Fuel- 1967 427/435

[Domenic T.]

Re: Fuel- 1967 427/435

Michael,
All advise is good here. Av gas is not all that easy to get but other than the advantages of performance is the fact that it will not turn to varnish and will last in a fuel system for many many years.
I have worked on planes that were not ran for over 10 years and found the fuel in the tanks in great shape.
In my experience av-gas seemed to run a bit better when blended with pump gas. I have a mix in my displayed motorcycles and they instantly start after years of sitting. I guess what I am saying is that I use it as a preservative when long term storage is needed. I am also licensed to, and have worked on airplanes since the early 70's and never saw a bulletin that recommended old gas be removed before flight.
The gas formula experts here may know why it has no shelf life, at least I never knew of a shelf life for av-gas.

Dom

[Michael W.]

Re: Fuel- 1967 427/435

The gas formula experts here may know why it has no shelf life, at least I never knew of a shelf life for av-gas.

Dom

Since you asked:

http://spirit.eaa.org/autofuel/autogas/articles/1What%20is%20the%20shelf%20life%20of%20avgas_.pdf

[Domenic T.]

Re: Fuel- 1967 427/435

Michael,
Than for the info. I will post it and find a good place to burn the old av-gas. There is a guy here who does not fly his plane but drains it every year and refills with fresh. Then he uses what he drained in his old truck.
I printed the page out and maybe can get some year old gas.

DOM

[Tim G.]

Re: Fuel- 1967 427/435

I have a very original '67 427/435 and I always splash a bit of leaded 110 in it. I usually add about one gallon to five gallons of 93 pump gas. All of our gas in central Texas has ethanol, no way around that. The beast runs well with this mixture.

[Robert D.]

Re: Fuel- 1967 427/435

I have a speed shop by me that orders 5 gallon drums of 98 and 104 octane leaded gas ethanol free my understanding is that the compression in a L-71 motor likes octane ratings between 98 and 106. when i use anything with ethanol hot starts are a nightmare ever since i switched to this my car runs much much better

[John S.]

Re: Fuel- 1967 427/435

I burn avgas in all my cars that do not have O2 sensors, never goes bad and has some lead to lube the old guides. The tailpipes have perfect color and it smells different, so those who know can tell you burn avgas 100LL.

[Duke W.]

Re: Fuel- 1967 427/435

... my understanding is that the compression in a L-71 motor likes octane ratings between 98 and 106.

Which octane rating method are you referring to?

Duke

[Robert D.]

Re: Fuel- 1967 427/435

Duke
here is a link to the fuel i use it is made for our cars leaded and no ethanol hope this helps this stuff is great a little pricey but our big blocks arent chep either
http://www.vpracingfuels.com/vintage they use R+M/2

Bob

[Michael W.]

Re: Fuel- 1967 427/435

Both of the fuels in the link have a RON of 100. That exceeds what the car required when new. Why do the cars need it now?

[Robert D.]

Re: Fuel- 1967 427/435

My car runs better better with it hot starts are better its the only access i have to ethanol free fuel as far as i know. Never said you needed it but its the best i have here so thats what i use its like night and day compared to the pump gas they have here.

[Michael W.]

Re: Fuel- 1967 427/435

If you're only having hot start problems and not detonation issues, there's better alternatives.

[Duke W.]

Re: Fuel- 1967 427/435

Avgas and race gas have higher mid range boiling points than any commercial E10 blend, so the primary benefit is likely the lower tendency to percolate. You can only determine if higher octane than your local pump premium is necessary by running some simple detonation tests, and converting ported to full time vacuum advance with a proper VAC that meets the Two-Inch Rule will reduce any tendency to detonate by lowering EGT and combustion chamber surface temperatures.

There are also other ways to reduce percolation such as wiring open the heat riser valve and insulating fuel lines that have been discussed here extensively. These steps will reduce fuel line and carb. bowl temperatures and should allow the use of commercial pump gas with no or minimum driveability issues.

Avgas and race gas are about double the price of pump premium in addition to the logistics issues, and I believe in the long run, the simple solutions to mitigate percolation is a better solution for most owners.

Duke

[Domenic T.]

Re: Fuel- 1967 427/435

Michael,
Maybe they don't need it but I think they want it. I can tell a huge difference over the best pump gas I can buy. I think most users will agree that life is good with it in the tank. Back in the day when we dialed SUNOCO gas, I dialed more than what was required and could tell the difference.
My test method is simple. With the car in 1st gear, about 10 MPH I step on it. With pump gas it may burn the tires a little, but with the better fuel the car wants to swap ends.
Putting a little more than is required can be better for the higher compression engines. I see posts referring to high compression engines that are really not high compression any more. Many are putting low compression pistons and thicker head gaskets in their engines so they can get along with today's fuel. They have made a low compression engine out of a high compression engine. If that is what makes them happy then so be it. I like the high compression pistons, thin head gaskets, and milling for a little more compression than the engine was born with.
My engines will not run on today's fuel if I use factory tuning specs. All this is great if you stay close to home. When driving long distance it's a different story. I might add that I used water injection on long trips to stop the pinging and it worked great. Worked good with a single carb but not so with 3 carbs.
Your point is well taken and I have tried it.

Dom