Author Topic: Valve guides (Read 4112 times)

zooky · « **on:** June 30, 2006, 07:21:58 am »

I replaced my sloppy valve guides, kind of a PITA. After pressing them in the valves wouldnt fit, is an interference fit into the head so they got squeezed closed a tad. I was afraid that. The specs calls out a max 'rock' of .051 for a wear limit (for used components). I set the 'rock' to .020-.025. Does that sound reasonable for new valves and guides?

duffer · « **Reply #1 on:** June 30, 2006, 07:44:03 pm »

Actually, a similar thing happened to me.

I ordered a set of new vales and valve guides

And, when I got them, the valves wouldn't

fit in the guides.

Turned out I'd been given the 7mm guides

found on the 15V gasoline engine.

zooky · « **Reply #2 on:** June 30, 2006, 08:47:16 pm »

they fit fine before installing them but that may be engineered to compress to 7mm when insalled. Oh well, they fit now

moosiah · « **Reply #3 on:** July 01, 2006, 01:53:17 am »

When I installed new guides they did'nt fit either ..... it's common for this to happen, your supposed to run a reamer thru them after installation to size them. proper clearance is built in.

fatmobile · « **Reply #4 on:** July 09, 2006, 04:51:38 am »

I've heard that you aren't supposed to press the old valve guides out because it drags aluminum with it. My mechanic suggested drilling them until they are thin then pulling them out.
Chill them when putting them in.
Not related to your problem but thought it needed to be mentioned.

duffer · « **Reply #5 on:** July 10, 2006, 03:06:10 pm »

Yes, when I worked on Jaguars (my old 1958 XK150

and my two MkII's) the valve guides can be pressed

out, but the new valve guides are oversized outside diameter

and the cylinder head holes are reamed to provide an

interference fit with the new o/s guides.

This addresses the issue you describe, above, vis a vis

the removal of some of the cyl.head material when removing

the old guides.

I would think that on a VW Diesel, this might be counselling

for perfection, though.