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[mab01uk]

How to Convert a BMC A-Series Cylinder Block From Automatic to Manual

"In the USA, an Austin America (ADO16) has often been the source of a 1275cc engine for an early Mini that came with a smaller powerplant. Many Austin Americas have the optional 4-speed automatic, and the cylinder block is different enough to prevent its use on a manual trans without certain modifications."
This web page will tell you in great detail how to convert a 1275 block:-

http://www.home.eart...1/convert1.html

 

To fit a 1275 auto block to a manual, apart from drilling the dipstick hole, there are a few mods needed to oil plumbing:
1. Auto block doesn't have the drilling all the way from the oil pump to the relief valve.
2. Auto block has 2 holes in the relief valve seat `cotton reel' to let oil get into the main gallery, because the normal filter flange is blocked off with a plate- the motor's lube oil comes UP the banjo pipe from the auto trans to the motor.
3. Auto block pump mounting recess is .250" deeper than in a normal 1275 block.
AusMini Link:-
http://www.ausmini.c...hp?f=25&t=90470

 

According to one of the Mini magazines a lot of auto Mini cylinder blocks are also being converted in Japan where many of the Rover Minis sold were automatics.
 

Edited by mab01uk, 10 June 2020 - 02:31 PM.

[mini-mad-mark]

Interesting - I guess this has been around some time but was less attractive until now as there are starting to be less manual engines to go around (here mainly talking about 1275) - maybe was conceived/more popular in the US if there were always more autos than manuals

 

Anyone doing this in the UK?  I see a few auto 1275's on Ebay at more reasonable prices than manual engines - maybe more autos would appear if this became more normal and so made them more attractive

 

What do we estimate would it cost/how much should we be willing to pay?  I suppose it would be sensible to do a normal rebuild at the same time so this would be on top of the normal stuff - although beyond the scope of the average home mechanic (no offence to the very skilled ones out there) I don't think it looks like a massive amount of work for a competent engine builder (if they would be happy to stand behind such a conversion of course) and the oil pump spacer would probably become a stock piece so cheaper than one off every time