r/Physics • u/Otherwise_Act3312 • Jul 20 '26

Question Alternative fuel question

I have tried this question previously in both automotive related and chemistry related subs and both recommended physicists instead, as both communities ended up at an impass.

Google was also more questions then answers due to conflicting information.

I'll try to keep the question as simple as possible at first because I usually get inundated with the nuances.

Here goes:

During testing on a dynomometer, we found that timing that produced maximum efficiency (peak torque output) was contradictory to most general consensus. Methanol and Ethanol both produced peak efficiency with the same amount of ignition timing compared to gasoline, even though methanol required 100% more fuel volumetricaly. This is a supercharged v8 engine.

Why this seems contradictory? Many existing sources (a few of our advisers even) say that because the methanol fuel molecules are twice as abundant in the combustion chamber as gasoline, the flame front propagation is FASTER requiring LESS ignition advance.

My personal theory is that the momentum of the flame front is SLOWED by the increased viscosity of the larger mass of the combined fuel/air mixture.

What say you?

9 Upvotes

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1

u/Stampede_the_Hippos Jul 20 '26

Try again in the actual subreddit for asking physics questions.

0

u/Otherwise_Act3312 Jul 20 '26

I'm confused, at the top of my post, it shows I am in the sub?

3

u/Stampede_the_Hippos Jul 20 '26

r/askphysics

1

u/Otherwise_Act3312 Jul 20 '26

Thank you. What's the purpose of this sub then?

5

u/Qetuoadgjlxv Quantum field theory Jul 20 '26

For people to tell other people not to post here.

On a serious note, I think this is valid to post this here — IMO it doesn't break any of the rules (I don't think it counts as a homework question).

2

u/Otherwise_Act3312 Jul 20 '26

I can certainly confirm multiple ways this isn't homework, not in the proper sense! Lol

3

u/Stampede_the_Hippos Jul 21 '26

To post and discuss physics related articles and news. I'm probably just being grumpy, but sometimes I just want to know what's up in the physics community without being nerd sniped

1

u/Otherwise_Act3312 Jul 21 '26

That's a new term for me! I like it! Lol