replacing valve guides

[Alan L]

I am stripping my SC down to the crank - had couple of broken studs, and has done 250k km.
I have Waynes invaluable book on the subject but still can't quite figure out the valve guide bit. To remove, you drill/tap in a cap screw. You use this to pull the old guide out - but how?
What size replacement guides should I use. The oversize seem to be the Outer Diameter sizings, or can I replace with standard if measurements OK. Or do you always go a size up in OD when removing a guide.
These motors are seriously cool inside. Have rebuilt many motors but these take the biscuit for design and workmanship.
Alan

[MBEngineering]

HI the porsche guides are over size out side and inside, i usualy use TRW guides with no prob', drill the guide out to reduce the wall thickness, do NOT drill through all the way or through the side, make a drift to fit the hole and drift out, refit to correct depth and re'cut the seats, if you are not to happy at doing the guides, send them to henry at
www.supertecperformance.com if you are in the USA, looking at the time /date you are not, them PM me.

regards mike

[quint22cp]

MBEngineering,

Have you got a contact number/web site for the TRW guides in the UK ?
After fitting the guides are they the right size for the valve stems or do you have to ream them out ?

thanks

[MBEngineering]

HI the contact for the TRW guides is bert gear at berlyn services
www.partsforporsche.co.uk
the guides come sized to fit, only require reaming if you are a bit heavy handed fitting them, heat the head, cool the guide, use a press. good luck

regards mike