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Posted by: Joe Ricard Aug 2 2004, 07:45 AM

So the Machinist says that the new intake valve is .039 larger than the hole it is supposed to go into. What is the size +.000 to put the guide in. 2.0L head. And I guess I have the wrong Exhaust. Need 15mm guide vice 13mm

Gosh this is fun

Posted by: ArtechnikA Aug 2 2004, 07:58 AM

spec book says stem dia 7,94-7,95 Intake; 8,91-8,92 Exhaust
guide dia 8,00-8,02 Intake (wear limit 8,06); 9,00-9,02 Exhaust (wear limit 9,06)

i'm pretty sure the guide ID is measured after installation and honed to fit, but you probably knew that.

Posted by: Joe Ricard Aug 2 2004, 08:50 AM

Art, I have no idea what you said.
In simple terms how much do I need to take off the outside diameter of the valve guide to achieve the correct fit with respect to the bore in the head. I would imagine it is something like + .002 or is the head heated and valve guide frozen with a certain interferance.

Posted by: Lawrence Aug 2 2004, 09:06 AM

I gave some bad advice... so I edited it out.

Posted by: ArtechnikA Aug 2 2004, 09:06 AM

originally, you said

" the new intake valve is .039 larger than the hole it is supposed to go into. "

which i took to mean the valve stem is too big to fit the installed guide. (valve is larger than its hole - i donno how else to interpret that ...)

i think you're now asking for the size difference of the OD of the UNinstalled guide to the ID of the guide hole in the head to achieve the proper shrink/press fit.

i have no idea, and i doubt the Spec Book or Haynes would be reliable on this matter, since techniques and valve guide materials have changed so much in the intervening 30 years.

hopefully someone with a track record of successful valve guide replacement wil be able to chime in; this is an area of head work i've never even attempted.

who's Art ?

Posted by: Demick Aug 2 2004, 09:08 AM

Joe

Really - if your machinist doesn't know how to handle this - that is a very very bad sign. I would get my parts and run away fast to someone who knows what they are doing.

Demick

Posted by: JOHNMAN Aug 2 2004, 09:31 AM

Posted by: Joe Ricard Aug 2 2004, 09:55 AM

Yea I suppose I could screw them up for alot less money.
Sorry didn't look at your real name Rich, just "ArtechnikA" I imagine there is a meaning behind all of our log-ins.

Posted by: watsonrx13 Aug 2 2004, 09:56 AM

Joe, now I'm scared....

Posted by: Joe Ricard Aug 2 2004, 10:40 AM

Na don't be scared Rob, this is all going to come out alright. How ever I did not know that there were two different sizes to Exhaust valve guides. Remember the ones you ordered? you need the other ones. (15mm).

Posted by: Joe Ricard Aug 2 2004, 06:00 PM

OK the prefered method is, the interferance is +.002 heat head up to 300 degrees and freeze the guide.
Guide should move into head 1/4" per medium whack of proper drift punch and hammer.

Oh yea going to find better Machinist. not an easy task as there are maybe a half a handfull of VW's around here.

Posted by: Mark Henry Aug 2 2004, 08:42 PM

A couple of thousands press fit, you (I) don’t heat the head, or chill the guides. I have a special tool and I drive them in with an air hammer. I rarely have to size them after install and if I do I use a ball broach.
If you need to install an OS guide, then the bore must be reamed to size first.

The whole trick is removing them! The guide must be cored so you don’t damage the bore.

P.S. I’ve probably done several thousand by now.

Posted by: watsonrx13 Aug 3 2004, 05:50 PM

15mm exhaust valve guides have been ordered....