Av gas

[copterzach]

Does anyone one run avgas? I know that it is 100 octane low lead. Do you need to add lead addditive or run it strait? Compression is 10.5 to 1. Just wondering?

[YeLLowBoaT]

for 10.5 to 1 you don't need avgas( witch has lots of lead compared to auto fuels in the "good old days")
on cast iron you can run to about 9.8 on 91( unless is ca crapy gas then takes some timing out)
on al you can run up to about 10.5 on 91. ( unless its ca then like above take some timing out)
You should be fine with 93 octane that you can get in most places in the us.
You can cut your gas with avgas/race gas to get you up to the level you need.

[DaveA]

Does anyone one run avgas? I know that it is 100 octane low lead. Do you need to add lead addditive or run it strait? Compression is 10.5 to 1. Just wondering?
Agreed...10.5:1 with 93 octane shouldn't be a problem if you're correct on your ignition timing, but other factors come into play such as cam specs etc. More than I can get into without researching. There are several threads chock full o'info regarding the use of 100LL in boats with radical engine specs, and several board members that have a wealth of research knowledge about it's use. I only know to put it in airplane tanks, and still lament the loss of 80/87, but that's another story.
Search using the term "avgas" in here, gearheads, and v-drives. You'll have more than you can read in one night.
DaveA

[LakesOnly]

View a good AvGas link by clicking HERE. (http://www2.***boat.com/forums/showthread.php?t=53599)
LO

[IMPATIENT 1]

my compression is more close to 11 to 1 than 10.5 to 1 bbf, but i run super swill during normal outings and run 50% avgas on race days.i run a 200hp shot too, and don't like to do it alot on super, race fuel is hard to get here.my timing is all in by 3200-3300rpm's at 34 degrees total.

[olbiezer]

iam running 12.5 to one on 110 in a 496 hyd roller moter alum heads.....(dont mean to hi jack this thread but thougt it was related) can i cut the 110 at all? just food for thought i hate 110 at 7 $ a gal :argue:

[james]

I always use AV gas, It will increase the longevity of the motor besides if you happen to have all AV gas left in your tank over the off season it won't go bad. AV gas can sit up to 4 to 5 years before going bad. If you can do as I do, fill up at a small aircraft airport where they run singal engine planes. By FAA regulations the AV gas there has to be checked every 24 hours for water and other elements. Also when doing that make sure your grounded you will see a clamp and Ground wire near the pump, just clamp on the trailer.

[copterzach]

I happen to have all the AV gas that I can use for FREE. That is why I ask.

[YeLLowBoaT]

I happen to have all the AV gas that I can use for FREE. That is why I ask.
Shit then put some dombers in there and get that CR up to 12 to 1. :crossx:

[OkieDave]

I have run AV gas for years without issues. On my one of my current 557 BBF motors, I mix it half and half with regular 87 pump gas. It is 14.77 to one compression and I have a 230 shot of NOS on it. no problems.

[don johnson]

All I run is 100% Av Gas with Marvel. With Av at virtually the same price as premium, why not. The Marvel does wonders for the motor as well. When I went thru my motors last year we did not have to restrip the blowers and Littlefield made note that they can always tell a motor that runs Av Gas and Marvel by how good a shape the blower is in...

[shaun]

Also when doing that make sure your grounded you will see a clamp and Ground wire near the pump, just clamp on the trailer.
Just curious as to why the trailer, the boat doesn't have any metal touching the boat other than the bow eye and that connects to fiberglass... I'm assuming the ground clamp is to ground the vehicle that the gas is going into?

[james]

just thought I would ask. Has anybody took there Header off after running AV gas. What Color is a good color, or does it matter. Mine is a lite yellowish green. :)

[Sleek-Jet]

That's probably about right... on airplanes we like to see a nice white stack with a hint of brown... almost like a good spark plug... but we don't run water through the stacks on airplanes, so a greenish color is probably good...
Once that lead is baked on, it ain't comming off though...

[Bense468]

Add Marvel myster oil to the gas. Av-gas is really dry, fine for the motor, but is hard on fuel pumps and blower strips. The marvey mystery oil takes care of that for ya.

[james]

Thanks guys thats what I was looking for. I pulled all the plugs and of course the the worst one on Chevy's cylinder # 5, and all was good. So that white stuff is lead than??

[BUSBY]

Does anyone one run avgas? I know that it is 100 octane low lead. Do you need to add lead addditive or run it strait? Compression is 10.5 to 1. Just wondering?
check out the link to Rockett Brand ... (formerly 76 racing fuels) ...
http://www.rockettbrand.com/technicals/bulletins.htm
a lot of good information about fuel here ... call me with any questions at the shop ... we are Southern California's distributor for them as well as others ...
Brian

[Taylorman]

What comp ratio is avgas good up to?
How much Marvels to run per gallon?

[don johnson]

What comp ratio is avgas good up to?
How much Marvels to run per gallon?
For what its worth I am running 2 GT 572 CI Blower motors, each making 1,100 HP. They are running at 11 lbs of boost which effectively equates to approx 14 to 1 compression. However, I am running intercoolers which makes a big difference.... So tough to say what the effective compression is after you factor in the intercooler.
I run 4 ounces of Marvel for every 10 gallons.

[Taylorman]

So do you just drive up to the airport and fil'er up? Whats the price of AV gas compared to premium pump gas?

[Sleek-Jet]

So do you just drive up to the airport and fil'er up? Whats the price of AV gas compared to premium pump gas?
Here's what it goes for at an airport near you... I think...
http://www.airnav.com/airport/KLFT
Scroll down to the bottom of the page... a skosh more than premium...

[jfarrjl]

What is the difference between 100LL and Jet A? No experience with airplane fuel, however there is a sea plane base nearby. :idea:

[Clearlake Kid]

All I run is 100% Av Gas with Marvel. With Av at virtually the same price as premium, why not. The Marvel does wonders for the motor as well. When I went thru my motors last year we did not have to restrip the blowers and Littlefield made note that they can always tell a motor that runs Av Gas and Marvel by how good a shape the blower is in... How much marvel do you use ????

[mach1alaska]

What is the difference between 100LL and Jet A? No experience with airplane fuel, however there is a sea plane base nearby. :idea:
100LL is avgas jet A is kerosene more or less

[SmokinLowriderSS]

What is the difference between 100LL and Jet A? No experience with airplane fuel, however there is a sea plane base nearby. :idea:
Jet A turbine fuel is basically kerosene, and as such is not burnable in a gasoline engine, It would burn fine in a diesel, but deliver less power than diesel fuel due to the lower parafin wax content (basically none).

[james]

where can I get Marvel and what does it usually cost

[Sleek-Jet]

where can I get Marvel and what does it usually cost
All the autoparts stores sell it... couple bucks a quart usually. Look for a red container..

[Squirtcha?]

Everyday Price: $4.49
http://us.st11.yimg.com/us.st.yimg.com/I/rodi_1907_97659908
Marvel Mystery Oil can be added to gas or oil. It combats internal motor rust and corrosion, lubricates valves, piston rings, upper cylinder walls, and eliminates valve sticking. Keeps rings free and reduces piston and cylinder wear. Also keeps fuel pump and carburetor parts clean, eliminating the need for frequent adjusting. Marvel Mystery Oil retards formation of power dissipating motor deposits, such as gums, varnish, and sludge.

[Taylorman]

So does it do the same thing as Sta Build?

[Bense468]

I think its better because it lubricates

[3 daytona`s]

I have not seen this discussed here so,here`s my experience.I have been using Max Race for about 12 years.Price chemical company of Texas.Look up Max Race in search engine,all there products will be shown.Thay also have a detailed booklet explaining jetting mixture etc.Max race is 40% Nitro they also have Mighty Max which is 80% Nitro.They explain AV gas and Premium Unleaded I used to use Av but changed to Premium with 1 quart of Max Race to 10 gallons,which bumps it to approx.110.The product stays mixed also works as a stablizer for long periods of non use.I love it and hope this is of help.