3.25 ratio crownwheel & pinion

[Graham Freeman]

Asking on behalf of a friend here in NZ.
Has anyone had any experience with running a 3.25 : 1 crownwheel & pinion in a 46 mercury.
Car has stock running gear but on 195/70 x 15" radials.
Car is mostly used in flat country running.
Just looking for a few less revs at 60mph.
Also what ratio would be required for the driveshaft turtle?
Thanks
Graham

[Mart]

Would a pair of tyres closer to stock size be easier?

[35fordtn]

You’d need a 17 tooth speedometer drive to even be close. A 3.25 gear is my preferred choice but it’s hard for a bone stock engine to pull. My cars that have the 3.25 have the 29/15 transmissions gear to make taking off from a dead stop a bit easier

[38 coupe]

A 1946 Mercury should have 3.54 gears from the factory. Given the weight of the car and the New Zealand roads I personally would not want to go higher speed gears than the 3.54. I had a friend with 3.25 gears in a 47 Ford sedan and he wanted to go down to 3.54s.

[pistonbroke]

Sponsored Links (Register now to hide all advertisements)

That would be the tallest I would go as I put a 3.00 9" in my 42 pickup and it was just barley drivable with a stock 8cm and 70 series 15"s. If you do mostly out of town driving I think 3,25 would be perfect and in town acceptable. Tim