Fuel for 1923 roadster

[Guest Gary turbo baker]

Hello all can any one tell me the correct fuel to use.

[Grimy]

If a it's stock engine still with compression about 4.5 to 1, use cat p*ss regular (i.e., lowest octane available, 87 here).  That doesn't mean low quality gas:  in my relatively-infrequently used vintage cars I usually use Chevron or Shell for their additive packages at least half the time. 

[Guest Gary turbo baker]

Thank you Grimy cheers

[dwollam]

There wasn't any lead or high octane back then. Run the cheapest stuff you can find.

 

Is that an Aussie bodied roadster? They are different than ours in the states. Nice looking!

[Guest Gary turbo baker]

Yes it is a Aussie one how is it different ?

[dwollam]

Appears different from the back of the cowl on back. I think they were shipped with no body from cowl back, then body produced "down under". Rear pics?

[C Carl]

Gary , here from Marks' "Mechanical Engineers' Handbook" , 3rd Edition , June 1930 is a smoking gun (pun ?) of sorts. Bear in mind gasoline in 1923 was 40 something octane. A foul mixture if the text and distillation curves are to be believed. You probably suffer some significant undesirable intake heating as did cars late 'teens through '20s and beyond. Pick whatever easy remedies for this , such as blocking heat source (exhaust) , and breaking whatever thermal bridging to your intake manifold as is reasonably possible. If pure alcohol free gasoline is available where you live , get the lowest octane you can find. Many of us shut off the fuel supply to the carb and let the engine run the gasoline out of updrafts for shutdown at the end of the day for safety reasons. Safety ? Safe driving is delightfully slow driving in these old cars.  - Carl