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914World.com _ 914World Garage _ Valve spring shifting around in head

Posted by: reharvey Jun 20 2012, 08:42 AM

Was looking for a rebuildable 2.0 head in my pile of stuff and I came across this one with an issue I've never seen before. It looks like the base on the valve spring has been moving back a forth in the head. If you look at the first pic you can see the metal has been pushed up to make a ridge at one side. The second pick shows that the valve guide boss as been repaired and is smaller then normal. So--has anyone seen this happen before? What needs done to repair the damage to the head? Thanks, Ray

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Posted by: ldsgeek Jun 20 2012, 08:52 AM

I'm not sure, but shouldn't there be a steel washer under the spring? When I worked at an auto machine shop (too many years ago) every aluminum head I touched had steel between the spring and the head to protect the softer head.

Posted by: reharvey Jun 20 2012, 10:10 AM

These heads never came with washers under the valve spring

Posted by: ldsgeek Jun 20 2012, 10:41 AM

Ok, I was wrong about these. Sorry. It does make sense but I guess VW/Porsche tested and found they weren't needed.

Posted by: wingnut86 Jun 20 2012, 01:35 PM

Send it off to Len at Hoffman Machine or find a "Type 4" head specialist close by.

Valve guides that start to wear can cause this, add in the possibility of valve seats that have come loose or are wearing unevenly and you have this.

Experts can weigh in but this has been my experience in aluminum heads so far.

A rebuilder can build up that surface and machine to spec if not to "wallered out"

Jake, Cap'n, McMark, Chris or Len??

Posted by: Katmanken Jun 20 2012, 01:46 PM

I'm almost thinkin the spring and valve are at a different angle than stock. One way to get that effect is to weld up the exhaust guide boss and mis-drill the hole for the guide at an angle. Then when you put the spring on, it's off center and tipped. Measure with calipers and compare to your other head.

What does the combustion chamber look like? Specifically look at the valve seat to see if it's canted, or if the valve seat cuts are cut at an angle to "accomodate" a mis-angled valve.

Posted by: McMark Jun 20 2012, 02:16 PM

The seats could have been recut too far and allowed the valve to seat farther in the head. This would make more clearance for the valve spring, and with enough cutting the spring could ride relatively freely and spin.

Pics of the valve head / combustion chamber please.

Posted by: reharvey Jun 20 2012, 03:02 PM

The valve seat looks original and is in good condition. No other visable damage on the combustion chamber side.

Posted by: reharvey Jun 21 2012, 08:40 AM

I added two more photos of my valve spring problem. Anyone else have any ideas? Thanks, Ray

Posted by: McMark Jun 21 2012, 09:36 AM

Perhaps that spring lost tension...