Topic: Mixing fuel for target octane?

[slikwilli420]

My fearless cylinder head guru informs me that the 110 light lead I've been running is causing some unwanted buildup of deposits on my valve stems and suggested going down to around 105. 105 octane non oxygenated fuel is out there but I worry about long term supply and having to commit to large quantities to make sure I always have some ready. I do, however have ready access to the 110LL I'm already using and non ethanol 90 octane. I can get to the target 105 octane by mixing them appropriately. The cost of designer fuel isn't the end all but I get 110 locally for under $8 a gallon and jumping to $15-20 is a bit eye watering. Does anyone have any real experience with this?

[Tracksnblades1]

110LL avgas would be similar to 96 octane RON+MON/2 pump gas.

[slikwilli420]

110LL avgas would be similar to 96 octane RON+MON/2 pump gas.

96 octane is too low for my needs and I do not have a ready supply of 100LL avgas (couldnt find anything on 110LL avgas as you mentioned).

[dragracer]

I'm sure you've already checked this out Matt. Looks like 103 octane, very close to what you need. I've used this fuel in a street/strip bike before with good results.  It's not overly expensive and comes in 5 gallon pails and should be readily available anywhere that sells VP fuel.

[Rocketman]

100LL av gas is 100 MON. https://www.faa.gov/newsroom/leaded-aviation-fuel-and-environment Generally RON is higher than MON so it’s (R+M/2) is probably higher than 100. Sorry I don’t know what the RON of 100LL is.

[Don R]

  Our 567" drag car is on VP Q16. It makes me miss the gas sipping 383" we used to have. At close to $20 a gallon for the Q, a barrel of E85 is looking better all the time.

[MRieck]

I'm sure you've already checked this out Matt. Looks like 103 octane, very close to what you need. I've used this fuel in a street/strip bike before with good results.  It's not overly expensive and comes in 5 gallon pails and should be readily available anywhere that sells VP fuel.

VP says a shelf life of 2 years but it actually longer than that if the can is unopened. That fuel would be OK....non ethanol is a big plus too.

[Don R]

 I would do the mix but be careful about the source. I've been using canned gas only since getting bad fuel out of tanks twice in 10 years.
 One stock car shop had accidentally mixed methanol in their race gas tank and a gas station had blended Unocal race gas with pump gas. In the winter I went by, and they were selling kerosene out of the same pump. The unocal cost me a good set of #292 chevy heads, they were prone to cracking but detonation made it happen quick. The methanol just cost me a lot of tuning and a points season.

[dragracer]

I would do the mix but be careful about the source. I've been using canned gas only since getting bad fuel out of tanks twice in 10 years.
 One stock car shop had accidentally mixed methanol in their race gas tank and a gas station had blended Unocal race gas with pump gas. In the winter I went by, and they were selling kerosene out of the same pump. The unocal cost me a good set of #292 chevy heads, they were prone to cracking but detonation made it happen quick. The methanol just cost me a lot of tuning and a points season.

I stopped buying bulk fuel from a pump 20 years ago. You really never know what's going on with the storage procedures. I only buy in 5 gallon pails now so I can at least control my fuel age and quality.  One obvious tip; if you do buy fuel from a pump, do not use clear or even slightly opaque type containers. The least amount of sunlight will degrade the fuel quality.

[bwaller]

I'm not an expert, but will chime in because that's what this forum is for! LOL

In my early talks with VP guys, I determined I should chose fuel, not so much for power, but for fuel consistency that would help prevent detonation. I started with VP's C10 mixed 50/50 with 91 pump gas. Then in teardowns saw that the 500/550 squish shelf really isn't prone to detonation anyway.

I now use V98L in 5 gal cans, just a good clean, reasonably priced fuel for my needs. Again non ethanol. As Mike mentioned these sealed cans are good for at least 2 years, and as everyone agrees purchasing in 5 gal cans is best as you can see the date.

I'm not sure why you feel you need more octane, but my feeling though is the 750 chambers may be more prone to detonating (depending naturally) so a lead component would help. What Frank suggests would work, for me as well, but my local guy always has the 98. Some really fast superbikes here run pump gas with an octane additive, go figure!

We found with Tyler's FZR the one fuel that made power is VP's U4.4 oxygenated. I'm not sure whether it would aggravate detonation, but it's a great fuel. Stinks like hell though!

[MRieck]

I'm not an expert, but will chime in because that's what this forum is for! LOL

In my early talks with VP guys, I determined I should chose fuel, not so much for power, but for fuel consistency that would help prevent detonation. I started with VP's C10 mixed 50/50 with 91 pump gas. Then in teardowns saw that the 500/550 squish shelf really isn't prone to detonation anyway.

I now use V98L in 5 gal cans, just a good clean, reasonably priced fuel for my needs. Again non ethanol. As Mike mentioned these sealed cans are good for at least 2 years, and as everyone agrees purchasing in 5 gal cans is best as you can see the date.

I'm not sure why you feel you need more octane, but my feeling though is the 750 chambers may be more prone to detonating (depending naturally) so a lead component would help. What Frank suggests would work, for me as well, but my local guy always has the 98. Some really fast superbikes here run pump gas with an octane additive, go figure!

We found with Tyler's FZR the one fuel that made power is VP's U4.4 oxygenated. I'm not sure whether it would aggravate detonation, but it's a great fuel. Stinks like hell though!

That FZR400 made big power Brent......more than we were told was possible. It made a lot of people unhappy too. Matt was using 110 octane which isn't necessary as he is 12:1. My thought is he can probably get some extra horsepower out of a lower octane fuel and not have to worry about detonation.
 The 5 gallon pail is the absolute best way to purchase race fuel. It is consistent and it will always be fresh. I have seen guys getting fuel from the 55 gallon drums at Loudon  which isn't the best idea IMO. A lot of the lighter elements in the fuel get released into the air with the venting and hand crank unit. The fuel at the bottom of the barrel isn't the same as what was originally packed in there. Plus if half a barrell was used the vendor comes back with that same barrel 2 or 3 weeks later. Forget about it.
 The VP fuels are very good and using the 5 gallon pail insures consistency and minimal jetting changes for temperature etc.
 As an aside.....I went through Matt's head a few weeks ago and have to say the CycleX Kibblewhite iron guides had virtually no wear....they were perfect which is.....as I always say......a good start.
 Now....the intake seats and guides did move around a bit but that's racing.

[Don R]

 I did buy a couple barrels of VP oxygenated Q16, it took 3 seasons to finish it off and at the end I expected a big change in throttle stop settings although our mph was still consistent. I purposely didn't try to blend fuel when we made the change from the old to fresh gas (like ripping off the bandaid) but it continued to run the same numbers.
    The barrel lived in a heated shop, saw minimal temperature changes and I kept it wrapped in a thick moving blanket. My fuel dealer was charging the same per gallon price for the barrel or the 5's that's when I went to 5's. The fireman next door was having a cow about the barrel too.

[johno]

Hi Matt,
Modern racing is getting to the point we have so many options you need a degree in chemistry to choose a fuel 
Re the price up until 3 years ago I used Sunoco Supreme and getting it here ( OZ) was expensive, costing me $245. for 5 galls pail, since Covid the price has nearly doubled        Wish I was in the states

[Don R]

Hi Matt,
Modern racing is getting to the point we have so many options you need a degree in chemistry to choose a fuel 
Re the price up until 3 years ago I used Sunoco Supreme and getting it here ( OZ) was expensive, costing me $245. for 5 galls pail, since Covid the price has nearly doubled        Wish I was in the states

Yeow! I was whining about $85 a can for Q16.

[NitroHunter]

Here on the West Coast I used to run ERC 110 in my hot rod bikes, there was a sprint car guy with an old gas station / parts shop where me and my pals could just ride up to the pump Friday evening and empty our wallets. Lots of real street muscle pulled up there. Cost us a whopping $3.85 a gallon but it sure ran good, didn't leave that grey-ish film inside the combustion chamber and plugs like the VP I'd tried, don't remember what which one it was. I met with the ERC owner some time later when I had the turbo bike on display at a large car show, he got interested, and had me test a batch of ERC118 so I could crank up the boost to stupid levels. He most strongly advised against trying to mix a (cost saving) concoction for our high compression street bikes, basically we'd be messing up their formulation and it could produce some unanticipated negative results. 

With the prices of current race gasolines, that CH3NO2 we burn in my pal's bike is starting to sound cheaper now.   

Some FYI about nitro. It's all imported from China and heavily regulated by Homeland Security, for NHRA Big Show use is sold in 42 gallon drums by the 'Official Supplier'. It is REQUIRED for us to use in our TF dragster. The last drum we bought 2 years ago was $1450. That's enough for 2 runs and a short warmup. One time one of the NHRA mega teams (DSR) was fined $100,000 for having another manufacturer's brand in 55 gallon drums in the pits!
For use outside of those regulated events, there are other sellers of 99.9% pure nitro at greatly reduced prices. The drum pictured was 55 gallons and cost $900 at the time, of course we expect that could double. It's what we run in the Heritage Series Nostalgia nitro funnycars that you see at the March Meet and Hot Rod Reunion events (limited to 21gpm fuel pumps) and others.
It burns just like the other stuff... 

[Don R]

 I remember Schumacher was seriously PO'ed. He said he was using it for testing and not competition. He then imported some of the brand X fuel for racers that could use it, just for payback. 

[Tracksnblades1]

110LL avgas would be similar to 96 octane RON+MON/2 pump gas.

96 octane is too low for my needs and I do not have a ready supply of 100LL avgas (couldnt find anything on 110LL avgas as you mentioned).

The best thing about AVGAS is formulation. It’s always pretty much the same regardless what part of the US your in..
Performance fuel peddlers will tell you a lot of stories about pitting pistons, valve burning, and slow burning flame fronts, etc. not exactly what I believe the FFA would want happening in our piston engined planes...but plane engines don’t see prolonged rpms over 3500..
I ran 110ll in sbcs with consistent results with high compressions without any adverse conditions. Total lead was 43 though back in those cylinder heads days...
Now we have a somewhat local VP station we purchase 100 real gasoline for our two stroke Honda CRs. Jetted accordingly

I think VP will provide you with the specification and btu content of any of their fuels..

As Old Smokey Yunick used to say, “Run as much compression as you can” “because someone else will and you’ll lose”…

Merry Christmas and the best to you in 22

[grcamna2]

subscribed 

[bear]

My contribution to this thread will be of no use to any of you.
Every thing I've raced since the early eighties ran on methanol.
Smells great, makes your eye's water on the dummy grid, gives you a splitting headache and I suspect I will be diagnosed with alzhiemers shortly.
BUT if you want an engine with real compression it's "the ducks guts"

[Ramrod_Racing]

My contribution to this thread will be of no use to any of you.
Every thing I've raced since the early eighties ran on methanol.
Smells great, makes your eye's water on the dummy grid, gives you a splitting headache and I suspect I will be diagnosed with alzhiemers shortly.
BUT if you want an engine with real compression it's "the ducks guts"

Yeah we're limited to "gasoline only" w/ a 115 octane max. Not sure if that's a good or a bad thing.