Effects of high octane fuel

Man I wish I had 93 out in Cali. Hell if I can get away with burning some higher octane through the carbs, might have to pour a liter or two of some 110 I usually have a drum of C-16 and 110 on hand for dyno tuning. Anyone know how E85 would react? I know on some of the cars my shop does, we have to swap out a few rubber fuel lines for the ones that have the green writing on it. Wonder how the diaphragms would react?


ed

I like the smell of Turbo Blue Racing Fuel in the Morning

It Smells Like Victory :evil:

I_Tig_in_piece wrote: Man I wish I had 93 out in Cali. Hell if I can get away with burning some higher octane through the carbs, might have to pour a liter or two of some 110 I usually have a drum of C-16 and 110 on hand for dyno tuning. Anyone know how E85 would react? I know on some of the cars my shop does, we have to swap out a few rubber fuel lines for the ones that have the green writing on it. Wonder how the diaphragms would react?


ed

Definitely do not put e85 in it without rejetting.

Rubber compatibility is an issue too, and it doesn't keep well. Alcohol likes to absorb water, hence all the issues these days with letting bikes sit with e10 and ending up with carbs full of jelly.

E85 is ~85% alcohol. The octane is higher, but alcohol is a completely different fuel and you will need much larger jets. And get worse fuel mileage, if you are worried about that type of thing.

I think e85 is approximately 110 octane. But I could be off there. It is pretty detonation resistant.

I believe putting E85 in a KZ would be a very bad idea. Not only would it destroy rubber bits because they were not formulated to handle alcohol, it also would lower the engine's performance. This is because E85 has 33% less energy content than 100% gasoline and 30% less than the E10 gasohol blend that is sold by almost all retailers in the US.

My 2006 GMC Z71 truck has a "flex-fuel" engine than can use E85 without damage, but since E85 is nowhere to be found in MD I have never tried it. Other than just as an experiment, I wouldn't use it in my truck anyway because it has 30% less energy content per gallon than the fuel sold here but nation-wide is only 15% less expensive than gasoline. Consequently, each mile driven would cost more and the truck wouldn't have as much pep as it does with gasoline. Ed

I finally found a station that sells 91 oct pure gas too (maybe 50 cents more a gal) that I've used a few times ....... son was going to school there for a while so it worked out but now that its a 45 mile trip I stopped....... knew a few guys (in the 80s) that were big into racing that talked me into advancing the timing 2 to 4 degree's and ran that for a while...... magazine article too suggested 2 degree's advance on the 650 ..... I'm back to stock now (and for a long time) as I saw very little if any performance gain...... always ran prem then..... thinking it was 94-95 back then?

650ed wrote:

pete greek1 wrote: I'm just saying that in the 70s regular leaded gas was 90 octane, & premium gas was 98-100 octane, so I'm saying our older bikes were built to run on higher octane than 87
Pete

Even though many folks run 87 octane just fine, I tend to agree with you on this. I don't even think 87 octane was even available when my bike was made. Probably the lowest octane in my area back then was 91. I know for sure you could still get 95 and 100 octane in my area. When I bought my KZ650 (April, 1977) the dealer told me to use premium gas. 93 octane is considered premium now; back then it would have been mid-grade at best.

I've read that some folks mention that their manuals call for 87 octane. I would really be interested to know exactly which manuals for which year and model bikes state that. My Owner's Manual does not name a specific octane level. It simply says you should use unleaded gasoline. Ed

I agree with everyone on this topic, I just want to say this ......from a "Seat of the pants feeling"....when I put Racing gas 110 octane mixed half and half with 92 oct. Ethanol free gas ( believe it or not my local Farmers Co-Op sells both!) in my 75 Z1B 900...It DEFINITELY RUNS BETTER!! Theres no doubt! The actual reason?? I could care less. But it does run better.
Regards to all
Ed

If you rebuild the motor for really high compression, convert the carbs to stainless steel, and replace all the rubber, you could probably get more performance using E85. That is what my street racer buddies do. Turbo'd E85 usually spanks the equivalent vehicle running gas. Less energy content just means you need to use more, or use it more efficiently, ie run higher compression. The real benefit is the high compression that E85 allows. Flex fuel cars are not usually built to take advantage of E85, so they really don't do any better performance with E85.

But it's a lot of work to make a 35 year old bike go faster. It would be way easier to just get a 30 year old bike instead.

Ed, My owner’s manual for my 75 Z1B stated to use regular fuel. As I member, the 74 Z1A I had when it was new also stated to use Regular fuel. But it also stated the fuel could be leaded or unleaded. As I member I liked Standard and Mobil regular gas but had to go up in octane with some of the other supposedly top tier gas stations...back in the day. One of these days real soon as I get ready for winter storage, I’m going to get some pure 92 octane gas and try it out to see if it runs better on that. Typically I’m using todays Conoco regular without problems .

It would be way easier to just get a 30 year old bike instead

So true.....my 09 Concours 14 runs better than any street legal ZED ever thought of. It will do triple digits in 2nd and I still have 4 gears to go. :whistle:
Tim

Z1Driver wrote: Ed, My owner’s manual for my 75 Z1B stated to use regular fuel.Tim

Wasn't regular gas about 92 - 94 octane back in 1974? I remember around 1970 that premium was in the 98 - 102 octne range.

Clean air act of 1970 killed the hopes of high performance and high oct after that..... 74-75 is when they really started to faze it out....... glad they were able to bring back the super cars in the last 10 years but now I'm too broke.

Unless youre running a lot more compression than stock Id say all youre doing is loading up your combustion chambers with carbon.

bountyhunter wrote:

Z1Driver wrote: Ed, My owner’s manual for my 75 Z1B stated to use regular fuel.Tim

Wasn't regular gas about 92 - 94 octane back in 1974? I remember around 1970 that premium was in the 98 - 102 octne range.

I think if I remember right which is getting harder to do BTW, I believe the formula for figuring the octane rating changed some place around there. I remember my Grand Father liked this off brand stuff which boasted having regular at 93 octane. It was great for use in his 53 Chev pickup but as I member wasn’t good enough for anything with a little compression. Other gas stations were not advertising that much octane for regular gas.

It is also my observation that vehicles made to run on Regular leaded gas 50 years ago do just fine on today’s regular fuels if the valve seats are replaced with hardened valve seats.