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Tue Jun 07, 2011 8:02 am

Okay for use with ACVW heads on slightly worn guides?

Tue Jun 07, 2011 8:48 am

Sure - but its better to replace the guides.

Tue Jun 07, 2011 8:56 am

I've always heard that you do not knurl vw guides. Something about oil will pass thru the valve guide very easy, especially on the 3/4 side due to that side filling up with oil in the head.
Not for sure, just what i've heard.

Tue Jun 07, 2011 10:57 am

You can knurl bronze guides. If you need the heads back in service and you cannot machine or replace guides, knurling can get you out of a bind.

Of course it does not last as long as a new guide. Might give you close to a year's worth of mileage.

I have tried coiled bronze too before and i did not like it. I would rather just core it out and push a new guide in.

Tue Jun 07, 2011 11:03 am

nsracing wrote: You can knurl bronze guides. If you need the heads back in service and you cannot machine or replace guides, knurling can get you out of a bind.

Of course it does not last as long as a new guide. Might give you close to a year's worth of mileage.

I have tried coiled bronze too before and i did not like it. I would rather just core it out and push a new guide in.

The guides I have are within factory tolerances but justttt barely. They are usable as is but I'd like a little extra insurance. Will knurling them lessen the life span?

Tue Jun 07, 2011 11:15 am

lessen the lifespan of almost wore out guides?or new guides? are they to be reamed,honed or broched after knurling?.is there a problem with the rocker system killing the guides? are the valve springs dead and there killing the guides? if knurled and broched properly I see no problem if there isant any other problem.but some bronze guides are hard to knurl, use plenty of bronzelube,good knurlingtool ,lube broach.

Tue Jun 07, 2011 11:26 am

mark tucker wrote: lessen the lifespan of almost wore out guides?or new guides? are they to be reamed,honed or broched after knurling?.is there a problem with the rocker system killing the guides? are the valve springs dead and there killing the guides? if knurled and broched properly I see no problem if there isant any other problem.but some bronze guides are hard to knurl, use plenty of bronzelube,good knurlingtool ,lube broach.

Lessen the lifespan of "almost worn out" guides. Like I said, they are in good shape. I could easily toss another 50k miles on them without any issues but ya know, since I've got the engine apart I might as well do the work if it won't harm it.
Everything seems to be just normal guide wear. The valve train and rocker geometry is was dead on when I pulled them. FYI these are the heads you commented on my last post about. The machine shop said they NEEDED to be replaced but to avail, not even close. I've still got a fairly generous amount of meat left, they are just a hair more worn that I would like for having the small amount of miles on them.
I would be knurling and broaching them correctly.
Also, do you know the ID of the guides? My kit has nothing that will fit these.

Tue Jun 07, 2011 5:49 pm

like many things, what matters most is the clearance.

So what you do is measure the stem, add .002-.003, and that is what your "new" guide size should be.

They are supposed to be 8mm or .315", but since aftermarket valves often have kinda small stems you can go a bit smaller.

If it's got more than .0055+ clearance, the guide would need to be changed before I'd want to cut the seat. No sense recutting the seat if the guide is more than halfway worn out.

the guide should be measured about a half inch in from the ends, using a expanding ball or mini-snap gauge or with go/no go gauges or with a sunnen guide bore gauge or by seeing what size pilots fits in the hole.