Cracked guide boss

[fclmscott]

Opinions please. Replaced a valve guide on an 043 casting, guide has been cut for dual springs. I pulled the old guide out after heating to 300f using the drill and tap method and old guide came out without much gaulding and boss did not crack. Checked clearance and was right at .0025 between the new (std) guide and the guide bore. Deburred the guide boss, heated the head to 300, froze the guide, leveled the head and drove the new guide in using hammer and guide tool. Guide had expected resistance. Guide boss cracked as seen below. So what are my options? is it safe to use? TIA

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Something witty and wise goes here.

[madmike]

I wouldn't use it that way, weld it ,clearance it ,,use it
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Rail Buggy 1915 turbo
76 Drag/Street bug 2180cc 'Turbo' 11:85 @113 mph"If I go any faster I'll burn up the Hamster" ,gets 28 mpg. also 10/09/22 11.90 @115 mph
"If I'm ever on Life Support,UNPLUG Me, Then Plug me back In see if that Works"

[Dan Ruddock]

Yes, you must have it repaired. Most shops cut the boss down to .625" when most dual springs have a .700" .I.D.

Here is the solution to this common problem.

https://www.thesamba.com/vw/classifieds/detail.php?id=2077442

[nsracing]

And who thought it was a good idea to hammer the crap out of the guide?

Most shops will use an airtool to gently get the guide in place.

The head is instant trash. Such a shame you got thru all that work removing the guide and ruin everything after. Nothing like ruining a part to learn a lesson.

Removal of the old guide should be done in such a way so you do not damage or deform the guide boss bore. Relieve the guide by coring it and just gently tapping the old guide out.

Hammering usually deforms the guide and guide boss breakeage is a usual thing.

[modok]

It's a tricky job, we all have our ways. Too much press tho IMO