What Octane for a Stock 2F Engine?

[Solace in Solitude]

Hey,

I'm so new that my first (1978) FJ40 hasn't yet been delivered - seller's upholsterer screwed up and reupholstered my front seats, instead of the '71 seats he was supposed to do.

At any rate, I've searched and found only three references to 'octane' for the 2F engine.

The only reference that was specific basically said, "...re-bored and still run 87 octane..." - one reference said "...may need 91 octane...".

Mine is supposed to be stock, since there have been many changes to gasoline since 1978, is there a consensus as to what octane I should run?

Thanks - here's a picture of my engine (I know the battery bracket is missing :

 

[AdamKFarmer]

Haha! Put 85 in there and call it a day. These aren't sports cars

...via IH8MUD app

 

[JohnnyC]

This thread is a good read...

This is a link... Clickit>>>https://forum.ih8mud.com/40-55-series-tech/784473-fuel-do-you-give-your-f-2f-engine-why.html

 

[FishTacos]

I think you can burn muddy river water in a 2f with only minor negative consequences.

I just get the cheap stuff for my Fj60 and I put some sea foam in each fill and stabil in when it is going to sit for more than a week. Just my .02$

 

[1911]

Stock 2F is only 6.8:1 compression ratio, so anything more than the lowest-octane regular is a waste.

 

[Solace in Solitude]

Thanks everyone! And thanks for the link JohnnyC - I missed that one!

 

[Sethro60]

Just to throw in another opinion, I run 91 in both of my 40 & 60 series. I have been told that in Japan where these were designed and build 91 octane would be mid or low grade gas, so the engines were designed for that. I'm not sure I'm right, but I always put the good stuff in my toys.

 

[Spike Strip]

Use lowest octane available. If it pings, move up to the next. If you go any higher and it's not pinging, you're wasting money.

 

[Fast Eddy]

Just to throw in another opinion, I run 91 in both of my 40 & 60 series. I have been told that in Japan where these were designed and build 91 octane would be mid or low grade gas, so the engines were designed for that. I'm not sure I'm right, but I always put the good stuff in my toys.

You're wasting good money. Higher octane is not 'better' gas. It will prevent detonation in higher compression engines, which a 2f is not.

The river water comment is not far off. LOL.

 

[Solace in Solitude]

Well...

akingf5371 says "it's not a sports car"... Well,

it's the closest I've ever been to owning a sports car - first time I ever bought a vehicle 'just for fun'!

FishTacos says "muddy river water would probably work" - I won't go that low - he, like others 'burn cheapest' - '...anything more than lowest octane is a waste'.

Others, like Sethro60 and Claudia (in the link that JohnnyC sent) are more comfortable running the best fuel they can get.

And others, use additives.

So, I think the consensus is that 'we should run whatever fuel and/or additives we are comfortable with'.

Thanks for all the great information!

When my 40 arrives, I'll start 'playing with it' and see what gives the best performance and best comfort level, at the best price.

Thanks again!

 

[multimediasmith]

My 79 2F is running really smooth now... especially since my oil now has the correct zinc content for the rockers. I have always tried to run non ethanol gas and have my regular stations located. At one point, I was experiencing some detonation and even loud scary backfires... I switched to premium non-ethanol and voila, the backfiring was cured.

 

[crazyjakedana]

on my 2F if i ran anything over 85 it didnt run very well then with my 350 carbed it would only run great on 89 91.

 

[bsevans]

I've been running premium for 29 years. The only time it has pinged is when regular was the only grade available. Most of my driving is 2000 to 7000 feet in Altitude.

 

[45Kevin]

Dish water.

You think they get the good stuff in the middle of the jungle? Or that it was delivered from the refinery yesterday?

They are made to run on low quality gas.

If it makes you feel good to buy premium, go for it but you will be wasting your $$.