Hi All
Sorry another PA speedo question.
The speedo now has new balls in it’s bearings, it has been lightly oiled and works almost without a quivering needle ....... but it reads slow. About 30% according to my mobile phone app. I’ve verified this with my cordless drill that has a 1500 rev/min maximum speed. Attached to the speedo it reads about 27mph.
The excellent chart by Ron Burchett suggests that the A7 speedo has 35mph at 12 O Clock on the dial, which mine has. The chart also states that there should be 2240 revolutions per mile. If my calculations are right (and I’d welcome them being checked) that means 1500 r/min on the speedo input should read 40 mph. So it is about 30% under allowing for the drill not delivering max power.
I attach a photo of the back of the speedo. Can anyone please identify if it is for an Austin Seven (44 to 9 diff and 19” wheels)? Or is it from a different car?
I guess the best option is a 1.3 to 1 gearbox? Simply refacing the dial will mean the odometer is out.
Cheers
Howard
Sorry another PA speedo question.
The speedo now has new balls in it’s bearings, it has been lightly oiled and works almost without a quivering needle ....... but it reads slow. About 30% according to my mobile phone app. I’ve verified this with my cordless drill that has a 1500 rev/min maximum speed. Attached to the speedo it reads about 27mph.
The excellent chart by Ron Burchett suggests that the A7 speedo has 35mph at 12 O Clock on the dial, which mine has. The chart also states that there should be 2240 revolutions per mile. If my calculations are right (and I’d welcome them being checked) that means 1500 r/min on the speedo input should read 40 mph. So it is about 30% under allowing for the drill not delivering max power.
I attach a photo of the back of the speedo. Can anyone please identify if it is for an Austin Seven (44 to 9 diff and 19” wheels)? Or is it from a different car?
I guess the best option is a 1.3 to 1 gearbox? Simply refacing the dial will mean the odometer is out.
Cheers
Howard