ghostrider20

I have run 100 octane Low Lead (100LL) in my vette, (off road of course!)
and have found it to be great. I try to run a 50/50 mix or if I run pure 100LL
I mix a bottle of Marvels Mystery Oil with it to compensate for the dry fuel.
If your out there Duke, I would like your opinion on this. What engine temps are ideal for 100LL? My car has 11:1 and I think the octane is essential.
If I run pump gas, I add a bottle of 104 booster, but still find myself turning the timing down. With the 100LL I can advance the timing back up. Plus it smells really neat when it is burned!!!

SWCDuke

I'm not certain how avgas octane is measured, but I think it is basically the same as the Research method so 100LL would have about the same antiknock qualities as the premuims from the sixties, but with a lot less TEL.

I'm sure it would be satisfactory in a vintage SHP engine with the original high compression ratio, but I don't understand your logic for adding Marvel Mystery Oil. I hope the gasoline I buy is "dry". Water in gasoline is not good.

As far as temperature is concerned, I'd recommend the OEM theromostat (180 or 195, whichever it is) and if you can run 38 degrees total intial plus centrifugal advance on a SB (40 on a BB) without detonation your engine should be able to put out maximum power.

I'm not a big fan of "octane boosters" and I question their effect and economic viability. I think you're better off working out and appropriate blend of commercially available fuels that will allow the engine to operate detonation free.

Duke

ghostrider20

In high school I worked at an airport refueling aircraft. I had to test the fuel product occasionally. The 100LL is actually about 115 octane. It always tested 114 to 116 octane. I was told by a rep that this was to ensure that it was 100 octane, an aviation safeguard. When I say DRY I mean it is not very oily. I add the Marvels for upper valve lube only. Do you think it hurts?
I have been adding marvels to my airplane for a few years and it has saved greatly on valves and jugs. But those are air cooled engines and there temps can get much higher.
Thanks for the input duke!
Mark



[Modified by ghostrider20, 7:36 AM 2/8/2002]

Weasel

I agree,the smell is great.But,get a case of real lead from Jack Podel. P.S. I hope I'm allowed to say that.

67435animal

Octane boosters are a waste of money. I tried TEL as suggested but the results were unsatisfactory (in a 67 400CI 442 engine).

I mix Sunoco 112 leaded with (not so) Super Unleaded to achieve a 100 octane level.

You probably do not need to add upper cylinder lubricant but it won't hurt.

Since you have avgas available, continue to use it; I tried to buy it and they would not sell it to me.

SWCDuke

[QUOTE]In high school I worked at an airport refueling aircraft. I had to test the fuel product occasionally. The 100LL is actually about 115 octane. It always tested 114 to 116 octane. I was told by a rep that this was to ensure that it was 100 octane, an aviation safeguard. When I say DRY I mean it is not very oily. I add the Marvels for upper valve lube only. Do you think it hurts?
I have been adding marvels to my airplane for a few years and it has saved greatly on valves and jugs. But those are air cooled engines and there temps can get much higher.
Thanks for the input duke!
Mark

[QUOTE]In high school I worked at an airport refueling aircraft. I had to test the fuel product occasionally. The 100LL is actually about 115 octane. It always tested 114 to 116 octane. I was told by a rep that this was to ensure that it was 100 octane, an aviation safeguard. When I say DRY I mean it is not very oily. I add the Marvels for upper valve lube only. Do you think it hurts?
I have been adding marvels to my airplane for a few years and it has saved greatly on valves and jugs. But those are air cooled engines and there temps can get much higher.
Thanks for the input duke!
Mark


Gasolines typically have poor lubricating qualities, but lubrication quality is not necessary on carbureted gasoline engines or modern EFI engines. Diesel does have some lubricating qualities; it's necessary for their precisely machined close toleranced mechanical fuel injection pumps.

"Top end" lubrication in a gasoline engine is provided by the small amount of oil that slips through the valve guides and past the piston rings. So called "top end" lubricants are snake oil IMO. They just burn with the other hydrocarbons during combustion.

I'm curious how you tested gasoline at an airport. Octane testing is done using a variable compression ratio CFR engine according to standarized tests. The two major tests are Motor Method" and "Research Method", but aircraft fuels might have a different test. Octane testing is normally done by the refiner/blender and is essentially a continuous operation as the new product is produced. For aircraft fuels, no doubt, there are FAA standards that must be followed by both refiners and FBOs.

So how did you determine the octane rating of 115 and which rating was that.

Duke

ghostrider20

Duke-
We packaged a small sample (about a quart) and delivered it to our
supplier across town with the other samples (jet fuel). They did the testing, How I am not sure. So I should correct myself, I just drew and packaged the samples. We called it testing because we did water tests and gravity tests (twice daily) as well. (The gravity test consisted of a sample in a large beaker, we then inserted a sealed glass tube, much like a thermometer, and noted on a scale were it floated at.) This gave the density of the fuel. So fuel loads could be accurately measured. Large planes use pounds, not gallons. Everything is in pounds per hour of burn, etc. They would send the results in the mail or deliver them. The octane was usually 114, 115 or 116. And there were some other figures about "flash-point" and "micro-organisms". I guess there are living things in the jet fuel? Not very big, but there was a test for them. I only saw the results a few dozen times. I was not in charge of deciding if these figures or the other information was acceptable, I just happen to arbitrarily be the middle-man. So I averaged the 115 number. Curiosity is the only reason I cared at the time. We used to do it weekly, now I guess they do it less frequently. (The supplier does this now) It has been 8 years since I worked there so all the info is hazy.
For those who care! you can go to your local refinery and purchase 100LL, I think a 55 gallon drum is the minimum. But it is illegal to burn it on the street, my guess is because you are bypassing road tax (again only what I was told)! Where I live, I don't think anybody cares, (IF I were to drive it on the street). It has a very unique smell when it burns, so if you did run it in your vette, anybody behind you, if they are familiar with the smell, will notice it. (most of the world would just think your car smelled different, not many people know what burning 100LL smells like, much like alcohol). A 50/50 mix of 93 octane pump gas and 100LL is less noticeable and still yields a good mix. Were I live 93 octane pump gas last summer was $1.95 a gallon. CAM 2 racing fuel with a 114 octane was about $5.75 per gallon. The 100LL from the refinery was about $1.75 per gallon @ 55 gallon purchase. (bring your own drum). So it was a matter of money. I was spending $10 dollars a tank for octane boosters, that IMO did nothing. I will stop using the Marvels duke if you think that is not useful. I Just had such great results in my plane with it that I thought I would give it a try.
PS – 100LL CANNOT BE USED WITH A CATOLYTIC CONVERTER OR O2 SENSORS, I WAS TOLD IT WILL DESTROY THEM.


Thanks agian duke-
Mark
65 Coupe, Nassau blue, 327/365

WB6HRO

Aviation gas is measured in lean mixture and rich mixture so there are typically two numbers except 100 LL. The low lead means lower than 100 / 130, which fouls plugs alot easier. They also put dye in each octane to identify it. The dye goes clear if you mix it, so you know it's not stock, big concern in aviation. As you can see from octanes if the ocatane is not high enough to keep it from detonation, a richer mixture will help.


80 / 87 Red

100 / 130 Green

100 LL Blue (really 100 / 130)

145 / ? Purple (Haven't seen this for 30 years)