It's all about the FUEL

General engine tech -- Drag Racing to Circle Track

Moderator: Team

RAS
Pro
Pro
Posts: 304
Joined: Mon Jun 04, 2012 9:46 am
Location: Edmund Ok.

It's all about the FUEL

Post by RAS »

Friends there are a lot of great engine designs out there and endless parts either CNC or made on a 3D printer. You can build what ever you can imagine these days. When all is said and done, assuming the engine can achieve over 100% efficiency Torque numbers will be based on how much fuel that engine can consume in a given amount of time. HP numbers are factored after the fact. If you can burn the most fuel with your engine you will win. I don't care if it's a Hemi, BBC, Etc. Don't care. Blower, turbos, Nitrous, etc. Don't care. How much fuel are you burning? A steam engine regardless of size will accelerate indefinitely until the boiler can no longer supply enough steam to the cylinders. Fuel engines make power on volume not the percentage of nitro. Pack it in there and light it off. The Pro Mod engine guy's crack me up. What is the next engine combo of the week? Then someone with a 440 inch small block comes along and kicks their ass'. A Perfect example is are they Injected Fuel dragster class. Fuel Volume!
User avatar
FC-Pilot
HotPass
HotPass
Posts: 913
Joined: Tue Mar 17, 2009 2:23 pm
Location: Springtown, TX
Contact:

Re: It's all about the FUEL

Post by FC-Pilot »

We ran an injected funnycar over 20 years ago. Had the bypass stick closed and it pushed all the fuel from the pump to the engine. We increased the volume of fuel to the engine and for some reason it did not go faster. Maybe there is more to it than just more fuel.

Paul
"It's a fine line between clever and stupid." David St. Hubbins
fabr
Expert
Expert
Posts: 584
Joined: Sun Jul 21, 2019 8:35 pm
Location:

Re: It's all about the FUEL

Post by fabr »

This one sentence " If you can burn the most fuel with your engine you will win." is critical to his post. The key is ya gotta burn it not just pump it through.
User avatar
ptuomov
Guru
Guru
Posts: 3587
Joined: Fri Aug 07, 2009 3:52 am
Location:

Re: It's all about the FUEL

Post by ptuomov »

If you think it’s all about fuel, then you might be interested in John Clarke’s book “Ignition” which is the informal history of liquid rocket propellant development.
Paradigms often shift without the clutch -- https://www.youtube.com/watch?v=cxn-LxwsrnU
https://www.instagram.com/ptuomov/
Put Search Keywords Here
HQM383
HotPass
HotPass
Posts: 1021
Joined: Sun Sep 12, 2021 7:25 am
Location: Geelong, Vic

Re: It's all about the FUEL

Post by HQM383 »

FC-Pilot wrote: Sun Sep 26, 2021 8:22 pm We ran an injected funnycar over 20 years ago. Had the bypass stick closed and it pushed all the fuel from the pump to the engine. We increased the volume of fuel to the engine and for some reason it did not go faster. Maybe there is more to it than just more fuel.

Paul
The fuel can't burn without oxygen. Stuff as much as you want in there with the best ignition system in the world and you will only burn the fuel that consumes the oxygen.
"Don't think of an engine as an air pump. That's a very inhibiting way to discover or understand the factors in an engine. I think its better to think of an engine as a machine to raise the energy level of a fuel to as high as possible prior to initiating controlled combustion".
- Shrinker

Must have the oxygen for release of the energy.
I’m a Street/Strip guy..... like to think outside the quadrilateral parallelogram.
engineguyBill
Guru
Guru
Posts: 1264
Joined: Fri Feb 26, 2010 11:15 am
Location: Gold Canyon, AZ

Re: It's all about the FUEL

Post by engineguyBill »

Fuel will burn efficiently and produce torque/horsepower if it is being introduced into the engine with the proper amount of oxygen AND the fuel is atomized completely with the air/oxygen. That is one of the reasons why Nitromethane works so well in a Top Fuel/Funny Car application. The fuel actually contains oxygen within its molecular profile.
Bill

Perfect Circle Doctor of Motors certification
SAE Member (30 years)
ASE Master Certified Engine Machinist (+ two otherASE Master Certifications)
AERA Certified Professional Engine Machinist
dannobee
Expert
Expert
Posts: 898
Joined: Mon Nov 04, 2019 9:01 pm
Location:

Re: It's all about the FUEL

Post by dannobee »

Bill's right. A top fuel car will still make something like 2000hp with a broken blower belt and no "air" going into the engine. And the oxygen in the fuel is why you can't shut off a nitro engine by just shutting the throttle. You need to shut off the fuel valve.
hoodeng
HotPass
HotPass
Posts: 1092
Joined: Sat Mar 04, 2017 6:53 pm
Location: South Australia

Re: It's all about the FUEL

Post by hoodeng »

FC-Pilot, was that methanol or nitro? I have know of engines still running super fat on methanol,, Also a fuel HD engine that had a reversed main can that ran ok, the H1 and H2 cans i think were doing the most bleeding, just wouldn't top end.
David Redszus
Guru
Guru
Posts: 9633
Joined: Tue Nov 27, 2007 9:27 am
Location: Chicago
Contact:

Re: It's all about the FUEL

Post by David Redszus »

A comparison of nitromethane to methanol reveals the following:

Nitromethane
Oxygen content = 52.4%
Heat of combustion = 4529 BTU/lb
Stoich = 2.21
Specific power = 2049 BTU/ lb air.

Methanol
Oxygen content = 49.9%
Heat of combustion = 8589 BTU/lb
Stoich = 6.47
Specific power = 1328 BTU/lb air.

Since the oxygen content of nitro and methanol are very similar, and methanol has a higher
heat of combustion, one would expect methanol to make more power than nitro.

However, when considering the required oxygen the reverse is true. Based on the BTU per lb of air,
nitro makes about 54% more power than methanol, 2049/1328 = 1.54.

Beside nitro, only ethylene oxide makes more specific power than methanol, 1519 BTU per lb of air.

The charge density improvement due to fuel evaporation has not been considered.
dannobee
Expert
Expert
Posts: 898
Joined: Mon Nov 04, 2019 9:01 pm
Location:

Re: It's all about the FUEL

Post by dannobee »

I've never run in the nitro classes, but a couple of my friends wrench on current TF and TF Nostalgia stuff. I *thought* stoich of 100% Nitro (even though limited by rule by NHRA to 90%) was 1.7:1, but that still doesn't tell the whole story because the engines will make even more power if you run it richer than that. I've been told that at certain times they'll run stoich less than 1:1, making even more power and still not blow up.
Adger Smith
Guru
Guru
Posts: 2211
Joined: Sun Jul 25, 2004 7:35 pm
Location: Texarkana, Ar-Tx

Re: It's all about the FUEL

Post by Adger Smith »

The alky Stoich is 6.47 which is more than the nitro's 2.21
Don't forget about that.
No one mentioned the rate of the burn...
Adger Smith
Adger Smith Performance Engines
903 794 7223 shop
903 824 4924 cell
adgersperf@aol.com e-mail
User avatar
FC-Pilot
HotPass
HotPass
Posts: 913
Joined: Tue Mar 17, 2009 2:23 pm
Location: Springtown, TX
Contact:

Re: It's all about the FUEL

Post by FC-Pilot »

We were running alcohol. I was being slightly argumentative for the sake of proving a point. As all of you know and have stated, without the oxygen molecules either in the fuel or in the air it does not matter how much fuel you put in if it can’t be properly burned.

Paul
"It's a fine line between clever and stupid." David St. Hubbins
User avatar
ptuomov
Guru
Guru
Posts: 3587
Joined: Fri Aug 07, 2009 3:52 am
Location:

Re: It's all about the FUEL

Post by ptuomov »

David Redszus wrote: Mon Sep 27, 2021 1:47 pm A comparison of nitromethane to methanol reveals the following:

Nitromethane
Oxygen content = 52.4%
Heat of combustion = 4529 BTU/lb
Stoich = 2.21
Specific power = 2049 BTU/ lb air.

Methanol
Oxygen content = 49.9%
Heat of combustion = 8589 BTU/lb
Stoich = 6.47
Specific power = 1328 BTU/lb air.

Since the oxygen content of nitro and methanol are very similar, and methanol has a higher
heat of combustion, one would expect methanol to make more power than nitro.

However, when considering the required oxygen the reverse is true. Based on the BTU per lb of air,
nitro makes about 54% more power than methanol, 2049/1328 = 1.54.

Beside nitro, only ethylene oxide makes more specific power than methanol, 1519 BTU per lb of air.

The charge density improvement due to fuel evaporation has not been considered.
How about using methylhydrazine as a fuel additive?

https://cameochemicals.noaa.gov/chris/MHZ.pdf
Paradigms often shift without the clutch -- https://www.youtube.com/watch?v=cxn-LxwsrnU
https://www.instagram.com/ptuomov/
Put Search Keywords Here
BLSTIC
Expert
Expert
Posts: 869
Joined: Wed Dec 05, 2018 7:14 pm
Location:

Re: It's all about the FUEL

Post by BLSTIC »

ptuomov wrote: Mon Sep 27, 2021 9:20 pm
David Redszus wrote: Mon Sep 27, 2021 1:47 pm A comparison of nitromethane to methanol reveals the following:

Nitromethane
Oxygen content = 52.4%
Heat of combustion = 4529 BTU/lb
Stoich = 2.21
Specific power = 2049 BTU/ lb air.

Methanol
Oxygen content = 49.9%
Heat of combustion = 8589 BTU/lb
Stoich = 6.47
Specific power = 1328 BTU/lb air.

Since the oxygen content of nitro and methanol are very similar, and methanol has a higher
heat of combustion, one would expect methanol to make more power than nitro.

However, when considering the required oxygen the reverse is true. Based on the BTU per lb of air,
nitro makes about 54% more power than methanol, 2049/1328 = 1.54.

Beside nitro, only ethylene oxide makes more specific power than methanol, 1519 BTU per lb of air.

The charge density improvement due to fuel evaporation has not been considered.
How about using methylhydrazine as a fuel additive?

https://cameochemicals.noaa.gov/chris/MHZ.pdf
I specifically remember reading about someone doing that to a nitro car. Or at least adding something that sounded similar to the fuel to act as some kind of energizing agent/catalyst/what-have-you. Small dosage results were a moderate gain in power. Cowboy sized dose after the chemist wasn't looking resulted in longer flames from the zoomies, the sonic recreation of the end of the world, and cracks in everything exposed to the combustion chamber. The engine was a total loss. Apparently it seemed like it made hundreds, if not a thousand, more horsepower.

I'd love to read the story again if I could find it

EDIT: A quick google search on "top fuel hydrazine" returns stories of power outputs increasing, engines being destroyed, and green flames

https://www.dragzine.com/news/flashback ... hydrazine/
User avatar
ptuomov
Guru
Guru
Posts: 3587
Joined: Fri Aug 07, 2009 3:52 am
Location:

Re: It's all about the FUEL

Post by ptuomov »

I was actually thinking about using a relatively small amount of methyl hydrazine in engines that normally run on some other fuel and sprayed nitrous oxide. Might require direct injection, as methyl hydrazine and some nitrous oxides are hypergolic together.
Paradigms often shift without the clutch -- https://www.youtube.com/watch?v=cxn-LxwsrnU
https://www.instagram.com/ptuomov/
Put Search Keywords Here
Post Reply