Honda’s Turpentine Engine

[Mgt3]

TL;DR Summary

How did Honda effectively substitute turpentine for a gas/oil mix in a 2 cycle engine?

Honda’s first motorcycle was powered by a 2 cycle engine that ran on straight turpentine instead of a gas/oil mix. How were they able to do that without burning up the engine. If someone wanted to replicate this, would adding graphite to the turpentine improve lubricity?

 

[Baluncore]

I thought turpentine was a good lubricant.
Turpentine was once a blend of distilled terpenes from pine trees.

Turpentine substitutes, derived from the petroleum industry, are called "mineral turpentine", "white spirit", or "petroleum spirit". They may not have the same lubricant properties as the original distilled tree turpentine.

Why add graphite for better lubricity, when two-stroke oil is widely available.

 

[Rive]

Honda’s first motorcycle was powered by a 2 cycle engine that ran on straight turpentine instead of a gas/oil mix. How were they able to do that without burning up the engine. If someone wanted to replicate this, would adding graphite to the turpentine improve lubricity?

A lot depends on translations and in case of old stuff, on changes of terminology.
I may be wrong but I believe that specific 'turpentine' was somewhere halfway between gas and gasoline in properties. In Europe in some areas it was known as 'lamp oil' - which is not the same lamp oil you can buy now.

 

[Mgt3]

A lot depends on translations and in case of old stuff, on changes of terminology.
I may be wrong but I believe that specific 'turpentine' was somewhere halfway between gas and gasoline in properties. In Europe in some areas it was known as 'lamp oil' - which is not the same lamp oil you can buy now.

In that case would it need added lubricant?

 

[Rive]

If your question is about operating an oldtimer bike (for an exhibition or a show) then you should not trust any opinion except owners and successful operators of such engines. Oldtimer owners or collectors are usually a helpful community - once you find them.

If it is about brewing up some alternative fuel/engine, then just don't. It'll violate several regulations.

 

[Mgt3]

If your question is about operating an oldtimer bike (for an exhibition or a show) then you should not trust any opinion except owners and successful operators of such engines. Oldtimer owners or collectors are usually a helpful community - once you find them.

If it is about brewing up some alternative fuel/engine, then just don't. It'll violate several regulations.

If your question is about operating an oldtimer bike (for an exhibition or a show) then you should not trust any opinion except owners and successful operators of such engines. Oldtimer owners or collectors are usually a helpful community - once you find them.

If it is about brewing up some alternative fuel/engine, then just don't. It'll violate several regulations.

I’m just trying to recreate the original bike. No one seems to know about the original fuel mixture.

 

[Flyboy]

Given the historical context of the time period when that engine was fielded, I think there’s no reason to pursue an exact replication. It was introduced fairly quickly after WWII, in 1947, and gasoline was still only available in limited supply. Traditional turpentine, as derived from pine products, was much more available. It wasn’t the best fuel choice by any stretch, but it made logistical and economic sense at the time.

 

[jack action]

Why add graphite for better lubricity, when two-stroke oil is widely available.

This

 

[Baluncore]

It seems with waste wood pulp, the first heating and distillation gave "lamp oil" as a pure wood turpentine of high value, less than 1 kg from each 1000 kg of product. Too valuable to be used as a fuel.

The pulp product was then fermented. A distillation then removed the alcohol with more crude turpentine produced, that would be similar to gasoline with two-stroke oil. I believe it was that ethanol/methanol, with the secondary turpentine kept as lubricant, that was used as two-stroke fuel in post-war Japan.

That distillate would smell like turpentine when burnt as fuel, but the fuel value came from the greater ethanol and methanol content. The rider would not know exactly what they were burning, while the actual post-war recipe, has been lost in time.

Methanol is toxic "wood alcohol", but the fermentation employed would have produced a majority of ethanol. (Methylated spirit is ethanol, deliberately contaminated with bittering agents, to prevent human consumption). By calling the ethanol based fuel "turpentine", it would be expected to be toxic, so would not be consumed as ethanol by the rider.

https://paper360.tappi.org/2019/03/...-near-forgotten-turpentine-powered-motorbike/

 

[Mgt3]

Thanks! If I’m reading that correctly, was the turpentine the lubricant in the methanol?

 

[DaveC426913]

...somewhere halfway between gas and gasoline in properties...

Are those ... different things?

(I mean, sure, gas is a generic term that includes gasoline. But how do you make a side-by-side comparison?)

 

[Baluncore]

If I’m reading that correctly, was the turpentine the lubricant in the methanol?

Yes, but I suspect the alcohol produced by the fermentation stage was ethanol, not the more toxic methanol.

"Wood alcohol" can refer to ethanol, produced from a wood feedstock. Methanol was called "wood alcohol" because it was originally produced from wood.

By cooking the wood-waste in dilute sulphuric acid, the cellulose polymer, a polysaccharide, was broken down into monomers of glucose. That could then be fermented with brewer's yeast, to produce ethanol. Turpentine, released later during the cooking stage, was not digested, so became a lubricant in the ethanol fuel that was distilled.

https://en.wikipedia.org/wiki/Cellulose
https://en.wikipedia.org/wiki/Cellulosic_ethanol

 

[Rive]

Are those ... different things?

Those area-dependent names kills me: quite possible that I've messed up.
There is that lighter stinky stuff, and there is that thicker stinky stuff.

 

[Baluncore]

Those area-dependent names kills me.

On a scientific forum, gas is a state of matter. Gasoline should be referred to as gasoline, benzene, or petrol.
"Gas" as a fuel, can then refer to LPG, CNG, or maybe hydrogen.

 

[DaveC426913]

Those area-dependent names kills me: quite possible that I've messed up.
There is that lighter stinky stuff, and there is that thicker stinky stuff.

Genuinely curious: do gas and gasoline mean different fuel types where you hail from?

Ooh maybe 'natural gas' which is distinct from gasoline?

 

[Rive]

where you hail from?

Here it's benzin (the light stinky) and (as translated word to word) gas-oil (the thicker stinky, for diesel engines).

I give up, I think. Never, ever managed to find the right words and this always ends with confusion and lengthy clarifications afterwards

On a scientific forum, gas is a state of matter.

You won't get too far with that from the filling station.