23 replies to this topic

[minilee94]

I just sent head off for new stem seals valve re grind etc I bought this head from eBay I just looked at the collets and noticed on all of them there is a gap between the 2 halts is this right I just checked my old head and there is no gaps at all this head has big valves and double valve springs

Head is a 12g940 casting but a 12g938 stamped on it

Pic below shows

[Artful Dodger]

Doesn't look seated correctly. But if I was fittin an unknown head I would remove the valves and check the seats, valve guides etc.

[smartie93]

As above the collets look like they're not seated properly in the grooves.

[minilee94]

Yeah that's what I thought and yeah the head was by a local engineering place they stripped it and inspected it and replaced oil stem seals and re lapped the valves cleaned it all out etc and a skim

It didn't need seats as unleaded seats can't be fitted and guides were okay

[KernowCooper]

If you have a valve compressor whip that one out and have a look

[minilee94]

Nar I don't have one

[minilee94]

I don't wuna play with it my self I would rather some one who knows tell me so then I can ring the local place up and tell them

[rally515]

the left hand collet on the right spring in the picture isnt seated properly atall,you can see it raised up visibly

[minilee94]

Yeah nearly all of them are like it

[KernowCooper]

Have you tapped all the stems with a nylon hammer to see if they collets seat ? I always after every head build run through all the valve striking eack one to ensure correct seating, just something I have always done after assembly

Edited by KernowCooper, 23 February 2013 - 07:24 PM.

[minilee94]

Nar I haven't I know you said nylon hammer but iv never seen one and I take it te stem is the top on the valve

[KernowCooper]

Yes the stem is the top of the valve exposed between the collets and yes nylon hammers are widely used and plentlyful in tool outlets or Snap On and te like trade vans, you shouls not use a steel one as this could damage the machined face of the stem where the rocker arm works the valve.

[minilee94]

Okay .nar I won't use a normal hammer lol wen you say nylon can I use the leather type on the the end of a copper hammer

Thanks

[MRA]

This is fine on single groove collets used on all early minis and derivatives, if they are triple groove as used on later A+ series engines including MG turbo engines.

[minilee94]

I don't have a clue what it is I have never taken an mini head apart to know an I don't know engine this came from