Jump to content


Photo
- - - - -

Valve Clearances


  • Please log in to reply
8 replies to this topic

#1 topcat

topcat

    Mini Mad

  • Members
  • PipPipPipPip
  • 276 posts
  • Local Club: Six-Ex Mini Owners Club

Posted 30 December 2005 - 10:42 AM

Hi, Just about to check the valve clearances, in the Haynes Manual it gives 0.30mm for all engines except 12A and 0.33 to 0.38 for 12A engines.

1. What does 12A mean?

2. I have a 1991 cooper carb. What should the valve clearances be?

Thanks alot.

#2 dan__wright

dan__wright

    Speeding Along Now

  • Members
  • PipPipPipPipPip
  • 322 posts

Posted 30 December 2005 - 10:45 AM

look on the head, it was have a casting number on it, will be a mix of letters and numbers, thats what it refers to.

#3 The Matt

The Matt

    You don't escape that easily.....

  • Admin
  • PipPipPipPipPipPipPipPipPipPipPip
  • 17,221 posts
  • Name: Matt
  • Location: Overton, North Wales
  • Local Club: Welsh Border Minis

Posted 30 December 2005 - 10:46 AM

I think the 12A was a lower compression engine but not 100% sure. I imagine yours is a 12H but you can tell by looking at the engine number on the front right of the block (alternator end) the 12 means 1275 and is the start of the engine number. There should be a little plate there to help you ID it.

Edited by mini mad me, 30 December 2005 - 10:47 AM.


#4 The Matt

The Matt

    You don't escape that easily.....

  • Admin
  • PipPipPipPipPipPipPipPipPipPipPip
  • 17,221 posts
  • Name: Matt
  • Location: Overton, North Wales
  • Local Club: Welsh Border Minis

Posted 30 December 2005 - 10:52 AM

but this says it could be a 12A??

engine codes

#5 Bluemini

Bluemini

    Mini Doctor

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 4,436 posts
  • Location: Canada
  • Local Club: Blacktop Bombers

Posted 30 December 2005 - 11:28 AM

Close them down to 10 thou, gives a little more lift than standard and is perfectly ok to do so before people start saying otherwise.

#6 topcat

topcat

    Mini Mad

  • Members
  • PipPipPipPip
  • 276 posts
  • Local Club: Six-Ex Mini Owners Club

Posted 30 December 2005 - 12:52 PM

Cool thanks alot everyone

#7 The Matt

The Matt

    You don't escape that easily.....

  • Admin
  • PipPipPipPipPipPipPipPipPipPipPip
  • 17,221 posts
  • Name: Matt
  • Location: Overton, North Wales
  • Local Club: Welsh Border Minis

Posted 30 December 2005 - 01:31 PM

Close them down to 10 thou, gives a little more lift than standard and is perfectly ok to do so before people start saying otherwise.

sounds like good advice to me! IIRC Bluemini does have alot of experience with the top ends of A-series engines (lots more than me anyway)! :wink:

#8 Sprocket

Sprocket

    Great on Injection faults

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 7,266 posts
  • Location: Warrington
  • Local Club: Manchester Minis

Posted 30 December 2005 - 04:16 PM

12A or 12H is the first three digits of the engine number, either stamped into a plate riveted to the front right of the block above the alternator or is laser etched in the same place but on the later blocks.

:nugget:

Edit: Already been posted :cry:

Edited by Mini Sprocket, 30 December 2005 - 04:16 PM.


#9 Sprocket

Sprocket

    Great on Injection faults

  • Members
  • PipPipPipPipPipPipPipPipPipPip
  • 7,266 posts
  • Location: Warrington
  • Local Club: Manchester Minis

Posted 30 December 2005 - 04:21 PM

Now here's a thought. :smartass:

Exhaust valves by thier nature run hotter than inlet valves and as such will expand that bit more. Has any one thought about setting the inlet valves clearance that little bit less than the exhaust. Might make the engine run that bit quieter rather than make it more powerfull. Duno?? Anyone??? Just a thought??? :fear:




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

Mini Spares