1936 Ford flathead - is a fuel additive required
 

Hi Guys
So many different ideas on a 1936 ford flathead as in type of fuel is best
So are you better to use 91 or 95 grade fuel ??
Do you need a fuel additive??
Then got told better of to put little Wynn's or moreys upper cylinder lubricant to prolong life of engine and valves
Correct or incorrect

Re: 1936 Ford flathead - is a fuel additive required
 

70 octane would be OK as compression ratio is very low like 5-6. Modern motors are 10:1. Super is a waster of money. What is the octane rating in Auckland? Research octane? Here in the states it is (research + motor)/2

1936 Ford flathead - is a fuel additive required
 

I’m curious what others will say... I use 87 unleaded normally and 89 on rare occasions if 87 is not available. They say you have a cleaner burn the higher the octane and is more efficient. Maybe for newer cars that require the premium but not for me.

Ethanol free gas is the way to go for these cars since ethanol will break down over time and gum out and attack certain gaskets.

Then I use a lead substitute by adding 18mL per gallon of gas. Lead substitute acts like a stabilizer for gas by the way just don’t use it on modern cars. =P




Sent from my iPhone using Tapatalk

Re: 1936 Ford flathead - is a fuel additive required
 

We do thousands of K,s in our 33, towing all over Australia,
we use 91,no additives and no worries, remember the engine has hardened valve seats and modern valves .
Lawrie

Re: 1936 Ford flathead - is a fuel additive required
 

If like Australia.. 91 is fine and yes a little additive, if it doesn't have hardened seats.

Re: 1936 Ford flathead - is a fuel additive required
 

A cap full of ATF with every $20 gas might help, if you don't have anything else. I do it.

Re: 1936 Ford flathead - is a fuel additive required
 

I have several comments for you, take it or leave it:

87 is fine, you got that right.

Higher octane cleaner burn more efficient? Higher octane may be more efficient for a high compression engine, as it burns slower, producing a continuous burn throughout the power stroke, preventing knock. For a low compression engine like the flathead, the knock won't happen unless your timing is way out of spec. As for cleaner burn, that would be related more to the oxygenation rather than the octane.

Ethanol free is certainly preferred for our old cars for the reasons you stated, but curiously, ethanol raises the octane, and will also help prevent carbonization in the cylinders.

Now, lead substitute... Lead was used to raise the octane, as it interferes with combustion, slowing down the burn. Coincidentally, it was found to help cushion valve seats as well. Stabilize fuel? I never heard that. And you're right, don't use it in modern cars, not that it would hurt the engine, but it burns up those expensive catalytic converters!

And by the way, if you have grandchildren, they are the reason lead was banned all over the place. It took us car guys a long time to relate to lead poisoning our little ones, but I for one don't want to put my great grandson in danger so I can drive a collector car.

Re: 1936 Ford flathead - is a fuel additive required
 

Lawrie gave you the correct information; your engine came from the factory with hardened valve seats in all holes, no need for additives. And yes, 91 will be fine...although I run 95 or 98 in my 35, partly as an aid in getting it to run quieter; it has 165 lbs compression and tends to want to ping a bit at certain loads/speeds.

Re: 1936 Ford flathead - is a fuel additive required
 

westie, I presume you have a Repco store near you. They sell FLASHLUBE which is an upper cylinder lube and valve saver to add to your fuel tank. There is also the Penrite VALVE SHIELD which is a popular additive. Both made in Australia. For fuel just use 91 octane in your flathead. I use these products in my original 34 Ford. Whatever you do don't use any ethanol blend fuel in your old car. Just for our USA friends 91 octane is the lowest fuel we use here in Australia. We also have 95 and 98 plus ethanol blends at our normal service stations. Regards, Kevin.

Re: 1936 Ford flathead - is a fuel additive required
 

Question, is a different octane rating method being used? There are different methods to calculate octane, does that account for the higher octane rating? In the US they are normally 87, 89 & 91 and a some locations 85. The method used is listed on the pump here, just above the octane number. In the case shown it is (R+M) / 2.

R is the Research Octane Number (RON) and M is the Motor Octane Number (MON). MON is lower than RON and the pump rating number is the two averaged.

Re: 1936 Ford flathead - is a fuel additive required
 

I've got over 60,000 miles on my engine using 87 octane non-ethanol fuel. NO additives.

Re: 1936 Ford flathead - is a fuel additive required
 

Octane is a rather mysterious and technical subject. Higher octane means more resistance to igniting by compression rather than spark. Igniting by compression gives knock, a sound that can be heard as a clattering noise. Higher octane doesn't burn cleaner or more efficient or "slower." Higher octane allows running higher compression which most of us don't do and stick to the very low 6:1 ratio of the v8 flathead. Shave your heads on a flathead v8 to raise the compression and you may need higher than 87 regular grade octane.

Research octane used to be the octane method before unleaded gasoline. Remember the old 100 octane(research) leaded gasoline? It would be equivalent to today's 93 octane(road) gasoline. When the USA started requiring unleaded some fuels started knocking in city driving at the same research octane. The EPA came up with the motor method which simulates city driving and required it also be satisfied.

Octane is measured on a standard one cylinder motor. An unknown sample is compared to a sample of known octane with an analog meter measuring knock. The knock engine laboratory I often visited in the refinery I worked at as an engineer had 8 or so engines going all the time and a cacaphony of knocking going on. The known octane samples are a mixture of n-heptane of 0 octane and iso-octane of 100 octane. Any octanes of greater than 100 are obtained by adding lead.

Regular gasoline is 87 octane a sea level. As elevation goes up octane requirements go down. So Regular is 85 octane in Denver at 5,000 feet.

Wish I had used no alcohol gas in my 49 Ford. I let it sit for a couple years without use and the in tank fuel pump and gas gauge rusted up solid from the moisture the alcohol had attracted. The tank is plastic so no rust there but cost me $200 to replace the rusted parts. It's a 25 mile trip one way for me to get no alcohol premium gasoline and costs $1 more than premium so $3.75 rather than $2.75 a gallon.

Re: 1936 Ford flathead - is a fuel additive required
 

I'm currently dealing with the same problem as MrTexas, rusted gas sending unit due to old ethanol gas. Problem is I cant find alcohol free gas in California (except racing gas, which is not really where I want to go..). Has anyone found a good stabilizer to add to corn gas to prevent moisture issues with low car usage? I've seen some but hard to tell which is better..

Re: 1936 Ford flathead - is a fuel additive required
 

Emmit, a lot of marine and boat guys use Startron.

Re: 1936 Ford flathead - is a fuel additive required
 

Why not make your own ethanol-free gas? Take a translucent five gallon plastic square container, add four gallons ethanol gas and one gallon water, and mix. Turn upside down and let it settle. The water will absorb the ethanol and settle to the bottom. Then simply drain off the water/ethanol mix, and what is left is pure, ethanol-free gas. Note: Premium 91/93 octane ethanol gas is made by adding ethanol to 87 octane regular (non-ethanol) gas so removing the ethanol from premium leaves you 87 octane real gas.

Re: 1936 Ford flathead - is a fuel additive required
 

Interesting. Thank you explaining ethanol free. It’s not worth my time, I’ll spend the extra few cents more for ethanol free at the pump.


Sent from my iPhone using Tapatalk

Re: 1936 Ford flathead - is a fuel additive required
 

Thanks Guys for all your Feedback - I get that 91 is recommended and not to use any fuel with Ethanol in it . Which in New Zealand is Gull Fuel which we are already avoiding as many companies have diesel utes and when using Gull Fuel are complaining they lack power and even though it is cheaper at the pump , you get way less distance driving, might even be a problem some are saying with injectors etc

Re: 1936 Ford flathead - is a fuel additive required
 

thanks Tinker! Will check it out

Re: 1936 Ford flathead - is a fuel additive required
 

I found this very interesting, and noticed there are a few guides online for doing this as well.



Problem is, I'm doubtful this would actually be useful. Sure if you add enough water to ethanol-gas, you will form a separate layer that is mostly water with ethanol, and draining this off would likely remove a good amount of ethanol from the gas. Problem is that since the ethanol also dissolves in gas, some will remain in the gas, and it will also dissolve water into the gas. This is basically the problem with old gas, water absorbs into the gas due to the presence of ethanol.


So, you can remove some ethanol, but will also add water into the gas. No disrespect intended to 40Deluxe, but I wouldn't do this.

Re: 1936 Ford flathead - is a fuel additive required
 

Well 90% of 87 and 10% of 113 gives me 89.6 which is slightly above mid grade. How do you come up with 91/93?

"In terms of its octane rating, ethanol has a rating of 113. " https://mnbiofuels.org/media-mba/blo...-for-beginners

Another web page says it is 109 which would give 89.2.