BMC 9/16 Tractometer

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mark williams
Posts: 27
Joined: Tue Jun 20, 2023 2:24 pm
Wales

BMC 9/16 Tractometer

Post by mark williams »

does any one have or know where to get a tractometer for a BMC mini 9/16
or something that will work and be made to fit


thank you

mark


mark williams
Posts: 27
Joined: Tue Jun 20, 2023 2:24 pm
Wales

Re: BMC 9/16 Tractometer

Post by mark williams »

can any one tell me where the leyland 154 and Nuffield 4-25 get a 3:1 taco speed from ?
and the leyland mini has a 2:1 but seam to use the same angle box from the cam drive

thanks in advance

mark
Ley154
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Location: Gloucestershire UK
Great Britain

Re: BMC 9/16 Tractometer

Post by Ley154 »

Hi Mark, if you want to be authentic www.tractorspareparts.co.uk has some original Smiths new tachos for the Mini, correct 2:1 ratio. John Poulter
Ley154
Senior Member
Posts: 256
Joined: Sun Apr 01, 2018 8:22 am
Location: Gloucestershire UK
Great Britain

Re: BMC 9/16 Tractometer

Post by Ley154 »

Hi Mark I started typing a reply to the 154 question and seem to have lost it so here goes again! If you want a replica rev counter for a 154 with the 3:1 ratio they are on ebay now made in India. Price varies from week to week and they may stay working or not in my experience. If you were asking why 3:1 its down to the ratio of the crank to camshaft and then the ratio between the gear on the end of the camshaft and its mating cable drive spindle. The right angle drives for the 9/16 and 154 are different - Charnleys list both but you could go straight to Speedograph-Richfield who makes them. John Poulter
mark williams
Posts: 27
Joined: Tue Jun 20, 2023 2:24 pm
Wales

Re: BMC 9/16 Tractometer

Post by mark williams »

Ley154 wrote: Thu Aug 17, 2023 7:27 am Hi Mark, if you want to be authentic www.tractorspareparts.co.uk has some original Smiths new tachos for the Mini, correct 2:1 ratio. John Poulter
They have no more in stock John when I looked last week they were available
Now it says phone for price.
I have phoned and they have no more
mark williams
Posts: 27
Joined: Tue Jun 20, 2023 2:24 pm
Wales

Re: BMC 9/16 Tractometer

Post by mark williams »

mark williams wrote: Thu Aug 17, 2023 8:22 am
Ley154 wrote: Thu Aug 17, 2023 7:27 am Hi Mark, if you want to be authentic www.tractorspareparts.co.uk has some original Smiths new tachos for the Mini, correct 2:1 ratio. John Poulter
They have no more in stock John when I looked last week they were available
Now it says phone for price.
I have phoned and they have no more
I have repaired my original angle box as the short bit of flexible drive has sheered off,
I opened the box and drifted the remaining bit from inside drive cog
Then cut a short price from the end of a BMC mini ( the car) Speedo cable and epoxy resined it to the ferrule and inside drive cog

What are the differences between the 9/16. And 154 angle boxed John ?
Ley154
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Posts: 256
Joined: Sun Apr 01, 2018 8:22 am
Location: Gloucestershire UK
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Re: BMC 9/16 Tractometer

Post by Ley154 »

On the 9/16 the threaded boss in the block is 19mm diameter fine thread, replicated on the output side of the right angle drive which also reverses the rotational direction. On the 4/25 and early 154 there is no right angle drive and the boss on the block is 22mm dia - see photo. Later 154's have the right angle drive with a 22mm collar to screw onto the original boss and a shorter cable again with a 22mm attachment collar. I can't remember if this drive is clockwise to clockwise or reverses. Even more recent Marshal 302's have a coarse thread boss and need yet another style right angle drive. I can't remember if I told you that if you just want to read the revs then you can use a 39 inch cable from a Mini Van , dispense with the right angle drive altogether and use an anti-clockwise 80mm dia rev counter from an IH414 which has the correct 12mm thread for the cable. If you don't want the bonding to shear make sure there is no friction in the cable or rev counter. JohnP.
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mark williams
Posts: 27
Joined: Tue Jun 20, 2023 2:24 pm
Wales

Re: BMC 9/16 Tractometer

Post by mark williams »

thank you John P
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