FORMULAVEE.ORG

My source for Avgas is no longer, What gas will be available @ the track?...

thankx,
eugene

See this page...
http://www.roeblingroad.com/trackinformation.html

Steve, FV80

Before I switched to E10 street gas, I used http://www.100ll.com/ to find avg while traveling. Use Google satellite to evaluate the easy of access.

Follow your planned route on Google map looking for small airfields and then look them up.

Brian

Thankx Guys,
See yaz In Savannah

While on the subject....

Why are some running av gas in a relatively stock ACVW engine?

It is a high octane (100) slow burning fuel meant for under 4000 RPM at high altitudes. (Actually it is NOT 100 octane(RON+MON/2) using the automotive measurements. It is measured at different intake pressures and temps. It is well under the 100 octane. The FV engine is under 8:1 compression ratio. Pump gas at 91-93 octane is plenty for these engines. (and cheaper) WIth MORE energy (BTU) and more HP when tuned for it.

The ONLY positives to Avgas: Arguably it has better quality control. (However any name brand busy gas station pump gas is fine.) Avgas is less prone to vapor lock. You ever had vapor lock on the track at speed? Nope. Since we have only mechanical advance distributors, if you are pulling a boat and run at 3500 RPM and under, Avgas MIGHT help a bit to prevent spark knock. (Since we are at full advance at 2000 RPM+. If you run at 10,000 to 30,000 feet altitudes, I would use it.

If you don't meet the above criteria you are LOSING HP and Throttle response. E-10 ~93 octane is excellent for our engines. It burns at the highest peak pressures during the power stroke and doesn't waste fuel or BTU. It's cheaper. The ethanol (10%) runs slightly cooler (more fuel per lb of air and even more energy.) If you are running CR's of 11:1 you can use Avgas (but race gas is better.) We don't need or want the lead in 100LL, but if you want it, add some additives.

Other than the ridiculous fuel tests that the SCCA initially used, I have no idea how this Avgas thing became in vogue. We have been using street pump fuels for 20 years (except those years when fuel testing prohibited it. When doing SG tests and jetting properly a pump fuel will ALWAYS better out Avgas.

There are some very expensive race gas concoctions with flame front enhancers, etc. that can give you better HP, but I suspect most aren't using them.

Re: the issue of fuel cells. Proper care (for us anyways) has eliminated fuel cell issues. I have owned, raced and rented up to 4 cars per season for those 20 years and have yet to replace a cell.
Call Fuel Safe or ATL and they will tell you not to expect more than 5 years out of any cell no matter what fuel you are using. (E10 or not). We have had them in used for much longer than that.

Like very high octane fuels, AvGas is NOT better. It is a necessary evil for engines running in those particular environments. Private aircraft are hardly racing engines. (an ACVW isn't one either , but we do stress them and wnt the additional Hp.)

What jet change to go from avgas to E10?

With some caveats: Avgas SG is typically .70 to .71. Pump premium varies seasonally but typical summer gas is .75. The formula for changing jets is NewSG - OldSG/ NewSG. So a ~ a 5% larger flowing jet would be required when going from Avgas to Pump.

Herein are some problems:

You can not depend on the markings on FV jets sizes, over the years people have checked them with drill bits, jet measuring tools and drilled or honed them larger. (often not symmetrically).
People not understanding how the main and a/c jets interact along with the float bowl levels have messed with the carbs. But if we assume that it is working well at WOT at above 4000 RPM on AvGas, you can assume that a increase of .5 or 1 jet size will get you close. (eg. 1.80 to 1.85 or 1.90. Or 1.95 to 2.0, etc.) with pump premium,

However, due to the above I would not depend on that change OR that you are even jetted perfectly now. We do jetting on the dyno with Wide band 02 sensors and 4 EGT's. WIthout a dyno (on the track) I would only make changes with a WB 02. A single EGT's is NOT adequate, 2 would be ok, 4 better. With these induction systems you often have to do slight compromises to balance the four cylinders. A wide band 02 system costs less than a rear tire and is more valuable than your tachometer. (Use a Shift Lite for shifting We do.)

With a WB 02 you can actually make changes at the track based upon barometric pressures and temps, etc. (However typically barometric pressures don't have a large effect compared to large altitude changes. We run in the 500 to 900 ft above sea level range and jet changes are not USUALLY not going to make significant differences.

I think 90% of our drag racing customers have a WB 02 sensor and meter in the car, or at least log it via D/A.

BY far the best way to jet is to have your engine builder use the fuel you want and jet it for the atmos conditions you will run at. Unless you really know what you are doing and have the instrumentation, I would not make any changes. Hopefully if jetting properly now, you are at risk of being down only a slight bit of HP with a fuel change.

In that vein, we had a customer stop by with a decent running FV a couple weeks ago. We made a few jet changes and picked up a solid 2+ HP. It also performed very well on the track.

SR Racing wrote:While on the subject....

Why are some running av gas in a relatively stock ACVW engine?

It is a high octane (100) slow burning fuel meant for under 4000 RPM at high altitudes. (Actually it is NOT 100 octane(RON+MON/2) using the automotive measurements. It is measured at different intake pressures and temps. It is well under the 100 octane. The FV engine is under 8:1 compression ratio. Pump gas at 91-93 octane is plenty for these engines. (and cheaper) WIth MORE energy (BTU) and more HP when tuned for it.

The ONLY positives to Avgas: Arguably it has better quality control. (However any name brand busy gas station pump gas is fine.) Avgas is less prone to vapor lock. You ever had vapor lock on the track at speed? Nope. Since we have only mechanical advance distributors, if you are pulling a boat and run at 3500 RPM and under, Avgas MIGHT help a bit to prevent spark knock. (Since we are at full advance at 2000 RPM+. If you run at 10,000 to 30,000 feet altitudes, I would use it.

If you don't meet the above criteria you are LOSING HP and Throttle response. E-10 ~93 octane is excellent for our engines. It burns at the highest peak pressures during the power stroke and doesn't waste fuel or BTU. It's cheaper. The ethanol (10%) runs slightly cooler (more fuel per lb of air and even more energy.) If you are running CR's of 11:1 you can use Avgas (but race gas is better.) We don't need or want the lead in 100LL, but if you want it, add some additives.

Other than the ridiculous fuel tests that the SCCA initially used, I have no idea how this Avgas thing became in vogue. We have been using street pump fuels for 20 years (except those years when fuel testing prohibited it. When doing SG tests and jetting properly a pump fuel will ALWAYS better out Avgas.

There are some very expensive race gas concoctions with flame front enhancers, etc. that can give you better HP, but I suspect most aren't using them.

Re: the issue of fuel cells. Proper care (for us anyways) has eliminated fuel cell issues. I have owned, raced and rented up to 4 cars per season for those 20 years and have yet to replace a cell.
Call Fuel Safe or ATL and they will tell you not to expect more than 5 years out of any cell no matter what fuel you are using. (E10 or not). We have had them in used for much longer than that.

Like very high octane fuels, AvGas is NOT better. It is a necessary evil for engines running in those particular environments. Private aircraft are hardly racing engines. (an ACVW isn't one either , but we do stress them and wnt the additional Hp.)

I think its about the LEAD, What do you think?

grimes34 wrote:I think its about the LEAD, What do you think?

Not sure of what you mean. If you mean people get Avgas for its lead content you may be right. (But it is still the wrong choice.) Lead (in fuel) is a octane improver and a lubricant of sorts. A fuel rated at 93 octane is 93 octane whether it has lead or not. However a 91 unleaded (eg.) can be made 93 with the addition of lead. Lead's lubricating or cushioning properties haven't been needed in automobile engines for years. VW announced long ago that their seats never needed lead.

BTW, excessive lead dirties up the cylinders and fowls plugs. (and of course the environment) Plus if you happen to have a wide band o2 system, it drastically reduces the life of the sensor.

In any engine you want the LOWEST octane that that engine will run on without detonation. Higher octanes burn slower and have less BTU content in most all cases. Madison Avenue has convinced people that high octane is good. It is ONLY a necessary evil. It is used when temps, high effective compression ratios (or turbos, etc) ) or environmental issues cause detonation.

Thankx Jim.

The consistancy

grimes34 wrote:


I think its about the LEAD, What do you think?

The consistancy and quality of avgas is far superior to any other affordable fuel.
You know what you are getting, everytime.
Good luck. Have fun!

problemchild wrote:You know what you are getting, everytime.

Yep. 100LL, for low piston speed aircraft, with less BTU and lower burn speed, for 15,000 ft.. Consistantly

+1