View Single Post
  #22  
Old 12-31-2012, 03:10 PM
Stretch's Avatar
Stretch Stretch is offline
...like a shield of steel
 
Join Date: Sep 2009
Location: Somewhere in the Netherlands
Posts: 14,461
Quote:
Originally Posted by Blue300SD View Post
I have tested the new valve guides that were purchased for this job.

The valve stems fit perfectly into the new valve guides without any need for any kind of machine work.

The valve guides do not need to be reamed or drilled or modified in any way.

This may only be true in this single case.

Maybe the members that posted that the guides were purposely undersized were thinking of another engine.
The bore really ought to be checked after fitting (as mentioned in the previous post).

If you have a look at chapter 5 -135 in the FSM you can find all you need to know (and more importantly what the machine shop should know).

After the valve guides have been fitted the valve seat should be cut - and then a gas tight seal should be made with grinding paste.

When I had my head re-worked by a local machine shop (who did seem to know what they were doing) they managed to leave swarf in the assembled head between the valves and the new seats and they also gave me an OM615 valve which just happens to be smaller in diameter than a non turbo OM617 one...

...if you are nervous about what other people are doing (I am too) it is best to check and recheck the work they have done. If I had a machine shop like 1960mog I'd be doing the work myself; but there's no way a DIYer will be able to re-cut valve seats without some nice reliable equipment.

The only thing you can do is go through the FSM with a fine tooth comb and measure everything before you refit it.
__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!
Reply With Quote