15 replies to this topic

[Stu1961]

Hi All,

 

Have just started to rebuild my head (12G940 from a 1990 Metro,  fitted with new std valve guides as supplied by Mini Spares. Valve sets recut to take larger inlet valves)

 

Ordered new double valve springs and collars to stop inner springs wandering about, however the collars will not pass over the guides. The size difference is not big probably only a few thou but it is enough to stop them fitting correctly. Note springs and collars also purchased from Mini Spares.

 

Any help very much appreciated, many thanks

 

Stuart  

Edited by Stu1961, 10 December 2013 - 07:14 PM.

[The Principal]

Give Simon at Minispares a call to discuss

[Deejayry]

Its been a while since i did any head work, but if my memory serves me correctly the spacers are a tight fit on the valve guides, i think i pressed mine on with a bit of brass tube,

[Stu1961]

Thanks for the reply's,

 

Deejayry just tried one used a 12mm socket went on perfectly, just not sure as this is the first time I have built a head.

Advice much appreciated.

 

Stuart

[Gremlin]

Theres obviously different types/sizes as mine just slid on, with a bit of force but well within being able to push with your fingers

[Stu1961]

You maybe be right, mine would not push on by hand though you would only need half a thou difference to make them a socket and hammer job.

[kezzkitkat]

I wouldn't use a hammer have you tryed 2 bocks and a large g clamp to start it and a peice of tubbing like said above with the blocks and g clamp to push it down basically a home made press

[Stu1961]

Went on very easily and squarely with hammer and socket with no damage to guide or collar. Why would you not use a hammer? Though I wholly agree with what you are saying if I was trying to push a bush into a hole. 

[kezzkitkat]

^ because I brake things with a hammer lol so I think of other strange ways unless Im shaping panel that have 10 tons of filler

[Ethel]

I imagine it's the guides, there's no other reason for the diameter above the head to be a particularly specific size.

[Stu1961]

Thinking about it they do need to be a very close or very slight interference fit so they stay put themselves,

wouldn't be very good if they were able to move up and down on the guide freely.

 

Stuart 

[Gremlin]

Apart from the spring holding them down

[Deejayry]

The spring doesn't sit on the spacer, it sits around it, the purpose of the spacer is to hold the spring centrally around the valve guide / stem

provided that you are careful with how you do it, pretty much any bush, bearing or similar press fit item can be safely installed using a hammer, it takes slow methodical gentle taps with the hammer and a bit of brass, bronze or even alloy turned to the right diameter to get the part in nice and true, then increase the effort a little to drive it home.

It is just as easy to mess things up when using a press as you have less feel of the amount of friction.

Having said this I wouldn't ever use a hammer when fitting new valve guides though.

Edited by Deejayry, 12 December 2013 - 07:59 PM.

[Gremlin]

I'm pretty sure mine sat on and around it

[Stu1961]

Could not agree more Deejayry especially regarding the valve guides.