05-05-2021, 02:47 AM
(This post was last modified: 05-05-2021, 02:51 AM by Bob Culver.)
Depends largely on the shape and depth of dent in forehead preferred in a crash.
On the vacuum type a manual lever is essential. Mine has a home made one but the spindle may be ditto.As per Tony above gives you something to pass the time going uphill. Keeps you off the cellphone.
Dave Mann's observation intriguing. Original road tests of the early RN with updraught seemd to extract a performance better than later versions. Hardly to be expected if the venturi is smaller and the vacuum consequently greater.
At about 50 mph the 26VA recovers slightly to about one cycle per 10 secs!
With a Seven an accumulator tank would have to be the size of the car, and exhausted before moving off!.
The artifical vacuum suggests a myriad solutions. perhaps the passenger could be provided with a bike pump, seal reversed.
On the vacuum type a manual lever is essential. Mine has a home made one but the spindle may be ditto.As per Tony above gives you something to pass the time going uphill. Keeps you off the cellphone.
Dave Mann's observation intriguing. Original road tests of the early RN with updraught seemd to extract a performance better than later versions. Hardly to be expected if the venturi is smaller and the vacuum consequently greater.
At about 50 mph the 26VA recovers slightly to about one cycle per 10 secs!
With a Seven an accumulator tank would have to be the size of the car, and exhausted before moving off!.
The artifical vacuum suggests a myriad solutions. perhaps the passenger could be provided with a bike pump, seal reversed.