toddk911

I know you can run alch/meth injection but can you run it directly in the fuel like adding Xylene?

If so, what mixture %?

I know Methanal has high laten heat evap and also a very high octane rating. But can it be used directly in to the gas tank?

danny951

here is a chart with several common fuel additives and their octane rating along with other info:

http://www.team.net/sol/tech/octane_b.html

for quick answer, per this chart, methanol is 101 octane which is kind of low, but it's quite a bit cheaper. Also, I noticed the chart says it's not recommended to use more a higher mixture such as 20% or 30%. it says, "Methanol is wood alcohol. Ethanol is grain alcohol and found in Gasohol in 10% ratios. Both alcohols are mildly corrosive and will eat gas tank linings, rubber and aluminum if used in excessive ratios. Main ingredient in "Gas Dryers", combine with water."

toddk911

ok.

yea, I did some searching and found estimates of Methanal having octane of 140+ ???

But it is more oxeninated and thus you will run lean. Also has half of the BTU energy of gasoline.

I saw that also about 10% mix of Ethanal is what makes "gasahol".

In terms of corrosivness I have read the same about Toulene/Xylene so not sure about that one.

Oh well.

Porsche-O-Phile

This may help. I'm contemplating building a methanol-powered 3.0L 944 with very high boost levels. . .

https://rennlist.com/forums/924-931-944-951-968-forum/266514-methanol-944-a.html

toddk911

But what about just a 10-20% mix?

Porsche-O-Phile

Dunno. I think "standard" gas is about 10% ethanol as-is. If I come across anything on this I'll post it.

tedesco

Are you shure your 140+ octan rating was not for methan (liquid gas)? This in fact has got a very high rating. Looking to two different source, I found almost exactly the same numbers for:

o Methanol: 105-115 ROZ, 89-91 MON
o Ethanol: 108-115 ROZ, 90-92 MON

So the MON ratings are not very high and even lower than pump gas. Still it shows higher knock resistance in real live due to its big cooling effect when it evaporates. You also need a lot higher fuel flow due to the ideal AFR of only aroud 4:1 (three times more than with gas).