Posted: May-06-2008 08:33AM

"but then it will quit soon anyhow."....lol.....I hear that.

It's one of the later (nippon?) speedos, maybe the odometers are better.

A FATHER CARRIES PICTURES WHERE HIS MONEY USED TO BE 

1130cc, 12g295, SW5 cam, LCB, HIF38, CA spec.

Posted: May-06-2008 07:52AM

Do not change anything.

There is about a ten percent difference, and your speedo will likely be ten percent out, so it will read more accurately with a 3.1.  The odometer will possibly be less accurate, but then it will quit soon anyhow.

Posted: May-06-2008 07:02AM Edited:  May-06-2008 08:43AM

crap...made a mistake in first post.

Motor is going into a car with 12"....forgot the numbers...165/60?  will check at lunch
But...a friend is also installing a 3.1 with 10", 145's

A FATHER CARRIES PICTURES WHERE HIS MONEY USED TO BE 

1130cc, 12g295, SW5 cam, LCB, HIF38, CA spec.

Posted: May-06-2008 07:00AM

10"....165/70

Thanks for all the tips/links

A FATHER CARRIES PICTURES WHERE HIS MONEY USED TO BE 

1130cc, 12g295, SW5 cam, LCB, HIF38, CA spec.

Posted: May-06-2008 04:14AM

http://www.guess-works.com/Gearbox/ratio.htm

Play around here - it might help.

Nothing is so bad that you can't make it worse by doing something rash or going berserk.

Posted: May-05-2008 02:54PM

1280 and 1300 are not that far off, so your choices may be the same with slight differences for the tire/wheel diameter.

The 7 blue/17 white combo I got from a UK board a while back, but the post has fallen off that board.
The 6/16 combo was from a USA mini supplier with a custom pinion they provided.
then the Calver suggestion of 7 blue/16 green

My original combination(correct for the 2.76 - 7 yellow/15 black) read high with a 3.1, so it seems logical that the lower combination (6/16) would make sense. But the other sites suggest otherwise.

As Calver mentioned in his article it may be easier to have the speedo head recalibrated. Hopefully someone can explain the math to me and help you out in the process.

Posted: May-05-2008 01:40PM

1280

A FATHER CARRIES PICTURES WHERE HIS MONEY USED TO BE 

1130cc, 12g295, SW5 cam, LCB, HIF38, CA spec.

Posted: May-05-2008 01:13PM

With your expected spindle drive gear being a standard 6 tooth, according to Calver's article you would need to change both the spindle drive gear and pinion.

7 tooth blue

16 green

3.1

Which speedometer head do you have or what is the TPM marked on it?

I am only going off what I have read and can not figure it our for myself, so I am not sure I should be trying to help someone else.

Posted: May-05-2008 12:49PM Edited:  May-07-2008 07:09AM

I am trying to figure out this also. I have found some info on a few sites,but I don't understand the mechanical logic. The two suggestions I have go in different directions, one will generate more turns than the current setup and the other less. Which is correct? Tom's site agrees with the 7/17 combo.

This what I had before:
7 tooth yellow spindle drive,  15 tooth  black pinion, 2.76 FD, 1300 TPM 110Mph Nippon Seiki speedo, 13" tires

Both of these have been suggested for a 3.1 in my car:
7 tooth blue spindle drive, 17 tooth white pinion   
6 tooth standard spindle drive, 15 tooth custom pinion

Calver article:
http://www.minimania.com/web/SCatagory/ENGINE/DisplayType/Calver%27s%20Corner/DisplayID/889/ArticleV.cfm

Suggestion from Calver article:
7 tooth blue spindle drive,  16 tooth green  pinion

Additional information is on these two sites:
http://www.guess-works.com/Gearbox/ratio.htm

http://www.tomsminisite.co.uk/speedo_calculator.php

Posted: May-05-2008 12:08PM Edited:  May-06-2008 07:04AM

Going to a 3.1 FD from a 3.44

Anyone know which is the correct drive pinion for the speedo?

From looking, looks like DAM6028 may be correct.  But it states for 12" wheels

Mine is 10" wheels, pre 1980 box.

edit:  correction...car will have 12"

Thanks

A FATHER CARRIES PICTURES WHERE HIS MONEY USED TO BE 

1130cc, 12g295, SW5 cam, LCB, HIF38, CA spec.