General engine tech -- Drag Racing to Circle Track

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Doug Schriefer
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Joined: Tue Jan 18, 2005 2:46 pm
Location: Lake Lanier, GA

Postby Doug Schriefer » Sun Dec 07, 2008 3:55 pm

Greezer wrote:

Like E85?
E85 is Ethanol and Gasoline. Ethanol and Methanol are different.

Now while Tuner & David are both correct. The bottom line is that there are much better alternatives than trying to mix methanol and racing gas so why waste your time

I only injected that because, as you state here, 'why waste your time?' E85 is what it is, there are engines running it at 9:1 on up to 14:1 and some claim higher. No need to mix anything. I'm about to try the E85 on a 383 or 400 based mill as soon as I figure out exactly what I want. This for my own personal use, carbed.

E85 is a very good choice for certain combinations, I would use in in a heart beat over Methanol Gasoline mixtures.... The why waste your time was in reference to METHANOL and Gasoline.
Doug Schriefer

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David Redszus
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Joined: Tue Nov 27, 2007 9:27 am
Location: Chicago

Postby David Redszus » Mon Dec 08, 2008 11:37 pm

I think it’s irresponsible to tell people “organometallics such as TEL and TML, have absolutely NO effect on the octane rating of methanol” when the addition of TEL to alcohols is cited in several reputable sources as causing preignition and abnormal combustion.

I think that to label an opposing technical viewpoint as irresponsible is in itself irresponsible.

The true octane rating of methanol is very much in doubt. The MON value being especially low. Methanol octane values have been misreported numerous times, and all too often repeated as fact.

While I canot refute the conclusions in the VW SAE paper that you cite since I have not yet read it, (neither can I accept them) there is sufficent other research upon which to base a conclusion.

One very valid source is the Ethyl Corp which is the manufacturer of TEL (TML is no longer available) and is perhaps the most knowledgable, most qualified source on the topic of lead additive performance.

Having discussed the topic with respected fuel researchers and fuel blending experts at a major race fuel refinery, and with the manufacturer of TEL, I will stand by my pervious statements regarding the performance of methanol and TEL.

Lead has no effect on the octane rating of methanol. Period.

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Joined: Tue Mar 01, 2005 7:50 am
Location: Colorado

Postby hotrod » Tue Dec 09, 2008 1:45 pm

Methanol can be mixed with gasoline without separation but it is much more sensitive to stratification than ethanol is. I know a guy in the UK that routinely runs 10% methanol mixed with gasoline.

The key to keeping it mixed is that both the alcohol and gasoline must be very dry (very little absorbed water). The mixture is also temperature dependent, at lower temps stratification is much more likely. Also the chemical mixture of the gasoline will effect how it mixes. Certain chemicals such as Acetone, and the aromatics like toluene act as "co-solvents" that help methanol mix with the gasoline.

In David Vizards book "Performance with Economy" he has a section on methanol gasoline mixtures. In one example a mixture of 89% gasoline, 8.9% methanol, 1.8% acetone and 0.3% water remains mixed. A mixture of 87% gasoline, 8.7% methanol and 4.3% water will separate at room temperature into layers (stratification).

In hot dry conditions you can get up to about 20% methanol to dissolve in gasoline. Ethanol is much easier to deal with, which is why it is so popular in E85. It has very nearly the same power potential as methanol without many of its disadvantages.

The detonation and octane issues with alcohols are all over the map depending on the sources you read. For example the official octane of the E85 mixture is listed as 105 but in use it behaves like a 112-120+ octane fuel. It will tolerate 38-42 PSI boost in street applications with base compression ratios of 8:1. Even top line racing gasoline is hard pressed to beat those numbers. According to what I have seen methanol and ethanol are both more prone to preignition than gasoline. This is normally not an issue due to their high cooling effect but if you go too lean they will melt stuff just like gasoline.

In those areas where E85 is easy to find it would be the fuel of choice for alcohol blends, if not available methanol can be used within the above limits but you have to deal with all its down sides like corrosion, poisoning through skin, lung absorption etc.


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