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Damaged head at valve guides?

Hi, got back my 2.0L heads after sending them out for rebuild and noticed there is damage to the casting at the base of the valve guides recently (newly) installed in one of the 2 heads. The tech guy said that was common for thapart of the casting to break off and that it should still be usable as is. I asked if he could repair that by welding back on some alloy that had broken off. He said to do so would mess up the bronze guides.

I've posted photos showing the damage. Anyone like Jake Raby like to comment on how best to repair or is it usable as is? Thanks
Old 02-06-2005, 01:13 PM
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Damaged heads in 2.0L rebuild

Adding photo of normal rebuilt head for comparison to my other post
Old 02-06-2005, 01:20 PM
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Wink

Here's Raby's forum - you might want to ask him there too or contact Len Hoffman who does most of the head work for him.
Old 02-06-2005, 04:08 PM
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Welding on the aluminum head will mess up the guides and the valve job. Aluminum tends to "move around" when heated as much as welding will heat it. (Not to mention the pre- and possibly post-welding heat that should be used.) SOP is to pull all the non-aluminum parts out of the head, then weld, then install new valve guides and seats and such. Then do a valve job.

I am told that you don't always have to pull the guides and seats, but that chances are pretty good that one or more valves will no longer sit properly on the valve seat after welding is done.

--DD
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Old 02-07-2005, 09:16 AM
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Dave, given that it is such a small area that's missing and it is at the exit end of the flow, could I just use it as is? How much catastrophic damage can occur from these guides failing when put into service as is?
I figure right now if I have to pay for a new head or get it repaired for about the costs of a new head (used but good) then why don't I take the risk if the future damage will be about the same costs not counting labor to repair said damage.
Old 02-07-2005, 10:50 AM
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It's a calculated risk, if you want to take it, no one will stop you. But keep in mind if that guide starts moving around, and you snap the head off that valve, you will break more than just that head. I guess it comes down to how much money you are, and if your a lucky guy I can't stand driving around something I can't trust, so I would pony up and fix it, but that's just me. Or, better yet, find a good used one, that is rebuilt, or can be gone through.
Old 02-07-2005, 11:09 AM
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Re: Damaged head at valve guides?

Quote:
Originally posted by tshih
Hi, got back my 2.0L heads after sending them out for rebuild ...
Who rebuilt them? The truth will set you free ...
Old 02-07-2005, 11:53 AM
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Alred,

A local machinist at an Auto Parts store in Trenton, NJ who specialized in VW heads.
Old 02-07-2005, 09:46 PM
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Quote:
Originally posted by tshih
Dave, given that it is such a small area that's missing and it is at the exit end of the flow, could I just use it as is?
I don't know. Try contacting Len Hoffman and see what he has to say. He's seen more Type IV cylinder heads than I've seen Porsches...

--DD
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Old 02-08-2005, 08:17 AM
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I see you asked Jake on his forum - from what I've read, he generally won't answer questions like these because he's afraid that someone will sue him if he names names (It's true so don't everybody get your pants in a knot).
Old 02-08-2005, 08:40 AM
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Dave,


How do I get in touch with Len Hoffman?
Old 02-08-2005, 01:22 PM
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Click on the link I provided above.
Old 02-08-2005, 01:51 PM
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Thanks Alfred,
have contacted Len by email thru your link.
Old 02-08-2005, 04:26 PM
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Tshih,

Len answered your question on Raby's forum.
Old 02-08-2005, 04:38 PM
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Alfred1 and everyone else with replies,

From the master Len Hoffman, it doesn't appear to be a problem to use these heads as is, so the risks are small that I'm going to take.

Sometimes one gets too worried over what appears to be a big issue but when given enough info (from experts) really is not.

That's the value of this website forum and others in the links provided.

Thanks all for your help.

Tom
Old 02-09-2005, 10:59 AM
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hmmm...I would try a dab of JB weld........
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Old 02-09-2005, 01:45 PM
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Jb weld will never stand up to Exhaust heat. Some port modifications intentionally grind that hump out. I would be more concerned with the flow characteristics being equal port to port. I may (but not telling you to) grind the other 3 down to matchthe broken one.
Old 02-10-2005, 12:00 PM
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[QUOTE]Originally posted by Joe Ricard
[B]Jb weld will never stand up to Exhaust heat.

Ya think? (wink wink...nudge nudge....with tongue press firmly into cheek...)
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Old 02-10-2005, 12:04 PM
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Yes, I was told by Len Hoffman that race engines have the boss area ground down. since I don't intend to use this engine primarily for DE (occassional 2-3 events per year), I am not going to worry about the uneven flow between the 2 heads.
Old 02-10-2005, 12:10 PM
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