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infurno
11-24-2008, 01:56 PM
Got a new quote for some work on my cylinder head.

$100 - labor for replacing valve seals + replace all exhaust valves
$103.80 - for 6 new exhaust valves ~$18.00 ea. from NAPA
$4 labor to replace each valve guide

Looks good to me so far.

Trouble is that they can't find the correct valve guides for the M20 the computer system. I'm going to have to find the parts at another store.

So here is my question:

1) Do I need valve guides? I tried grabbing a valve head and wobble it around and found one thats a bit loose. Moves about 1mm, but I have not checked them all. Can I use this to judge the shape of the valve guides? Or bad idea?

2) Which guides should I order? "Valve Guide - Oversized -- Outside Diameter = 13.2 mm" or "Valve Guide - Standard Size -- Outside Diameter = 13mm" Is there any way I can tell without them taking the head apart?

I'm trying not to spend any money I don't have to.

whiskychaser
11-24-2008, 05:31 PM
The way to check valve guide wear is in Bentleys: You need to put a new valve in the guide with the stem tip level with the end of the guide. Then measure how much lateral play there is at the valve head. Max movement is 0.8mm. Bentleys says use a dial gauge but you may well be able to improvise. HTH

Ross
11-24-2008, 07:04 PM
The guide size will be determined by the machine shop. If the hole they are pressed into isn't buggered then standard size.
The guides can also be knurled which will close up the tolerance but be less durable, the valve guide seals should help with any oil getting past marginal guides.
Looks like you are doing very well with prices.