Jump to content

AVGAS VS. RACE GAS?


donkeypuncher

Recommended Posts

here is my experience with avgas.. iwhen i first built my 392 cub i tried using 100LL in it.. it owuld not run right!! i tried everything with the jetting and timing.. it ran good until i opened it up.. at high rpms the motor would sputter!.. i never figured that one out. so i switched back to 93 and everything was fine...

Link to comment
Share on other sites

  • Replies 38
  • Created
  • Last Reply

Top Posters In This Topic

If you really want to go fast, throw a big chunk of powdered aluminum in your exhaust with some ammonium perchlorate...

:banana:

 

Side note: True or False- One of the Hindenburg's fuel cells exploded, causing a chain reaction fire?

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

V

False! The structure was covered with fabric coated with dope. Powdered aluminum was added to the dope to help protect the fabric from the sun. Static electricity ignited the powdered aluminum in the dope, causing the fire to spread rapidly and burn out of control. The rest is history...

Link to comment
Share on other sites

To answer your question first, I'd say that if cost was of no concern, of course I'd want to run Race Gas.

 

That's what these small manufacturers make. Specialized Race Fuel. It should be as good as can be. Of course, one of the things that differentiate these race fuels from standard pump fuels is the lack of emissions related additives and the very close consistency from one batch to the next. That is what true racers need and are paying for. Consistency.

 

But in the real world, I've been running a 50/50 mix of 100LL AVGAS/pump premium for more than a decade in 2-strokes because it costs less than half the price of race fuels. All I can offer is what I've found so far....

 

I took the top end apart on my 2000 YZ250 to replace the piston/rings after 4 years of mega riding. Piston dome was clean and carbon free, as were the ring lands, and transfer ports. I literally wiped away the discoloration. I use Yamalube 2R at 32/1.

 

I just looked through the exhaust ports of my Banshee while I had the pipes off and plugs out. I could read the part #'s on top of the pistons (100% carbon free) and the exhaust port/domes are spotless too!!

 

2-strokes operate best on leaded fuel. Period. Longevity is increased because of the lead lubrication. I've been running the same plugs going on my 3rd season so I don't understand why some claim to have carbon/fouling issues...it certainly isn't because of the fuel!!

 

100LL is an ultra clean fuel. One of the specs is that they place an amount on a stainless steel tray and it can't leave any deposits behind. Another spec is that it has a 15 month shelf life...compare that with standard /race gas of 5 weeks.

 

In it's liquid state, it doesn't smell like fuel as we are accustomed to, but it works great for me. If it atomizes well enough in a thin air environment (10,000') it will do an outstanding job at sea level too.

 

I did an internet search on the properties of 100LL and I'm satisfied in it's ability to kick every 4-pokes ass up Old's :cool: without detonation.

 

BTW: Someone commented on the outboard application with 100LL. The TCW oil used in outboards is some vile stuff.

NEVER run that crap in your Banshee!!! It's for use with cold water intake...not a hot water recycling radiator cooling system. Plus, who can attest to the condition of said motor? "You know, my friend's friend's friend's brother said his uncles motor...."

If the low RPM thing people throw around about AVGAS had validity, it would operate better in outboards because of their (approx) 5500RPM redline.

 

My $.02.

Good post! :thumbsup:

Link to comment
Share on other sites

If you really want to go fast, throw a big chunk of powdered aluminum in your exhaust with some ammonium perchlorate...

:banana:

 

Side note: True or False- One of the Hindenburg's fuel cells exploded, causing a chain reaction fire?

V

V

V

V

V

False! The structure was covered with fabric coated with dope. Powdered aluminum was added to the dope to help protect the fabric from the sun. Static electricity ignited the powdered aluminum in the dope, causing the fire to spread rapidly and burn out of control. The rest is history...

That made me giggle. :biggrin:

Link to comment
Share on other sites

u know, i never would have thought this topic would get this many responses 5 MONTHS AFTER I POSTED IT. hahaha. its about damn time somebody gives me some usefull info. :yelrotflmao:

 

firehead i can tell it bugs you when people ask a question thats been asked hundreds of times because they dont use the search tool. so on behalf of all newbs, I WOULD LIKE TO SINCERELY APOLOGIZE FOR BEEING LAZY,!!! was a while ago when i posted this, so i hope u can find it in ur heart of hearts to forgive me. :biggrin: :beer:

Link to comment
Share on other sites

ive been buying avgas from the heliports for atleast 20 years and have ran it in every thing under the sun from drag bikes,dirt bikes,quads,hot rods ive owned etc.what i have noticed over a period of time it will leave deposits on the pistons and valves over a long period of time, it will get to the point where valves wont seat from all the deposits and also pitt the valve seat.i have run it straight and have mixed it with pump fuel depending on what octane/flash point im after.for the price difference in avgas and vp i run alot more avgas than i do vp fuel.

Link to comment
Share on other sites

ive been buying avgas from the heliports for atleast 20 years and have ran it in every thing under the sun from drag bikes,dirt bikes,quads,hot rods ive owned etc.what i have noticed over a period of time it will leave deposits on the pistons and valves over a long period of time, it will get to the point where valves wont seat from all the deposits and also pitt the valve seat.i have run it straight and have mixed it with pump fuel depending on what octane/flash point im after.for the price difference in avgas and vp i run alot more avgas than i do vp fuel.

How do you know what flash point you are after? Is this something you are measuring?

Link to comment
Share on other sites

u know, i never would have thought this topic would get this many responses 5 MONTHS AFTER I POSTED IT. hahaha. its about damn time somebody gives me some usefull info. :yelrotflmao:

 

firehead i can tell it bugs you when people ask a question thats been asked hundreds of times because they dont use the search tool. so on behalf of all newbs, I WOULD LIKE TO SINCERELY APOLOGIZE FOR BEEING LAZY,!!! was a while ago when i posted this, so i hope u can find it in ur heart of hearts to forgive me. :biggrin: :beer:

There are really only a couple topics that I really wish people would search for before asking questions about............. That AV gas vs. race gas thing is one of them since it takes alot if information to properly answer questions and this topic has been beat to death in the past.

 

Forged vs. cast pistons is another topic that people need to search for before posting........... :cool:

Link to comment
Share on other sites

To answer your question first, I'd say that if cost was of no concern, of course I'd want to run Race Gas.

 

That's what these small manufacturers make. Specialized Race Fuel. It should be as good as can be. Of course, one of the things that differentiate these race fuels from standard pump fuels is the lack of emissions related additives and the very close consistency from one batch to the next. That is what true racers need and are paying for. Consistency.

 

But in the real world, I've been running a 50/50 mix of 100LL AVGAS/pump premium for more than a decade in 2-strokes because it costs less than half the price of race fuels. All I can offer is what I've found so far....

 

I took the top end apart on my 2000 YZ250 to replace the piston/rings after 4 years of mega riding. Piston dome was clean and carbon free, as were the ring lands, and transfer ports. I literally wiped away the discoloration. I use Yamalube 2R at 32/1.

 

I just looked through the exhaust ports of my Banshee while I had the pipes off and plugs out. I could read the part #'s on top of the pistons (100% carbon free) and the exhaust port/domes are spotless too!!

 

2-strokes operate best on leaded fuel. Period. Longevity is increased because of the lead lubrication. I've been running the same plugs going on my 3rd season so I don't understand why some claim to have carbon/fouling issues...it certainly isn't because of the fuel!!

 

100LL is an ultra clean fuel. One of the specs is that they place an amount on a stainless steel tray and it can't leave any deposits behind. Another spec is that it has a 15 month shelf life...compare that with standard /race gas of 5 weeks.

 

In it's liquid state, it doesn't smell like fuel as we are accustomed to, but it works great for me. If it atomizes well enough in a thin air environment (10,000') it will do an outstanding job at sea level too.

 

I did an internet search on the properties of 100LL and I'm satisfied in it's ability to kick every 4-pokes ass up Old's :cool: without detonation.

 

BTW: Someone commented on the outboard application with 100LL. The TCW oil used in outboards is some vile stuff.

NEVER run that crap in your Banshee!!! It's for use with cold water intake...not a hot water recycling radiator cooling system. Plus, who can attest to the condition of said motor? "You know, my friend's friend's friend's brother said his uncles motor...."

If the low RPM thing people throw around about AVGAS had validity, it would operate better in outboards because of their (approx) 5500RPM redline.

 

My $.02.

 

+1 never had any issues with it in my bikes, sandrail, or the race cars other than it saving a bunch of money. some race fuel companies use av gas as a base stock then put in their own additives. The only thing I had to do with av gas is go slightly richer on jetiing.

Link to comment
Share on other sites

How do you know what flash point you are after? Is this something you are measuring?

 

 

kinda im not actually testing the fuel for a accurate flash point.theres no real science to what i do,

on the engines i have built with a substantial amount of compression and feel a higher octane is needed i just take egt readings and do plug chops and compare the 2 till im happy with the results.

there is way more to this subject than i can grasp,nor have i taken the time to understand it completely. this method is just what has worked for me over the years with good results.so i really have no clue to my actual flash point number wise but know the engine is in parameters for safe running conditions and non-detonation.

Link to comment
Share on other sites

here is what i can say about the issue. race gas like vp, torco, trick, shell and all other companys is, you have to know where to look for in octane ability. they all give you three different octane numbers.

 

1 mon (MOTOR OCTANE NUMBER) this is the one that you need to look for, this number is measured when fuel is under a load.

2 ros (RESERCH OCTANE NUMBER) this is the number the company came up with threw resarch under a control condition.

3 R+M/2: ( OCTANE NUMBER) that's the number you see on a yellow tag when you go to a gas station. it's the differece of mon and ros number (mon + ros= x/2)

 

vp 110 for example. race fuel brand.

mon 107

ros 113

R+M/2 110

 

Air BP av100 for example. a brand of avgas

mon 100

 

so race fuel in this case would have a higher octane. if your going all out in your race engine why would you cut corners with your fuel. imo

 

good info to know when storing race fuel, store in metal or plastic containers, black is the best. when using plastic, if you can see the fuel level it's to light. uv rays in sunlight breaksdown fuel. so keep it out of the sun.

just like beer, sunlight can spoil beer and NOBODY likes spoiled beer. :beer:

Link to comment
Share on other sites

here is what i can say about the issue. race gas like vp, torco, trick, shell and all other companys is, you have to know where to look for in octane ability. they all give you three different octane numbers.

 

1 mon (MOTOR OCTANE NUMBER) this is the one that you need to look for, this number is measured when fuel is under a load.

2 ros (RESERCH OCTANE NUMBER) this is the number the company came up with threw resarch under a control condition.

3 R+M/2: ( OCTANE NUMBER) that's the number you see on a yellow tag when you go to a gas station. it's the differece of mon and ros number (mon + ros= x/2)

 

vp 110 for example. race fuel brand.

mon 107

ros 113

R+M/2 110

 

Air BP av100 for example. a brand of avgas

mon 100

 

so race fuel in this case would have a higher octane. if your going all out in your race engine why would you cut corners with your fuel. imo

 

good info to know when storing race fuel, store in metal or plastic containers, black is the best. when using plastic, if you can see the fuel level it's to light. uv rays in sunlight breaksdown fuel. so keep it out of the sun.

just like beer, sunlight can spoil beer and NOBODY likes spoiled beer. :beer:

Good post. :thumbsup:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...