Forum » Build Threads » Austin 1800 Rally car - BMC B Series

Austin 1800 Rally car - BMC B Series

Build Threads

Keep everyone up to date with how your project is coming along. 

= Resolved threads

Page 1

Hi Everyone,

You will need to be patient with me as I fully expect this build will still be going 12 months from now... but I have started, so would appreciate any assistance or guidance. I am not very mechanically minded but have daydreamed a lot so i guess that is a positive :) I have attached a pic of my end goal so everyone has some context and can see what I am trying to achieve... any comments are greatly appreciated.

I dropped the engine off at the machine shop yesterday.... my first question is..

1. Do they knife edged, lighten and balance the crank and THEN get it tuftrighted? Is that the correct order?

2. Which hardening treatment is best for older forged steel cranks please?



Attached Files

Yes, it's normall to do all the machining processes before the treatments as otherwise they'd be removed during the process. Well, almost all - IIRC, nitriding used heated salts and sometimes the crank would need straightening after.

Hardening was generally used to make the crank journals more resistant to wear, especially as the oils and filtration would be poorer back then and 'race' bearings had low embedability - this was rather important as the maching and materials back then cause a lot of 'running in' debris to get into the oil - and often air filters weren't used, so also increasing bore and ring wear.

Different steels - do you know what yours is made from? - may benefit from different hardening processes, if required, but unless I knew I needed one, I would probably pass.

The head was dropped off today for some pretty serious work, it was great to browse through all the previous head details on the flow bench software.. we are aiming for 100hp per liter so around 185 at the flywheel... the machinist spent some time explaining to me the issue of diminishing returns... we talked in depth about what I wanted to achieve and set a budget and timeframe... so all good :)

Attached Files
  • 5227492C-FAE0-4909-BDCE-A4FC1FDF62E9.jpeg
  • Attachments may only be downloaded by paid Gold members. Read more about becoming a Gold member here.