Hello Tim

Yeah some of the designs would have caused siphon problems. I am using a OS61RFP so shouldn't have too many worries.

I think if one sticks to designs and engines of the period then it should be OK. For example the Curare was suited to the non-pumped screamers like the webra and OS 61VF. As the noise requirements came in the engines changed to the long stroke engines like the Hanno and the plane designs moved to match.

Cheers
Tarquin