MA12 in a K10 using the MA10 4 speed!

[rconry]

Hi people, I've just joined the club, I've had a 1989 K10 beast for almost 5 years now and am getting a little bored!

Before I get something else i'm considering doing a few mods, more for fun than anything. I've found a cheap 1.2 (MA12) engine on ebay and was wondering if dropping it in with the 4 speed box from the current MA10 would give it a little extra acceleration, although reducing top end speed due to the longer final drive, any thoughts?

 

[Turtle]

The ratio's of the first 4 gears of the normal 5 speed are the same as the 4 speed... so there isnt much point?

 

[rconry]

The ratio's of the first 4 gears of the normal 5 speed are the same as the 4 speed... so there isnt much point?

Well the actual gear ratios themselves are the same, but the final drive is different, longer in fact, making all the gears slightly longer.

3.810:1 on a 4-speed, 3.591:1 on a 5 speed. Check your haynes manual if you don't believe me! The other option is to use a 5 speed on the MA10, make it quieter on the motorway!

So far as changing the engine though, from my searches on here it seems like swapping an MA10 for an MA12 is relatively easy, I know its essentially the same block etc., so is it basically a "plug and play" or will i need to cut a few things?

Cheers,
Rich

 

[Arnold]

Straight swap, the mounts and linkages are the same. There are two different 5 speed boxes, Turtle is right in saying that the 4 speed is the same as the 5, however the 5 speed obviously has the final gear for better economy, this is the wide ratio box. The short ratio box is the equivilent of the 4 speed, but with 5 gears instead. Better accelleration, poorer economy.

 

[rconry]

Ok i see, didn't realise there was more than one 5 speed box Do you happen to know the different codes for the 5 speed boxes, if i get one i want to make sure i get the right one!
Cheers

 

[Arnold]

Do a search, i know that's been covered before

 

[RTLkyuubi]

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