valve guides

[sendiw]

I bought new exhaust valve guides and after driving one of the old ones out i offered the new one to the hole. It went in without any effort. I assume it is not tight enough but Just campers say they are the right part they sell loads of them. Has anyone else encountered this and if so how did you get round the problem?
the heads are AMC on a 2.0 litre CU engine..air cooled. J K will accept the returns but where do I go from here?
Hope you lads can help.

[silverbullet]

Its usual to heat any alloy head to about 120-130 degrees C before driving out valve guides, to ease the fit. You have to work fast too.
Belting them out cold is not how its done, as you have found to your cost. You will need an oversize valve guide making to recover the head.
I usually send heads away to an engine shop, cant really be messing about with hot work and they have the knack.

Sent from my Vectrex. Awesome!!!!

[bigherb]

the heads are AMC on a 2.0 litre CU engine..air cooled.

They are not original VW heads, AMC have tolerances you might say are a bit lax.

[sendiw]

The original guide I pressed out won't drop in so I assume there Is a difference in the diameter. Any ideas where I can get oversize guides?

[rockthebus]

This won't help you with the one already out but there are specialised techniques to bore out the old guides and fit inserts. They are used a lot in the states and I had them fitted to my Esprit. Sorry but can't remember who made the inserts. A machine shop would be able to make a new guide for you whilst doing the inserts.


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[123-jn]

When buying guides there are two sizes available 13.045 and 13.07, not much difference granted but if you have a head that has never been messed with the 13.045 should suffice, if it has been 'eased with a reamer in the past to remove muck and rust then the 13.07 is the one to use. The inlets are only normally available in the one size. Unfortunately an engine shop will tend to see what is in stock and as long as the internal size is ok they will re machine the head to take guides from other vehicles leaving you with an issue. As already said you need a machine shop to find a suitable guide and machine your head to fit it!!
When removing the guides you can use a threaded bolt and a large socket to wind them out which is far less likely to damage the head. The same technique can be used to fit the new ones or warm the head in the oven and tap the new ones in with a copper/brass hammer, Use a bolt and washer to protect the top of the guide.
Ignore what I said about two sizes . There is just one size for the CU!!! just read post again.

[sendiw]

Thank's very much for your advice. I phoned a reconditioner. He said they never bother with these heads just put new ones on. Too much work? Will make some more enquiries but looks like I might have to bite the bullet and buy new heads. Will let you know how I get on.
Thanks again
Richie