series-i-tech-garage-22/octane-booster-info-questions-6479/
it explains the basics, in particular two ways to make motor gas;

a - you can collect the liquids that condense out of natural gas pipelines (condensate) with an octane rating in the '60' range, and put two grams of TEL in it to bring the octane up to the 80's. A cheapandnasty way to make crappy gas.

b - without lead, MMT or ethanol, you have to pass the crappy raw gasoline over a platinum catalyst at high temperature (500*C) to make better molecules. This stuff comes out at 100+ octane, and then mix it down to 87/91/93, whatever you need. A really expensive way to make (good) gas.

In answer to the 'wankel powered planes use high lead fuel' issue - they do, but they don't expect their plugs to go two years between replacements. They also, almost universally use two-stroke oil, either pre-mixed or through Mr. Sohn's legendary adapter (that is what it was designed for), so the fuel could just as easily be lead-free, it's not an issue.

The answer, for me to the original question - "Is leaded gas better than premix?"
becomes a matter of comparing apples to orangutans.....

S

Just because people aren't dying of lead poisoning doesn't mean they aren't suffering serious long term neurological damage from it's ingestion. :icon_no2:

does lead taste good ?

Like a Big-Mac.

No, I don't.

I own a 1972 Mazda R100 with a Bridge Port 13B and a 2004 RX8 GT (Pettit SC).

I used to own a 1974 RX4 Station Wagon, 1984 RX7 GSLSE and 1988 RX7 GTU. :eyetwitch

Just added 10 ounces of Octane Supreme 130 (real lead additive) to about 7 gallons of crappy Florida 10% ethanol premium gas. Took the car for an hour drive including a test drive on the interstate. The ambient temperature was 85 degrees and AC on. All I got to say is “Holy Shiite Batman” WOW what a difference in power. Forget about butt dyno…I can really feel the difference. BTW, I don’t run a cat, the methanol does clean the plugs on the go and the A/F ratio stayed the same. See my garage to check my cars mods https://www.rx8club.com/vbgarage.php?do=view&id=36311. :eyetwitch

Garage is no longer an option in the user profile.

Got it, thanks. :eyetwitch

I put in a bottle of the Lead Substitute I got from Autozone (grey bottle). It didn't have the tetra ethyl lead in it but I had very similar results as marsredr100. I will say this though, the ambient temps around the Atlanta area were 10 degrees cooler than they have been in recent weeks so that could be one reason for the extra power, but my car just felt like it ran smoother for some reason.

Take it with a grain of salt but that is what I noticed and it very possibly could all be placebo as I do not have any dyno's to prove its worth.

Hmm, you guys should get some dyno results with the gas changes. I'm definitely interested if there's a performance gain!

carbon rx8 we are cool--i have a different opinion in that lead does have some lubrication component to it. Of course some other "good " things are included.
I didnt realize you were such a sesquipedalian (that is a compliment everyone).
nycaps--i am selectively retarded or psychotic such as the situation calls for:)
Good discussion all
and Stealth glad you are here and I have NEVER had a set of plugs to last me 2 yrs!!:) anyway.

I do have some reservations as to how good pre mix actually lubricates at the ratios we normally use--anything under 1/2 oz per gallon is not doing anything--I think--- based on some engine teardowns i have seen. Cant be certain but it is definitely under my microscope. But if you premix at the concentration required to have a proven effect 1oz per gallon--it WILL lower the octane of your gas.
Hey Juan--glad you have your controller back dude--see my idler pulley idea!
Please also notice how your gas mileage will increase with the good stuff!
With the high octane --watch your temps and spray her good.
lets keep the discussion going. Leaded on the track will happen for me even at 7 bucks a gallon:(
olddragger

this sunday, Im gonna go to this free track day thing.

b4 I go Im gonna premix it heavily, like maybe 1 oz per gallon ? with 93 gas of course

see what happens.

Off of Racing Beats website

RX-8 - Race Tips

While undertaking development work on the RX-8 Renesis engine for SCCA T2/T3 use, we decided to introduce extra oil into the fuel to monitor the effect. To our surprise, this additional oil increased power! Further dyno testing found that by adding 10 oz. of Royal Purple 2-Stroke Oil to 6 gallons of fuel, we gained an average of 1.7 HP from 2000-9000 RPM, along with an increase in peak power of 4 HP. We validated this increase by changing back to a “non-oiled” fuel - and the power returned to the previous level. Later, we tried the same test with another brand of synthetic oil with nearly the same results.

For racing applications, the addition of a high quality synthetic oil increases power and most certainly decreases wear. The only negatives are the cost of the oil and an increase in the tendency to foul the spark plugs. (Note: We have not performed these tests on non-RX-8 engines yet, these results are unknown.)

It'll clog your cat if your running one.

I've been running premix for a long time.

stock cat dies even without premix. I have warranty till 80K miles.

I understand that, but I'm sure you haven't been running 1oz per gallon all the time either. But whatever...