chaparral wrote:
One thing alcohol can do is substantially reduce the required intercooler size for a given power output. It absorbs a lot of energy on evaporation, and it's resistant to detonation. The methanol-burning 1050 hp ChampCars weren't intercooled.
1050 horsepower from something like 220 cu.in.. in an engine designed in the 1930's. Since all Indy cars of the turbo era were checked for the presence of nitro etc.. that power was based solely on what alcohol alone could make..
Can you imagine the sort of power that little motor would make if Nitro was allowed?
Buy one and find out! I understand that the real advantage to the Miller/Offenhauser engine was that it had a one piece block. No main caps. The crank was endloaded.
I don't remember if the four cylinder engines also had one piece cylinder/head setups or if that was only the older engines, but if they did... No main caps, no cylinder head gasket, boost it to the moon.
'Course, you can also make that much power from a stock block/heads Buick 231, briefly, if you start with a '109 casting. That's about the limits. The Stage II blocks, like what Buick used at Indy, can tolerate a lot more than 1000hp They never get scrapped, as even a stitched together Stage II with sleeves is stronger than anything else.
When I stopped paying attention to rotary drag racing, they were eliminating the intercoolers and relying on methanol injection. Supposedly, even without intercooling and with the heat of 45psi+ of boost, there'd be frost on the intake manifold.
In reply to frenchyd:
The Offy turbo fours were making that sort of power with unregulated boost, and so did the 1999-2000 Cosworth/Honda/Toyota/Ilmor engines on only 45 inHg manifold pressure (7 psi boost)!
That wasn't 220 CID, either. Turbo engines went down to 161 CID in 1968 and stayed that way until 2008.
chaparral wrote:
In reply to frenchyd:
The Offy turbo fours were making that sort of power with unregulated boost, and so did the 1999-2000 Cosworth/Honda/Toyota/Ilmor engines on only 45 inHg manifold pressure (7 psi boost)!
That wasn't 220 CID, either. Turbo engines went down to 161 CID in 1968 and stayed that way until 2008.
I bow to your superior memory. I only remember rebuilding a 270 cu.in. Offenhauser after a full season of sprint car racing and remarking how clean the combustion chamber was in spite of using a lot of oil towards the end of the 1958 season..
Ian F wrote:
Knurled wrote:
Kudzu is supposed to be a good feedstock for ethanol, and I heard it doesn't need much special to grow well.
Damn... then Atlanta could be the ethanol capitol of the world. I remember massive lots of the stuff when I lived there over 30 years ago. I doubt things have improved. Hell, there are a couple of areas near me in SE PA that will be covered with kudzu in a few months.
You do realize that a couple of decades ago Brazil stopped importing crude oil and switched to ethanol.. In doing so they were able to pay off a huge national debt and start prosperity.
alfadriver wrote:
In reply to Durty:
For corn, it's still under debate.
For cane, like Brazil, the math does work, other than cutting down the rail forests.
The hard part for the US is that corn gets subsidies, but other choices, which may be better, don't. So we may never know about southern grown cane, or northern grown sugar beets.
It's far more complex than they cut down the forests in Brazil to grow cane. It's a combination of massive crowding in urban centers like Rio and San Paulo, discovery of gold, the high valve of rainforest wood, grass land for beef production, and crop land for items like cane and other exportable crops..
Do I wish the rain forests could remain virgin? Sure but for that to happen all of the above would have to have another solution..
Knurled wrote:
Buy one and find out! I understand that the real advantage to the Miller/Offenhauser engine was that it had a one piece block. No main caps. The crank was endloaded.
I don't remember if the four cylinder engines also had one piece cylinder/head setups or if that was only the older engines, but if they did... No main caps, no cylinder head gasket, boost it to the moon.
'Course, you can also make that much power from a stock block/heads Buick 231, briefly, if you start with a '109 casting. That's about the limits. The Stage II blocks, like what Buick used at Indy, can tolerate a lot more than 1000hp They never get scrapped, as even a stitched together Stage II with sleeves is stronger than anything else.
When I stopped paying attention to rotary drag racing, they were eliminating the intercoolers and relying on methanol injection. Supposedly, even without intercooling and with the heat of 45psi+ of boost, there'd be frost on the intake manifold.
The prime advantage the 1920's designed Offy had was the one piece block and head.. No head gasket to blow! On some of the tall block (270 cu.in) you really had to get clever to do a valve job because most valve seat grinders didn't fit up the bore.. Replacing the valve seats almost required a trip to California to do properly.. etc..
As for buying one, I've never seen or heard of an Offy for sale.. There must be a network of OFFY engine hoarders out there..
T.J.
UltimaDork
5/29/17 10:56 a.m.
So, if the Offy block was one piece including the head and the crank was loaded in from the end, how where the rods connected to the crank? Just trying to envision how to assembled something like that. Seems like a ship in a bottle type magic trick.
In reply to T.J.:
The block was a separate piece from the cylinders/head. The main webs come out and split to change the bearings, windows in the case give rod bolt access.
/a>
http://www.hotrod.com/articles/assembling-270ci-offenhauser-indycar-engine-step/
patgizz wrote:
Real world: 2005 flex fuel avalanche
14.5 mpg on 87.
3mpg on e85. Yes, i burned 25 gallons in 75 miles. Stuck with regular 87 after that.
The real question is how much power will it add to a v12 jaaaaaaag
I bought E85 today at $1.75
87 octane gas was $2.29 54 cents more expensive.. that means It will cost me $300 more per year to use regular 87 octane pump gas.
If numbers bore you, it's cheaper using E85 while having a lot more power!!!
Ford said that the use of alcohol was worth 22% more power back in the early 60's later in the 60's Offenhauser took a much smaller turbo charged version and made 1100 horsepower using alcohol
T.J.
UltimaDork
6/5/17 7:25 a.m.
In reply to BrokenYugo:
Thanks. That makes sense now. I was too lazy/not interested enough to google it myself. I got the wrong impression from some of the earlier posts. Now I get it.
curtis73 wrote:
comparison chart
This guy's math is biased, but there are valid points
Case study of one vehicle, but an actual test showing slower acceleration and increased fuel cost with E85
So explain how people are getting massive horsepower gains from running E85 tunes on their turbo vehicles?
I mean, this is a rhetorical question - I can explain it, but I don't think you can, which is why you clearly don't understand the benefits of E85.
curtis73 wrote:
I would look hard into the claims about more HP. It might be an anomaly with the Miata, but in general, ethanol produces about 20% less peak cylinder pressure. After all, its BTU content is considerably less than gasoline.
Ethanol makes less power and the greater consumption/cheaper price is usually about a wash. Where ethanol really shines is in a purpose-built engine with higher compression. But just putting ethanol in a regular gasoline engine is not a power-adder.
I'm sorry but this magazine will prove you wrong.. When they tested alcohol they found that on their test mule Miata engine it made 15 more horsepower. E85 made 8 more horsepower..
If you check with Ford Motor company In the early 1960's when they wanted to compete in the INDY 500 against the mighty Offenhauser engines designed in the 1920's Their V8's made 22% more horsepower on alcohol than on the best racing gasoline they could buy!!!
There are reasons why INDY uses pure alcohol and NASCAR uses 15% alcohol.. chief among them is more power!!!
gearheadmb wrote:
Well ethanol is 113 octane, so theres that. I think i would like to do an ethanol build for the mustang, but ethanol is kind of hard to find in my area, which is ironic because i live in corn country.
Long ago we racers stopped buying fuel at the pump.. Too many variables, how long has that fuel been in the tank? How much water is already in the tank? which refinery did the fuel come from (yes it's not uncommon for gas stations to buy based on a lower price)
But good news, You've been buying alcohol in your gasoline.. at least 10% Some stations are buying 10%, 15% and E85 which can be from 30% to 85 % alcohol depending.... Unless your pumps are marked Non-oxygenated which means it's illegal for you to pump that into a non-Collector car. (It's for boats, lawn mowing equipment and collector cars)
frenchyd wrote:
Unless your pumps are marked Non-oxygenated which means it's illegal for you to pump that into a non-Collector car. (It's for boats, lawn mowing equipment and collector cars)
Not necessarily. Around here, some stations sell 91 octane non-ethanol instead of 93 octane E10 and it's perfectly legal to run in any car. I don't bother though, as I'd rather have the extra octane. For the Jeep, it doesn't run noticeably differently on E0 vs E10, just a very small mpg difference.
rslifkin wrote:
frenchyd wrote:
Unless your pumps are marked Non-oxygenated which means it's illegal for you to pump that into a non-Collector car. (It's for boats, lawn mowing equipment and collector cars)
Not necessarily. Around here, some stations sell 91 octane non-ethanol instead of 93 octane E10 and it's perfectly legal to run in any car. I don't bother though, as I'd rather have the extra octane. For the Jeep, it doesn't run noticeably differently on E0 vs E10, just a very small mpg difference.
You may not be able to feel the difference in a Jeep, however careful testing would revel some power gain at the cost of some mileage.. As far as higher octane, Ethanol has a 114 octane rating so when it's added to fuel they can use a lower/crappier base and still get the required 87/88 octane..
If your Jeep runs better on higher octane fuel you may have a build up of carbon. Alcohol does a remarkable job of cleaning the combustion chamber of an engine.. Back in my sprint car days we used to race a whole season on dirt which in those days resulted in high oil consumption.. However instead of carbon coated parts they stayed remarkably clean..
frenchyd wrote:
If your Jeep runs better on higher octane fuel you may have a build up of carbon.
No carbon issues, anything 91 octane or better is good enough. I just like to have a little more safety margin just in case. Less than that would need a less aggressive tune (timing is pushed pretty far and it doesn't have knock sensors).
I did once run about a 30/70 mix of E85 and E10 for testing. Once the computer sorted out the fuel trims, it ran great. That did produce a little extra power, especially when things were good and hot (better intake charge cooling due to it flowing more fuel).
For not being able to feel the difference between E0 and E10, I'm sure there is one, it's just small. I've also never tested the fuel, so it's entirely possibly that the E10 is only 5% ethanol or something.
rslifkin wrote:
frenchyd wrote:
If your Jeep runs better on higher octane fuel you may have a build up of carbon.
No carbon issues, anything 91 octane or better is good enough. I just like to have a little more safety margin just in case. Less than that would need a less aggressive tune (timing is pushed pretty far and it doesn't have knock sensors).
I did once run about a 30/70 mix of E85 and E10 for testing. Once the computer sorted out the fuel trims, it ran great. That did produce a little extra power, especially when things were good and hot (better intake charge cooling due to it flowing more fuel).
For not being able to feel the difference between E0 and E10, I'm sure there is one, it's just small. I've also never tested the fuel, so it's entirely possibly that the E10 is only 5% ethanol or something.
That is exactly the sort of issue there is with any pump gas/fuel. You simply do not know enough to make even wild assumptions about what you are working with..
More power comes at a price and part of that price if you don't want to be chasing your tail, is control of variables.. One variable is how often the engine is destroyed. Or in other words, how much is safe to use..
That is why serious racers buy racing fuel with it's documented content.. Yes it is an added cost (and hassle) but it also it eliminates the variables..
alfadriver said:
In reply to Knurled:
Either Lambda or Phi- which is 1/lambda.
Lambda follows a/f, so when we are all referenced that rich is lower, it works well.
Phi follows f/a, so it follows richer is more fuel. So the math is a little easier.
But 100% that we should be thinking in lambda or phi vs. air fuel- O2 sensor output, regardless of what it is or where it comes from, is in lambda or phi. If you see a/f numbers coming out of it, it's using an assumed fuel property. The actual sensor does not care or even come close to measuring it- all it does is measure the relative amount of O2 left in the exhaust- which is directly related to lambda or phi on a chemical balance.
What you just explained to me is brilliant! Also why a flex fuel vehicle works.
The O2 sensor doesn't care what fuel is being burned. All it wants is the correct air fuel ratio.
So why won't every computer automatically adjust? What unique properties does a flex fuel computer have that older/ non- flexfuel computers don't have?
Please explain it to me like I'm a 5 year old. I'm such a Luddite I fail to grasp a lot of technology
I think it has a lot to do with compression, Alcohol has less inherent energy, so you need to squeeze it more. I am pretty sure that my Rover could benefit from E85 as it is already a "premium fuel only" vehicle.
In reply to frenchyd :
Flex fuel setups often have a sensor in the tank to tell them how much ethanol is in the fuel. That lets them pre-adjust, rather than having to rely on the O2 sensor for 30+ percent fueling corrections (which would also leave the fueling being wrong for the first bit of driving after swapping fuels).
On top of that, a flex fuel version of a vehicle will have bigger injectors and more alcohol resistant fuel system parts than a non flex fuel one.
So how to figure out how much fuel is needed on e85? Specifically for like injector and fuel pump sizing, but also for approximating a starting point for fuel tables?
I've found some injector calculators online, but they seem to say my stock injectors can barely handle stock power levels, and that seems wrong.
In reply to Robbie :
IIRC, adding 30% to the fuel needs on gas should get you in the ballpark.
In reply to mad_machine :why then does a stock compression Miata make 15 more horsepower on alcohol than on 93 octane gas?
Fact
as tested by grassroots magazine.
Alcohol also makes more horsepower than race gas.
Bottom line? Alcohol makes more power.
In reply to Robbie :E 85 requires about 65% more than gasoline and methanol requires about 92% more
grassroots has a wonderful article about fuel they tested everything in a fairly stock Miata
But gas stations vary constantly they can sell gas with 30-85% ethanol as E85 plus how long has that fuel been in their tanks?